Tabie X (Continued) (169) Staroscik. R., Manczyk, R.; F a r m . Pol.; Vol.:0028 Page:1151 Issue:12 Y r . : 7 2 CA. 79 0099305. (170) Staub, H., P e r r o n , W.; Anal. Chem.; Voi.:0046 Page:0128 Issue: Yr.:74 CA. 80 078138X. (171) Stefek, S.. Zahradnicek, M.; Cslka. F a r m . ; Vol.:0022 Pase:0158 Issue: Yr.:13 AA, 25 003365. (112) Subert, J.; Farmaceutickv. Obz.; Vol.:0041 Page:0445 1ssue:lO Yr.:72 AA. 2 4 003690. (173) Takacs, M.; Gvogyszereszet; Vol.:0016 Page:0281 Issue:08 Yr.:72 CA. 7 1 130634K. (174) Teodorescu, N.; Lucr. Coni. S a t . Chim. Anal.; Vol.:0003 Page:0337 Issue: Yr.:71 CA, 7 7 009608B. (179) T e s i o , O., Nikolic, K.; Arh. F a r m . ; Vol.:OO22 ?age:0217 Issue:O4 Y r . : 7 2 CA. I 9 1396631. (176) Thieieninnn, H.; Scientia. Pharm.; Vol.:0040 Page:0058 Issue: Yr.:l2 AA, 23 003436. (177) T r e i b e r , L. R., Oertengren, B., Lindsten, R.. Oertegren. T.; J . Chromatop’.; Vol.:0013 Page:0151 Issue: Yr.: 7 2 A A . 25 000558. (178) Tsunnkauw, N.; Chem. P h a r m . Bull. Tokyo; Vol.:OO19 P a ~ e : 2 5 7 91 s s u e : l l Yr.:71 AA. 23 001807. 1179) Tuckprrnan . M. M.. Ace1 K.. B i c a n - F i s t e r . T.. Billmi, J., Gibbs. I. S.; J. P h a r m . Sci.; Vol.:0061 Paee.0448 Issue: Y r . : 7 2 A A . 23 003440. (180) Tcihak, E , , Held, G.; P r o g r . Thin L a y e r Chroniatogr. Reiat. Methods. Vol:OO02 Page.0183 Issue: Yr:7l CA. 77 0248339. (181) Leda, F . ; Vitamins; Voi.:0047 Page:0529 Issue: Yr.:73 C A , 80 014353R. (1821 Vandeneeckhout, E., Denioerloose, P.; P h a r m . Weekbl. Ked.: Vol.:OIO6 Pace:0749 Issue:40 Yr.:71 A A . 23 000714. 0023 Issue: Y r . : 7 2 CA. 7 8 115253K. (183) Varda. S. P . ; Ervpt. P h a r m . J.; Vol.: (184) Vegh. A , ; Gvopvszereszet; Vul.:OO17 Issue:O3 Yr.:73 CA, 79 023597V. 12 Pace:0233 1ssue:OB Yr.:72 A A , 23 002712. (185) Wagner, P., Schuflels. P . ; Dt. Apothz (186) Wani, K . T.. Weinstein, B.; ?roc’. Thin Laver Chroniatogr. Relnt. Methods: Vul.:0003 Page:0177 Issue: Yr.:72 C A . 7 6 145201V. (187) Want. R. T., T s a i , Y. H.,Fuh, T . J.: Cheniistri Taikei; Vol.: Pa:e:0013 1ssue:Ol Yr.:72 AA, 24 003704. (1881 Wasternack. C . ; P h a r m a z i e ; Vol.:0027 Paee:0061 Issue: Yr.:72 AA. 23 002378. (189) Westgard, J . O., Lahnieyer, B. L . ; Cltn. C h e n . ; Vol.:OO18 Pare:0340 Issuc:04 Yr.:72 AA. 24 002887. (1901 U’ragg. J . S . : P h a r m . 3.; Vol.:0209 Pase.0611 Issue. Yr.:72 AA. 25 000410. (191) Wrasp. J . S.; P h a r m . J.; Vol.:O211 Pace:0192 Issue: Yr.:73 CA. 80 041065V. (192) W r a e g . J . S . ; Pharni. J.; Vol.:O2ll P a ~ e : 0 5 6 5Issue: Yr.:73 CA. 80 112690H. (193) Zacek. H.; Cslka. F a r m , ; Vol.:OO22 Pai.e.0126 Issue:03 Yr.:73 AA, 25 002536. (l(14) Zadeczky, S . ; Acta. P h a r m . Hung.; Vol.:0043 Pnge:0033 Issue: Yr.:13 AA, 2 5 001849. (195) Zadetzky, S., Kuttel. D., S r i r e t v a r v , 31.; Acta. P h a r m . Hunr.: Vol.:0042 Pace:0007 1ssue:Ol Y r . : 7 2 AA. 23 004126. (1861 Z a p c . M., Ksiezniakienicz, B.; F a r m . Pol., Vol.:OO28 Pace:O959 1ssue:lO Y r . : 7 2 CA, 7 8 047857K. (197) Zlatkis, A , , Bertsch, W., Lirhtenstein. H . A , . Tishbee. A , , Shumbo, F . . Liebich, H . X l , ; Annl. Chem.; Vol.: 0045 Page:0763 Issue:04 Yr.:73 A A , 24 003208. ~~
~
Analysis of High Polymers John Mitchell, Jr., and Jen Chiu Plastics Department, E. 1. du Pont de Nemours &
Co.,Inc., Wilmington, DE 79898
This review covers published general developments in analysis of polymers during the period November 1972 to November 1974. Emphasis is on techniques useful for assigning chemical and physical structure primarily associated with characterization of synthetic high polymers. An increasing number of books has been published covering general and specific areas. Mandelkern (66) provided an introduction to polymers, and Saunders (108) discussed the organic chemistry of adhesives, fibers, paints, plastics, and rubbers. Wunderlich (130) published the first of a series on macromolecular physics covering crystal structure, morphology, and defects. Polymer physics of glossy or amorphous macromolecules was reviewed with respect to thermodynamics, morphology, dynamic mechanical behavior, and diffusion (34). Numerous books were devoted to polymer science. Collins, Bares, and Billmeyer, Jr. (14) described effective laboratory courses in synthesis and characterization of polymers with emphasis on the latter. It is a timely update of Billmeyer’s textbook published in 1971 (6). Kirshenbaum (57) provided graded questions and problems in his study guide. Volume 1 2 of Advances in Polymer Science was published (11).Progress in Polymer Science in Japan, volume 1 Authors have not been supplied with free reprints for distribution. Extra copies of the revlew issue may be obtalned from Special Issues Sales, ACS, 1155 16th St., N.W., Washlngton, DC 20036. Remlt $4 for dornestlc U.S. orders; add $0.50 for additlonai postage for foreign destlnatlons.
