Anal. Chem. 1994,66, 17R-25R
Thermal Analysis D. Dollimore Department of Chemistry and College of Pharmacy, The University of Toledo, Toledo, Ohio 43606 Review Contents
Instrumentation Thermodynamic Measurements Reaction Kinetics Inorganic Compounds Organic and Polymeric Materials Biological, Medical, and Pharmaceutical Studies Minerals and Energy-Related Topics
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This review covers publications reported in Chemical Abstracts Thermal Analysis (CA Selects) from December 1991 to November 1993. The increasing number of publications and limitations on the space available in this review make it reasonably certain that some important contributions to thermal analysis have been omitted. This is unintentional and apologies for any omission of this kind are offered in advance. The big event of the period covered was the ICTA Conference held at Hatfield and published in three volumes in Journal of Thermal Analysis ( I ) . The first volume dealt with earth science; cements, glasses, and ceramics; archeology and conservation; and metallurgical systems and superconductors. The second volume dealt with pharmaceutical and organic compounds, polymers, and biological and biochemical materials. The final volume dealt with instrumentation; inorganic compounds, catalysis; theory and kinetics. These three volumes contain the most up-to-date information on thermal analysis, practice, and instrumentation. A third edition of For Better Thermal Analysis and Calorimetry has been published ( 2 ) . This book is published by the International Confederation for Thermal Analysis, which is affiliated with IUPAC and is the organization which promotes international understanding and cooperation in thermal analysis. It works through various committees which include nomenclature, standardization, procedures for reporting data, with working parties dealing with mineralogy, kinetics, and education. A special issue of Thermochimica Acta under the title New Directions in Material Characterization by Thermal Analysis presents 27 papers given at the 20th North American Thermal Analysis Society in 1991 (3). The Proceedings of the Fifth European Symposium on Thermal Analysis and Calorimetry in 1991 was published in the Journal of Thermal Analysis ( 4 ) . A two-day course on thermal analysis held at Leeds Metropolitan University sponsored by the Royal Chemical Society resulted in a publication entitled Thermal Analysis- Techniques and Applications ( 5 ) . A new edition of the book Thermal Analysis, edited by Kambe and Ozawa is available (6). In the series Treatiseon Analytical Chemistry, a volume dealing with thermal analysis covers the topics of kinetics by Dollimore and Reading; thermometric titrations and enthalpimetric analysis by Jordan and Stahl; thermogravimetry by Dunn and Sharp; the application of ther0003-2700/94/0366-0017$14.00/0 0 1994 American Chemical Society
D. b o l l h e received his B.S. (1949), Ph.D. (1952), and D.Sc. (1976) degrees from London University. He held a postdoctorate position at Exeter University (1952-19541 and held a facutty appointment at St. Andrews University (1954-1956) before joining the University of Salford (19561982) where he held a Faculty position as Reader. He has been a Professor 01 Chemistry at the University of Toledo since 1982 and holds a similar position in the College of Pharmacy at that University and serves in an Adjunct capacity in the Geology Department. He is on the editorial board of Thermochimica Acta, was the Mettler Award Winner in 1979, and was Chairmano et1 Group (1969-1971). He is the author of several books and editor of various Conference Proceedings. I n 1988 Dr. Dollimore attended the ICTA Conference to receive the DuPont/ICTA Award in Thermal Analysis. He is President of a consulting firm dealing with problems in surface science and heat treatment of solids.
modilatometry to the study of ceramics by Moshe Ish-Shalom; pyrolysis techniques by Irwin; and applications of thermal analysis to problems in the cement industry by Bhatty (7). A specialized volume on Thermal Analysis in the Geosciences was edited by Smykatz-Kloss and Warne based on review papers presented at an International Meeting held in October 1990 at Berghausen, Karlsruhe, Germany (8). Other books that have appeared contain sections dealing with thermal analysis. One contains material on the preparation of active carbons by thermal treatment ( 9 ) . The kinetic aspect of phase changes is recognized in a recent publication ( I O ) . Wachtman has written a book on Characterization of Materials which includes a chapter on thermal analysis ( I I ) . The importance of thermal analysis applied to pharmaceutical materials is also recognized in Modern Methods of Pharmaceutical Analysis ( I 2 ) . New thermal techniques have been emerging. One of these, thermally stimulated current depolarization (TSC), is now available commercially. The principle of TSC is to orient polar molecules or pendant polar groups of macromolecules by applying a high-voltage field at a high temperature and then quenching the material to a much lower temperature where molecular motion ceases. After this polarization, the material is heated at a constant rate causing it to depolarize and thereby create a depolarizing current. This thermally stimulated depolarizing current can be related directly to molecular mobility, indicating the physical and morphological structure of materials. Ibar of Solomat has produced a book on the topic (13). The technique has found a wide application to polymers (Z4-Z6). It has been used to characterize the amorphous phase of polymers (I7-I9). There is a kinetic feature in thermally stimulated processes which shows a compensation law (20). The technique of high-resolution thermal analysis also deserves mention. In principle it could be applied to any Ana&ticalChemistry, Vol. 66, No. 12, June 15, 1994
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thermal analysis technique but is offered as a special program by T A Instruments to thermogravimetry (TG). In this, the heating rate is decreased whenever a mass loss is detected, establishing a minimum or almost zero heating rate, and the heating rate is reintroduced when the rate of mass loss tends to zero. This introduces a very sharp loss of mass for a transition over a small range of temperature ( 2 1 ) . Another technique marketed by T A Instruments is modulated differential scanning calorimetry. In this, the temperature is subjected to a sinusoidal ripple (modulated) while an overall heating rate is maintained. Now, if an irreversible effect is present on the heating part of the “ripple”, then by definition it will be absent on the cooling part of the ripple. The word reversible is not used here in the thermodynamic sense but in the practical sense. Thus, dissociation or boiling are thermodynamically reversible, but in a DSC system the loss of material incurred in the transition renders it experimentally irreversible. The conventional DSC signal can then be resolved into a modulated DSC (MDSC) signal for the nonreversing component