Coatings M. H. Swann, M. L. Adams, and G. G. Esposito U . S. A r m y Coating and C h e m i c a l Laboratory, A b e r d e e n Proving Ground, Md.
The important contributions to the analysis of coating materials as selected by the reviewers since the previous summary (84) are contained in this biennial review. The period covered extends from January 1971 through December 1972, b u t literature from some countries, located by abstract, will predate this period. In this attempt to be selective, we hope that valuable publications have not been omitted. There has a been a noticeable reduction of 25% in the amount of literature appearing in this period on coating analysis and most of the analytical methods involve instrumental techniques. So few papers have appeared on oil and fatty acid analysis that the section is omitted for this review and the three papers on the subject are included under “Associated Materials.” A new section on “Solvents” has been added. Other reviews on specific subjects were also made in this two-year period and concern the subjects of water-soluble coatings (52), atomic absorption (69), and NMR spectroscopy (70). Some books on coating analysis were published in this period and the most generally useful is the 13th edition of the Paint Testing Manual (85) which describes all test methods, chemical and physical, that are believed to have significance in the field of paint technology. This edition is composed of 600 pages and 56 chapters contributed by 43 authors. There are detailed analytical procedures in nine of the chapters. The second volume of “Techniques and Methods of Polymer Evaluation” (81) deals with thermal characterization and contains chapters on differential scanning calorimetry, pyrolysis-GLC, thermal conductivity, electrochemical analysis, semimicro techniques, and others. The proceedings of a symposium on analytical calorimetry (66) include studies of polyfins, polymer single crystals, copolymers, polyblends, elastomers, epoxy resins, and thermosetting polymers, along with descriptions of thermal depolarization, microscopy, thermomechanical, and thermogravimetric techniques. Craver (65) has edited and enlarged the symposium on interdisciplinary approaches to the characterization of polymers sponsored by two divisions of ACS. The papers refer to most of the newer instrumental techniques as applied to resins and polymers. Volume I of an atlas (38) on the infrared analysis of polymers, resins, and additives was published in this period. Six new procedures concerning the analysis of coatings and raw materials were issued by the ASTM in this period (3), as follows: D2832 Determining Nonvolatile Content of Paint and Paint Materials, D2930 Test for Maleic Acid in Maleic Anhydride by Potentiometric Titration, D 2998 Determination of Polyhydric Alcohols in Alkyd Resins, D2999 Test for Monopentaerythritol in Dipentaerythritol, D3008 Determination of Resin Acids in Rosin by GLC, and D3132 Solubility Range of Resins and Polymers.
GENERAL ANALYTICAL SCHEMES A progress report was made (18) on a study of the precision of pyrolysis-gas chromatography for various polymers such as styrene-butadiene, methyl methacrylate-styrenebutadiene terpolymer, and styrene homopolymer. The various techniques used in 18 laboratories involved in the
study were described and they reported good qualitative but poor quantitative results. M e n i i and Roux (56) demonstrated the establishing of the composition of a twopolymer mixture with gel-permeation chromatography. A high and a low molecular weight polymer were used and tetrahydrofuran was used for sample solvent and for elution, In a two-part report, recycle gel-permeation chromatography was also described (10) in principle and design and in its application to the ana1y;is of epoxy resins. An alternate pumping principle and recycle circuit design were explained in part 1, and fractionation of epoxy resins was given in part 2. The two paris were also published separately (8, 9). Thin-layer and paper chromatography were used by Lee (45) to analyze t i e reaction products of urea and formaldehyde and R f values of nine compounds were calculated. Thin layer chromatography was also used (7) to correlate Rf with molecular weight of such resins as polystyrene, polymethylmethacrylate, polyethylene oxide, and their copolymers. X-Ray fluorescence spectrometry was employed (23) to determine the level of heavy metal inorganic and organometallic toxins in antifouling coatings. The authors discussed the use of the technique for monitoring quality control and determining coating thickness. Some additional applications of X-ray fluorescence appear in later sections (21, 40, 44). A report is available (24) of investigations into quantitative analysis of paints for zinc, zinc oxide, and asbestos by X-ray diffraction, and its combination with infrared spectroscopy for distinguishing between classes of exterior oil paints. In the second part of a comparison of paints by the use of neutron-activation analysis, Snow and Washington (82) attempted to distinguish between 300 samples of various color products and showed that distinctions could be made between paints of the same color from different manufacturers and also between different batches of the same ma1,erial. A 261-page report was issued (76) on effective m e m s of comparing paint samples for forensic purposes. Samples of 155 different paints were used and