Anal. Chem. 1980, 52, 1 0 6 R - 1 1 2 R (84) Waiinga, J. Sci. Ind. 1978, 7 7 , 1-3. (85) Dienwiebel, I. Scanning Electron Microsc. 1978, (l), 807-812. 186) Echlin. P. Scannino Electron Microsc. 1978. (1). 109-131. (87) Thinh,'T. P.; LeroG, J. X-Ray Spectrom. 1979; 8 , 85-91. (88) Kieser, R.; Mulligan, T. J. X-Ray Spectrom. 1979, 8 , 164-168. (89) Lurio. A.; Reuter, W.; Keiler, J. Adv. X-Ray Anal. 1977, 20, 481-486. (90) Keith, H. D.; Loornis, T. C. X-Ray Spectrom. 1978, 7 , 217-224. (91) Watson, R. L.; Michael, M. W.; Hernandez, J.; Leeper. A. K.; Wendt, C. D. Adv. X-Ray Anal. 1978. 27, 105-118. (92) Quinn, A. P. Adv. X-Ray Anal. 1979, 22. 293-302. (93) Criss, J. W.; Birks, L. S.; Gilfrich. J. V. Anal. Chem. 1978. 50, 33-37. (94) Thomas, I. L.; Haukka, M. T.; Anderson, D. H. Anal. Chim. Acta 1979, 105, 117-184. (95) Nielson. K. K. Adv. X-Ray Anal. 1979, 22, 303-315. (96) Keith, H. D.; Loomis, T. C. X-Ray Spectrom. 1978, 7 , 225-240. (97) Giauque. R. D.; Garrett, R. 6.; Goda, L. Y. Anal. Chem. 1979, 5 1 , 5 11-5 16. (98) Vie le Sage, R.; Quisefit, J. P.; Dejean de la Batie, R.; Faucherre, J. X-Ray Spectrom. 1979, 8 , 121-128. (99) Kubo, H.; Smyth, W. R. Anal. Chem. 1979, 57, 1194-196. (100) Lachance, G. R. X-Ray Spectrom. 1979, 8 , 190-195. (101) de Jongh, W. K. X-Ray Spectrom. 1979, 8 , 52-56. (102) Di Fruscia, R.; Dick, J. G.; Wan, C. C. X-Ray Spectrom. 1978, 7 , 86-91. (103) Chamberlain, G. T. X-Ray Spectrom. 1978, 7 , 190-194. (104) Plesch, R. X-Ray Spectrom. 1979, 8 , 114-116. (105) Plesch, R.; Thiele, B. Anal. Chim. Acta 1979, 712, 75-82. (106) Riveros, J. A.; Bonetto, R . D.; Mainardi, R . T. Anal. Chem. 1978, 5 0 , 1386- 1388. (107) Gardner, R. P.; Doster, J. M. Anal. Chem. 1978, 5 0 , 1703. (108) Gardner, R . P.; Doster, J. M. Adv. X-Ray Anal. 1979, 22, 343-356. (109) Schreiner, W. N.; Jenkins, R . X-Ray Spectrom. 1979, 8 , 33-41. (110) Jenkins, R. Adv. X-Ray Anal. 1979, 22, 281-292. (111) Stankiewicz, W.; Sanner, G. X-Ray Spectrom. 1979, 8 , 169-174. (112) Claisse, F.; Thinh, T. P. Anal. Chem. 1979, 57, 954-957. (1 13) Reimer, L. Scanning Electron Microsc. 1979, (2), 11 1-124. (1 14) Moll, S. H.; bumgarten, N.; Doneliy, W. Proc. Annu. Conf. - Microbeam Anal. SOC. 1977, 12, 33A-33F. (1 15) Schwaab, P. Edax Editor 1979, 9 , 12-14. (116) Love, G.; Cox, M. G.; Scott, V. D. J . Phys. 0: Appl. Phys. 1978, 1 1 , 7-21. (117) Love, G.; Cox, M. G.; Scott, V. D. J . Phys. 0: App. Phys. 1978, 7 1 , 23-3 1. (118) Love, G.; Scott, V. D. J . Phys. 0:Appl. Phys. 1978. 7 1 , 1369-1376. (119) Parobek. L.; Brown, J. D. X-Ray Spectrom. 1978, 7 , 26-30. (120) Russ, J. C. Proc. Annu. Conf. - Microbeam Anal. Soc. 1977, 12, 34A-341. . . . - ... (121) Goldstein, J. T.; Costley, J. L.; Lorimer, G. W.; Reed, S. J. B. Scanning Electron pdicrosc. 1977. 70. 315-324. (122) Janossy, A. G. S.; Kovacs; K.; Toth, I. Anal. Cbem. 1979, 51, 491-495. (123) Barbi, N. C. Scanning Electron Microsc. 1979, (2), 659-672. (124) Bengtsson, B.; Easterling, K. E. Scanning Electron Microsc. 1978, ( l ) , 655-662. (125) Joy, D. C.; Maher, D. M. Scanning Electron Microsc. 1977, 10, 325-333. (126) Russ, J. C. Scanning Electron Microsc. 1979, (2), 673-682.
(127) Cox, M. G. C.; Love, G.; Scott, V. D. J . Phys. 0: Appi. Phys. 1979, 12, 1441-1451. (128) Schrader, M. Mikrochim. Acta, Suppl. 1979, 8 , 377-391. (129) Van Ass, H. Edaxfditor 1979, 9 , 5-11. (130) Statham, P. J. Proc. Annu. Conf. - Microbeam Anal. SOC.1977, 12, 95A-95F. (131) Statham, P. J. X-Ray Spectrom. 1978. 7 , 132-137. (132) Nuliens, H.; Van Espen, P.; Adarns, F. X-Ray Spectrom. 1979, 8 , 104-109. (133) Wielopolski, L.; Gardner, R. P. Adv. X-Ray Anal. 1979, 22, 317-323. (134) Nass, M. J.; Lurio, A.; Ziegler, J. F. Nucl. Instrum. Methods 1978, 754, 567-57 1. (135) Ingamells, C. 0.; Fox, J. J. X-Ray Spectrom. 1979, 8 , 79-84. (136) Russ, J. C. Adv. X-Ray Anal. 1978, 27, 221-227. (137) Ekelund, S.; Thuren, A.; Werlefoss, T. X-Ray Spectrom. 1979, 8 , 2-6. (138) Myklebust, R. L.; Fiori, C. E.; Heinrich, K. J. F. R o c . Annu. Conf. Microbeam Anal. Soc. 1977, 72,96A-96D. (139) Fiori, C. E.; Myklebust, R. L. Proc. Annu. Conf. - Microbeam Anal. SOC. 1978, 13, Paper No. 52. (140) Russ, J. C. Edax Editor 1979, 9 , 12-13. (141) Russ, J. C. Roc. Annu. Conf. - Microbeam Anal. Soc. 1978, 13, Paper No. 46. (142) Hurley, R. G.; Goss, R. L. X-Ray Spectrom. 1978, 7 , 70-72. (143) Verbeke, P.; Nuliens, H.; Adams, F. Anal. Chim. Acta 1978, 97, 283-294. (144) Van Espen, P.; Van't Dack, L.; Adarns, F.; Van Grieken, R. Anal. Chem. 1979, 51, 961-967. (145) Gardner, R. P.; Wielopolski, L.; Doster, J. M. Adv. X-Ray Anal. 1978, 21, 129-142. (146) Armstrong. J. T. Scanning Electron Microsc. 1978, ( l ) , 455-468. (147) Statham, P. J.; Pawley, J. B. Scanning Nectron Microsc. 1978, ( l ) , 469-478. (148) Statham. P. J. Mikrochim. Acta, Suppl. 1979, 8 , 229-242. (149) Smail. J. A.; Heinrich, K. F. J.; Newbury, D. E.; Myklebust, R. L. Scanning Electron Microsc. 1979, (2), 807-816. (150) Springer, G. Proc. Annu. Conf. - Microbeam Anal. SOC.1977, 72, 43A-43C. (151) Hawthorne, A. R.; Gardner, R. P. %-Ray Spectrom. 1978, 7 , 198-205. (152) Ruste, J. R o c . Annu. Conf. - Microbeam Anal. Soc. 1977, 12. 35A35c. (153) Russ, J. C. Scanning Electron Microsc. 1977, 10, 289-296. (154) Anon. X-Ray Spectrom. 1978, 7 , 44-47. (155) Anon. X-Ray Spectrom. 1979, 8 , 200-203. (156) "NBS Standard Reference Materials Cataloa. 1979-80 Edition" Natl. Bur. Stand. ( U . S . ) , Spec. Pub/. 260. (157) Knott, A. C.; Mills, J. C.; Belcher, C. B. Can. J . Spectrosc. 1978, 23, 105-1 11. (158) Dzubay, T. G.; Lamothe, P. J.; Yasuda, H. Adv. X-Ray Anal. 1977, 20, 411-421. (159) Briska, M.; Bohg, A. Ger. Offen. 2716689 (CI. OlN23/223) 19 Oct. 1978. (160) Waish, J. M.; Gurnz, K. P.; Breiman, E. M. Proc. Annu. Conf. - Microbeam Anal. SOC.1977, 12, 39A-39C. (161) Gries, W. H.; Wybenga, F. T. X-Ray Spectrom. 1979, 8 , 175-179. (162) Roomans, G. M. Scanning Electron Microsc. 1979, (2), 649-658.