of which was published in 1971 (41), was continued through volume 6 published in 1973 (39, 40, 42, 47, 88,89). Volume 16 on reports on progress in polymer physics in Japan was published in 1973 (46). Polymer materials science was reviewed by Schultz (111) and in two volumes edited by Jenkins (47, 48). Guillet (29) edited a publication on polymers and ecological problems based primarily on a symposium sponsored by three ACS Divisions and the National Academy of Sciences. International symposiums under IUPAC sponsorship on macromolecular science were held in Prague (113) and Helsinki (31). The second international symposium on polymer characterization was held in Seattle (118) while the ACS sponsored one meeting on interdisciplinary approaches to polymer characterization (15) and another on mechanical behavior of plastics (8). Chemical transformations of polymers was the subject of a IUPAC conference (102). Structure and properties of polymer films with extensive discussion of techniques was published in a book edited by Lenz and Stein (62) while van Krevelen (125) reviewed relationships between polymer properties and chemical structure. CRC Critical Reviews (110) contained chapters on scanning electron microscopy (Broers), surface analysis (van Oostrom), electron solid scattering (Duke), and recent advance in surface characterization involving Auger electron spectroscopy (Tracy and Burkstrand), wave induced desorption (Lichtman), thermal desorption and infrared (Greenler), and molecular
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beam interactions (Somorjai). Scanning electron microscopy of polymers and coatings was the subject of a fine ACS symposium (100). Optical rotatory dispersion and circular dichroism were discussed (13). A new edition was published of Haslam, Willis, and Squirrell’s book on “Identification and Analysis of Plastics” (32). This excellent laboratory guide covers instrumental and chemical techniques suitable for analysis of a variety of commercial resins. “Adsorption of Polymers” is discussed by Lipatov and Sergeeva (63) covering theory and methodology. Powell’s book on “Plastics for Industrial Designers” (99) includes simple qualitative tests for polymers. Books were published on “Functional Monomers” (131) and “Cyclic Monomers” (25).“Radiation Chemistry of Monomers, Polymers, and Plastics was surveyed by Wilson (129). Publication of an expanded version of an ACS symposium on “Water-Soluble Polymers” was edited by Bikales (5) and covered applications, synthesis, and characterization. Numerous reviews and general papers appeared covering synthesis and structure-property relationships. Joshi (49) surveyed methods for calculating monomer reactivity ratios. Gandica and Magill (26)derived a model from crystallization data to describe crystallization kinetics of polymers. Nonisothermal crystallization theory was compared to primary and secondary processes with polyethylene used as an example (83). Structure-property relationships were reviewed by Kryszewski (58), Dawkins ( 1 6 ) on block copolymers, and Henning (36). Discussion of weighting methods for computing polymer configurations was made by McCrackin (68). North (85) discussed internal motion in polymers and effects on chemical, physical, and electrical properties. Structure and electrical conductivity of organic polymer semiconductors was reviewed (30).Structure-property relationships were discussed on three-dimensional polymers (51) and on polymer mixtures in solution (59). Polymer morphology was reviewed by Siegmann (116) and by Folkes and Keller (24) on block copolymers. Reviews on effects of morphology and structure on properties were published by Samuels (107),Andrews ( I ) , Pelzbauer ( 9 5 ) ,and Bartenev and Zelenev ( 4 ) with respect to polymer relaxation. General thermodynamic and thermokinetic interpretations were presented concerning the influence of the equilibrium or induced rigidity on morphology of crystallization of polymers from solutions or melts ( 1 3 7 ~ ) . A series of lectures was published on trends in polymer science from dedication of the Midland Macromolecular . physical chemistry of filled and reinInstitute ( 1 8 ~ )The forced plastics was described in a series of papers, primarily from the Kiev Institute of Macromolecular Chemistry (62a). The first of two volumes on “Block and Graft Copolymerization” dealt with their properties and applications ( 1 2 ~ ) . Rotary, translational, and molecular motion was reviewed ( 9 ) .classification of polymers according to relaxation processes was made by Zelenev and coworkers (134). Techniques for measuring orientation in polymers was critically reviewed by Desper ( 1 8 ) who covered X-ray diffraction, birefringence, sonic velocity, fluorescence, infrared, Raman, and dynamic techniques. Influence of monomer absorption spectrum on that of its linear polymers was discussed by Ziv and Rhodes (137).Molecular spectroscopy of polymers was reviewed by Willis and Cudby ( 1 2 8 ~ 1pri, marily on analytical applications of infrared, Raman, and nuclear magnetic resonance spectroscopy. 290R
Reviews were published on phase transformations in high polymers (56), multiple transitions in semicrystalline polymers such as polyethylene (7), polymer spherulites (75),and crystalline states (133).Methods for determining masses and mean molecular dimensions on macromolecules were reviewed by Quivoron (101). Characterization and solution properties of block copolymers was reviewed by Dawkins ( 17 ) . Mikhailov (71) discussed relations between physical structure and light scattering with respect to X-ray and optical diffraction patterns. Relaxation processes around the glass transition temperature were reviewed by Nose (86). Estimating nonhomogeneity of chemical composition of copolymers was reviewed by Tomescu (124), while Sibinski (115) discussed concepts of absolute and relative heterogeneity related to degree of polymerization from the Schulz distribution. Formation and structure of polymers used for preparation of membranes were reviewed by Nakajima (82).Polymer structure and adhesive behavior was reported by Schneberger (109). Structure and viscoelasticity of inorganic polymers were reviewed by Murakami ( 8 1 ) and structure-property relationships of comb-shaped polymers by Plate and coworkers (97). Amorphous state in relation to physical properties was reviewed (50) as well as morphology of fracture surfaces in amorphous polymers (60). Surface structure of polymer single crystals was examined by Wada (127). McCrum and Pearce (69)used a least squares method to calculate energy for creep as applied to linear polyethylene. Andrianova ( 2 ) published an extensive review of structure changes in crystalline polymers during deformation. Weatherability of plastics was reviewed by Kalhura (52). Test methods for determining weathering resistance on outdoor exposure were reported by Lukkedal (64). Testing of plastics was reviewed by Ledwoch (61)and Mueller (79). Apparatus for analytical, optical, rheological, and thermal testing was described by Carlowitz (12). Significance of tests for determining flammability, flame spread, smoke and gas generation waq reviewed by Malhotra (65). Determinations of flash point and autoignition temperatures of thermosetting and thermoplastic polymers were described by Masarik (67). Molecular design of polymers by control of polymerization, crystallization, and heterogeneity was reviewed by Ikada (38). Reviews were published on diffusion and sorption of gases and vapors in glassy polymers ( 3 7 ) ,on moisture absorption (122),and on determining moisture permeability of plastic films (20). Polymer analysis with emphasis on epoxy cement was examined utilizing infrared and chemical procedures (22). Also discussed were control of toxic materials, identification of additives, and polymer structure determinations by infrared and nuclear magnetic resonance methods (22). Polymer analysis was reviewed relative to testing of plastics for building, food, coatings, and other applications ( 2 1 ) . Analytical methods were discussed by Searle (112) for studies of photodegradation. A mathematical method was presented for analysis of relaxation deformation vs. time curves for polymers including polyethylene (93).Stein and Finkelstein (120) reviewed applications of dynamic optical methods of analysis of solid polymers involving birefringence, infrared dichroism, Raman and fluorescence polarization, and X-ray scattering. Nishijima (84) reviewed fluorescence methods for analysis of polymer systems; Hasaczyc and Walczyk ( 3 3 ) ,procedures for determining hydroxyl groups. Analytical methods for chemical additives were described with emphasis on chemical procedures involving
ANALYTICAL CHEMISTRY, VOL. 47, N O . 5 , APRIL 1975
John Mltchell, Jr., has been with the Du Pont Company since 1935 and, currently, is a member of the Research and Development Division of the Plastics Department, Experimental Station, Wilmington, DE. He is Manager of the Analytical and Physical Measurements Section, responsible for chemical and physical structure research, development, and service on polymers and intermediates. Most of his career has been devoted to analysis where he has been active in developing new analytical techniques and in applying them to problems arising from research, marketing, and production activities. He received a BE in gas engineering from Johns Hopkins University and MS in organic chemistry from the University of Delaware. He has over one hundred publications, principally on applications of the Karl Fischer reagent to the determination of water, on functional group analysis by chemical and instrumental methods, and on microscopic characterization of crystalline species. Mitchell is coauthor with D. M. Smith of "Aquametry", which describes techniques for determining water in solids, liquids, and gases. He has lectured extensively, inciuding invited Plenary Lectures at IUPAC'Meetings in Vienna and Prague. He is active in American Chemical Society activities and has served as Chairman of the Analytical Division, Councilor, and Chairman of the Delaware Section. Mitchell received the 1964 Fisher Award in Analytical Chemistry, administered by ACS. In 1972, he launched a new business venture for the Du Pont Company, an Analytical and Physical Measurements Service, which offers unique expertise in a broad area of analytical problem solving and special measurements. He received the Anachem Award in 1974 for distinguished service and contributions to Analytical Chemistry.