they were analyzed by neutron activation followed by gamma-ray spectrometry and computerized data reduction. The authors observed 37 elements, as high as 25 in one sample. Tke same techniques were also used by Liebscher (46) to compare forensic samples by trace elements and he descrihed his complete scheme of analysis. O’Neill and Falla (63) compared the infrared spectra with the laser Raman spectra of drying oils and alkyd resins and pointed out potentially useful bands for quantitative measurement usagc!. They concluded that unsaturation in linseed and tung oils and in pentaerythritol-linseed-phthalic alkyd resins can be determined more accurately with the laser Raman spectra than with the IR. They also claim that the band for total unsaturation in these spectra is strong enough for quantitative use. In a separate study (19), the laser Raman spectra were obtained and discussed on a number of polymers. Bartels evaluated (5) the application of multiple interna! reflection spectrometry to aircraft materials. Using thin films mounted in a Wilks Model 50 internal reflectance attachment he examined polyurethane foams, silicone sealants, ANALYTICAL CHEMISTRY, VOL. 45,
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potting compounds, and studied the degree of polymecization of epoxy-polyamide formulations and solvent re tention characteristics. In a continuation of their treatise on infrared Fourier transform spectroscopy in the coating industry, Low and Mark have described the recording of spectra and measuring of film thickness in part I1 (47) and optimum conditions for transmission/absorption spectra in part I11 (48). Other applications of infrared spectrophotometry described in later sections include phenolic resins (go), nitrocellulose ( I ) , acrylic terpolymers (73), and silicone polymers (55). Price (69) has reviewed briefly the principles and us3 in the paint industry of atomic-absorption spectrophotornetry, especially in analysis for such toxic elements as arsenic, antimony, barium, cadmium, lead, and chromiiim. He listed sensitivities for 19 elements present in paints. McKay (51) has also written on atomic absorption srlectrophotometry and related the analysis of metallic d e ments in solution to quality control of pigments, paints, UV stabilizers, and fungicides. Other applications of atomic-absorption spectrophotometry are referred in other parts of this review for metal analysis (25, 26, 78). Nis3et (60) published a brief discussion of the principles and iipplications of nuclear magnetic resonance and electron spin resonance in the field of surface coatings. In another contribution (71), nuclear magnetic resonance spectrosccpy was used to examine a variety of drying oil alkyds, related esters, and urethanes. Pusey (70) reviewed the uses of NMR spectroscopy for the analysis of coatings quoting examples that include iodine number, saponification value of glycerides, identification of unknown epoxy resins, a i d the relative amounts of monomer in copolymers. Appliciitions of differential thermal analysis to paints and viirnishes were presented (41) and weight loss curves were supplied for alkyd resins, nitrocellulose, butyl methacrylate, and others. Applications of GLC to coating analysis are described in other sections for solvents (27, 31, 57, SCl), oils and fatty acids (39), plasticizers (43), water (28), arid various resins (59, 61, 62).
0.2M ethanolic sodium hydroxide in 1:1 water: methanol medium followed by titration. The application of pyrolysis GLC analysis to vinyl chloride-acetate copolymers has been reported (61). O'Mara (62) applied pyrolysis GLC analysis to poly(viny1 chloride) by measuring the HC1 liberated. He worked with the resin, plastisols, and copolymers. Mak and Rogers (53) investigated the use of nuclear magnetic resonance spectrometry to determine the chain branching in bisphenol A epoxy resins. Peak area comparisons were used to make the calculation. Some specific chemical tests were outlined (12) for the qualitative analysis of phenolic resins but the authors stressed the use of examination of pyrolyzates by gas-liquid and thin-layer chromatography. Infrared spectrometry was used to determine the amount of terpolymer present in acrylonitrile butadiene-styrene polymers (89) and to establish the chemical composition of fiethy1 methacrylate-butadienestyrene terpolymers (73). Post (67) has outlined two quantitative methods for the determination of styrene-butadiene, vinyl toluene-butadiene, or vinyl toluene-acrylate; one based on the difference in weight of the portions extractable with benzene and with n-pentane, the other based on an infrared absorbance ratio method applied to a solvent-free film of the benzene extractable. A procedure for analyzing carboxylic esters was published (33) which uses alkali fusion and GLC and was demonstrated on phthalates, polyacrylates, polymethacrylates, and copolymers. Mayhan et al. (55) used infrared spectrometry in a systematic approach to the identification and classification of organosilicon liquids and presented spectra with identification of various absorption bands. The principles, applications, and limitations of liquid and gas chromatography, infrared and ultraviolet spectrometry were discussed (49) as applied to the identification of a number of paper coatings and pigments. McLean (52) has presented a general review on analytical methods for water soluble coatings.