Thermal Analysis C.
B. Murphy
Xerox Corporation, Xerox Square, W- 139, Rochester, New York 14644
This review covers trends in thermal analysis from the previous review (139) to October 1979. The Nomenclature Committee of ICTA has continued to put forth its recommendations (119),which essentially remain as reported in the last review. Thermomechanometry was proposed to the ICTA as a group name for thermoanalytical techniques based on changes in mechanical characteristics of materials (101). The ICTA report (119) does list dynamic thermomechanometry as a technique in which the dynamic modulus and/or damping of a substance under oscillatory load is measured as a function of temperature.
a solid-solid phase change 30 "C below its melting point. While peaks are easily detected in DTA and DSC, phenomenological assignment is not always obvious. The 244 "C endotherm in co[poly(ethylene terephthalate)-p-oxybenzoate] containing 30 mol % oxybenzoate was initially identified as a nematic isotropic transition. However, the eak disappears if heated to the isotropic melt or dissolvec?and reprecipitated. Viscosity and NMR have contributed to the peak assignment of melting crystallites formed during high temperature annealing (108). Equipment for DTA in the range of 20-1000 "C, suitable for teaching and research, has been developed (104). In a discussion of thermal analysis experiments for the undergraduate laboratory (59),a description of an oven built into a can was given and other components were discussed. Arrangements for use of differential calorimeters under selective radiation for the study of photoinduced chemical reactions have been demonstrated (201). The new SETARAM DSC
-
DIFFERENTIAL THERMAL ANALY SIS-DYNAMIC SCANNING CALORIMETRY It has been suggested that NaN03 is a poor reference material (50)because of its hygroscopicity and because it exhibits 106 R
0003-2700/80/0352-106R$Ol .OO/O
C
1 9 8 0 American Chemical Society
THERMAL ANALYSIS
was developed for estimation of these values. The decomposition mechanism of CU~(OH),NO:~, based on DSC data, was proposed to follow the reaction (13)
C. 8. Murphy received his B S and M S. degrees from the College of the Holy Cross in 1941 and 1942, respectively. After three years of Navy duty, he returned to Holy Cross as a member of the Chemistrv Deoartment faculty I n 1952 he received his Ph D.from Clark University I n the same year he joined American Cyanamid's Stamford Research Laboratory After 10 years with General Electric's Advanced Technology Laboratories, he joined the Xerox Corp as manager of the Materials Analyses Area Ye IS now a Principal Scientist.
CUZ(OH)~(NO --*~ ~CUO,,, ) + "O3(,)
The theoretical AH was 41 360, while measured with 41 200 f 250 cal/mol. Copper divanadate was examined by DTA and X-ray methods (42) and the temperature transitions were 6, 710, and p a , 605 "C. DTA indicated reassigned: a that A H 3 undergoes a 110 "C transformation which is followed by a 150 "C decomposition (45). Desolvation of tetrahydrofuran from Nd(BH4),.8THF was shown to occur through three low temperature steps (135). Many phase equilibria have been studied by DTA. Some of these systems have been PbO-PbGeO, (95),V-0-Te (158), Biz03-Mo03 (60), SmZO3-V,O3 (137),and CuC1,-LiC1 and CuC12-LiC1-KC1 (183). The (K,NA1-,)Nb03 ( I 7 ) and. m(Nb,Ta)03and (Li,Na,K)Nb03(141) also have been studied. The lead decanoate-decanoic acid system (3)and Pb2+,Zn2+ Cd2+,Mn2+,and H2+octadecanoate mixtures ( 4 ) have beed studied by DTA. Addition of dodecanoic acid to lead dodecanoate did not affect hvdrocarbon chain order in the solid or liquid state. Ammonium perchlorate dissolved in anhydrous NH, and recrystallized from water shows an endotherm a t 240 "C and an intense exotherm a t 300 "C ( 5 ) . Decomposition below 300 "C was suppressed owin to the presence of excess N H in NH4C10,. TG, DTG, a n i DTA were simultaneously appfied to Ce(HPO4),.1.33H20 (207) and showed four endothermic processes accompanied by weight loss. Water and oxygen were evolved during the weight loss processes. Sulfation of metal oxides with (NH4)*S04has been studied (166, 167). In the case of CaO and ZnO (167),theoretical and DTA AH values agreed well, but Alz03and CdO values did not agree. DTA was employed (202)to show SrCO and SiOz reacted to form SrzSi04which subsequently reacted with SiO, to form SrSiO Barium and titanium citrates were shown to react by DTA and TG, as well as other methods, to form Ti02-BaC03which subsequently formed BiTiO, (91). However, doubt was expressed about complete mixing of reactants. High alumina cement undergoes conversion on aging which results in a loss of strength. The degree of conversion, D,, may be expressed:
-
has been described 1123)and was claimed to have a sensitivitv of -0.05/W/mm3. A DTA method was developed (178)wherein the temperature increased steDwise with heat effects being determined by analysis of transient thermoelectric effects d%ereach step. When steps were 2 "C and heating rates ranged from 1015O/min, melting of inorganic materials always required two steps. However, the temperature interval of the transition was smaller in the step method than in conventional DTA. The use of COz, instead of NP, improved identification and determination of carbonate minerals in soils (198) and in distinguishing magnesite from pyrite in coal (197). The decomposition of 4MgCO3.Mg(OH),-4HZOhas been shown to occur differently under different CO, partial pressures (170). In a gas flow-type, high-pressure DTA, He gas was switched to H z when temperature stability was attained in a study of hematite reduction (188). An electrical model of DTA, incorporating base-line shift, signal intensity, leading edge slope, heating rate, etc. (173) was developed. T I N 0 3 showed two solid-solid transitions before melting at 207 "C (44). These occurred a t 77 and 145 "C with heats of transition of 0.15 and 0.87 kcal/mol, respectively. The heat of melting was 2.18 kcal/mol. Heats of sublimation for Ni(II), Cu(II), and Co(II1) diethyldithiocarbamate complexes were measured by DSC (36). Melting points and heats of melting were determined by DSC for the following polymers: poly(ally1 behenate), 59 "C, 8.51 kcal/repeat unit; poly(ally1 brassidate), 26 "C, 5.17; poly(ally1 erucate), -22 "C, 2.92; and poly(ally1 oleo-erucate), -30 "C, 2.60 (38). The isothermal heat of polymerization of phthalic anhydride, maleic anhydride, and propylene glycol (2:1:3), with styrene added for cross-linking, was followed by DSC from 8 2 to 122 "C (156). A computer assisted heat capacity measuring system has been described by Wunderlich and co-workers (73)which gave values for Zn with accuracies better than f0.5%. Measurements with Se with three commercial equipments were compared with limited adiabatic calorimetry data and gave i 3 % accuracy (130). Another data acquisition system for DTA and DSC also has been described (54). Its applicability and simplicity of operation were illustrated with DSC scans of N,N'-terephthalylidene-bis(4-n-butylaniline) and tetra-rzhexyl-ammonium perchlorate. Pan displacement was overcome by a centering device (203) which gave results with demineralized water and phenyl ether with an accuracy and precision of better than 2 % . Specific heats of ethylene glycol homologues determined by DSC showed high temperature slope changes which were attributed to hydrogen bonding (182). A procedure has been proposed (190)which corrects for thermal lag in DSC specific heat measurements. Polymorphism was investigated in Biz03 (88),ammonium and alkali metal dihydrogen phosphates and arsenates (82, 144) and their deuterated analogues (321, PbzWOS(69),and mercury carboxylates (2). A phase change in fcc solid solutions of the Nd-H system was shown by DTA to depend on com/3 transition position (23). The effects of grinding on the cy of SiO, resulted from surface damage (138) which could be recovered by annealing. It was shown that Ni2+ and Zn2+ doped KzS04 decreased the enthalpy of the orthohombichexagonal transformation with increased concentration (157), while increasing Cd2+doping resulted in a A H increase. Ferric laurate was shown (76)to undergo a phase transition at 55-105 "C and decomposed a t -300 "C. Copper carboxylates, solvated by amines, were studied by T G and DTA (27). Their standard heats of formation were determined and a relation ~I
-
+ HzO(,)
-
D, =
100 . . [CAHlOl 1+[AH,]
where [CAH,,] is the amount of Ca0.A1,O3-1OH,O in the sample and [AH,] is the amount of A1203.3H20. Using the 270 "C peak for AH3 and the 100 "C peak for CAH o, measurements were made by DTA, calorimetric DTA, DbC, and DTG for the D,of one sample (132). The following results were obtained: method
DTA calor. DTA DSC
DTG
mean std. dev.