and a n MDSC reversing component. Examples are given by Gill et al. (22),and the theory is outlined by Reading et al. (23). It is particularly useful in the determination of the heat capacity and the glass transition point, but further examination might be necessary in other processes. Some other techniques should also be noted. A unit is described by Bahra et al. ( 2 4 ) to investigate the mechanical and rheological properties of drying films. In another method, a pore size distribution can be obtained by a calorimetric study of the liquid-solid-state transition of a capillary condensate (25). There are quite a few instances of thermal analysis being used in an historical context. Wiedemann and Bayer (26) discussed the use of thermal analysis in the study of ancient Chinese artifacts. Kawiak (27)used thermal analysis to study gypsum mortars from a 12th century church in Wislica, Poland. Regai et al. (28) used a combination of H g porosimetry and thermal analysis to study Egyptian mortars extracted from the Sphinx and from the Khafra Valley temple. Adams et al. (29, 30) used thermal analysis techniques to investigate medieval mortars from French and English cathedrals. The history of thermal analysis is traced in a series of papers by Keattch and Dollimore (31). INSTRUMENTATION Some new techniques have already been discussed. Here we deal with modifications to already well-established techniques. Wahlbeck (32) shows that the T G experiment is similar to a transpiration experiment. Gimzewski (33) provides a design for a compact high-pressure thermogravimetric unit. Czarnecki (34) describes a T G unit in which the flow of products of decomposition is arranged such that condensation on the support, on the sample, and in the reaction chamber is minimized. A unit described by Lavrenko et al. (35) as a microgravimetric plasmachemical apparatus provides the means of studying the interaction of atomic and molecular gases with solids over a wide range of temperature and pressure. In other developments microwave drying is used (36, 37). 18R
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Tanaka (38) extends the theory of a heat conduction calorimeter normally operated under isothermal conditions to cover a programmed temperature regime. Crighton and Wilburn ( 3 9 )continue to investigate the role of heat transfer in the production of DSC curves. Flynn (40) shows that the integration of DSC data to obtain enthalpy vs time or temperature can be performed easily with the aid of the computer work station. The calculation of the thermal time constants in DSC has been demonstrated by Patt et al. (41). Various high-pressure DSC units have been described, but the temperatures for dissociation reactions at high pressures of product gas are often pushed beyond the limit of the equipment ( 4 2 - 4 4 ) . To develop a scanning calorimeter for heat capacity measurements up to 1500 K, a “triple-cell” system was adopted by Takahashi and Asov ( 4 5 ) , together with a triple-adiabatic temperature control. Gas analysis used in studying thermal decomposition processes is almost always a simultaneous “coupled” technique. A temperature-programmed decomposition mass spectrometric (TPD-MS) system, where the gases are evolved during the thermal decomposition of a chemical within the TPD reactor, may be cited as an exception. Wang and McEnaney describe methods of calibrating such a system for CO and COz using calcium carbonate and calcium oxalate (46). Leskela et al. ( 4 7 )describe an inexpensive evolved gas analysis (EGA) system in which a quadrupole mass spectrometer is coupled with a T G unit. The use of gas chromatography (GC) as a gas detector and analyzer involves intermittent testing of the evolved gases. Nevertheless, such systems have been described and used involving TG, GC, and M S (48) and differential thermal analysis (DTA) coupled with G C (49). Systems employing Fourier transform infrared spectroscopy coupled with a variety of other thermal analysis techniques have also been described (50-52). There have been many articles published dealing with thermomechanical analysis in materials science. The review by Neag should be consulted (53). One of the problems in dealing with thermal expansion is the choice of suitable reference materials ( 5 4 ) . A preliminary study carried out on the ICT.4 reference materials for DTA identified those materials that were most useful in calibrating T M A equipment (55). A detailed study by Earnest and Seyler (56) led to the development of a standard method for calibration of thermomechanical analyzers. The dynamic mechanical thermal analyzer has been used to determine the molecular microstructure of elastomers ( 5 7 )and, together with DSC, the glass transition of epoxy composites (58). A high-pressure dilatometer has been used to determine transition points in nperfluoroeicosane (59). McGhie ( 6 0 ) uses a combination of thermomechanical analysis and electric thermal analysis to characterize polymer electrolytes. THERMODYNAMIC MEASUREMENTS Data relating to thermodynamics required the accurate measurement of temperature. Charsley et al. (61)confirmed the choice of potassium chromate as an ICTA certified reference material suitable for DSC, DTA, and simultaneous TG/DTA units with a transition temperature in the range 668.9-669.3 OC. Hohne et a]. ( 6 2 ) make the point that
temperature calibration is necessary in both the heating and was used in the measurement of heat capacities of hexadecooling modes for DSC measurements. cyltrimethylammonium chloride in aqueous solutions (95). DSC is an effective tool to investigate smectic phases of Edwards (63) introduces the contentious postulate that liquid crystals (86). DSC was also used to measure critical triple points are pernts, i.e., really an indistinct point, even in micelle temperatures and thermodynamic micellization funcidealized models. In other words, Edwards is contending that tions in the system oxyethylene/oxypropylene diblock cothe temperature and pressure are not fixed by the presence polymers in aqueous solution (87). of three phases at equilibrium for any real substance. Once this postulate is fully understood by readers there should arise a great deal of discussion on this issue. REACTION KINETICS There is little speculation on the use of isothermal studies The evaluation of purity by examining DSC curves and in the kinetic evaluation of solid-state decompositions, possibly analyzing the data using Raoults law leads to correction factors because it is covered by numerous publications covering the being applied which undermine the theory and anyway leads theory prior to 1950 (88) and definitive formulations for to units being used to express purity, which differ from all identification of the kinetic mechanisms in the 1960s (89). other methods. However, new programs continue to appear There is also the fact that most commercial instrumentation (64, 65). Most other purity methods express purity as is designed to cope with rising temperature programs and a “percent” by weight, but methods based on Raoults law lead truly isothermal