Jen Chlu is a research associate with the Analytical and Physical Measurements Section, Research and Development Division, Plastics Department, E i. du Pont de Nemours 8 Co., located at the Experimental Station, Wilmington. DE He received his BS in chemistry from the Chinese National Hunan University and his MS and PhD in analytical chemistry from the University of Illinois. Dr Chiu joined Du Pont in 1960 and has been doing analytical research in the area of polymer characterization. His primary research interests include chromatographic techniques, thermal methods, organic functional group analysis, and chemical analysts. He has published extensively and holds patents in these areas. He is a member of the American Chemical Society, international Confederation for Thermal Analysis, North American Thermal Analysis Society, Sigma Xi, and Phi Lambda Upsilon societies and is on the Editorial Board of Thermochimica Acta
acetylation for hydroxyl, phenol, primary and secondary amines plus halogenation for substituted phenols and primary aromatic amines ( 7 0 ) . For example, bromide-bromate in acetic acid was suggested as a general reagent for determining phenols including trialkylphenols ( 7 0 ) . The National Bureau of Standards offers standard polymers such as polystyrene and polyethylene for instrument ,and method calibration (128). Effect of branching on rheological properties of polyethylene was reviewed by Miltz (72) and of irradiation on physical and chemical properties of polyolefins by Karpov et al. ( 5 3 ) . Identification of polymers in cosmetics was reviewed by Zeman and coworkers (77, 135), based on use of chromatographic separation techniques, spectroscopic, and other methods. Simple methods for identification of pharmaceutically useful plastics was discussed by Auterhoff and coworkers ( 3 ) utilizing flame and solubility tests, precipitation, chemical and spectroscopic techniques. Tests were described for detection of coating binders for paper (123). Simple methods for identification of several polymers were described by Moustafa ( 7 8 ) utilizing density, thermal ef-
fects, and solubility. He provided tabular listing of densities in the range 1.0 to 2.5, pyrolysis products, and qualitative solubilities in water and organic liquids ( 7 8 ) . Instrumental analysis of cotton cellulose was covered in a book edited by O'Connor ( 8 7 ) . Polyvinyl alcohol was the subject of a book by Finch ( 2 3 ) . Physical properties were assembled for compositions involving methyl methacrylate-styrene-vinyl acetate-ester copolymers ( 138 ). Physical and chemical properties of poly(ethy1ene terephthalate) (PET) were reviewed (119) and description was given of molecular orientation in P E T films based on NMR, optical, and X-ray diffraction measurements ( 5 4 ) . Degradation of polyesters, hydrocarbon polymers, acrylics, and polymers containing heteroatoms or aromatic groups was reviewed extensively by Grassie (28). Chemical and weathering resistance of glass-reinforced polyesters was discussed (103). Properties and characterizations were given of poly(ary1ene ether sulfones) (105), epoxides and epoxy resins ( 4 5 ) ,and polycarbonates ( 5 5 ) .Structure studies were reported on copolymers of unsaturated benzyl esters and dimethoxyethylene (11 7 ) . Reviews involving characterizations of olefin polymers included ethylene-vinyl acetate copolymers ( 7 3 ) and graft polyolefin copolymers (80). The latter referred to procedures based on infrared spectroscopy, X-ray diffraction, electron microscopy, and thermal analysis. Reviews on poly(viny1 chloride) (PVC) discussed morphology of suspension PVC ( 1 9 ) , characterization and properties of suspensions (106), simple tests on finished products employing PVC including separations of monomer, pigments, fillers, stabilizers and lubricants ( 7 4 ) . Rayleigh scattering from monodisperse polystyrene (PS) was discussed by Yoshimura and coworkers (132). Thermal decomposition analysis of products and toxicity studies was reviewed for PS, PVC, polymethanes, and phenolics (98). Mass, NMR, infrared, and kinetic data were obtained to determine the structure of the tetramer of Lu-methylstyrene (104).Chemical, instrumental, and physical methods were reviewed for characterization of styrene-amylose graft copolymer ( 9 4 ) and for determining carbonyl groups in styrene-a,@-unsaturatedaldehyde copolymers (121). Structure and reactivity of vinyl monomers on radical polymerization were reviewed by Otsu ( 9 1 ) .Structures and properties of ABS resins were reviewed by Moore ( 7 6 ) .Voronovitskii et al. (126) calculated conformations of poly(vinylidene chloride), poly(viny1idene fluoride), and poly(methylene oxide). Properties of tetrafluorethylene homoand copolymers were reviewed by Iwashita ( 4 4 ) .Structureproperty relationships of thin layers of fluorocarbon polymers prepared by cathodic sputtering were given by Sella and Travot (114). A variety of chemical and physical analytical techniques were used in characterizing polyacroleins ( I O ) , poly(diphenylsi1oxy)arylazines ( 2 7 ) , polypivalolactone ( g o ) , polycyanates ( 9 2 ) , and synthetic polypeptides (35). Structureproperty relationships were assembled for silicone oils ( 4 3 ) and silicone polymers (136). Perkins ( 9 6 ) reported on electronic band structures of polyacene, polypyrazine, and polypyridine and on excited states of catena-condensed linear polyacenes, pyrazines, and pyridines.
CHEMICAL AND ELECTROCHEMICAL Kalinina and Doroshina (C25) reviewed chemical methods for qualitative and quantitative analyses of phenolic resins, polyesters, epoxy resins, polyamides, polyimides, polyacrylates, polyurethanes, polystyrene, polyethylenes, and polycarbonates. Philipp and Dautzenberg (C53) reviewed electrochemical methods for cellulose derivatives
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and other polymers primarily with respect to low molecular weight species, characterization of polymer chains, and analysis of dispersions. Chatterjee and Gupta (ClO)employed conductometric and potentiometric titrations in determinations of carboxylic, phenolic, and amine functions in copolymers of aminobenzoic acid or hydroxybenzoic acid with formaldehyde; these authors used the analytical data to estimate degree of polymerization and structure of the copolymers. These authors ( C 2 I ) used similar titrimetric procedures in characterizations of polynuclear phenolic compounds. Polarography and titrimetry were used by Novak and Lohr (C49) for analysis of acid-anhydride mixtures such as maleic, o-phthalic, trimellitic, and pyromellitic acids and anhydrides; they reported a relative error of 0.5%from polarographic analyses in 0.03M LiCl in CH30H or DMF (0.1M HzS04 in acetone for pyromellitic dianhydride). Resin content of epoxy-boron fiber laminates was determined ( f 4 % ) by dissolving the resin in HzS04 and weighing the residue (C45). Residual monomers in some polymer mixtures were determined (3% relative) by a mercurimetric procedure; advantage was taken of differing reaction rates of a$-unsaturated compounds and unsaturated end groups with methanolic mercuric acetate for monitoring polymerization of styrene, methacrylic acid, and copolymers (C30, C31). Low temperature ashing was used by Narasaki and Umezawa (C44) for controlled decomposition of polypropylene, polystyrene, polyvinyl chloride, polyacrylamide, poly(ethylene terephthalate) and phenolic resin. For simultaneous determination of nitrogen and halogens in polymers, Vladimirova and coworkers (C62) decomposed the sample with Devarda’s alloy at 600° to convert these elements to nitride and halide, respectively. The former is converted to NH3 which is collected in standard boric acid solution and titrated, and the latter by argentometric titration. Phosphorus in alkaline phosphate solutions was determined by conductometric titration with FeClz at pH 4-5 (C8). Acrylics. Degree of conversion in emulsion polymerization of methyl acrylate was measured by bromide-bromate titration for double bonds (C35). Spektor and Shur (C58) evaluated reactivities of methacrylate and vinyl double bonds in vinyl methacrylate-ethyl methacrylate, and vinyl isobutyrate polymerizations by polarography in aqueous alcohol solutions with tetraethyl ammonium iodide and tetraethyl ammonium hydroxide as supporting electrolytes. Structure of graft copolymers of methyl methacrylatevinyl carbonate prepared by y-irradiation was established by hydrolysis and oxidative cleavage by periodate (C65). Acidimetric potentiometric titrations were employed in analyses of acrylic acid-ethyl acrylate copolymers in 4:l isopropyl alcohol-water solution (C60), of polymeric acrylic acid, methacrylic acid, and methacrylic acid calcium salt ( C l ), and poly(acry1ic acid) in ethyl alcohol-water solution (C43). For determination of polyacrylamide concentrations in dilute aqueous solutions, Kruglitskii and coworkers (C33) employed a differential amperometric procedure. Carboxyl groups in acrylic copolymers having a three-dimensional structure were determined by exchange reaction with calcium acetate (C36). Polyamides. A conductometric study was made of the hydrolytic polymerization of caprolactam, permitting determination of the influence of additives (‘2.51 ). Strukova et al. (C59) developed a quantitative polarographic method for determination of carbonyl groups in oxidized polycaprolactam; as little as 0.5 X g equiv/g of carbonyl was detected. 292R
Dabrowska and Majewska (C13) determined acid in caprolactam-terephthalic acid copolymers by acid hydrolysis, recovery of the terephthalic acid, and titration with 0.1N NaOH in hot dimethylformamide solution. An alternate method employed ultraviolet spectrophotometry (C13). Amino groups in aromatic polyamides and polysulfonamides were determined by acetylation using acetic anhydride in dimethylacetamide, followed by addition of diethylamine and potentiometric titration of the excess amine with 0.1N HCl in isopropyl alcohol using Ag-AgC1, glass electrodes ( C I S ) . Identification of a crystalline reaction product [1,2-(N,N’-diphthalimido)ethane]from an alkyd polyamide reaction (phthalic anhydride-polyamide) was made by elemental analysis, acid hydrolysis, infrared, nuclear magnetic resonance, and mass spectrometry (C50). Polyesters. Hydroxyl groups and ethylene glycol analyses during poly(ethy1ene terephthalate) synthesis were measured by acetylation and periodate methods, respectively ((238). Saponification conditions were established for surface reaction of poly(ethy1 acrylate) emulsion particles (C39). For polyesters, Sestrienkova and Singliar (C56) established order of glycerol liberating efficiency by amines as follows: ethanolamine > 2-phenylethylamine > butylamine for alkyd resin aminolysis to identify polyols in polyesters (see ASTM method D-2456-69 A). The liberated polyols were determined by acetylation employing titrimetry or gas chromatography. In the latter case, the esters were extracted into chloroform. Polyethers, Epoxides. Moiseeva et al. (C41) observed 2 inflections in the potentiometric titration of 1,4-diazobicyclo[2.2.2]octane, a catalyst used in foaming of polyesters and polyethers. The titrant was 0.1N HC1 in methyl ethyl ketone. The method permitted determination of the above catalyst in the presence of other amines, sodium acetate, or KOH. Formation of poly(thio ethers) was monitored by polarography with dropping mercury electrode (C52).Polarography also was used to determine high molecular weight poly(ethylene oxide) stabilized with organic compounds, such as urea, thiourea, hexamethylenetetramine, glycerol, pinacone hydrate, diethylene glycol ( C I 7 ) . The amines had essentially no effect on the method employing suppression of a maximum of Co2+ on reduction waves in ammonia solution; the glycols caused some increase in apparent oxide concentration Epoxy resin content and fatty acid composition in an epoxy ester were determined by saponification (C66). Composition of the acid fraction, a mixture of and CIS saturated and unsaturated acids, is determined by gas chromatographic separation of the methyl esters. Polyolefin Copolymers. Structure of single crystals of ethylene-carbon monoxide copolymers was established by calculation of CO groups from elemental analysis (CHNO analyzer) and determination of molecular weight by osmometry (C2). Maleic anhydride in ethylene copolymers was determined by acid-base titration and by conductometric titration (C18). The latter permitted distinction between acid and anhydride functions. Infrared absorption also was used for anhydride determination ( C I S ) . Vinyl acetate in ethylene copolymers was determined by elimination of acetic acid in molten toluene sulfonic acid at 160° followed by acidimetric titration ((25). Poly(viny1 chloride) (PVC). Mitterberger and Gross (C40) described simple analytical tests for use in PVC processing, including detection of plasticizers and stabilizers.