SPECIFIC CLASSES OF HIGH POLYMERS Braun and Jung (13) distinguished between amino resins such as urea-, thiourea-, melamine-, and aniline-fornialdehyde. They hydrolyzed with sulfuric acid and USE d color tests and thin-layer chromatography for the identification. Dawson and Haken (20) reported a color reacticii for the identification of methacrylate monomer and polymer. They treated the sample with nitric acid and sodiuin nitrate and extracted the color formed into chloroform. .4 combination of the Zeisel reaction, gas chromatography, and infrared spectrometry was used to analyze acrylic polymers (2). Following cleavage of the esters, GLC was used to separate the alkyl iodides formed and infrared examination was used for quantitative measure of styrene and for qualitative identification of acrylic acid, methacrylic acid, and the half ester of maleic acid. A procedur,? was published (86) for determining the composition of copolymers of vinyl acetate and acrylic ester. Identificatioii was made by differences in saponification value with ana without water present-the value being lower in the absence of water. The acetate content was measured by use of saponification and ion exchange resin columns. Chifor ( I 7) identified vinyl acetate copolymers (with maleic esters and acrylic acid) by differential thermal analysis. Thermograms of the copolymers were compared with those of the monomers and mixtures of monomers. The vinyl acetate content of copolymers with vinyl chloride or polyacrylonitrile was measured (34) by hydrolysis with
SPECIFIC CONSTITUENTS A method for the determination of fumaric and maleic acids in polyester resins or in admixture was described (91) in which two separate resin samples are saponified and the total acids measured by titration of one sample, followed by the precipitation of fumaric acid with cadmium on the second sample. Atkinson and Calouche (4) published a procedure for analyzing polyethylene terephthalate prepolymer by trimethylsilylation and gas-liquid chromatography. The components included in their work were ethylene glycol, diethylene glycol, terephthalic acid, and both mono- and bis-(2-hydroxyethyl) terephthalate. Isophthalic acid in unsaturated polyesters was determined polarographically by Kratky and Novak (42) following nitration, They claim no interference from styrene, polyols, fumaric or maleic acids. Details of a technique for separating organic acids with thin-layer chromatography on gradient lasers were presented (75). Ten fatty acids (C, to (222) and 8 dicarboxylic acids were separated on gradients of silica gel to combined silica gel and silver nitrate, kieselguhr to silica gel and silver nitrate, and silica gel to kieselguhr. Acids included were oxalic, succinic, glutaric, adipic, pimelic, suberic, azelaic, and sebacic. Scoggins (77) used column chromatography to analyze potassium terephthalate-benzoate mixtures. Amberlite XAD-2 resin was used and the terephthalate was eluted with saturated sodium chloride solution, benzoate with water or methanol, and the eluted salts were measured by UV spectro-
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photometry. I t was stated that the procedure also allows for the determination of less than 0.1% of benzoic acid in isomeric phthalic acid mixtures. Determination of the molar ratio of phenol and formaldehyde in resol-type phenolic resins using infrared spectrometry was illustrated (90). A method for determining the phenol component in phenolic, cresolic, and xylenolic resins was published (59) and includes a description of the pyrolysis unit, listing of the decomposition products, and typical chromatograms. Hanson and Smith (35) explained their technique for measuring the alkoxy and vinyl content of siloxane materials using alkali fusion and gas chromatography. Ages and Bowen (I) published their quantitative method for nitrocellulose in alkyd lacquers using infrared spectroscopy. The solvent used was dimethylacetamide and calculation was by the method of standard additions. Secrest and Heckman (79) illustrated with 1R spectra the loss of ether and methylol groups during drying of amino polymers for nonvolatile content determinations and proposed a modified technique using a 60 "C vacuum oven. Chemical methods for determining melamine and dicyandiamide in samples of technical melamine were published (58). 2,4,6-Trinitroresorcinoland the nickel salt of amidinourea, respectively, were used to determine the two products. Heuser et al. (36) reported on the determination of free monomeric 2,4- and 2,6-diisocyanatotoluenes, both colorimetrically and by GLC in benzene with phenanthrene as internal standard. To determine 1,6-diisocyanatohexane, the authors used distillation followed by IR examination of the distillate. They included instructions for analyzing mixed types of diisocyanate monomers. Campbell (14) has described his radiochemical method for measuring the residual isocyanate groups in soluble polyurethanes. He used Cia-butylamine to form labeled derivatives by reaction with residual isocyanato groups and gave details for isolating the labeled derivative for scintillation counting, The method of using gas chromatography for identifying the poly01 base compounds in polyurethane polyethers was presented (87) in which degradation is accomplished with acetic anhydride and p-toluene sulfonic acid. The poly01 acetates are identified by standard GLC techniques. Beazley (6) determined the polymeric isocyanate content of polymers in the presence of reactive halides by titration with dicyclohexylamine. A colorimetric method for the determination of abietic acid in rosin and resin mixtures was published (54) but it was not clear why related resins did not interfere. The Houston Society for Paint Technology has evaluated (37) a centrifugal method for solids-volume of highly pigmented inorganic zinc coating systems. The method developed is based on measure of the volume of the sediment formed on centrifugation.