71.6 0.9
71.0 0.9
69.2 0.4
70.3 1.4
It was concluded that DTA methods give D, to an accuracy not greater than 5 % . DTA gave 15.8 f 0.2% Ca(OH)z in portland cement, while DTG gave 15.3 f 0.05% and 12.0 f 0.9% was obtained by X-ray diffraction (133). The differences were attributed to detection of amorphous Ca(OH), by thermal methods, but not by X-ray. Simultaneous DTA/TG were used to measure differential heat of adsorption of CO, on Na mordenite a t 30 "C (172) over the range 0.2 Torr to 1 atm. A model was developed to explain the data. Some predominantly kalonitic tropical soil clays were subjected to DTA in Nz and gave two exothermic reactions (SSO", 950') instead of the usual single exotherm (96). Iron, reduced by or anic carbon, reacts with metakaolin to form hercynite and Fe8, causes mullite to form a t a lower temperature. The higher temperature exotherm is due to formation of a-AlzO T w e A zeolites were shown to form inclusion comDounds witff niGates (150). The glass transition temperature, Tg,of poly(N-vinylcarbazole) was investigated as a function of mol_ecular weight (24) and it was shown that a plot of Tgvs. 1/Mn X lo5 was ANALYTICAL CHEMISTRY, VOL. 52,
NO. 5 , APRIL 1980
107R
THERMAL ANALYSIS
linear. Polymer Tg's determined for polyundecamide-pmethylbenzoates, polyundecamide-nonanoates, and polyundecamide-undecanoates showed that they were strongly influenced by the comparative length and stiffness of the two monomer units (7). Simultaneous DTA T G measurements were made on poly(hydroxy methylene) 161). On the initial run, T g was determined and on the second run the sealed sample was punctured to measure weight loss attributable to water. Data showed the effect of moisture to be in agreement with a previously given mathematical expression (159). The T gof copolymers of methyl methacrylate and dodecyl methacrylate were found to follow the usual relationship for such measurements, T g= mlTg,+ mzT , where ml is the mole parts of M and m2 the mole parts of i f f z(181). Hydrogenation of poly(a-methyl styrene) gave poly(isopropeny1 cyclohexane) and its copolymers with a-methyl styrene depending on reaction time and catalyst system. Poly(isopropeny1 cyclohexane) had a T g of 185.4 "C (78). The 33:67 and 92% isopropenyl cyc1ohexane:a-methyl styrene copolymers had Tg's of 164.0 and 165.5 "C, indicating chain stiffness did not increase rapidly with hydrogenation of the highly syndiotactic polymer. Effects of side chain length and backbone structure on the T gof comblike polymers was investigated (160). n-Alkyl side chains were characterized by a monotonical decrease in T g toward a critical value as the C atoms in the side chain increased toward a corresponding critical value, n,. Polysulfone-polycarbonate block copolymers were found to have two T,'s by DSC (196). Melt blends of bisphenol A polycarbonate with poly(buty1ene terephthalate) showed incompatibility of exhibiting two T i s on DTA (195). Poly(buty1ene terephthalate) crystallization also occurred in the blends. Linear high-density polyethylene was rapidly quenched from the melt to cryogenic temperatures and examined by X-ray diffraction, Raman spectroscopy, and thermal analysis, with results indicating a glassy phase which crystallizes above 170 K (48).DSC, however, did not clearly demonstrate this and it was concluded that the ACp a t T g is small and that crystallization is relatively slow or A", is small. Drawn, linear polyethylene melting was examined by DSC as a function of draw ratio and molecular weight (46). The highest melting point was 145 "C for a draw ratio of 25 and weight-average molecular weight of 312 000. Polyethylene crystals, dry and in suspension, in a variety of liquids, were investi ated by DSC (86). Polyethylene crystal grown at 87 "c ancfAHf of 60.2-61.9 cal/g ( % crystallinity 87.2-89.7), whereas dried material was ca. 56.8 cal/g (7' Crystallinity 82.3). In this work, the polyethylene in suspension was determined from the peak area of the melting endotherm produced on rescanning the sample after heating above its melting point. T h e melting points of polyethylene single crystals, dry and in suspension, were determined as a function of heating rate (85). It was observed that there was some dependence of T , on heating rate which was contrary to previous DTA data (87). T h e difference most probably resulted from use of peak maxima in DSC which is the point of maximum rate, rather than onset temperatures. Physical blends of low, medium, and high density polyethylene were examined by DSC and were found to give two peaks (55). Using data from pure components, crystallinity of blends was calculated according to an additivity relationship. Melting of fibrillar polyethylene crystals has shown three peaks (149): 141, 150.5, 159.5 "C. These were due to melting of unconstrained fibrillar crystals, transformation of orthorhombic to hexagonal form, and melting of the hexagonal phase, respectively. Equilibrium melting parameters for poly(ethy1ene terephthalate) were found to be: 553 K, 2.69 kJ/mol, and 48.6 J/deg./mol (131). The T J T , relationship was determined for some novel polycarbonates and was found to range from 0.828 to 0.847 (77). No reason could be found for these high ratios. High-pressure, micro-DTA was applied to determination of melting and crystallization temperatures of poly(viny1idene fluoride) (127), where pressure was found to have the same effect on the melting of the a , /3, and 6 forms of this polymer. Crystallizations of polyethylene were carried out a t controlled cooling rates and were followed by hot stage microscopy and DSC (68). I t was shown that the effective crystallization temperature was a function of the nucleation density. DSC curves for polyethylene, unannealed and annealed a t temperatures from 120 to 124 "C, showed two melting peaks (62) which were attributed t o morphologies of a different order. Ethylene-
i
108 R
ANALYTICAL CHEMISTRY, VOL. 52, NO. 5, APRIL 1980
butadiene with short ethylene sequences and degrees of polymerization to 250 were studied (89): block copolymers with 20-30 degrees of polymerization were amorphous; with sequences of 35-45, crystallization into extended chain crystals occurred; and, above 45, polyethylene blocks crystallized with chain folding. Fusion of hydrogels containing NH4N03was investigated (6). In some cases, two distinct freezing points were observed and a significant portion of the water did not freeze. Peak areas and total water content permitted differentiation between ordinary, intermediate, and bound water. Phase diagrams of polyesters with solvents have been established by direct and DTA (153). DSC of p-oxybenzoate copolymers with substituted poly(ethylene terephthalate) showed nematic transitions (109). Transitions in poly(6-n-alkyl L-glutamate) were attributed to side chain dispersion ( T I )and crystalline transition ( T2).Both T 1and T z decreased as the alkyl group increased from methyl to hexyl (169). DSC examination of gellation and melting of aqueous gelatin (179) showed this phenomenon could be considered as a crystallization process. In the potato starch-water system, two endothermic transitions were observed by DSC (56). The lower temperature, 66 "C, transition was the only endotherm when excess water was present. The other occurred a t increasing temperatures as the water content was reduced and its size decreased with decreased water content. This was interpreted as melting point lowering of starch crystallites by solvent water. Association of yellow mealworm cr-amylase with two protein inhibitors from wheat flour was investigated by DSC (177), and thermal denaturation of aspartate transcarbamoylase of E. coli was examined by DSC (194). DSC examinations indicated that cortisol-12-palmitate was held in the liposome phospholipid bilayer by the acyl side chain (66) and incorporation was limited to 13 mol % . It was said that arthritic treatment should involve levels below the limiting concentration. Copper, deformed by cold rolling with thickness reductions of 3G90%, gave peaks associated with release of stored energy (115) which did not depend on grain size. Recrystallization in A1 sheet also was followed by DSC (94). Splat-quenched P b was examined by DTA and electron microscopy (8). A metastable hcp structure was found in the splat-quenched P b which was converted to the fcc structure on heating to 270 "C. Among the numerous metal phase diagrams that have been investigated have been Dy-Sb (134), Nd-Ga (122),and Ni-Cr-Si (116). The Pb-Sn system has been used as an experiment to introduce DTA to students (40). In the AlZn-Mg alloy system, high heating rates (80°/min) were necessary to give DSC curves characteristic of phase structure (191). However, in the A l X e alloys, DTA was conducted with heating rates of 0.2, 0.5, and 1.5"/min and gave significant peaks (93). DSC has found use in energy studies. Heats of combustion of solid waste were determined (100) and gave energy equivalents of 7800 to 8600 BTU/lb. While this value is better than wood (5000-6000 BTU/dry lb.), it falls somewhat short of coal values (7oo(r15000 BTU dry lb.). Paraffin wax, urea, phthalimide, and NazSO4.10Hz were examined by DSC for thermal energy storage capability (34). Na2SO4-10Hz0heat of fusion decreased with thermal cycling and supercooling. Urea's melting point and heat of fusion decreased with cycling and showed supercooling. Phthalimide did not decompose, but exhibited supercooling. Paraffin wax did not supercool, nor was there any indication that AH decreased during cycling. However, test tube experiments indicated DSC supercooling data should be applied with caution. A study of New Zealand oil shale was made by DTA (162) and shale heats of combustion ranged from 0.2 to 8.5 MJ/kg. The DTA combustion curve exhibited four peaks indicating kerogen combustion to be complex. Coal decomposition was examined by DTA, TG, TMA, and EGA (11). Phase transitions have been observed in octadecyl acrylate which were different from those observed in octadecyl methacrylate (175). Melting points and heats of fusion were determined in methoxycarbonyl-benzenes and naphthalenes (57) and in waxes and petrolatums (64). DSC has been used extensively in characterization of liquid crystal systems. Among those studied have been 4"-n-alkoxyphenyl biphenyl-4-carboxylates (33),trans-p-cyanophenyl-p-alkoxy-amethylcinnamates (65),p-n-heptyloxybenzylidene-p-amino-
-
d
THERMAL ANALYSIS
benzoic acid (121),and p-sexiphenyl (110). DTA has been used to study polymorphism and to determine phase diagrams 1,4-phenylenediamines of some bis(4,4'-n-alkoxybenzylidene)up to 3 kbars (180). Purity measurements were made on aminophenazone (126) and a laboratory experiment for purity measurements with phenacetin has been described (29)., Phase equilibria in the phenanthrene-fluorene system (105); in 1,2-dicarbaclosodecaboranewith benzene, toluene, and dioxane (81);and in mixtures of CY- and P-naphthols and hydroquinone with p-chloroaniline and p-anisidine (146)have been studied. Urea-paraffin intercalation compounds were examined by DTA and X-ray structural analysis (39). It was found that the usual hexagonal adducts are converted to orthorhombic a t low temperatures by an order-disorder transition of the guest molecule about the channel axis. Vapor phase intercalated H N 0 3 in graphite was examined by DSC (58). On cooling (270 to 240 K), exothermic peaks were observed at 245 and 250 K; on heating, they occurred a t 252 and 261 K. Solid-state reactions between donor p-bromophenol and acceptors benzoquinone, chloranyl, and bromanyl were examined by DSC ( 1 ) . p-Bromophenol and p-benzoquinone reacted in the solid state, bromanyl reacted in molten p bromophenol, and chloranyl did not react. DTA has shown that SbC& reacts with diphenylamine, triphenylamine, and aniline hydrochloride t o form compounds (112). Among the drugs examined by DTA have been tetracycline (74) and aminobarbital (102). Phase equilibria in the aminophenazone--phenazone and aminophenazone-4-aminophenazone systems were examined by thermomicroscopy, DSC, and DTA, and the systems were found to have simple entectics (125). Polymorphs of phenazone and 4-aminophenazone were not found. DTA has shown that the stability of tetracycline hydrochloride is affected by magnesium stearate, but not by talc or lactose (74).