experiment is very difficult to achieve (90). to results on a mole basis, which allows comparison only when The nonisothermal determination of kinetic parameters the impurity is known and can be assigned a molar mass. continues to be based upon the three basic relationships, namely Methods have been published which allow the determination of vapor pressure in equilibrium with a liquid from DSC or da/dt = kF(a) DTA measurements (66, 67). where a is the fraction decomposed, t is the time, k is a rate Two-component systems can be represented by a temconstant, and F(a)is the algebraic function of a that identifies perature+omposition plot showing condensed phases present. the a-t relationship, plus the Arrhenius equation and another The systems In-Cd (68),lanthanide chlorides-alkali chlorides describing the relationship between T (the temperature) and (69),Li~ZnC14-Na2ZnC14and LizZnCl4-Li~MnCl4 (70),and time, t . Flynn (91)points out that the F(a)is often given only water-methylhydrazine and water-1,l-dimethylhydrazine as (71) have all been examined systematically using DTA or DSC techniques. A T G technique was used by Abood and F(a)= (1 - a)” Kerridge (72) to follow the oxidation of potassium iodide in molten nitrate eutectics to form iodine above 220 OC and to where n is the order and that such a formulation does not form a paraproiodate above 400 OC. Uram and Edwards generally describe solid-state kinetics. Ozawa (92)introduces (73)used simultaneous Knusden and Torsion effusion methods the concept of reduced time into isoconversionmethods, which to establish the vaporization chemistry in the gallium-sulfur necessitates, however, a combination of rising temperature system. The systems LaP04-K4P207, K ~ L ~ ( P O ~ ) ~ - K ~ P Z O ~ , isothermal methods. Koch (93) points out that some and YP04-Na4P207, Na3Y (P04)2-Na4P207, Y203-K3Y(P04)2, kind of shape index to the kinetic a-Tcurve serves to identify and Y203-K3P04 have all been studied by a group of Polish a kinetic mechanism. This approach is adopted in a series of workers using DTA, X-ray diffractometry, and microscopy papers by Dollimore and co-workers (90, 94-97). (74-76). Cooling curves have been used to establish phase Militky and Sestlk (98) stress that statistical methods for behavior in many systems and two examples may be cited parameter estimation offer definite possibilities in realizing here, namely, a study of the MgC12-KCl-CaC12 system (77) an estimation of the form of the reaction equation and the and the LiF-Na3AlFs-Na3FS04 system (78). Arrhenius parameters. Dollimore et al. (95, 99) provide In the determination of glass transition points, the use of computer programs which allow the creation of simulated T G DMTA and DSC is described by Wetton and co-workers curves or an a-T plot by fixing definite values for the Arrhenius applied to organic polymer systems (79,80). Cooling curves values and specifying a reaction mechanism. Using these were used by Sutton (81)in aqueous cryoprotectant solutions computer simulations, they then go on to study the effect of containing polymers. In this case the intention was to the reaction heat on kinetic analysis by T G under a rising determine the critical cooling rates, which avoided ice temperature program and the importance of the prehistory of crystallization. a sample on its thermal behavior (100). The same approach allows previous methods of calculating the Arrhenius paOne of the main uses of DSC has been to obtain heat rameters to be tested and often modified (101). capacities either from the normal plots or as already mentioned Urbanovici and Segal (102, 103) in a continuing series of by presenting the DTA data in the integrated form (40).A papers point out that the maximum rate and inflection points typical example is the study by Wunderlich et al. (82). The on the DTG curves can be used to characterize the reaction ATHAS computation scheme was used to compute heat mechanism. The suggestions made are extended to the capacities over a range of temperatures and to determine glass interpretation of DTA data (104). transition points. A heat flax DSC unit capable of measuring Ceipidor et al. (105) also use computer simulations to heat capacities up to 1500 OC is described by Le Parlouer estimate the influence of calorimetric, instrumental parameters (83). Callanan et al. (84) found that the heat capacity of and other experimental constraints on the evaluation of kinetic 9-methylcarbazole over the temperature range 120-355 K parameters. They stress the effect of heat-transfer perturbameasured by DSC agreed well with data collected more tions. Vyazovkin and Lesnikovich (106) point out that the conventionally in an adiabatic calorimeter. A DSC technique Analytical Chemistty, Vol. 66, No. 12, June 15, 1994
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isoconversional method provides an estimate of E a t particular mass conversions independent of a kinetic model. Vyazovkin (107) reinforces the use of this method by noting that the preexponential function A is related to E by a compensation effect. Vyazovkin and co-workers (108) provide computer software that make calculations based on the isoconversional method reliable. Kim et al. (109) use a master plot to obtain a kinetic analysis. This may be suspect becauseA and E are apparently treated as constants whereas changing the mechanism also involved changing A and E to obtain a fit to the kinetic plot. In a study by Orfao and Figueiredo (110) two dimensionless parameters are used y = E/RT,
and
/3= AT,Ib
to help define the kinetics where Tois thestarting temperature, b is the heating rate, and E , A , and R have their usual significance. Mianowski and Radko (111) demonstrate that the methods of solving the temperature integral in a standard kinetic equation in nonisothermal conditions can affect both E and A . Ozao and Ochiai (112), using fractals to describe the particle size distribution, show that this is reflected in the kinetics of decomposition. Aggrawal(113) extends the system for simple reactions to a discussion on the theoretical behavior of complex reactions. Rate-controlled nonisothermal procedures continue to be a subject for discussion (114, 115). Strictly rate-controlled processes do not conform to the definition of thermal analysis, where it is stated that temperature is the imposed parameter and the property measured the dependent property. Rather than ponder on these semantics, the result here is an estimation of kinetic parameters and we should probably seek a wider and more flexible definition of thermal analysis. Zhengquan et al. (116) set out a scheme for the estimation of kinetic parameters from a single nonisothermal DSC curve. This must be contrasted with the findings of Malek and Criado (117) that for a reliable analysis of a single experimental result the value of the true activation energy should be known. Bezjaket al. (118)in a DTAstudypoint out that simultaneous nucleation and growth in a kinetic process could result in an overlapping of an exothermic and endothermic peak which is capable of resolution based on an appropriate model.