SOLVENTS Flack (32) has discussed the disadvantages of various techniques for obtaining gas chromatographic separation of the solvents in whole paint, including direct injection, the use of head space vapor, and vacuum distillation. He has recommended solvent isolation by passing a stream of dry nitrogen gas through the heated paint (40-60 "C) and condensing the vapors in Dewar flasks. In the same volume, Flack (31) presented his method of obtaining GLC analysis of the solvents in aqueous paint systems. He determined solvents such as glycol ethers or lower alcohols in electro-deposition baths having 85% water by the technique of direct injection onto chromatographic columns of 2% zinc stearate and 5% poly(ethandio1 adipate) on acidwashed, ignited, silanized Porolith a t 85 to 105 "C, using
either flame ionization or thermal cc nductivity detectors. Miller and Spagnola (57) used GLC to determine the residual solvent in cellulose acetate butyrate films. Most of the work in solvent ana1y:;is has concerned the separation of the hydrocarbon typeri, especially the aromatics. Soulages and Brieva (83) used GLC with flame ionization detection and split the sample into 3 streams; one allows the total sample to pass, the other streams selectively adsorb olefins and aromatics. The conditions are adjusted so that the sample from each stream reaches the detector at different times. The three peaks obtained represent total sample, saturates plus xomatics, and saturates only. Quantitation is obtained by calibration with knowns. The correction factors needed are excessively large and the saturates plus aromatic peak shows tailing which may cause some difficulty in measurement. The results of an investigation were published (88) in which the meta and para isomers of xylene m d chlorotoluene are separated by GLC using a column of 20% naphthalene1,8-diamine as the stationary phase on Chromosorb W a t 80-95 "C with helium as carrier. These isomers are normally difficult to separate. A report was issued (29) which describes a rapid determination of total aromatic solvents in enamels and lacquer solvents using high-efficiency liquid chromatography. Separation was obtained across a small bore column containing silica beads of controlled .porosity without modifier. Another report (27) describes a more rapid and accurate procedure for enamel solvents and thinners involving a single chromatographic analysis, in which an aromatic internal staiidard is added to the sample prior to removal of the oxygenated compounds present. A paper was published (39) on a comparison of cyanoethyl type liquid phases for GLC columns for their aromatic-aliphatic selectivity. TheIe extremely polar materials are used for the separation of aromatic from aliphatic hydrocarbons; six were involved in this study.