THERMOGRAVIMETRY A vacuum microbalance, with infrared heating source, has been described (84) and applied to kinetic and capacity studies of Zr and A1 powders exposed to Ar containing 5 to 50 ppm H2,02,H 2 0 , and COB. A microbalance for measurement of H 2 sorption characteristics of metal hydrides was operable from 15 to 600 "C and from Torr t o 60 kbar (118). An ultrahigh vacuum ultramicrobalance system containing a quadrupole residual gas analyzer was designed to permit loading of up to 20-g samples from a controlled environment (193). A thermobalance with two symmetrical pans was constructed (75). Pressure, temperature, and gas flow rate effects on base-line deviation were studied. Kinetic curves a t 900 "C under H2 from 6 to 50 atmospheres showed existence of a nonhydrogenable lignite residue apart from ash. Another T G system was designed for use with corrosive atmospheres at pressures to 6 atmospheres and to 1100 "C (111). An induction coil-heated T G system was designed for operation of 2000 K and 136 atmospheres H2 (67). Apparatus for simultaneous computerized data collection of mass change and optical transmittance and reflection of thin films (154, 155) has been described. Equipment for factor-jump T G was described (51),was applied to several polymers (53),and had a computer program devised for activation energy measurements (52). A method, in Fortran IV language, was given for the calculation of frequency factor, activation energy, and reaction order from T G data ( I 8 4 ) ,and a nomogram was developed for deriving kinetic parameters (206). Interpretation of the shapes of T G curves from quasi-isothermal analysis was discussed (179) and a method was given for calculating activation energies from T G curves. It was found that styrene-alkyl methacrylate copolymers and terpolymers decomposed by a similar mechanism (199). Steric effects contributed by small alkyl pendant groups are insignificant, but, as side groups increase, chain flexibility is affected as shown by T . A number of pulps have been subjected to TG-pyrolysis (357. These pulps had pyrolysis activation energies ranging from 30 to 44 kcal/mol depending on the pulp, but also to some extent on the analytical method used. Integral methods gave higher values than differential methods, averaging 1.8 kcal/mol higher, but ranging from 0.4 to 3.6 kcal/mol. The integral method of Zsako (20Fi) was found to be rapid, giving activation energies very close t o those of other integral
methods. Comparison of the Achar, Brindley, and Sharp differential method with the integral method of Coats and Redfern was made with BaBrz-H,O and Li00CH-H20dehydrations and Pb(SCN)2 decomposition (124). The ABS method, at the lowest heating rate, 1.2" min, agrees well with isothermal data, whereas the Coats- edfern method gave satisfactory results only with Pb(SCN),. Ten different kinetic equations were tested by computer kinetic analysis of CaC03 decomposition by T G and DTG (47). Results indicated a phase boundary process, 2/3 kinetic equation, or a diffusion process (Jander equation). There was no way to differentiate between the mechanisms on the basis of TG and DTG curves. In pyrolysis of cellulose a t low pressure (28),three reactions were proposed: (A) formation of "active cellulose" which decomposes by two competitive first-order reactions, (B) one yielding char, and (C) the other yielding volatiles. Isothermal and dynamic TG in air and in N2 were applied to poly(viny1 formal) with fixed vinyl alcohol content, but varying amounts of vinyl acetate and vinyl formol(37). In the dynamic process, the activation energy decreased from 36 to 23 kcal/mol with increasing acetate content (6 to 22%) in N,, while in air the activation energy increased from 21 to 27 kcal/mol. The reduction of S n 0 2 (cassiterite) with coconut charcoal a t 1073-1173 K gave an activation energy of 220.9 kJ/mol, while with graphite a t 1198-1273 K the activation energy was 323.8 kJ/mol (145). The overall rate was controlled by C oxidation by C02. The H2 reduction of Fez03was found to proceed stepwise or simultaneously (176)depending on the preparation of the oxide. Isothermal and nonisothermal decomposition of 4MgC03.4Mg(OH)2.4H20was studied by T G in Ar. Decarbonation in a C 0 2 atmosphere was interrupted at -460-480 "C because of formation of a metastable intermediate and crystallization of MgCO, (171). DTA and X-ray analysis support this explanation. Decomposition of U 0 2 ( H C 0 0 ) 2 was examined by DTA and T G (25). The primary products are CO and HCOOH, which react in the presence of a-U03: CO reduces U03 to lower oxides (U308,U,09? and UOJ, while HCOOH is selectively decomposed catalytically to CO and H20. White lead, 2PbC03.Pb(OH)2,was studied by TG under various C 0 2 partial pressures (19)and was found to undergo a four-step decomposition to PbO and C02. The thermal decompositions of MA3.nH2) (M = Pr, Nd, Sm, Gd, and Ho; A = acetate, abietate, and benzoate) showed that the number of decomposition steps depended on the cation, as well as n (174). Some correlations were presented for carboxylate decompositions. Sodium and potassium persulfates were studied by simultaneous DTA-TG (14) with CuO or ZnO added a t various levels. The first decomposition stage (persulfate to pyrosulfate) moved to higher temperatures as the quantity of oxide was increased. The second stage (pyrosulfate to sulfate) occurred via double salts. The double salts ultimately decomposed to metal oxide, alkali metal sulfate, and SO3. Coprecipitated Zn-Cu oxalates were subjected to T G in N2 (49)and it was found that decomposition onset temperatures vary with composition, decreasing from 380 "C for ZnCPOl to 260 "C for CuC204. The Na2C03and NaCl contents of clays from a dry lake bed were analyzed by T G (12). It was pointed out that the advantages of thermal analysis over other methods were: more sensitive, more reproducible, and more efficient. T G in vacuum and DTA in air could not be used successfully for analysis of CaCr04 ( 4 3 ) ,but T G in air could be applied for QC. T G in Ar gave good results for CaC03 and H20 content. Glycerol-treated montmorillonite loses one layer of the twolayer glycerol complex on heating to 150-200 "C (120). The monolayer complex breaks down rapidly on heating above 250 "C. The vapor pressure of molten sodium chloride was measured at 1267-1438 "C by TG (107). An irregularity has been observed with magnetic materials (71) where ca. 0.1% weight loss occurs near the magnetic critical temperature. The kinetics of oxidation of zircaloy-4 by steam under isothermal conditions from 900 to 1500 "C was followed by TG (148). Oxidation of Au2Cu3a t 775885 K and low oxygen pressures was studied by microgravimetry (136). The reduction of oxidized Ni-based alloys by C, H,, and C + H, was examined by T G (92). Hz and H 2 + C were completely effective in reducing an alloy containing Cr, Nb, Ta, Mo, and W. However, with A1 and T i present, the reduction was limited to -81%.