ANALYTICAL CHEMISTRY, VOL. 47, NO. 5 , APRIL 1975
Included was analysis for PVC by reaction with Na202 and analysis for CY. Residual initiators in suspension PVC were estimated by polarography following extraction in benzene-methanol (C29). A sensitivity of 0.0001%was reported from use of 5-g samples. Wexler and coworkers (C63) developed a method for the simultaneous determination of plasticizers and lubricants in PVC based on saponification, e.g., mixture of P b soap, di-2-ethylhexyl phthalate and transformer oil. Cadmium, zinc, and barium in stabilizers used for PVC were determined polarographically following separation via ashing or boiling aqueous HCl extraction (C42). Polystyrene (PS). Styrene and a-methyl S were determined simultaneously by polarographic reduction of their pseudonitrosites (C48). Nishino et al. (C46) showed by potentiometric titration of poly(p-carboxystyrene) and poly(p-aminostyrene) derived from atactic, isotactic, and grafted P S that acid or base strength decreased in the order: grafted > atactic > isotactic. Greene ((219, C20) quantitatively determined surface carboxyl groups in acrylic and methacrylic acid modified S/butadiene copolymer latexes by turbidimetric titration and their distribution by activation analysis. Polarographic methods were used for differential determination of acrylamide and styrene in copolymers (C34) and for Na or K in styrene-methacrylate copolymers (C26). Other Vinyl Polymers. To determine F content of fluoropolymers, Noshiro and coworkers (C47) decomposed the polymer in a KzC03 capsule at 600' for 30 minutes, dissolved the capsule in water and analyzed using a F--selective electrode. Polarographic methods were used in studies of poly(viny1 alcohol)(PVA) adsorption in which maximum suppression was related to molecular weight (C55). Also adsorption processes of PVA and cellulose derivatives were studied by Horn and Jehring (C23). Potentiometric titrations were reported for polyelectrolytes from carboxyalkylated PVA ((222). Decomposition of hydrogen peroxide during vinyl acetate polymerization was followed by polarography (C64). Saponification kinetics were established for vinyl acetateN-vinylcaprolactam copolymers (C15). Vinyl acetate-vinyl propionate copolymers were analyzed following acid hydrolysis by potentiometric titration for total organic acids and gas chromatography for individual acids ((26). Lyashchova and Derevyanko (C37) used a polarographic procedure reported previously for estimating crotonal groups in poly(viny1 crotonal). Chemical methods reported by Thivollet and Gole (C61) for analyses of linear polyacroleins for carbonyl and unsaturated functions included reactions with phenylhydrazine, hydroxylamine, ozone, iodine, and mercuric acetate in methanol. Infrared analysis also was used (C61). Basic functions in vinylpyridine-N-vinyl-2-pyrrolidone copolymers were determined by potentiometric titration with toluenesulfonic acid and ultraviolet spectrophotometry (C9). Miscellaneous. Puchalsky ( C 5 4 ) described a procedure for dimers in aromatic diisocyanates utilizing treatment with diallylamine and total available NCO by treatment with dibutylamine. Thermal degradation products of polymethanes were determined by polarographic and chromatographic procedures; HCN was measured argentimetrically (C27). Chatterjee and Gupta (C11 ) obtained conductometric titration curves for fractionated p - aminobenzoic acid-formaldehyde-p-hydroxybenzoicacid polymers and discussed them in relation to composition, degree of polymerization,
intramolecular hydrogen bonding, and homoconjugation. Eek and Ciutat (C14) examined sulfite, hydroxylamine, ammonium salt, and isoamyl alcohol extraction methods for determining free formaldehyde in urea-formaldehyde resins, They recommended an aqueous sodium sulfite method with titration by 0.1N HzS04 a t 5-7'. A new polyalcohol was made by Morishima and coworkers (193) from sodium borohydride reduction of ethylenecarbon monoxide alternating copolymer. Structural features were established from the periodate cleavage reaction for 1,2-glycol content, infrared spectroscopy, and X-ray diffraction. Phenolate hydroxyl groups in phenol-formaldehyde resins were determined by high frequency titration with acid of phenolate ions resulting from alkali alcoholate treatment (C28). Total OH groups were measured by acetylation and methylol groups by difference. Kreshkov et al. (C32) analyzed phenol-formaldehyde resins for phenol by titration with KOH in acetonitrile and for water by reaction with sodium propionate and ethyl acetate followed by potentiometric titration of excess alkylate with acetic acid. Cresolformaldehyde condensates were titrated potentiometrically in nonaqueous systems and the curves related to ion association, intramolecular hydrogen bonding, and dielectric constant of the solvent (C12). Potentiometric titration behavior of aqueous solutions of poly(ma1eic acid) was reported by Barone and Rizzo (C7). Disulfide and thiol groups in dyed wool were determined by amperometric titration with ethylmercury chloride in 10% dimethylformamide solution of hydrolysis products (C3). Water contents of anion exchange resins in the OH-form were determined by oven drying and by Karl Fischer reagent titration; results between the two methods were in good agreement (C4). Potentiometric titrations of cation exchange resins were discussed by Isaeva and coworkers (C24) and Simonov and coworkers (C57).
INFRARED AND RAMAN SPECTROMETRY Infrared (IR) spectroscopy continued to be one of the major techniques for assigning chemical and physical structure details to polymers. Dechant (132) published a book on IR spectra of polymers including detailed discussion of band assignments for over 35 polymers. Zichy (1135) reviewed quantitative IR analysis of polymers in the 2nd edition of a general book on laboratory methods. Turrell (1125) published a book, useful for those starting in the field and also as a reference, on IR and Raman spectra of crystals. A chapter on polymers was included. Reviews on uses of IR in polymer structure studies were published by Slovokhotova (1115), Schutte (1109), Zerbi (1134),Kumpanenko and Kazanskii (173) who discussed IR and Raman studies on irregular polymers. Siewierska and Kozlowski (1212) reviewed applications of internal reflectance IR to polymers and fibers and Mookherji and Peters (190), to contaminants encountered in spacecrafts before and after UV irradiation such as diethyl adipate and tetramethyltetraphenyltrisiloxane. Near IR absorption of irradiated polymers was discussed by Vigneron and Deschreider (1127); included were polyesters, polystyrene, and cellophane. Analysis of IR band shapes was reported relative to monomer sequence distribution in macromolecules (172). Coleman et al. (129) discussed Fourier transform methods for determining crystalline vibrational bands, illustrating the approach by study of trans- 1,4-polychloroprene.