ASSOCIATED MATERIALS A guide was published (68) to thi: analysis of fatty acids and their esters by gas chromatography and includes instructions for esterification, physical properties, and a selected bibliography of' 684 references to fatty acid analysis. The fatty acid composition of soybean and castor oils has been determined (39) with a rapid GLC method in which saponification is avoided by on-column transesterification. The effect of different saponification media on the formation of isomeric Cls cyclic fatty acids during the treatment of linseed oil for fatty acid analysis has been discussed (74), along with detection and determination methods. Krishen has added (43) to the tabulated retention data for use in identifying ester plasticizers by programmed temperature gas-liquid chromatography. A method was described and illustrated (11) for transferring a sample of propellant from a pressurized spray can to the gas chromatograph. Comparative retentior volumes were given for eleven propellants. Simpson and Currell (80) gave details for the detection and determination of antioxidants, organotin compounds, and ultraviolet absorbers by TLC using commercially prepared silica gel coated plates containing a fluorescent additive. A report WAS issued (28) describing various operating parameters foi' a GLC procedure for measuring water in widely diver8;ent solvent systems including paint solvents and paint removers. The column was packed with porous polymer. Yellow and red iron oxide pigrients were examined by Riederer (72) by infrared spectroscopy using KBr disks. Spectra of 24 natural and synthetic pigments were includ-
ANALYTICAL CHEMISTRY, VOL. 45, Ni3. 5, APRIL 1973
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ed and the principal bands were tabulated. The presence of other constituents was illustrated and included the differentiation of the umbers from the iron oxides. Dentcln et al. (21) have described the use of automatic 14-channel simultaneous X-ray spectrometry for the analysis of titanium dioxide pigments, and presented data on the ac:curacy of determination of the elements. Raman spectrc8r;copy was utilized (15) for the rapid determination of low concentrations (0.03 to 10%) of anatase in rutile titanium dioxide pigments. The authors suggest the possible uso of anatase as an internal standard for other inorganic determinations. A procedure was described (64) for deterriining 98 to 100% zinc oxide in the presence of metallic zinc. The Det,roit Society for Paint Technology deve1ope:l a gravimetric method (22) for determining combustible organic pigments such as carbon black in the presence of organic, solvent-soluble resins and inorganic pigments. The total pigment is determined gravimetrically by the us12of filter disks 'of predetermined ash content, which are t tien ashed and the yield is converted to inorganic pigment content by a correction factor. There has been a noticeable increase in the numbe;. of contributions dealing with metal analysis due to the emphasis on toxicity reduction. McDuffie (50) reported on his technique for the rapid screening of pencil paint for lead content by inserting the edge of painted pencils into the edge of the atomic absorption flame, allowing for detection within a few seconds. Laurer et al. (44) devised an instrument to detect lead directly in painted surfaces such as walls, using X-ray fluorescence. The response was stated to be independent of the amount of paint and apprcximately 3% of lead in a single paint coat could be detec1,ed beneath 10 coats of lead-free paint. Searle and associates (78) applied atomic absorption analysis to the determination of lead in paint scrapings following a qualitative t?st first made on a paint chip with sulfide solution. The determination of lead in marine underwater anti-corrosive paint was published (16) using EDTA, and the method is claimed to be simple, rapid and accurate. Duffer (25) investigated the use of mercury-copper amalgam for det 51mining metallic, inorganic, and organic forms of mercury down to the parts-per-billion level. The mercury is removed from the amalgam and the vapors are transferred t,o an atomic absorption spectrometer. Test methods were discussed (40) for determining trace metal quantities in color pigments by the use of X-ray fluorescence spectrometry. Twenty-one metals were included in this survey. Eider (26) has given complete instructions for determining a large number of metallic elements in paint and virtyl additives in solid or liquid form by atomic absorpti'3n spectrophotometry. He also supplied coefficients of variation for seven of the metals. LITERATURE CITED (1) Ages, D.T., Bowen, B. C., J. Mater., 6, 766 (1971). (2) Anderson, D. G., Isakson, K. E., Snow, D. L., Tessari, D. J., Vandeberg. J. T.. Anal. Chem., 43, 894 (1971). (3) "Annual Book of ASTM Standards, Paint, Varnish, Lacquer a i d Related Products," Pt 20 8 21, ASTM, Philadelphia, Pa. 1972. (4) Atkinson, E. R., Calouche, S. I., Anal. Chem., 43, 460 (1971). (5) Bartels, T. T., ibid., 44, 1065 (1972). (6) Beazley, P. M., ibid., 43, 148 (1971). (7) Belenki, B. G., Gankina. E. S.. J. Chromatogr., 53, 3 (1970). (8) Biesenberger. J. A,, Tan, M., Duvdevani, I. J., Maurer. T., J. Appl. Polym. Sci.. 9, 353 (1971). (9) {bid., 15, 1549. (10) Biesenberger, J. A., Tan, M., Duvdevani, I. J., Maurer, T., U..?. Nat. Tech. Inform. Sew. AD Rep., 1970, No. 717638. (1 1) Blurnenthal, A,, Wullschleger, R., Alimenta, Zurich, 8, 43 (1969). (12) Braun, D., Arndt, J., Kunsfstoffe, 62, 41 (1972).