INORGANIC COMPOUNDS One of the ways in which thermal analysis can help in studying metals is to assess changes that take place in mechanical treatment. Thus, in studying the shear of thin surfaces of polyethylene on a steel surface upon grinding, the polymer debris can be studied by DSC (119). The alteration of microstructure of pure silicon and germanium has also been studied using DTA and DSC (120). Attention has been focused recently on systems in the nanometer range which as a consequence of their size possess extraordinary properties with regard to phase transitions, etc. It is reported that mechanical attrition has bought certain metal powders down into this range. It is shown that the excess stored enthalpy, apparent from the DSC studies, is 10-40% of the heat of fusion (121). A new preparative route involves deposition of copper and lead powders from formate and acetates dispersed 2QR
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or dissolved in glycerine and exposed to 248-nm KrF pulsed laser radiation (122). The powders produced were characterized by thermal analysis studies. Harmelin and co-workers find an extensive use of thermal analysis in studying alloy systems (1 23-128). This includes structural relaxation, the determination of the liquidous temperature on heating, the determination of peritectoid transitions and other phase transitions, the effect of mechanical alloying, and the detection of oxygen and carbon contamination due to the use of ethanol in the mechanical alloying process. Clavaguera-Mora and co-workers (129,130) have developed a new temperature vs heating rate transformation diagram and have used it to establish the crystallization behavior of Fe67,5Col~Nbl5B16metallic glass. MukdeepromBurckel and Edwards (131)constructed plots ofvapor pressure as functions of temperature for the system GaTe-Ga, using the simultaneous Knudsen and Torsion effusion methods. The lithium sulfate monohydrate dehydration has received attention (132-135). The results show that the kinetics of dehydration depend on the prehistory of the sample and the environmental conditions of the experiment. Oxalate decomposition studiesare reported. Galwey and Mohamed (136) conclude that the decomposition of ferric oxalate hydrate occurs either by electron transfer or by rupture of the C-C bond in the anion. This can be compared with the thermal decomposition of copper(I1) oxalate, where the same authors (137) postulate that thedecomposition proceeds with stepwise cation reduction (Cu2++ Cu++ Cue). A study by Dollimore et al. (138)emphasizes thedependenceofthethermalstability of this oxalate on the environmental atmosphere, sample preparation, and prehistory. Selcuk and Price (139), in studying the impurity effect of zinc in the decomposition of lead oxalate, conclude that the pressure of zinc in the crystal lattice restricts the formation of the Smekal cracks along which decomposition is favored. In the dehydration of erbium formate dihydrate Masuda et al. (140) find an anomalous effect on the kinetics caused by the effect of water vapor present in the environmental atmosphere. House and Goerne (141) used DSC to identify two reversible phase transitions in sodium nitrite. Strydom and Pretorius (142) find that Z r ( S 0 4 ) ~ 5 . 5H20 decomposes in five steps to tetragonal ZrOz a t 800 OC. Dehydration proceeds with the loss of 0.5, then 3, then 1, and finally 1 molecules of water of hydration. Allen and co-workers have produced a series of papers describing the thermal stability in air of different complexes of various metals. The metals include cobalt, nickel, copper, and manganese, while the ligands include 7,8-benzoquinoline, anthranilamide, 4-aminobenzylhydrazide, 2,6-diaminopyridine, 3-pyridinealdoxime, 1,6-hexanediamine, 4,7-phenanthroline, 1,lo-phenanthroline,2,3-bis(2-pyridyl)pyrazine,2,2bis(acry1amido) acetic acid, m-toluidine, nonylamine, poly(acrylicacid), and 2-butoxypyridine (143-149). Two patterns of behavior can generally bediscerned, one in which the chloro complex with the metal either decomposes directly to the oxide exothermically or decomposes endothermically to the metal chloride followed by an exothermic conversion to the oxide. It would seem possible that perhaps in the first case the decomposition in nitrogen might be to the powdered metal. This would provide, if a suitable starting material from the
above reaction was chosen, an excellent method of obtaining powdered metals of great reactivity. Allan (150) provides a review of earlier work on this topic. Peascoe and Clearfield (151) have published the hydrothermal synthesis of Na2(MoOP04)2(HP0&2H20, a layered molybdenium phosphate structure, and used TG to indicate the presence of H 2 0 in "tunnels" present in the structure. Clearfield and co-workers (152) also used TG in studying the pillaring of layered double hydroxides with poly(oxometa1ates) in aqueous solution without use of swelling agents. Hall and Sutcliffe (153) continue with their studies on the carboxylato complexes of zirconium( IV). The residue was zirconium dioxide. Microwave heating as a drying process or in the processing of inorganic materials will surely soon find more use in thermal analysis. An introductory article on the subject is by Mingos and Baghurst (154). An example of its use is the removal of poly(methy1 methacrylate) binder from alumina (155). It has already been noted that the preparation of nanophase materials is of interest (121), and temperature-programmed desorption from nanophase Ti02 powder showed its ability to dissociately adsorb H2S in an H2 environment (156). The degree of silyation on a modified silica surface has been determined by TG (157). Kim and MatijeviC (158) prepared magnesium and potassium niobate in the form of amorphous spherical particles by a homogeneous precipitation method. The isothermal decomposition of nickel permagnate under vacuum conditions has been interpreted kinetically by Galwey et al. (159). There are numerous research papers on barium titanates. The reason is that it shows a PTC effect if suitably doped and processed. There are orthorhombic, tetragonal, and cubic forms of the material. An introductory article has been written by Fagan and Amarakoon (160). Numerous methods of preparation designed to incorporate various dopants have been investigated (161-164). In these studies thermal analysis was used for characterization or to monitor progress in the processing techniques. Other titanates have also been investigated and typical examples are zirconium titanate (165) and lead titanates (166). Other systems which have been studied include the barium oxide-thallium oxide system (167). Synthetic zeolites are oxide structures with a porestructure built in capable of being able to take up definitive quantities of water molecules. Thermal analysis reveals this water loss as well as other events. Recent studies by Dyer and co-workers (168-170) on alkali metal and related exchanged forms of ZSM-5, NaA, MgNaA, CaNaA, and SrNaA zeolites, etc., show the use of thermal analysis in assessing the thermal stability of such systems. The main concentration of effort with ternary oxides continues to be with superconductors and specifically with the multiphase Y-Ba-Cu-0 samples and the superconducting phase identified as YBa2Cu307. A special report by Adrian and Cowan (1 71) provides an overview. The earlier preparations involved heat treatment of CuO, Y2O3, and BaCO3 often called the melt-powder-melt growth process (172). Alternative preparations have been studied by aerosol decomposition of nitrate solution (173), from soluble metal oxo alkoxide (174), or by a citrate gel process (175). However, there is an increased interest in producing this material as a thin film (I 76) or as wires (177). The temperature dependence of the
phase on the oxygen pressure in the range of 600-900 OC is reported by Pecina and Haerdtl (178). Oxygen diffusion in the YBazCa30y as a bulk material or as thin films is reported (179). Another material with a somewhat unusual superconductivity range is La2-xMxCu04 (171). The structural phase transitions of lanthanum barium copper oxide (La,BaCusO,) has been reported (180). The phase formations of high- Tc superconducting oxides in the Bi-Pb-Sr-Ca-Cu-0 glass is reported (181). There are many papers showing the use of thermal analysis in studying buckminsterfullerene. The subject is reviewed by Gallagher et al. (182). Wiedemann and Bayer (183) confirm that the sharp endothermic phase transition is observed at 200-270 K, and they measured the vapor pressure by the Knudsen method. Saxby et al. (184) report that rising temperature experiments of buckminsterfullerene in oxygen showed virtually no increase in weight due to added oxygen before weight loss occurred. Chemisorption of gaseous species however might better be observed in isothermal experiments. The small weight gain is confirmed by Gallagher and Zhong (185). Thermal analysis has also been used in studying synthetic diamonds (186, 187).