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Vettegren and Novak (1126) evaluated stresses on chemical bonds in axially stressed polymers. Generally useful studies were reported on applications of IR to bonding of polymeric materials (167), structure of phenolic antioxidants with IR examination of hydroxyl groups (1102), and studies of oligomeric acyl peroxides (156). Laser-Raman spectroscopy was reviewed by Brandmueller and Schroetter (117) and by Tasumi (1117), including studies on such polymers as polyethylene, poly(viny1 chloride), poly(viny1 alcohol) iodine complexes, and proteins. Chemical applications of Raman spectroscopy, including polymers were discussed by Schrader (1108). Koenig and coworkers published reviews on polymer applications (113, 114,166). Acrylics. Far IR absorption spectra were given for methyl methacrylate-ethylene copolymer and reflectance spectra for PMMA (123). Oi et al. (197) used the carbonyl group stretching vibration in assigning sequence distribution of methyl acrylate in its copolymers with styrene. Purvis and Bower (1104) used laser-Raman spectroscopy in studies of molecular orientation in PMMA, particularly with respect to wavenumber shifts of 486, 562, 604, and 1732 cm-l; observations agreed with those from wide line nuclear magnetic resonance. Boerio and Yuann (115) ;tilized the methylene bending mode near 1451 cm-l and carbonyl stretching a t about 1730 cm-' in determining composition of copolymers of glycidyl methacrylate, methyl methacrylate, and styrene. Conformational transitions of syndiotactic and atactic poly(methacry1ic acid) in aqueous solution were established by Lando, Koenig, and Semen (175). Cellulose. Basch and coworkers (110) assigned near-IRabsorption bands to estimate crystallinity ratios in natural and regenerated cellulose; they compared results with XRD values, noting that the near-IR ratios also appeared to depend on crystallite size. Kinetic studies by IR, ultraviolet, and gravimetric procedures were made in determining rate and extent of grafting of cellulosic copolymers (148). An IR analyzer was described for determining moisture in cellophane film using the absorbance a t 5200 cm-I as the analytical band and a t 5480 cm-l as reference (1124). Acrylonitrile (AN) Polymers. Formation of AN polymer films was followed by attenuated total reflectance (ATR) IR (1123). Raman spectroscopy was used in studies of the low-temperature polymerization of AN; changes in spectra were related to character of intermolecular reactions (116). Sequence distribution of AN in AN-styrene copolymers was determined from measurements of the CFN stretching mode with shift to lower frequency with decreasing AN content (196). Iyer and Padhye (157) used the C=N stretching mode for quantitative determination of AN in butadiene-AN copolymers. Comparison of ATR with transmission spectra on solid polymer indicated that AN concentration on the surface was the same as in the bulk (157). Kimmer and Schmolke (163) used IR and NMR in analyses of AN-styrene, AN-butadiene and methacrylonitrile-butadiene copolymers. Polyamides, Polyimides. Model amides, such as dimethylacetamide, N-octylacetamide, and N-methylacetyamide, were used by Nechtschein (194) to study nature of adhesion of polyamide resins to glass. IR analysis of nylon 6 by the KBr pellet technique served to identify monomer, dimer, and trimer in extracts from the polymer (137).The a and y crystalline forms of nylon 6 fibers were determined by IR and X-ray diffraction ( X 9 ) . 294R
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Examination was made of stretched and unstretched deuterated and nondeuterated nylon 6 films from 1200 to 500 cm-l (1113);spectra were given of the a form. Polarized IR spectra between 800 and 33 cm-' were obtained on nylon 6 ( a and y forms), nylon 66 ( a form), and nylon 77 (7 form) with resultant assignment of amide group and methylene chain vibrations (182). Structure and relaxation properties of poly(ester amide acids) were determined by IR and XRD together with mechanical and dielectric measurements (12). Kulikova and coworkers (171) described a calibration curve for relating absorption a t 726 cm-' of diaminodiphenyl ether-pyromellitic anhydride copolymer with number of unreacted carboxyl groups and its use in estimating degree of cyclization of the polyimide. Polyesters. Tirpak and Sibilia (1118) described a new technique for obtaining IR spectra of fine fibers. A single filament was wound between two salt windows separated by a spacer having about the same thickness as the fiber. The technique was applied to poly(ethy1ene terephthalate) (PET) and nylon 6 (1118).Application of ATR to IR analysis of blocks, filaments, and films of P E T was discussed by Gusev and Golovachev (147). Formation of a crystalline phase in P E T led to absorption bands a t 235, 138, and 85 cm-' (13). Bell and coworkers used IR, dynamic mechanical, and molecular weight measurements in studies of morphology of uni-axially oriented P E T (189) and of chain folding in annealed polymer (184). Bahl and coworkers (15)and Boerio and Bailey (111)discussed Raman spectra of P E T and interpreted nature of bands a t 1096,1000,857, and 278 cm-' and compared them with IR absorption. Raman spectrum of P E T and its relation to molecular order was reported by Derouault et al. (132, 133). The latter paper (133) also referred to use of high-pressure techniques in correlation splitting analyses of the laser-Raman spectra of poly(3-methyl-l-butene), poly(4-methyl-l-pentene), and ethylene-propylene copolymer. Molecular orientation in P E T was studied by polarized Raman scattering (134,1105). IR spectra of polyesters in the C-0-R stretching region were discussed (1116). IR and Raman band assignments were made by Hummel and coworkers (152-154) on linear aliphatic polyesters including influence of the ester and CH2 groups. The a and /3 forms of crystalline poly(ethy1ene glycol adipate) were examined by IR (159). Funke and Schuh (142) used IR in studies of the chemical structure of radiation cured polyester resins. Polyethers, Epoxides, a n d Polycarbonate. IR spectra gave evidence for inversion ring opening in ethylene oxide polymerization based on comparisons of nondeuterated and deuterated species (1132). Molecular weight of poly(phenylene oxide) was calculated from absorbance of the terminal OH groups measured a t 3615 cm-l in CCli solution (135). Structural modifications of polydioxolane and polyoxymethylene were determined by IR and X-ray analysis; a spiral form of the latter was found characterized by absorption bands a t 2900, 1125, 1028, 980, 970, and 938 cm-l. Nature of bonding of adsorbed poly(ethy1ene glycol) to silica was established from extinction of the 3300 cm-l band (162). IR band assignments in the 4000-400 cm-' region were made for crystalline poly(ethy1ene glycol dimethyl ethers) (183).Chemical structure information on poly(vinyl phenyl ether) was obtained from IR and NMR spectra
(N80). Pyatyshev and Golenev (1106) described a method for determining epoxy number of bisphenol A epoxy resins which did not require an internal standard. Absorbance is
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975 cm-l band and orientation-sensitive 899 cm-l band. obtained of the sample suspended in benzene, permitting Far IR spectrum of isotactic PP was obtained from 400 t o estimation of oxirane rings by reference t o a calibration 10 cm-I and several band assignments were made (146). curve (1106). Nature of gaseous decomposition products Isotacticity of PP was measured from IR spectra and pyrolfrom cured bisphenol A epoxy resin was dependent on type ysis-gas chromatography following calibration from stanof curing agent used (191);e.g., “3, CH3CHO or CH2=CHCHO from primary amine, Lewis base, or acid anhydard mixtures of isotactic and atactic PP (1119).IR spectra of oxidized PP indicated small amounts of OOH groups dride, respectively. plus larger concentrations of stable cyclic peroxides or epIR spectra distinguished between polycarbonate prepared from bisphenol A and 2,2-bis(4-hydroxyphenyl)-l,l- oxides in the PP chain (127). dichloroethylene or 2,2-bis(4-hydroxy-3,5-dichlorophenyl)- Raman spectra of isotactic PP a t 5-523 OK showed bands characteristic of the unit cell (141). Relations bepropane (1129). Polyolefins. Effects of processing conditions on ultravitween crystallinity and chain orientation were observed in the Raman spectra of oriented PP (16,17). olet light stability of