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109R
THERMAL ANALYSIS
Polyimides synthesized from 4,4'-diaminodiphenylmethane and pyromellitic dianhydride were spun into fibers and subjected to T G (80). The fibers were stable to 400 "C and, in the range 54C-610 "C, activation energy of decomposition was 101 kJ/mol. Polyimides prepared with different proportions of rn-phenylenediamine, p-phenylenediamine, or p,p'-diaminobiphenyl, with pyromellitic dianhydride has integral procedral decomposition temperatures ranging from 620 to 651 "C in air and 643 to 754 "C in N2 (192). Polyimides derived from 2,5-di(carboxymethyl)-terephthalicdianhydride and diamines decomposed from 370 to 445 "C in air and 420 to 470 "C in N2 (186). Hydroxyl-containing polyamides, prepared by ring-opening polyaddition of 3,3'-disubstituted bis-0-propiolactone with diamines, melted and decomposed around 200 "C (187). Spiropolymers containing biisoxazolinic units were synthesized by polycycloaddition of ketene dimer with dinitrile oxides (106). TG of these spiro olymers showed a very abrupt weight loss of 279 or 298 accounting for 3C-35% of the initial polymer weight. This phenomenon was associated with strong exothermic DTA peaks. TG and IR analyses applied to a styrene-acrylonitrile-acrylamide-trimethylolpropane trimethacrylate polymer system showed that increasin the curing temperature and using two initiators decr e a s e l the free monomer and increased thermal stability (204). The TG behavior of anionic and emulsion polymerized polystyrene was investigated in N2 a t 18"/min (165). Emulsion polymers degraded more slowly and with higher activation energies in the zero order (to 25% reaction) and first-order regions. Viscose rayon was modified by treatment with dimethyl and methylvinyl diacetoxysilanes (18). TG showed the cross-linked rayon had higher thermal stability. Decomposition of polybutadiene was studied isothermally and in the programmed heating mode (128). Isothermal decomposition occurred at 35C-375 "C, was exothermic, rapid, and temperature specific. On heating at 10°/min, decomposition occurred a t 447-461 "C, 100"higher than in the isothermal mode. Cellulose phosphonate was added to N,N-dimethyl acrylamide and 4-vinylpyridine in the presence of sodium ethoxide t o form cellulose 2-(N,N-dimethyl)carbamoylethylphosphonate and cellulose 2-pyridinylethylphosphonate(98). The former had flame retardant properties. Further effort in this direction resulted in cellulose phenylthiophosphonate (103) which was self-extinguishing when the phosphorous content was above 4.64%. TG and DTA have shown that o-bromostyrene cross-linking induces flame retardancy in polyesters (9).
"8
OTHER TECHNIQUES Dilatometers have been described for operation from -195 to lo00 "C in air (189),for operation in vacuum with a vertical pushrod of only 0.5 g (163),and for use to 1600 "C in oxidizing or reducing atmospheres (168). Dilatometry and DTA gave the stability regions of americium: C Y , 66-658"; @,793-1004'; and 6, 1050-1170 "C mp (164). The liquid crystal transitions for cholesteryl laurate were observed by dilatometry and optical microscopy (101, where it was shown that size affects the transition temperature. The relation between dilatometric and dielectric glass transition temperatures has been determined (152) through an Arrhenius relationship. Polymers having dipolar components along the backbone have a "dilatometric" frequency of Hz; a "dilatometric" frequency of lo4 Hz with polymers having dipoles in rigid side chains and Tgbelow 100 "C; and, above 100 "C, the "dilatometric" frequency could be to Hz. Cast SBS triblock polymers were examined by dilatometry and exhibited several transformations (63). Apart from the obvious dependence on molecular weight, copolymer type and drying temperature affected transition temperatures. Thermomechanical analysis, TMA, was one of the techniques of thermal analysis that was discussed relative to application to polymers (22). Disadvantages of TMA were the necessity for careful sample preparation and the measurement being affected by the applied stress. A novel use of TMA involved the measurement of polymer foaming (99). The ushrod movement was recorded as a function of heating rate, glowing agent type and concentration, blowing agent inhibitor, polymer viscosity, and cross-linking agent. Glass transition temperatures of polyimides containing dibenzo-p-dioxin and llOR
ANALYTICAL CHEMISTRY, VOL. 52, NO. 5, APRIL 1980
thianthrene fused ring systems were measured by TMA (143). TMA indentation values for Al-filled epoxies (185) were found to lie within predicted limits. In a series of benzil end-capped acetylene-terminated phenyl-quinoxalines, TMA was used to determine their softening point onset and maximum rate of softening (90). The DuPont Dynamic Mechanical Analyzer has been described and a number of applications of the equipment were discussed (26). Concurrent electrothermal analysis (ETA)-DTA-TG measurements were performed on a modified DuPont thermobalance (200) and utility of the equipment was illustrated by application to CuS04.5H20, (NH4)2C204.H20, and NH4N03.Formation of MCdBra and M2CdBr4(M = K, Rb, Cs) was illustrated by DTA, with simultaneous electrical conductivity and X-ray measurements (32). The reactions were assisted by a labile liquid phase, the composition of which was determined by DTA. Electrical conductivity and dielectric measurements showed a marked change at 124 "C when applied to CuSO4.5H20(140). This temperature corresponded to the second dehydration step. Dielectric and DTA measurements were applied to phase transitions of Na2S04(16). Electrical resistivity and DSC were used to study order-disorder phenomena in V2H and V2D (21). Effluent gas analysis ( E G A ) , employing thermogastitrimetry, was employed (147) to show Br, was the decomposition product evolved from CaBr,, not HBr. The decomposition of AlC13.6H20was similarly studied (142). The thermal stability of three boracites was examined by TG, DTA, and EGA (70) and the last technique indicated major differences in the decomposition products. Thermal volatilization analysis of cis-1,4-polybutadiene, polystyrene, and their blends showed no change in the nature of the products, but the degradation rate of polystyrene was reduced in the blend (129). The same technique was used to show the destabilization effect of silver acetate on poly(methy1 methacrylate). Pyrolysis-mass spectrometry was employed for comparative analysis of the degradation products of polystyrene and poly(p-N,N-diethyl-aminostyrene)(61) and to determine the gaseous products evolved from mixtures of poly(viny1chloride), poly(viny1idene chloride), and chlorinated paraffin with Sb203and (Bi02)C03,respectively (20). Torsional braid analysis has shown that the cross-linked residue from poly@-N,N-diethylaminostyrene) is formed on the heating cycle above 150 OC, rather than on cooling. Direct pyrolysis in the ion source with the (Bi02)C03and Sb2O3 (20) gave evidence for Bi4,BiC13, and Sb406,as well as the expected HCl. Mass spectrometry and total pressure measurements were made during the course of poly(buty1ene terephthalate) degradation (117) and Arrhenius plots were generated for CO, C02,THF, and 1,3-butadiene evolution. Gas chromatography applied to pyrolysis of poly(viny1 chloride) has shown that toluene is formed at much higher temperatures than benzene (31). The temperature of benzene formation was related to the dehydrochlorination process, but toluene formation appeared with a complex set of products. Gas chromatography of trapped ethyl cellulose degradation products showed the major products were H20, C H,OH, and CH3CH0, with some C02, C2Hs,and C2H4 (30). eombined mass spectrometry-gas chromatography has been used to determine coal pyrolysis products (72). Work on thermoparticulate analysis continued in application to organic compounds with 17 isocyanates being examined (151). Strong organoparticulate activity below 200 "C was observed, but was not correlated with melting point or compound decomposition temperatures. Thermosonimetry apparatus has been constructed (41). The technique was used to determine phase transitions in alkali metal dichromates ( 1 14) and decomposition of brucite (113). LITERATURE CITED