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(13) (14) (15) 26, 537
Braun, D., Jung, J. C., Gummi, Asbest, Kunstst., 23, 618 (1970). Campbell, D. R., Microchem. J., 14, 546 (1969). Capwell, R. J., Spagnola, F., DeSesa. M. A,. Appl. Spectrosc., (1972).
(16) Chaudhuri, J. C., Audi, A. K.. Sankholkar, S. C., Paintindia, 21, 31 (1971). (17) Chifor, A,, Chem., OilGas Rom., 7,45 (1971). (18) Coupe, N. B., Jones, C. E . R., Perry, S. G., J. Chromatogr., 47, 291 (1970). (19) Cudby, M. E. A., Wiilis, H. A,, Hendra, P. J., Peacock, C. J., Chem. lnd. (20). 531 (1971). (20) Dawson, T. S., Haken, J. K., J. Chromatogr., 45,346 (1969). (21) Denton, C. L., Hirnsworth, G., Whitehead, J., Analyst (London), 97,461 (1972). (22) Detroil SOC.Paint Technol., J. Paint Technol., 44, 95 (1972). (23) Driscoll, C.. Freirnan, A,. ibid., 42, 521 (1970). (24) Drlsko. R. W., Crilly, J. B.. U.S. Nat. Tech. Inform. Serv. AD Rep., 1971, No. 721696. (25) Duffer, J. K., J. Paint Technol., 43, 563 (1971). (26) Eider, N. G., Appl. Spectrosc., 25, 313 (1971). (27) Esposito, G. G., U.S. Naf. Tech. Inform. Serv. AD Rep., 1971, No. 731 790. (28) Ibid., 1972, No. 746608. (29) lbid., No. 748804. (30) Esposito, G. G., Jamison, R. G., J. Paint Technol., 44, 77 (1972). (31) Flack, J., Plaste Kauf., 18, 132 (1971). (32) lbid., p 858. (33) Frankoski. S. P., Siggia, S.. Anal. Chem., 44, 507 (1972). (34) Getrnanenko, E. N., Perepletchikova, E. M., Zh. Anal. Khim., 25, 1832 '(1 970). (35) Hanson, C. L., Smith, R. C., Anal. Chem., 44, 1571 (1972). (36) Heuser, E., Reusche, W.. Wrabetz, K., Fauss, R., Fresenius' 2. Anal. Chem., 257,119 (1971). (37) Houston SOC.Paint Technol.,J. Paint Technol., 44, 52 (1972). (38) Humrnel, D. O., Scholl, F., "Infrared Analysis of Polymers, Resins and Additives: An Atlas," Vol. I, Part 1. Spectra and methods of identification. Wiley. Chichester, 1971. (39) Kato, A., Yarnaura, Y., Chem. lnd. (London), 1970, 1260. (40) Kobliska, J. J., Kodarna, S. P., Eckhart. C. G., Gaydosh, R. J., McMeekin, L. J., Santacana. F., Prescott, W. B., Paint Varn. Prod., 62, 27 (1972). (41) Kovacs. L., Talas-Rohonczy, E., Horkay, F., Farbe Lack, 78, 304 (1972). (42) Kratky, B., Novak, V., Chem. Prum., 21, 340 (1971). (43) Krishen, A,. Anal. Chem., 43, 1130 (1971). (44) Laurer, G. R., Kneip, T. J., Albert, R. E., Kent, F. S., Science, 172,466 (1971). (45) Lee, W. Y., Anal. Chem., 44, 1284 (1972). (46) Liebscher, K., Microchim. Acta, 1971, 272. (47) Low, M. J. D.,Mark, H . , J. Paint Technoi., 43,31 (1971). (48) Low, M. J. D., Mark, H. Goodsel, A. J., /bid., p49. (49) Luciani, M., Corradlni, T., Ceilul. Carta, 22, 19 (1971). (50) McDuffie, B.,Anal. Chem., 44, 1551 (1972). (51) McKay,T. R.,Aust. PaintJ., (5) 9 (1971). (52) McLean, A,. Paint Manuf., 39, 37 (1969). (53) Mak, H. D., Rogers, M . G., Anal. Chem., 44, 837 (1972). (54) Maslennikov, A. S., Tabachkova, T. P., Spirina, V. D., Zh. Prikl. Khlm. (Leningrad), 42, 2318 (1969). (55) Mayhan, K. G., Thompson, L. F., Magdalin, C. F., J. Paint