polyolefins, including addition of UV Copolymers of propylene and vinyl chloride prepared stabilizers was followed by IR and ultraviolet spectroscopy with modified TiCl3-Et3Al catalyst were characterized (U18). from their IR spectra (164). Methyl group content of low density polyethylene (PE) The a, /3, and y crystalline phases of cationically synthewas determined with a standard deviation of 0.8% provided sized poly-3-methyl-1-butene were characterized by IR methylene group absorptions were compensated by P E of (136). Kinetic and IR data showed that a random copolysimilar structure (19). Unsaturation in low density P E was mer was formed from 4-methyl-1-pentene and vinylcycloestimated to f0.003 C=C/l@ C atoms by compensating with brominated polymer of the same thickness (19). Luhexane (151). Influence of side chain on stereoregularity, conformaongo (177) studied crystalline orientation effects in the 720/730 cm-’ doublet of transcrystalline PE. Effects of detion, and crystallinity of isotactic poly-a-olefins such as fects in the IR spectrum of P E crystals was established by poly-1-octadecene was determined from IR and Raman data (155).A new IR cell was described for measurements comparison with P E in the extended chain form (1133). IR study of oxidative crystallization of P E was made from exat -120 to 83 “C (155). Polyvinyl Chloride (PVC). Baker et al. (18) improved amination of the 1894 cm-I “crystallinity” band and 1303 on the method for quantitative estimation of chain branchcm-l “amorphous” band and of carbonyl absorption a t ing in PVC, based on use of the CH3 deformation band a t 1715 cm-l (174). Distribution of oxidized groups on the 1378 cm-l. These investigators determined the extinction surface of P E and PP was determined by ATR (1101). Milcoefficient by use of carefully calibrated P E containing ler and coworkers (188) used polarized IR spectra obtained known numbers of C1, Cz, and Cq side chains. Measureby Fourier-transform spectroscopy to study several absorpments were made on the melt a t 150 “C to eliminate crystions of P E crystallized by orientation and pressure in a tallinity effects. Millan and De la Pena (187) reviewed IR capillary viscometer. Kobayashi (165)reviewed the Raman spectroscopy of P E and NMR methods for identification of stereoisomers in crystals and polymer solutions. Gall et al. (143) made PVC. Bfick and Hummel provided detailed information on IR Raman band assignments on P E for fundamental modes, characterization of a series of vinyl chloride-isobutene coovertone, and combinations. Lindberg and coworkers (176) obtained IR and laserpolymers polymerized by y-radiation a t 23 O C : 1)high resoRaman spectra of chlorinated P E and compared them with lution spectra in the range 5000-400 cm-I from which it spectra of P E , PVC, and chlorinated PVC. Chlorine distriwas shown that head-to-tail structures predominate (118); bution in slurry-phase chlorination of high-density P E 2) separation of the superimposed CH2, CH3, CC1 bands were studied by IR and NMR (11). IR reflection was used between 1500 and 1350 cm-l, 1000 and 850 cm-l, 730 and in studies of oxidation of P E a t a copper surface in the 600 cm-l with determinations of half band widths and reladiphenyl-oxampresence and absence of an inhibitor, N,Ntive integral intensities (119);3) determinations of overall ide (122). composition, concentration of diads, and mean sequence Raman and IR spectra of ethylene-propylene (E-P) colengths (120). polymers indicated that overall amounts of P altered crysPropylene content of vinyl chloride-propylene copolytallinity in blocks of E (140). Tosi (1120) showed that exmer fibers was calculated from absorbance a t 1380 cm-l periment agreed with theory in E-P copolymer composiusing reference bands a t 690 and 1420 cm-l and sum of abtion and intensity of CH2 rocking vibrations of methylene sorbances a t 1420 and 1460 cm-I (1128). Comonomer ratio sequences. Tosi and Ciampelli (1121) reviewed use of IR in in films of vinyl chloride-vinyl acetate copolymers was deanalysis of E-P copolymers and E-P-diene terpolymers termined by IR and additives, by gas chromatography while Tosi and Simonazzi (1122) described preparation of (149). Chia and Chen (126) showed that vinyl chloridecalibration curves of % propylene vs. ratio of absorbance of vinyl acetate copolymers could be pressed without decomthe 1378 cm-l band and product of absorbance by halfposition between hot Cu plates a t 110-120° in preparation width of the 1460 cm-l band. Popov and Duvanova (1103) for IR analysis; the method was claimed to be superior to used a comparable approach to analysis of E-P block cocasting on Hg from T H F solution. Terpolymers of vinyl polymers. In addition to IR analysis for E-P-diene terpochloride-vinyl acetate-vinyl fluoride gave all the IR ablymers, Morimoto and Okamoto (192) used solubility tests, sorption bands of the chloride-acetate copolymer plus differential scanning calorimetry, XRD, and electron mipeaks for the fluoride (14) and also specific NMR signals. Fluorocarbon Polymers. Conformational order and decroscopy to characterize organic-solvent insoluble fractions. Methyl groups in E-a-olefin copolymers such as in fects in polytetrafluoroethylene (PTFE) were established E-1-butene were estimated from the relationship between with reference to IR bands a t 312 and 293 cm-’ (180);a peak a t 384 cm-l coincided with Raman active mode. Furabsorbance a t 1378 cm-l and 1369 cm-l (145). Wool and Statton (1131) developed a new technique to ther evidence that the P T F E unit cell contains a t least two study molecular mechanics of oriented PP during creep molecular segments was obtained from new bands observed and stress relaxation based on use of the stress-sensitive in the far IR spectrum a t 33, 291, and 308 cm-’ and a t 55 ANALYTICAL CHEMISTRY, VOL. 47. NO. 5 , APRIL 1975
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cm-' shown to be a close doublet (124).From Raman spec1411, and 540 cm-l (195). Laser Raman and' I spectra of tra, Boerio and Koenig (112) showed that the crystalline poly-p-xylylene were reported for the region 3400-7 cm-l phase for P T F E below 19' was monoclinic with unit cell di(181). mensions a = 5.59, b = 9.46 and c = 16.58 A. Polydimethylsiloxane films were examined by IR (1107) P T F E surfaces exposed to glow discharges were characand by Raman, IR (170).Property-structure relationships terized by ATR and differential ATR IR, X-ray photoelecin polymethanes were establshed through IR (178) as well tron spectroscopy, scanning electron microscopy, and conas determination of secondary bonds (168). tact angle measurements (130). Amorphous content of Chow and Chow (128) used Raman spectroscopy to monP T F E surfaces after friction and wear testing was deteritor formation of phenol-formaldehyde resin (resol). Methmined by ATR IR spectroscopy (158). ATR also was used ylol groups in the range 2.6-4.9% were determined quantito monitor sodium-etched PTFE surfaces used for bonding tatively in phenol-formaldehyde resins having vinylacetylto polymethane substrates (185); unbonded and bonded ene structure (144).IR spectra were obtained of certain inspecimens showed significant variations in the 1650 cm-l dustrial phenol-formaldehyde resins and absorbancies calregion. culated for tri- and tetrasubstituted benzene rings, 1,2,4Cessac and Curro (121) revised laser-Raman band asand 1,2,6-substituted benzene rings, methylol and phenol signments of phase-I samples of poly(viny1idene fluoride) groups (179). which were uniaxially oriented. ULTRAVIOLET-VISIBLE Styrene Copolymers. Analysis of styrene-isobutylene copolymers was achieved through IR, NMR, carbon, and In continuing examination of procedures for determining hydrogen determinations (139). Raman spectra were used copolymer composition, Acosta and Sastre ( U 2 ) reviewed for quantitative analysis of styrene-butadiene-methyl applications of ultraviolet spectrometry. Narasaki et al. methacrylate graft copolymer (1114); C=C stretching (U22) used spectrophotometry to compare recovery of bands were observed for the three configurations of polyphosphorus in organic additives via wet ashing and oxygen butadiene. Sequence distribution of styrene-l-chloro-1,3bomb and acid digestion of the residues. Both decomposibutadiene copolymers was established from IR, UV, NMR, tion procedures were satisfactory on a surfactant alone but, and chemical analysis (1130). in an ethylene-propylene copolymer system, the latter give