ORGANIC AND POLYMERIC MATERIALS Sbirrazzuoli et al. (188) point out that there is very often a high disparity in both temperature and enthalpy determinations of solid-plastic transitions in organic compounds when DSC data are compared with literature data. They note that determination of the kinetics associated with the transition might indicate a possible cause. DSC was also used to show that 2-bromothiophene possessed three different phases which melted at atmospheric pressure, i.e., showed three melting points (189). The nonisothermal crystallization kinetics of four high-purity even-numbered n-paraffins, n-C30H62, n-C34H70, n-C44H90, and n-CSOHlo2was also established using DSC (190). When the use of thermal analysis in studying chemical reactions of monomeric organiccompounds is being considered thereview by Briehl and Butenuth (191) should be consulted. Typical studies of recent origin includes thermal analysis of inclusion compounds of truns-9,lO-dihydroxy-9,lO-diphenyl9,lO-dihydroanthracene with acetonitrile, and 3-hydroxypropionitrile (192). Simultaneous TG-DSC measurements on some a-amino acids have been reported (193). The various decompositions reported involved loss of ammonia, water, carbon dioxide, ethyl alcohol, or various combinations of these gaseous species, depending on the starting material. In the decomposition of 2,5-dihydrothiophene- 1,l -dioxide and its derivatives a single-step degradation is seen with loss of S02. The kinetics of this degradation from the liquid phase is reported by Couture et al. (194). The synthesis of polymeric materials can be monitored by use of thermal analysis. Usually this is by characterization of products (195). A combination of DSC, TG, and T G / I R was used to characterize the preparation of copolymers of 2-sulfoethyl methacrylate and methyl methacrylate (196). T G and DSC studies were part of the study investigating the preparation and thermal properties of copolymers of acrylonitrile with resins of furfuryl alcohol (197). Another example of the use of thermal analysis occurred in the report Analytical Chemistry. Vol. 66, No. 12, June 15, 1994
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of the synthesis, properties, and photocuring behavior of poly (2-acrylamidoanthraquinone) (198). Cheng et al. (199)used TG-MS to study organosoluble segmented rigid-rod polyamide films. Some detailed studies on the kinetics of polymerization have been reported involving nonisothermal thermal analysis techniques (200, 201). It will be apparent that in the polymer field the use of thermal analysis is to characterize the material, either the reactant or products of a reaction. Thus the performance of Se as an antioxidant for high-density polyethylene could be investigated by isothermal chemiluminescence and by T G (202). In attempts to characterize linear low-density polyethylene, it was concluded that under the appropriate conditions DSC studies yielded parallel information to that from temperature rising elution fractionation (203). Aging characteristics in a polycarbonate were investigated by DSC (204). Thedetermination of theglass transition point ( Tg)in polymers attracts attention. If one is concerned with the elimination of the prehistory, then it is best done in the cooling mode. However, judging from the majority of publications, it is utilized as a tool to characterize the prehistory that has been built into the solid phase. The determination of the Tgpoint is a prominent feature in studies on films of polymers (205, 206). In one study the Tgpoint was determined from oxygen permeability measurements (207). Strain-induced crystallization of poly(ethy1ene terephthalate) was studied by various techniques including thermal analysis (208) Thermal degradation of polymers can take place by chain stripping when the product is a carbonaceous material, by depolymerization, or by extensive-cross linking. The degradation of vinylidene chloride-methyl acrylate copolymers in the presence of amines has been reported (209) and also in the presence of radical scavengers. McNeill and Liggat incorporate thermal volatilization techniques into their studies on styrene-methacrylic acid copolymers (210), poly(methy1 methacrylate)-poly(4-bromostyrene) blends and methyl methacrylate4bromostyrene copolymers and blends of polystyrene and poly(4-methoxystyrene) with Bisphenol A polycarbonate (211). N a m and Seferis (212) have presented a model for a generalized composite degradation kinetic scheme for polymeric systems under isothermal and nonisothermal conditions. In the case where extensive cross-linking occurs, DSC is an effective technique. The characterization of cure resins by DSC is described by Richardson (213). The toughening of epoxy resins with polyepichlorohydrin was studied using thermal analysis techniques (214). Peters and Still (215) found extensive cross-linking in the thermal degradation of poly(pheny1ene sulfide) under vacuum at above 450 OC. The presence of additives effect the cure as was shown by Kruger and McGill(216) in a study of the cis-1,4-polyisoprene-sulfur tetraethylthiuram disulfide-zinc oxide-stearic acid system. The most common composites comprise carbon blacks and elastomers. A temperature jump method was used to follow the gasification in air of carbon black in such systems and establish the Arrhenius parameters (217). Ahn et al. (218) used thermoanalytical measurements on commercially available carbon-fiber-epoxy prepreg systems to examine changes caused by aging. A general method of analysis consists of treating an elastomer-carbon system by T G A in nitrogen to determine plasticizer and polymer content. A change in I
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atmosphere to air then allows the carbon black content to be determined (219).