Techno/., 44, 85 (1972). (56) Menin, J. P., Roux, R., J. Chromafogr., 64.49 (1972). (57) Miller, M. W., Spagnola, F., J. Paint Technol., 44, 75 (1972). (58) Mlochowski, J.. Skrowaczewska. Z . , Chem. Anal. (Warsawl, 14, 1125 (1969). (59) Mosirnann, H., Weber, W.. Schweiz. Arch. Angew. Wiss. Tech., 36, 402 (1970). (60) Nisbet, P. S., J. OilGolourChem. Ass., 55, 285 (1972). (61) Okurnoto, T., Takeuchi, T., Tsuge, S.,Bull. Chem. SOC.Jap., 43, 2080 (1970). (62) O'Mara. M. M., J. Polym. Sci., 9, 1387 (1971). (63) O'Neill, L. A,, Falla, N. A. R., Chem. lnd. (London), 1971, 1349. (64) Ospanov. K. K., Aiirnpeva, S. D., Zavod. Lab., 37, 1051 (1971). (65) "Polymer Characterization: Interdisciplinary Approaches," C. D. Craver, Ed., Plenum Press, New York, N.Y., 1971. (66) Porter, R. S., Johnson, J. F., Ed., "Analytical Calorimetry, Vol. 2". Plenum Press, New York, N.Y., 1970. (67) Post, M. A,, Paint Varn. Prod., 61, 31 (1971).
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(68) Preston, S. T., Spreckelmeyer, S., "Guide to the Analysis of Fatty Acids and their Esters" Polyscience, Evanston, ili., 1971, (69) Price, W. J., Paint, OilColourJ., 158, 282 (1970). (70) Pusey. D. F. G., Paint Manuf., 41,38 (1971). (71) Reynolds, R. J. W., Walker, K. R.. Kirby, G. W., Polymer, 11, 333 (1970). (72) Riederer. J., Duet. Farben Z . , 23, 569 (1969). (73) Ruzicka, B., Rajkiewicz. M., Chem. Anal. (Warsaw), 16, 77 (1971). (74) Sagredos. A. N.,Fette, Selfen, Anstrichm., 71, 863 (1969). (75) Schettino, O., Ferrara, L., Riv. /tal. Sostanze Grasse, 47, 450 (1970). (76) Schlesinger, H. L., Lukens, H. R., Bryan, D. W., Guinn, V. P., Hackleman, R. P., Rep. Atom. Energy Commn. U. S., GA-10142, 1970. (77) Scoggins, M. W., Anal. Chem., 44, 1285 (1972). (78) Searle, B., Chan, W., Jensen, C., Davidow, B., At. Absorption Newsletf., 8 , 126 (1969). (79) Secrest, P. J., Heckman, S. E., J. Paint Techno/., 43, 81 (1971). (80) Simpson. D., Currell, B. R., Analyst (London), 96, 515 (1971).
(81) Slade, P. E., Jenkins, L. T.. Ed.. "Techniques and Methods of Polymer Evaluatlon, Vol. 2, Thermal CharacterizaJon Techniques," Marcel Dekker, New York, N.Y., 1970. (82) Snow, K. B., Washington, W. D.. J. Ass. 011. Anal. Chem., 54, 917 (1971). (83) Soulages, N. L., Brieva, A. M.. J. Chiomatogr. Sci., 9, 492 (1971). (84) Swann, M. H.. Adams. M. L., Esposito, G. G., Anal. Chem., 43, 41R, (1971). (85) Sward, G. G., Ed., "Paint Testing Manual, Physical and Chemical Examination of Paints, Varnishes, Lacquers, and Colors," 13th ed., ASTM, Philadelphia, 1972. (86) Trochimczuk, W., Czarczynska, H., Polinery, 16, 275 (1971). (87) Tsujl. K., Konishi, K.,Analyst (London) 91j, 457 (1971). (88) Uno. T., Okuda. H..Jap. Anal., 19, 1204 ,1970). (89) Weir, A. P., Williams, D. A , , Woodcock J. D., Chem. Ind. (London), 40,990 (1971). (90) Yamao, M., Watanabe, T., Tanaka, S . , Jap. Anal., 18, 958 (1968). (91) Zelenina, E. N..Zh. Prikl. Khim., (Leningrad), 43, 1630 (1970).
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