Quantitative IR in the 4000-450 cm-l region was used to considerably higher recovery of P a t about the 100-ppm characterize free radical styrene-methacrolein copolymers level. Determination of H F diffusion through some poly(160). Of particular value were the carbonyl band a t 1722 mer films was followed by its bleaching effect on the colored complex of zirconyl nitrate dihydride and Xylenol Orcm-' for free aldehyde groups, styrene band a t 540 cm-' related to shortening of sequence length of styrene units, ange, measuring absorbance a t 560 nm (U31). McKellar and Turner (UI 7 ) described cells for use with and styrene band a t 760 cm-l related with'distribution of the Aminco-Bowman spectrophotofluorometer to measure MSM triads and copolymer structure (160).In examination fluorescence and phosphorescence intensity of polymer of styrene-acrylonitrile copolymers, Fieber and coworkers films. A standardized reflection procedure was described (138) observed linear bathochromic shifts of styrene IR for measurement of fluorescence of fabrics (U7). Fluoresbands and hypsochromic shifts of the nitrile band; the noncence spectra were used by Amerik e t al. ( U 3 ) to identify linear CEN shift was related to triad variations and the interaction of chromophore groups during photostability linear shift, to strong effect of the C=N group. Other Vinyl Polymers. Hippe and Kerste (150) develstudies of polymers in dioxane solutions after irradiation a t oped an algorithm for IR identification of vinyl polymers. 313 nm. Polymers examined included poly(methy1 vinyl keMechanism of hardening of poly(viny1 alcohol) in the tone) homopolymer and its copolymer with methyl methacpresence of potassium bichromate was shown to involve inrylate and poly( 1-naphthyl methacrylate). Measurement of the degrading effect of light on Tesins teraction of OH and Cr bonds (1110).Padhye and Iyer (199, 1100) reported on IR spectra and band assignments for was described in a patent issued to Ackerman ( U l ) .Reflecpoly(viny1 formal). Structure of vinylcyclohexane-styrene tion spectra of several polymers (e.g., polystyrene, polyaccopolymer was determined by IR (161).Experimental data rylonitrile, bisphenol A polycarbonate) were made in the 54-250 nm range following excitation from a H-He glow showed that activity of the following monomers to copolydischarge at 0.1-1 Torr (U26). Grafting of cellulosic comerization was in the order: propylene > 4-methyl-1-penpolymers was followed by ultraviolet and IR (148). vinylcyclohexane tene> styrene > 3-methyl-1-butene Polyester, Polyether and Polycarbonate. Nissen and (161). coworkers (U23) described a method for carboxyl endMiscellaneous. Structure assignment was made of a pogroups in poly(ethy1ene terephthalate). Hydrazinolysis led lyalcohol synthesized from l : l ethylene/carbon monoxide to formation of terephthalomonohydrazide from carboxyalternating copolymer reduced by sodium borohydride lated terephthalyl residues to provide a selective analysis from results by IR spectroscopy and XRD (193);1,2-glycol for COOH via ultraviolet absorbance a t 240 nm. Terephcontent was obtained from the periodate reaction. thalic acid in caprolactam copolymers was determined by Raman spectral changes were observed during 1,4-addimeasurement of absorbance a t 242 nm and also by acid hytion polymerization of conjugated diacetylene associated drolysis-titration (C13). Concentration of active centers in with C=C vibrations near 2260 and 2100 cm-l and C=C the cationic polymerization of cyclic ethers was determined near 1500 cm-l (186).IR spectra of polyacetylenes were reby ultraviolet spectroscopy (U5). Terminal OH groups ported (169). Raman bands for 100% trans-polyacetylene were measured in polycarbonate and polysulfone following were observed at 1474 and 1080 cm-l; for 100% cis-, a t complexation with ceric ammonium nitrate; absorbance 1552, 1500, 1262, 1100, 1016, and 920 cm-l (1111). Deterwas measured a t 500 nm for the former, and a t 530-540 nm mination of the ethynyl group in p - diethynylbenzenefor the latter (U21). Differentiation was made between a phenylacetylene copolymer was made by IR and by AgN03 polycarbonate melt and solution by a compensation methtitration (125). od with the melt showing a characteristic maximum a t 316 Polymerization of p-xylylene was followed by IR specnm (U10). Reactivity of initial phenols and intermediate troscopy using quinoid absorption bands a t 1595, 1342, bisphenols in polycarbonate synthesis was followed by pho1322, and 470 cm-I and benzene ring bands a t 1510,1450,
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tometric titration with sodium isopropoxide observing the equivalence point a t 290-310 nm (U25). Polyolefins. Effects of additives on the ultraviolet light stability of polyolefins, such as 2,6-di-tert- butyl-4-methylphenol (“Topanol” OC), was followed by ultraviolet and infrared spectroscopy (VIS)Stabilizers for polypropylene were analyzed by spectrophotometry. For example, 2,4-ditert-butyl-6-(5-chlorobenzotriazol-2-yl)phenol(“Tinuvin” 327) was extracted from the polymer with chloroformethyl alcohol (19:l) and determined a t 315 or 355 nm (U24). Where necessary, the extract was fractionated by thin layer chromatography on silica gel with CHC13 as solvent. Kat0 (U13a) studied formation of carbonyl functions on polyethylene film treated with chromic acid. Changes in amount of hydrazones formed following reaction with 2,4dinitrophenylhydrazine were followed by ultraviolet spectra and compared to changes in wettability of the films with water. Poly(viny1 chloride) (PVC). Color stability of PVC resin was measured from reflection spectra in the 400-750 nm wavelength range; integrated light absorption was related to yellowing (U14). Daniels and Rees (U8) determined polyene concentrations in degraded PVC by UV spectra. They obtained extinction coefficients on known polyenes, observing that dienes usually have only one absorption maximum; trienes, three; higher polyenes, four. Small amounts of carbonyl groups in PVC and VC-vinyl acetate copolymers were determined following formation of the 2,4-dinitrophenylhydrazones by mineralization with H & 0 4 and photometrically determining nitrogen content using Nessler’s reagent (U12). Yashiro and Ueda (U29) reported on visible and UV spectra of perylene-coated or doped PVC films exposed in vacuo to nitrous oxide or ammonia. Polystyrene (PS). Energy transfers between styrene and PS during irradiation-initiated polymerization were followed through observing changes in absorption bands at 34400, 35500, and 36600 cm-l, decrease in extinction coefficient at 40000 cm-I. and appearance of a new peak a t 47000 cm-’ (U27). Maeda and coworkers ( V I S ) determined traces of styrene in the presence of durene by dual-wavelength spectrophotometry of T H F solutions a t 261.8 and 280.7 nm. Residual monomer in P S was detected by a UV method in tests to determine suitability as food containers ( U 9 ) .Regeneration of carbonyl groups from 2,4-dinitrophenylhydrazones formed on the surface of irradiated PS films was followed by absorption measurements at 378 nm (U13). Marked solvent effects were observed by Gallo and Russo (U11) on the hypochromism of styrene-methyl methacrylate copolymer measured a t 269.5 nm. Intensity was inversely proportional to dielectric constant of the solvent. Bogomolova et al. ( U 6 ) employed UV to follow interactions of styrene, a-methyl styrene, and P S in complexes with SnC14. Miscellaneous. Miscellaneous UV-visible studies include determination of 2-vinylpyridine and 4-vinylpyridine, respectively, in vinylpyridine-N-vinyl-2-pyrrolidone copolymers a t 262.5 and 256.5 nm polymer (20.03%) in 2methyl-Lvinylpyridine by absorbance measurements on isooctane solutions a t 257, 271, and 285 nm (U20),dehydration kinetics of sulfopropylic and alkyl derivatives of poly(viny1 alcohol) from UV-visible spectra (U19),condensation reactions in phenol-formaldehyde polymerization from UV measurement at 260 n m (benzene nucleus) ( U 2 8 ) , and vacuum UV circular dichroism of poly(L-alanine) films a t about 180 nm (L‘30).
Nessler reagent was employed to determine microamounts of polyacrylamide in brine after alkaline hydrolysis to form ammonia (C‘15). Bamford and Burley ( U 4 ) obtained spectra in the -300-650 nm range of red-colored polymaleimide synthesized in DMF solution; intensities of absorption bands were directly related to molecular weight and were probably associated with detection of ionic endgroups.