BIOLOGICAL, MEDICAL, AND PHARMACEUTICAL STUDIES New chemical agents have been described to vitrify organs for the purpose of preserving them a t low temperatures. A problem is to avoid crystallization during rewarming after vitrification. This has lead Mehl (220) to study glass transitions and crystallization in ethylene glycol-water and water-l,2-propanedial systems. DSC was also used in studying frozen sucrose and glycerol solutions (221). Studies on sustained release from tablets where thermal analysis was used to characterize the drug have been reported (222). In another study on tablets, the behavior of aspirin in the presence of excipient and moisture was established (223). Complex lipids form the membranes around body cells and around small structures inside the cells. Phospholipids containing a n alcohol, fatty acids, and a phosphate group and glycolipids containing carbohydrates have attracted several studies involving thermal analysis. These include studies on phosphatidylcholines containing terminal acryioyl, methacryloyl, and sorbyl groups (224),adsorption rates of phospholipid vesicles a t temperatures near the gel to liquid crystalline phase transition (225),and studies on phospholipid vesicles as drug delivery systems (226). Cholesterol is the most abundant steroid in the human body. The determination of cholesterol, calcium carbonate, and calcium oxalate in gallstones by thermal analysis forms the subject of several studies (227, 228). In another study, the connection between crystalline cholesterol monohydrate and gallstones was discussed (229). DSC was also used to study the effect of cholesterol and cholesterol esters on the enthalpy of phase transitions and the size of the cooperative unit for the pretransition of dimyristoylphosphatidylcholine membranes (230). In a study on cold destabilization of enzymes, Hatley and Franks (231) used DSC toestablish the heat capacities of thenative and denatured proteins in the undercooled solution. The use of DSC in studying the effects of amino acid replacements on thermally induced unfolding of proteins has been published (232). Other studies on thermal unfolding of proteins have also appeared which involve thermal analysis (233, 234). A new method of investigating the D N A melting process based on thermal conductivity has been put forward (235). Proteins consist of chains of amino acids. The shorter chains are called peptides, longer ones are polypeptides, and the even longer ones are proteins. However, the terms polypeptides and proteins are used interchangeable. There is an interest in the complexation of peptides with crown ethers as crown ethers can beconsidered as models for macrocyclic antibiotics and enzymes ( 2 3 6 , 2 3 7 ) . Studies on the mechanism and stability of thermal transitions in hair keratin have involved thermal analysis (238). Thermogravimetry can be used in the assessment of water binding in cosmetics (239). Determination of the thermoanalytical characteristics of powders in dental cast investment has involved both T G and DTA (240). Thermal analysis finds use in characterizing food stuffs; these include Australian wines (241), margarine (242), and starches (243) and vegetable oil oxidation (244). Examples of the use of thermal analysis in investigating modified
cellulosic fibers for processing requirements have also appeared (245, 246). The freeze preservation of foods prompted an investigationofthe inhibitionoftheinitialgrowthoficecrystals in hardy winter cereal plants (247). A similar study found that arabinoxylans produced by rye seed interacted with ice, reducing the rate of crystallization (248).
MINERALS AND ENERGY-RELATED TOPICS Many topics on the application of thermal analysis to minerals are examples of characterization, such as bernalite (249) or minerals isolated from meteorites (250). Others studies deal with the synthesis of minerals, such as hematites produced by dehydration of synthetic goethites (251). Dunn and co-workers have studied the oxidation of pyrite in air using FT-IR spectroscopy (252) and extended the study using a wide range of techniques to include the measurement of ignition temperatures on iron and iron-nickel sulfides (253). Changes in morphology and the existence of transitions on aluminas during their rehydration have been followed using TG-DTA (254). Thereare twoprocesses identified bythermal analysis in clays, a dehydroxylation process usually around 500 OC and an exothermic recrystallization process at 1000 OC. Both these temperatures are lowered during a micronization process (255). The effect of a planetary milling treatment on talc has been followed using DTA (256). Pressure-induced disorder in kaolinite shows no differences in DTA studies but does lower the temperature at which dehydroxylation occurs when studied by TG (257). Two papers deal with the aragonitecalcite transformation in limestone (258, 259). Another study deals with the enhancement of the reactivity of calcium oxide produced from limestone by means of hydration-dehydration treatments (260). The modifier content of calcium carbonate fillers can often be determined by thermal analysis (261). Thermal analysis studies on magnesite showed that the particle size was an important parameter (262). The fractal nature in particle size distribution is used in interpretating the decomposition of dolomite (112, 263). Cement is formed by the heating of limestone and clays-the resultant cement clinker is ground with additives and hydrated in situ. One of the products of the hydration is ettringite, the amounts being a function of different water/cement ratios and heat treatment (264). The effect of retarders on the hydration of portland cement is reported by Ramachandran and Lowry (265).The reactivity and composition of cement with condensed silica fume leads to high-strength concrete (266). Superplasticizers are added to the cement in order to allow a lower water/ cement ratio to be used and can be studied calorimetrically (267). There have been several studies reported by Chen et al. (268) on hydration in the system 3Ca0.3A1203.CaS04, 3Ca0.3A1203.BaS04, and 3Ca0.3A1203-SrS04 and the influence of ferric oxide on the properties of this system. Calcium sulfate is used as an additive in cement but has other uses in industry. Thermal analysis is used to characterize a-calcium sulfate hemihydrate and monitor its morphology under atmospheric conditions (269) and also to follow the other conversions of gypsum and phosphogypsum (270).The sulfation of high-purity limestones under simulated pressurized fluidized-bed combustion is reported by Krishnan and Sotirchos (271).
There is a review on the use of a derivative T G technique for fuel combustion studies (272). The calorific values of coals have been determined by DTA (273). Other thermal analysis techniques were used in investigations dealing with solvent swelling of the coal (274). T G and DSC techniques have also been used to characterize peats (275). A new technique-proton magnetic resonance thermal analysis of coals-has been reported (276). A combination of thermomechanical analysis and viscometric properties of motor oils at low temperatures is reported (277). Cyclicvoltametry and DSC were used in a study of amine antioxidants for lubricating oils (278). Millington et al. (279) used thermal analysis techniques to obtain information relevant to in situ combustion processes for enhanced oil recovery. Explosives and energetic materials receive a great deal of attention and typical is the study of Oxley et al. (280) on the thermal stability of ammonium nitrate. Drennan and Brown (281)have reported in depth on the pyrotechnic system of Mn and/or Mo and BaO2 and/or SrO2. There are other studies on pyrotechnic systems, for example, on the titanium-sodium nitrate-allophane system (282).