Abate, L.; Siracusa. G. Thermochim. Acta 1979. 29, 157. Adeosun, S.0. J. Therm. Anal. 1978, 74, 235. Akanni, M. S. Thermochim. Acta 1978, 27. 133. Adeosun, S.0.; Ellis, H. A. Thermochim. Acta 1979. 28, 313. Adeosun, S.0.; Adiga, K. C.; Jain, S.R.; Patil, K. C.; Verneker. V. R. P. Combust. Flame 1979, 34,209; Chem. Abstr. 1979, 9 0 , 154306. (6) Ahad, E. J . Appl. Polym. Sci. 1978, 2.2, 1665. (7) Akcatel. P.; Jasse, B. J. Polym. Sci., Polym. Chem. Ed. 1978, 16, 1401. (8)Akhtar, D.; Vankar, V. D.; Goel. T. C.; Chopra, K. L. J. Mater. Sci. 1979, 74, 983. (9) Alsheh, D.; Marom, G. J . Appl. Polym. Sci. 1978, 22, 3177. (10) Armitage. D.; Price, F. P. J. Polym. Sci., Polym. Symp. 1978, 63, 95. (1) (2) (3) (4) (5)
THERMAL ANALYSIS (11) Arseneau, D. F.; Wiltshire, J. F. Proc. Coal Coke Sess., Can. Chem. Eng. Conf., 28th, 1978, 56. (12) Asomoza, P. M . ; Razo, M. L.; Chaides, L. L.; Casillas, S. R. J . Therm. Anal. 1978, 13. 327. (13) Auffredic, J. P.; Louer, D.; Louer, M. J. J . Caiorim. Anal. Therm. [Prepr.] 1978, 9 A . 97; Chem. Abstr. 1978, 8 9 , 208355. (14) Babooti, M. M.; Jasim, F. J . Therm. Anal. 1978, 13, 563. (15) Badr, Y. A.; ECKabbany, F.; Tosson, M. Phys. Status SolidiA 1979, 5 3 , K51. (16) Badr, Y. A.; Kamel. R. Ref. 15, p K161. (17) Badurski, M.; Stroz, K. J . Cryst. Growth 1979, 46, 274. (18) Bajaj, P.; Mandal, T. K. J . Appl. Polym. Sci. 1978, 2 2 , 511. (19) Ball, M. C.; Casson, M. J. J . Inorg. Nucl. Chem. 1977, 39, 1949. (20) Baliistreri, A.; Foti, S.; Montaudo, G.; Pappalardo, S.; Scamporrino, E. J . POlym. Sci.. Polym. Chem. Ed. 1979, 17, 2469. (21) Bambakidis, G.; Pershing. M. W.; Bowman, R. C., Jr. Scr. Metali. 1979, 13, 441; Chem. Abstr. 1979, 9 1 , 100049. (22) Barton, J. M.; Lee, W. A , ; Wright, W. W. J . Therm. Anal. 1978, 13, 85. (23) Bashkin, I. 0.; Ponyatovskii, E. G.; Kost, M. E. Phys. Status Solidi8 1979, 9 1 , 401. (24) Bergfjord, J. A.; Penwell. R . C.; Stolka, M. J . Polym. Sci., Polym. Phys. Ed. 1979, 17. 711. (25) Bideau, M.; Claudel, B. Thermochim. Acta 1978, 2 7 , 285. (26) Blaine, R. L.; Gill, P. S.; Hassel, R. L.; Woo. L. J . Appl. Polym. Sci., Appl. Polym. Symp. 1978, 34, 157. (27) Borel, M. M.; Busnot, A,; Busnot, F.; Leclaire, A. Thermochim. Acta 1979, 3 1 , 189. (28) Bradbury, A. G. W.; Sakai. Y.; Shafizadeh, F. J . Appl. Polym. Sci. 1979, 2 3 , 3271. (29) Brown, M. E. J . Chem. Educ. 1979, 5 6 , 310. (30) Brown, W . P.; Tipper, C. F. H. J . Appl. Polym. Sci. 1978, 2 2 , 1459. (31) Burille. P . ; Bert. M.: Michel. A.: Guvot. A. J . Polvm. Sci.. Polvm. Lett. Ed. 1978, 16, 181. (32) Burmistrova, N. P.; Shakirova, D. M.; Davletshin, R. Yu.; Kamalova, R. K. Zh. Neorg. Khim. 1979, 2 4 , 1041. (33) Byron, D. J.; Lacey, D.; Wilson, R. C. Mol. Cryst. Llq. Cryst. 1979, 51, 265 (34i-Cantor, S. Thermochim. Acta 1978, 2 6 , 39. (35) Cardwell, R. D.; Luner, P. Tappi 1978, 61, 8 . (36) Cavell, K . J.; Hill, J. 0.; Magee, R . J. Thermochlm. Acta 1979, 33, 383. (37) Chanda, M.; Kumar. W. S. J.; Raghavendrachar, P. J . Appl. Polym. Sci. 1979, 2 3 , 755. (38) Chang, S.-P.; Miwa, T. K. J . Appl. Polym. Sci. 24, 441. (39) Chatani, Y.; Anraku, H.; Taki, Y. Mol. Cryst. Lig. Cryst. 1978, 48, 219. (40) Chiu, G. J . Chem. Educ. 1978, 55, 205. (41) Clark, G. M. Thermochim. Acta 1978, 27, 19. (42) Clark, G. M.; Garlick, R. J . Inorg. Nucl. Chem. 1978, 40, 1347. (43) Clark, R. P.; Gallagher, P. K.; Diliard, B. M. Thermochim. Acta 1979, 33, 141. (44) Clark. R. P.; Reinhardt, F . W. J . Therm. Anal. 1978, 13, 321. (45) Claudy. P.; Bonnetot, B.; Letoffe. J. M. J . Therm. Anal. 1979, 15, 129. (46) Clements, J.; Capaccio, G.; Ward. I. M. J . Polym. Sci., Polym. Phys. Ed. 1979, 17, 693. (47) Criado, J. M.; Morales, J.; Rives, V. J . Therm. Anal. 1978, 14, 221. (48) Cutler, D. J.; Glotin. M.; Hendra. P. J.; Jobic, H.; Moritz, K. H.; Cudby, M. E. A.; Willis, H. A. J . Polym. Sci., Polym. Phys. Ed. 1979, 17, 907. (49) Dalvi, B. D.; Chavan, A . M. J . Therm. Anal. 1978, 14, 331. (50) Dancy, E. A.; Phuc Nguyen Duy. Thermochim. Acta 1979, 31, 395. (51) Dickens, B. Thermochim Acta 1979, 29, 41. (52) Dickens, B. Ref. 51, p 57. (53) Dickens, B. Ref. 51, p 87. (54) Doelman, A.; Gregges, A. R.; Barrall, E. M., 11. Anal. Calorimetry 1977, 4 . 1. (55) Donatelli, A. A. J . Appl. Polym. Sci. 1979, 2 3 , 3071. (56) Donovan, J. W. Biopolymers 1979. 18, 263. (57) Dozen, Y.; Fujishima, S.; Shingu, H. Thermochim. Acta 1978, 2 5 , 209. (58) Dworkin, A.; Ubbelohde, A. R. Carbon 1978, 16, 291. (59) Earnest, C. M. J . Chem. Educ. 1978, 56 (9). A33 1. (60) Egashira, M.; Matsuo. K.; Kagawa. S.; Seiyama, T. J . Catal. 1979, 58, 409. (61) Ellis, T. S.; Still, R. H. J . Appl. Po/ym. Sci. 1979, 23, 2881. (62) El Sabee, M. 2 . ; Perkins, W. G.; Porter, R. S.; Baranov, V. G.; Frenkel, S. Ya. J . Therm. Anal. 1979, 15, 225. (63) Enns, J. B.; Rogers, C. E.; Simha, R. Polym. Prepr., Am. Chem. Soc., Div. Polym. Chem. 1978. 79(1). 75. (64) Faust, H. R. Thermochim. Acta 1978, 26, 383. (65) Fernandes, J. R.; Venugopaian, S. J . Phys. Chem. 1979, 70, 519. (66) Fildes, F. J. T.; Oliver, J. E. J . Pharm. Pharmacol. 1978, 30, 337; Chem. Abstr. 1978, 8 9 , 185976. (67) Forgac. J. M.; Angus, J. C. Ind. Eng. Chem. Fundam. 1979, 78, 416. (68) Fraser, G. V.; Keller, A.; Odeli, J. A. J. Appl. Polym. Sci. 1978, 22, 2979. (69) Fujita. T.; Muramatsu, K. Mater. Res. Bull. 1979, 14. 5. (70) Gallagher, P. K. Thermochlm. Acta 1979, 2 9 , 165. (71) Gallagher, P. K.; Gyorgy, E. M. Thermochim. Acta 1979, 31, 380. (72) Gallegos, E. J. Adv. Chem. Ser. 1978, 170 (Anal. Chem. Lia. Fuel Sources), 13 (1979). (73) Gaur, U.; Mehta, A.; Underlich, B. J. Therm. Anal. 1978, 13, 71. (74) Geneidi, A. S.; El-Sayed, L. Pharm. Ind. 1978, 40, 1074; Chem. Abstr. 1979, 90. 12241. (75) @=dsi. M.; Derie, R.; Lempereur. J. P. Thermochim.Acta 1979, 28, 259. (76) Ghosh, S. K.; Pathak, G. K.; Chaudhuri, A. K. Indian J . Chem., Sect. A , 1978, 16, 670. (77) Gibson, H. W.; Bailey, F. C.; Pochan, J. M. J . Polym. Sci. Polym. Chem. Ed. 1979, 17, 2499.
(78) Gipstein, E.; Barrall, E. M., 11; Yoon, D. Y.; Lyerla, J. J . Polym. Sci., Polym. Phys. Ed. 1978, 16, 1389. (79)78.Wpa r1817. d , P.; Biebuyck, J. J.; Daumerie, M.; Naveau, H.; Mercier, J. P. Ref.