MAGNETIC RESONANCE An extensive review of high resolution nuclear magnetic resonance (NMR) theory was published by Memory (N100) covering interpretation, chemical shifts, spin-spin coupling, double resonance, relaxation, and rate processes. Robb and Tiddy (N116) reviewed NMR studies on macromolecules while Palmisano and Danieli ( N I 1 1 ) reviewed interpretation of proton spectra based on a lecture on methodology. Reviews on analysis of polymer structure such as tacticity and sequence distribution were given by Katritzky and Smith (N71), Hatada ( N 5 5 ) , Cudby and Willis with emphasis on vinyl polymers (N31). Quantitative determination of copolymer composition by NMR was reviewed by Sastre and Acosta (N118).The 1973 Sadtler Guide to the NMR Spectra of Polymers included about 175 spectra of commercial polymers (N123). Major progress was made in Fourier transform NMR. Imanari (N63) reviewed principles and instrumentation as well as applications to determination of spin relaxation time and to 13C NMR. Morishima (N105)also discussed recent advances in 13C NMR covering relaxation time, dynamic structure, and paramagnetic solutions. Lyerla and coworkers (N94) described 13C NMR studies of alkane motion using neat 7, 10, 13, 15, 18, and 20 C alkanes and 2methylnonadecane. Rate of internal rotation of a CH3 group was calculated from longitudinal relaxation time (N143). Applications of lanthanide chemical shift reagents in proton NMR were reported for determining the internal rotation angles of Dpoly-6-hydroxybutyrate (N34) and structural features on linear polymers and rubbers (N70). Katritzky and Smith ( N 7 0 ) also discussed use of 13C NMR in studies of linear polymers and rubbers. Applications of NMR to studies of solid polymers was reviewed by McBrierty ( N 9 9 ) and Finer (N43). A spin-echo NMR apparatus was described for studies of glass transitions in polymers at pressures to 7500 kg/cm2 (N134) and applied to fluorocarbon resins. Studies of molecular motions in partially crystalline polymers were reported by Bergmann ( N I I ) on polyethylene, poly(ethy1ene oxide), and poly(viny1idene chloride) and by Weill (N142) on PE, polyisobutylene, and PMMA. Zachmann ( N I 5 5 ) reviewed general experiments on glass transitions and melting. Ho (N58) described a quantitative method for hydroxyl groups in polymers based on formation of the hexafluoroacetone adduct and measurement of 19F NMR. The method was capable of determining total hydroxyl and OH group types. Electron spin resonance (ESR) in polymer research was the subject of a Nobel Symposium in Stockholm, June 1972, the proceedings of which were published in 1973 ( N 7 5 ) .Several reviews on applications of ESR to the detection of free radicals in polymer systems included study of polymerization mechanisms and structure ( N 2 ) ,reports on free radical movement in polymers (N52, N84, N91), and on studies of crystalline and oriented polymers (N90). Reviews of more specific applications of ESR included studies on deformation behavior in cross-linked polymers
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( N 7 2 ) , mechanical stressing of thermoplasts ( N 7 3 ) , and photodegradation mechanisms after UV irradiation of polymers (N135). Ehrlich (N37) reviewed relations between ESR and electrical conductivity with respect t o conduction mechanism from dehydrogenation and donor-acceptor complexes. Nuclear quadrupole resonance response was obtained by addition of inert fillers to polymers and adhesives. Hewitt and Mazelsky (N56) reported on copper oxide tracer studies on an epoxy adhesive containing an aminopolyamide, a nitrile-phenolic, a polyurethane with curing agent, and primer. The NQR technique detected 10.5% antimony oxide (N56). Acrylics. Isotactic triads in dimethylformamide solutions of poly(methy1 methacrylate) (PMMA) were measured by NMR (N83).Amiya and coworkers (N4, N 5 ) obtained conformational information on PMMA in benzene solution with use of tris (dipiva1omethanato)europium as shift reagent. Adsorption and desorption behavior of tactic PMMA in chloroform solution on silica gel was followed by high resolution NMR (N103). Characterizations of poly(pheny1 methacrylates) were made from 100 MHz NMR spectra (N144).NMR data provided insight on polymerization mechanism of 2-allylphenyl methacrylate (N46). Ebdon ( N 3 6 ) obtained 220-MHz NMR data on triad and pentad MMA fractions in random and alternating MMA-butadiene copolymers which agreed with calculations from reactivity ratios. Suzuki et al. (N129a) obtained 300-MHz spectra on poly(methy1 acrylate) and poly(methy1 a,@-dideuterioacrylate) to interpret methylene proton resonance data in terms of tetrad configurations. Matsuzaki and coworkers ( N 9 6 ) studied 13C NMR spectra of poly(methy1 acrylates) and poly(isopropy1 acrylates) with model compounds to interpret peaks associated with triad, tetrad, and pentad placements. From methyl group chemical shift data, Kulkarni and Pansare (N8.2) developed quantitative analyses for species obtained in production of methyl acrylate monomer from acrylamide sulfate and methanol; average error of f2.0% was reported for methanol, methyl acylate, and water. Methyl acrylate-methacrylonitrile copolymers were characterized from methine and a-methyl proton resonance from 220-MHz NMR (N139). ESR studies included examination of methacrylate propagating radicals in polymerization of methacrylic acid and several methacrylates (N53). Studies of radical formation on mechanical fracture of PMMA were reported by Sakaguchi et al. (N116a). Experimental observations were reported by Bullock and coworkers (N18) on synthesis of PMMA with a nitroxide spin-label a t the chain end. Six free radicals were identified from y-irradiation of PMMA and poly(methy1 acrylate) (N47). Cellulose. Wide-line NMR spectra, used in studies of dissolved water in ultrathin (0.25 1)and thick (100 b ) cellulose acetate membranes, were interpreted in terms of “free” and restricted water (N79).Diamagnetic susceptibility effects were studied in NMR spectra of adsorbed water on membranes made of cellulose acetate, triacetate, and acetate butyrate (N1.22).Bound water in cellulosic gels was determined by NMR and calculations made of maximum values approximating a monomolecular layer (N.21). Polyacrylonitriles. Tacticity in polymethacrylonitrile (PMAN) was estimated from 13C NMR and triad tacticity of PMMA obtained by hydrolysis of PMAN was calculated from a-methyl proton resonance spectra (N66). The triad data indicated that a preponderance of syndiotactic placements and that simple Bernoullian statistics adequately described the stereospecificity of the polymerization (N66). 298R
Inoue et al. (N67) presented data on pentad stereochemical placements of PMAN based on proton-decoupled natural abundance 13C NMR and noted that results were described by the Bernoullian model for free radical polymerization. Similar observations were presented by Suzuki and coworkers (N129) from the a-methyl proton resonance signal from 220-MHz NMR. Suzuki et al. (N130)also interpreted 220-MHz spectra of acrylonitrile-butadiene copolymers in terms of random and alternating sequence distributions. Polyamides, Polyimide. Woodward and coworkers discussed relaxation behavior by dynamic mechanical measurements and wide line NMR of a group of synthetic and natural polyamides (N149) and of four aromatic polyamides: phenylene iso- and terephthalamides (N148). Sequence distributions of some aromatic copolyamides were determined by NMR on N,N-dimethylacetamide containing LiCl (N32).Conformational information on structurally rigid polyamides was reported using lanthanide shift reagents (N104). Tifio and Szocs (N13.2)extended their ESR studies of yirradiated polyamides to include data on trapped radicals in oriented as well as nonoriented nylon 6. NMR relaxation data were reported for several poly(Nsubstituted maleimides) including the N - amyl compound (A%),dodecyl polymer (N8, N 9 ) and poly(N-p- chloropheny1)malonimide ( N 9 ) . Polyesters. Structural information from NMR data on strongly extended noncrystalline chains in poly(ethy1ene terephthalate) and in nylon 66 were reported (N153). Olefinic proton resonance data were reported on unsaturated polyesters of fumaric acid with ethylene glycol and sebacic or adipic acid (N140). Slonim and coworkers (N124) described NMR methods to determine chain structure, composition, and molecular weight of unsaturated polyesters. Also reported were computer programs for automated analyses of polyester NMR spectra, and cis-trans isomerization kinetics; results from analysis of polyethylene glycol adipate sebacate having butoxy end groups were given (N124). Hydrolytic degradation of polyester plasticizers was studied by NMR spectroscopy; observations were reported for plasticizers in neutral media and in carboxy-terminated adipic acid-ethylene glycol and adipic acid-neopentyl glycol copolymers (N10). Cumene hydroperoxide in hardened polyester resins was determined by decomposition with cobalt naphthenate, reaction of the free radical with diphenylamine to form a stable radical measurable by ESR (N146). Polyethers, Polycarbonate. Cross and Mackay (N30) analyzed alkyl ethoxylates for average alkyl chain length and average number of ethylene oxide units from NMR spectra of trimethylsilylated derivatives. Hydrate formation in polyethylene oxides was followed by NMR (N95). Diad and triad sequences in ethylene oxide-propylene oxide copolymers were determined from 13C NMR intensities (N145).Stereoregularity in polypropylene oxide (PPO) was measured by I3C NMR, together with mechanism of polymerization (N86, N141). Schaefer (N119) used noisemodulated partial decoupling to aid in interpreting 13C NMR spectra of PPO. Diad, triad, and pentad sequences in poly(methy1 vinyl ether) were assigned from 13C NMR data; 2,4-dimethoxypentane served as model compound in these studies which included effects of solvent and temperature on chemical shifts (N97). Mechanism of polymerization and chemical structure of poly(viny1 phenyl ether) were established from NMR and IR data (N80).
ANALYTICAL CHEMISTRY, VOL. 47, NO. 5, APRIL 1975
Larsen and Strange studied relaxation times in relation to molecular motion by pulsed NMR on the uncured diglycidyl ether of bisphenol-A (N87) and on the ether cured with 4,4’-methylenedianiline (N88, N89), including a study of the curing process, Chandler and Stark (N26) studied effects of europium and praseodymium chelates on the NMR spectrum of the glycidyl ether of bisphenol-A. They observed a larger chemical shift for protons attached to the epoxy ring than those of the exocyclic OCH2 group following addition of the shift compounds in CC4 solution. Added tert- butyl alcohol complexed preferentially with the chelate, reversing the NMR spectra ( N 2 6 ) . Amorphous regions in polyoxymethylene were studied from second moment data calculated from NMR spectra (N57).High resolution NMR was used in studies of the solution polymerization of cyclic ethers ( N I 1 2 ) . Groom and coworkers (N50) employed trichloroacetyl isocyanate and trifluoroacetic anhydride acetylations to determine OH end groups in polyether polyols. The isocyanate reagent measured proton resonance and was best suited for samples having molecular weights