ACKNOWLEDGMENT The help provided by the Chemical Abstracts Service in providing CA Selects to aid in the literature search is greatfully acknowledged. LITERATURE CITED Morgan, D. J.; Ed. Proceedings of the loth InternationalCongress on Thermal Analysis. Hatfield, UK, Aug 1992; J. Therm. Anal. 1993. 40, VOl. 1, 1-386; VOl. 2, 387-869; VOI. 3, 871-1486. Hill, J. 0.. Ed. For Better Themre1 Analysis and Cdorimetry, 3rd ed.; Internatknai Confederationfor Thermal Analysis, 1991. Riga, A. T., Patterson, 0. H., Eds. Thermhlm. Acta 1992. 212. Castanet, R.. Karmarsln, E., Eds. J. Therm. Anal. 1992, 38. Charsley,I%L., . Warrington, S. B., Eds. ThemlAnnlys/9-Technlpues and Appllcabbns; Spec. pVbllc.-R. SOC.Chem. 1992, No. 117. Kambe, H., Uzawa, T.. Eds. Thermal Analyss, new ed.; KodanshaLtd.: Tokyo, Japan, 1992. Wlnefordner, J. D., Dollimore, D., Dunn, J.. Eds. Treetlse on Analyticel Chemktty, Part I, ThemrelMethods,2nd ed.; Interscience Publication, John Wlley and Sons: New York, 1993 Vol. 13. Smykatzkloss, W., Wame, S. J., Eds. T h e m 1 Analysls in the Geosciences Lect. Notes Earth Sei. 1991, 38. Jankowska, H.; Swlatkowskl, A.; Choma. J. Acthre Carbon Ellis Horwood: New York, 1991. Chvoj, Z., Sestak, J., Trlska. A., Eds. KineticPheseDiegyems;Elsevbr: Amsterdam, 1991. Wachtman,J. B. Chaf8Cterk8t/Ot?of Ma*rterfels:Butterworth-Heineman: Boston, MA, 1993; Chapter 46, p 451. Schlrmer, R. E. Modern Methods of PharmaceutlcalAnal)rsls,2nd ed.; CRC Press: Boca Raton, FL, 1991; Vol. 1, Chapter 8, p 355. Ibar, J. P. Fundementals of ~ISNmuletedCurrentandRelexatlon Map Ana@& SLP Press: New Canaan, CT, 1993. Vanderschueren, J.; Nlezette, J.; Ylanakopouios. G.; Thielen, A. ThermocMm. Acta 1991, 192, 287. Bernes, A.; Chataln, D.; Lacabanne, C. Cabrim. Anal. Therm. 1991, 22, 111. Bernes, A.; Chataln, D.; Lacabanne, C. Thermhim. Acta 1992,204, 69. Saffell, J. R.; Matthiesen, A.; McIntyre, R.; Ibar, J. P. Thermhim. Acta 1991, 192, 243. Ibar, J. P.; Matthiesen, A.; McIntyre, R.; Saffebi, J. R. Annu. Tech. Conf.-Soc. Mast. €ng. 1991, 49, 1655. Ibar. J. P. Polym. €ng. Sei. 1991, 31, 1467. Ibar, J. P. Thermochm. Acta 1991, 192, 91. Crowe, B. S.: Seuerbrunn. S. R. Eur. Pat. Appl. EP 494,492, 1992 U S . Appl. 638,847, 1991. Gill, P. S.; Sauerbrunn, S. R.; Readlng, M. J. Therm. Anal. 1993. 40. 931. Reading, M.; Elliott, D.; Hili, V. L. J. Therm. Anal. 1993, 40, 949. Bahra, M.; Elllott, D.; Reading, M.; Ryan, R. J. Therm. Anal. 1992, 38. 543. Jailut, C.; Lenolr, J.; Bardot. C.; Eyraud, C. J. Membr. Sci. 1992, 68, 271. Wiedemann, H. G.; Bayer, 0. Thermochlm. Acta 1992, 200, 215. Kawiak. T. S W . Consew. 1991. 36, 142.
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Ragai, J.; Sing, K. S. W.; Yates, M. Stud. Surf. Sci. Catai. 1991,62,
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i94j
Adams, J.; Kneller, W.; Dollimore, D. Thermochim. Acta 1992,27 7,93. Adams, J.; Dollimore, D.; Griffiths, D. L. J. Therm. Ami. 1993,40,275. Keattch, C. J.: Dollimore, D. J. Therm. Anal. 1991,37,2089. 2103; 1993,39,97, 755. Wahlbeck, P. G. Thermochim. Acta 1992, 797,469. Gimzewski, E. J. Therm. Anal. 1991,37, 1251. Czarnecki, J. P. US. Patent, 5,055,264, 08 Oct 1991. Lavrenko, V. A.; Tikush, V. L.; Shchur, D. V. Zh. Priki. Khim. (S.-Petersburg) 1991,64,2176. Thompson, R. Q.; Ghadiali, M. J. Chem. Educ. 1993, 70,170. Moore, E. H.; Ahmad, I.; Clark, D. E. Ceram. Trans. 1991,27,675. Tanaka. S.Thermochim. Acta 1992, 198,103; 1992,204,261; 1992, 205, 11; 1992,210,67. Crighton, J. S.; Wilburn, F. W. Thermochim. Acta 1992,203, 11. Flynn. J. H. Thermochim. Acta 1993*277, 129. Patt, M. E.; White, B. E.;Stein, B.; Cotts, E. J. Thermochim. Acta 1992, 797,413. Blankenhorn,K.; Hoehne, G. W. H. Thermochim. Acta 1991, 187,219. Wiedemann, H. G. Thermochim. Acta 1991, 787,245. Tuma, L. Thermochim. Acta 1992,272,179. Takahashi, Y.; Ason, M. Thermochim. Acta 1993,223, 7. Wang, J.; McEnaney, B. Thermochim. Acta 1991, 790, 143. Leskela, M.; Lippmaa, M.; Niinisto, L.; Soininen, P. Thermochim. Acta 1993,274,9. Chung. H. L.; Aldridge, J. C. Anal. Instrum. 