(80)Goel, R. N.; Varma, I. K.; Varma, D. S. J . Appl. Polym. Sci. 1979, 24. 1061. (81) Gorbacheva, I . I.; Volkov, V. V.; Myakishev, K. G . Zh. Neorg. Khim. 1978. 2 3 , 2511. (82) Gough, S. R.; Ripmeester, J. A.; Dalal, N. S.; Reddoch, A. H. J . Phys. Chem. 1979, 83, 664. (83) Gritter, R. J.; Seeger. M.; Gipstein, E. J . Polym. Sci., Polym. Chem. Ed. 1978. 16, 353. (84) Gaulbransen, E. A. Thermochim. Acta 1979, 2 9 , 295. (85) Harrison, I.R.; Runt, J. J. Polym. Sci., Polym. Phys. Ed. 1979, 17, 321. (86) Harrison, I. R.; Runt, J.; Stanislow, L. J.; Bell, D. A. Ref. 85, p 63. (87) Harrison, I. R.; Stutzman, G. L. Anal. Calorimetry 1974, 3 , 576. (88) Harwig. H. A.; Gerards, A. G. Thermochim. Acta 1979, 2 8 , 121. (89) Hay. J. N.; Wiles, M. J . Polym. Sci., Polym. Chem. Ed. 1979, 17, 2223. (90) Hedberg, F. L.; Arnold, F. E. J . Appl. Polym. Sci. 1979, 2 4 , 763. (91) Hennings, D.; Mayr, W. J . Solid State Chem. 1978, 26, 329. (92) Herbell, T. P. Thermochim. Acta 1978, 26, 337. (93) Hidvegi, E.; Kovacs-Csetenyi, E.; Keebe, Gy. J . Therm Anal. 1977, 1 1 , 221. (94) Hiidebrandt, W. H. Metall. Trans. A 1979, 10, 1045. (95) Hirota. K.; Sekine, T. Bull. Chem. SOC.Jpn. 1979, 5 2 , 1368. (96) Hughes, J. C. Clay Miner. 1979, 14. 21; Chem. Abstr. 1979, 97, 42261. (97) Ikeda. M.; Teramoto. Y.; Yasutake, M. J . Polym. Sci., Polym. Chem. Ed. 1978, 16, 1175. (98) Inagaki, N.; Katsuura, K. Ref. 97, p 2771. (99) Jacovic, M. S.; Frisch, K. C.; Porter, R. S. J . Therm. Anal. 1979, 75, 55. (100) Jensen. T. E.; Eatough, D. J.; Hansen, L. D. J. Chem. Educ. 1977, 54, 700. (101) Kambe, H. Thermochlm. Acta 1978, 2 6 , 209. (102) Kaneniwa, N.; Ikekawa, A.; Sumi, M. Chem. Pharm. Bull. 1978, 26. 2734; Chem. Abstr. 1978, 8 9 , 220807. (103) Katsuura, K.; Inagaki, N. J . Appl. Polym. Sci. 1978, 2 2 , 679. (104) Kniep, R.; Mootz, D.; Schaefer, A. Thermochlm. Acta 1979, 2 9 , 1121. Rabczuk, A. J . Therm. Anal. 1979, 75, 343. (105) Kotula, I.; (106) K u r b K.; Hirakawa, N.; Dobashi, T.; Iwakura, Y. J . Polym. Sci., Polym. Chem. Ed. 1979, 17. 2567. (107) Kvande. H.; Linga, H.; Motz, K. Acta Chem. Scand., Ser. A 1979, 33, 281. (108) Ladder, H. J.; Krigbaum, W. R. J. Polym. Sci., Polym. Phys. Ed. 1979, 17. 1661. (109) Lenz, R. W.; Feichtinger. K. A. Polym. Prepr., Am. Chem. Soc., Div. Polym. Chem. 1979, 20(1), 114. (110) Lewis, I.C.; Kovac, C. A. Mol. Cryst. Liq. Cryst. 1979, 5 1 , 173. (111) Li, Kun; Rogan, F. H. Thermochim. Acta 1978, 26, 185. (112) Lipka, A. Thermochim. Acta 1979, 29, 269. (113) Lonvik, K. Thermochim. Acta 1978, 2 7 , 27. (114) Lonvik, K. Thermochim. Acta 1979, 2 9 , 243. (1 15) Lucci, A,; Tamanini, M.; Battezzati, L.; Venturello. G. J . Therm. Anal. 1978, 14, 93. (116) Lugscheider, E.; Knotek, 0.; Kloehn, K. Thermochlm. Acta 1979, 29. 323. (1 17) Lum, R. M. Polym. Prepr., Am. Chem. Soc., Div. Polym. Chem. 1978, 19(2), 574. (118) Lutz, H. M.; Schmitt, R.; Steffens, F. Thermochlm. Acta 1978, 24, 369. (119) Mackenzie, R. C. J . Therm. Anal. 1978, 13, 387. (120) Madsen, F. T. Thermochim. Acta 1977, 21. 89. (121) Manohar, C.; Kelkar, V. K.; Yakhmi, J. V. Mol. Cryst. Liq. Cryst. 1978, 48, 165. (122) Manory, R.; Pelleg, J.; Grill, A. J . Less-Common Met. 1978, 6 1 , 293. (123) Marano, R. T. Thermochim. Acta 1979, 26. 27. (124) Marini, A.; Berbenni, V.; Flor, G. 2. Naturforsch. A 1979, 34, 661. (125) Masse. J.; Chauvet, A. J . Therm. Anal. 1978, 14, 299. (126) Masse, J.; Chauvet, A. Ref. 125, p 313. (127) Matsushige, K.; Takemura, T. J . Polym. Sci., Polym. Phys. Ed. 1978, 16, 921. (128) McCreedy, K.; Keskkula, H. J . Appl. Polym. Sci. 1978, 2 2 , 999. (129) McNeill, I.C.; Ackerman, L.; Gupta, S. N. J . Polym. Sci., Polym. Chem. Ed. 1978, 16, 2169. (130) Mehta, A,; Bopp, R. C.; Baur. U.;Wunderlich, B. J. Therm. Anal. 1978, 13, 197. (131) Mehta, A,; Gaur, U.; Wunderlich, B. J . Polym. Sci., Polym. Phys. Ed. 1978, 16, 289. (132) Midgley, H. G. J . Therm. Anal. 1978, 13, 515. (133) Midgley, H. G. Cem. Concr. Res. 1979, 9 , 77. (134) Mironov, K. E.; Burnashev, 0. R.; Valignat, N.; Dombre, M. J . LessCommon Met. 1978, 59, 211. (135) Mirsaidov, U.;Rotenberg, T. G.; Samieva, Ya. Zh. Neorg. Khim. 1979, 24, 1995. (136) Moeller, P. J. Thermochim. Acta 1979, 29, 339. (137) Molodkin, A. K.; Belan, V. N.; Remizov, V. G.; Bogatov, Yu. E. Zh. Neorg. Khim. 1978, 2 3 , 2859. (138) Moore, G. S. M.; Rose, H. E. J . Therm. Anal. 1979, 75, 37. ANALYTICAL CHEMISTRY, VOL. 52, NO. 5, APRIL 1 9 8 0
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Anal. Chem. 1900, 5 2 , 112R-122R (139) Murphy, C. B. Anal. Chem. 1978, 50, 143R. (140) Nandi, P. N.; Deshpande, D. A.; Kher, V. G.Proc. Indian Acad. Sci., Sect. A , 1979, 88, (Pt. 1, No. 2), 113. (141) Nassau, K.; Wang, C. A.; Grasso, M. J . Am. Ceram. Soc. 1979, 62, 503. (142) Naumann. R.; Petzold, D.; Paulik, F.; Paulik, J. J . Therm. Anal. 1979, 15, 47. (143) Niume, K.; Nakamichi, K.; Takatuka, R.; Toda, F.; Uno, K.; Iwakura, Y. J . Polym. Sci., Polym. Chem. Ed. 1979, 17, 2371. (144) Pacey, R. A,; Clark, J. B. Thermochim. Acta 1979, 30, 115. (145) Padilla, R.; Sohn, H. Y. Metall. Trans. B 1979, IO, 109. (146) Palepu, R.; Moore, L. Thermochim. Acta 1979, 30, 384. (147) Paulik, F.; Paulik, J.; Buzagh-Gere, E.; Arnold, M. J . Therm. Anal. 1979, 15, 271. (148) Pawei, R. E.; Cathcart. J. V.; McKee, R. A. J , Electrochem. Soc. 1979, 126. 1105. (149) Pennings, A. J.; Zwijnenburg, A. J . Polym. Sci., Polym. Phys. Ed. 1979, 17, 1011. (150) Petranovic, N.; Susic, M. Thermochim. Acta 1979, 37, 211. (151) Phillips, D. C.; Smith, J. B. D.; Meier, J. F.; Kaczmarek, T. D. Microchem. J . 1978, 23, 165. (152) Phillips, P. J. J . Polym. Sci., Polym. Phys. Ed. 1979, 17, 409. (153) Ponge, C.; Rosso, J. C.; Carbonnel, L. J . Therm. Anal. 1979, 15, 101. (154) Prince, E. T.; Helbig, H. F.; Czanderna, A. W. J . Vac. Sci. Technol. 1979, 16. 244. (155) Prince, E. T.; Helbig, H. F.; Czanderna, A. W. Thermochim. Acta 1979, 29. 353. (156) Pusatcioglu, S. Y.; Fricke, A. L.; Hassler, J. C. J. Appl. Polym. Sci. 1979, 24, 937. (157) Rao, C. R. M.; Mehrotra, P. N. Thermochim. Acta 1979, 2 9 , 180. (158) Reichek, W.; Oppermann, H.; Wolf, E. Z. Anorg. Allg. Chem. 1979, 452, 96. 159) Reimschuessel, H. K. J . Polym. Sci., Polym. Chem. Ed. 1978, 16, 1229. 160) Reimschuessel, H. K. J . Polym. Sci., Polym. Chem. Ed. 1979, 17, 2447. 161) Reimschuessel, H. K.; Turi, E. A.; Akkapeddi, M. K. Ref. 160, p 2769. 162) Rogers, D. E.; Bibby. D. M. Thermochim. Acta 1979, 30, 303. 163) Rose, R. L. J . Phys. E 1979, 12, 13. 164) Rose, R. L.; Kelley, R. E.; Lesuer, D. R.; J , Nucl. Mater. 1979, 79, 414. 165) Rudin, A,; Samanta, M. C.; Reilly, P. M. J . Appl. Polym. Sci. 1979, 2 4 , 171. (166) Sahoo, P. K.; Bose, S. K.; Sircar, S. C. Thermochim. Acta 1979, 37, 303. (167) Sahoo, P. K.; Bose, S. K.; Sircar, S. C. Ref. 166, p 315. (168) Sandison, R. D.; Eggerding, C. L. Rev. Sci. Instrum. 1979, 5 0 , 129. (169) Sasaki, S.; Nakamura, T.; Uematsu, I.J . Polym. Sci., Po/ym. Phys. Ed. 1979, 17, 825. (170) Sawada, Y.; Uematsu, K.; Mizutani, N.; Kato, M. Thermochim. Acta 1978, 27. 45. (171) Sawada, Y.; Yamaguchi, J.; Sakurai, 0.;Uematsu, K.; Mizutani, N.; Kato, M. Thermochim. Acta 1979, 33, 127.
(172) Sefcik, M. D.; Yuen, H. K. Thermochim. Acta 1978, 2 6 , 297. (173) Seybold, K.; Meisel, T.; Cserfalvi, T. J . Therm. Anal. 1979, 15. 93. (174) Shaplygin, I . S.; Komarov, V. P.; Lazarev. V. B. Ref. 173, p 215. (175) Shibasaki, Y.; Fukuda, K. J . Polym. Sci.. Polym. Chem. Ed. 1979, 17, 2947. (176) Shimokawabe, M.; Furuichi, R.; Ishii, T. Thermochim. Acta 1979, 28, 287. (177) Silano. V.; Zahnley, J. C. Biochim. Siophys. Acta 1978, 533, 181. (178) Simonsen, K. A.; Zaharescu, M. J . Therm. Anal. 1979, 15,25. (179) Sorenson, 0. T. Thermochim. Acta 1979, 2 9 , 211. (180) Spratte, W.; Schneider. G. M. Mol. Cryst. Liq. Cryst. 1979, 51, 101. (181) Stahl, G. A. J . Polym. Sci., Polym. Chem. Ed. 1979, 17, 1883. (182) Stephens, M. A.; Tamplin, W. S. J . Chem. Eng. Data 1979, 24. 81. (183) Sutakshuto-Trivijitkasem. S.; Holm, B. J.; Oeye, H. A. Acta Chem. Scand., Ser. A 1978; 32. 969. (184) Swamianthan, V.; Madhaven. N. S. Thermochim. Acta 1979, 33, 367. (185) Theocaris, P. S.; Paipetis, S. A.; Papanicolaou, G. C. J . Appl. Polym. Sci. 1978, 22, 2245. (186) Ueda, M.; Takahashi, M.; Hishiki, S.; Imai, Y. J . Polym. Sci., Polym. Chem. Ed. 1979, 17, 2459. (187) Ueda, M.; Takahashi, M.; Imai, Y. Ref. 186, p 2477. (188) Ueda, Y.; Sayama, S.; Nishikawa, Y.; Ueda, S.; Yokoyama, S.; Makino, K. Ind. Eng. Chem., Process Des. Dev. 1979, 18, 353. (189) Valentich, J. J . Mater. Sci. 1979, 14, 371. (190) Vallebona, G. J . Therm. Anal. 1979, 16, 49. (191) Varhegyi, G.; Groma, G.; Lengyel, M. Thermochim. Acta 1979, 30, 311. (192) Varma, I.K.; Goel, R. N.; Varma, D. S. J . Polym. Sci., Polym. Chem. Ed. 1979, 17, 703. (193) Vasofsky, R.; Czanderna, A. W.; Thomas, R . W. J , Vac. Sci. Technol. 1979, 16, 711. (194) Vickers, L. P.; Donovan, J. W.; Schachman, H. K. J . Biol. Chem. 1978, 253, 8493. (195) Wahrmund, D. C.; Paul, D. R.; Barlow, J. W. J . Appl. Polym. Sci. 1978, 22,2155. (196) Ward, T. C.; Wnuk, A. J.; Henn, A. R.; Tang, S.; McGrath, J. E. Polym. Prepr., Am. Chem. Soc., Div. Polym. Chem. 1978, 1 9 ( 1 ) ,115. (197) Warne, S. St. J. J . Inst. Energy 1979, 52, 21. (198) Warne, S. St. J.; Mitchell, B. D. J . Soil Sci. 1979, 30, 111. (199) Wen, W. Y.;Lin, J. W. J . Appl. Polym. Sci. 1978, 2 2 , 2285. (200) Wendiandt, W. W. Thermochim. Acta 1978, 26, 19. (201) Wight, F. R. J . Polym. Sci., Polym. Lett. Ed. 1978. 6 1 , 121. (202) Yamaguchi, 0.; Yabuno. K.; Takeoka, K.; Shimizu, K. Chem. Lett. 1979, (4), 401. (203) Yuen, H. K.; Yosel, C. J. Thermochim. Acta 1979, 33, 281. (204) Zeldin. A. N.; Kukacka, L. E.; Fontana, J. J.; Carciello, N. R.; Reams, W. J . Appl. Polym. Sci. 1979, 2 4 , 455. (205) Zasko, J. Ref. Roum. Chim. 1970, 15,693. (206) Zsako, J. J . Therm. Anal. 1979, 15, 369. (207) Zsinka, L.; Szirtes, L.; Le Van So; Poko, S.J . Therm. Anal. 1978, 14, 245.
Chemometrics Bruce R. Kowalski Laboratory of Chemometrics, Department of Chemistry, BG- 10, University of Washington, Seattle, Washington 98 195
INTRODUCTION Many new developments in chemical analysis have followed closely on the heels of advances in electronics, physics, computer science, and various areas of engineering. For this reason there are, and will continue to be, strong interdisciplinary ties between analytical chemists and researchers in other areas of science and engineering. However, since the measurements made by analytical chemists are associated with some degree of uncertainty and an analytical result is usually derived from a mathematical formula, it is difficult to conceive of a more perfect marriage than analytical chemistry and statistics and applied mathematics. Unfortunately, a t this time the relationship between these fields can be characterized only as an engagement. This is not to say that there has been a complete absence of statistical and mathematical methods in analytical chemistry. Prior to the 1960’s, much of the statistical methodology that could be implemented without computers had been introduced in the literature by chemical statisticians working at the National Bureau of Standards and various industrial laboratories. As the computer entered the analytical 112R
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laboratory, however, significant changes occurred. These changes were noted and reported in 1976 by Shoenfeld and DeVoe, the authors of the Fundamental Review section entitled “Statistical and Mathematical Methods in Analytical Chemistry” ( A 5 ) . T h a t review, and its more exhaustive predecessor ( A I ) ,are absolutely required reading for serious students of chemical analysis. Besides writing an excellent critical review of their topic from 1972 to 1976, Shoenfeld and DeVoe injected an element of optimism for the future of statistical and mathematical methods in analytical chemistry, offered a note of caution to those using multivariate methods to deduce causation, and suggested that analytical chemists pay much more attention to such fundamentals as experimental design, measurement characterization, and the testing of assumptions. They even provided the editor of ANALYTICAL CHEMISTRY with a new title for the present review. Chemometrics has been defined as the application of mathematical and statistical methods to chemical measurements ( A 2 ) . A more detailed definition of chemometrics and information about the Chemometrics Society can be obtained C 1980 American Chemical Society