1992,20, 123. Liang. T.; Cal, G.: Gao, Y.; Xu, G.; Zhou, Y.; Huadong, H. Xuebao 1991, 17,481. McCiennen, W. H.; Buchanan, R. M.; Arnold, N. S.; Dworzanski. J. P.; Meuzelaar, H. L. C. Anal. Chem. 1993,65,2819. Jansen, J. A. J.; Vander Maas, J. H.; DeBoer, A. Appi. Spectrosc. 1992, 46,88. Mullens, J.; Carleer, R.; Reggers, G.; Yperman, J.; Vanhees, J.; Van Poucke, L.C. Thermochim. Acfa 1992,272,219. Neag. C. M. ASTM Spec. Tech. Pubi. 1991,No. 1736,3. White, G. K. Thermochim. Acta 1993,278,83. Charsley, E. L.; Hill, J. 0.; Nicholas, P.; Warrington, S. B. Thermochim. Acta 1992, 795,65. Earnest, C. M.; Seyier, R. J. J. Test. Evai. 1992,20, 430, 434. Wetton, R. E.; Foster, G.; Corish. P. J. Polym. Test. 1991, IO, 175. Cassel, 8.; Twombly, B. ASTM Spec. Tech. Pubi. 1991, 7736, 108. Tsubakihara, S.;Higashi, K.; Taki, S.; Matsushige, K.; Yasuniwa, Y. M. Polym. J. (Tokyo) 1992,24,777. McGhie, A. R.; Jones, G. K.; Farrington, C.; Paul, E. ASTM Spec. Tech. Pubi. 1991,No. 7136, 129. Charsiey. E. L.; Laye, P. G.; Richardson, M. Thermochim. Acta 1993, 276,331. Hohne, G. W. H.; Schawe, J.; Schnick, C. Thermochim. Acta 1993, 227, 129. Edwards, J. G. Thermochim. Acta 1992,270,273. Wldmann, G.; Scherrer, 0. J. Therm. Anal. 1991,37, 1957. Calvet, T.; Tauler, M. A.; Cuevas-Diarte, M. A,; Housty, J. R.; Mondleg D., Haget, Y.; Van Miltenburg,J. C. Thermochim. Acta 1992,204,271. Brozena, A.; Fielder, D. Thermochim. Acta 1992,212,63. Contreras, M. D.: Girela, F.; Parera, A. Thermochim. Acta 1993,279, 167. Horrocks, P. J.; Hayes, F. H.; Moulson. N. D. Thermochim. Acta 1992, 204,25. Seifert, H. J. Thermochim. Acta 1993,274,41. Lutz, H. D.; Stelner. H.J. Thermochim. Acta 1992,277,189. Ferrioi, M.; Giudice, M.; Cohen-Adad, M. T.; Foulon, M.; Guinet, Y.; Lebrun, N.; Muller, M.; Bureau, J. C.; El Widadi, J. fluid Phase Equiiib. 1993,86,187. Abood, H. M. A.; Kerridge, D. H. Thermochim. Acta 1992, 798,297. Uram, R.; Edwards, J. G. Thermochim. Acta 1992,204,221. Jungowska, W.; Znamierowski, T. Thermochim. Acta 1992, 798,81. Szuszkiewicz, W. Thermochim. Acta 1992,202,71. Czypinska, G. Thermochim. Acta 1992,202,81. Perry, G. S.;Fletcher, H. Thermochim. Acta 1993,277,277. Fellruer. P.; GabEovg, J. Thermochim. Acta 1992,206,321. Duncan, J. C.; Van de Velde, J. G.; Wetton. R. E. Kautsch. Gummi, Kunstst. 1991,44,768. Wetton, R. E. Eur. Po/ym. J. 1993,29, 131. Sutton, R. J. Chem. SOC., faraday Trans. 1991. 87,3747. Varma Nair, M.; Jin, Y.; Wunderlich, B. Polymer 1992, 33,5272, LeParlouer, P. Thermochim. Acta 1991, 192,55. Calianan, J. E.;McDermott, K. N.; Weir, R. D.; Westrum, E. F., Jr. J. Chem. Thermodyn. 1992,24, 233. Biandamer, M. J.; Briggs, B.; Brown, H.; Rowan, H.; Burgess. J.; Butt, M. D.; Cuiiis, P. M.; Engberts, J. B. F.N. J. Chem. Soc., Faraday Trans. 1992,88,979. Furman, I.; Butcher, R. J.; Catchings, R. M.; Weiss, R. G. J. Am. Chem. SOC.1992, 174,6023. Deng, Y.; Yu, G. E.; Price, C.; Booth, C. J. Chem. SOC.,Faraday Trans. 1992,88,1441. For a review of this see: Brown, M. E.; Dollimore. D.: Galwey, A. K. Comprehensive ChemicaiKinetics, Vol. 22, Reactionsin the Solidstate; Elsevier: Amsterdam, 1980. Sharp. J. H.; Brindiey, G. W.; Narahaki Achar, B. N.J. Am. Ceram. SOC. 1966,49,379. Dollimore, D. J. Therm. Anal. 1992,38, 111. Flynn, J. H. Thermochim. Acta 1992,203,519. Ozawa, T. Thermochim. Acta 1992,203, 195. Koch, E. Thermochim. Acta 1992,203,43. Dollimore, D. Thermochim. Acta 1992,203,7.
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Dollimore, D.; Evans, T. A.; Lee, Y. F.; Pee, G. P.; Wllburn, F. W. Thermochim. Acta 1992, 796,255. Doliimore, D.; Evans, T. A.; Lee, Y. F.; Wllburn, F. W. Thermochim. Acta (96) 1992, 798,249. Gao, X.; Chen, D.; Doilimore, D. Thermochim. Acta 1993,223, 75. Mllitky, J.; SestBk, J. Thermochim. Acta 1992,203,31. Chen, D.; Gao, X.; Dollimore, D. Anal. Instrum. 1992,20, 137. G o , X.; Chen, D.; Dollimore, D. Thermochim. Acta 1993,215,83, 97, 119, 133; 1993,227, 1. Chen, D.; G o , X.; Doilimore, D. Thermochim. Acta 1993,215, 109. Urbanovici, E.; Segal, E. Thermochim. Acta 1992,203, 153. Urbanovici, E.; Segal, E. J. Therm. Anal. 1992,38,721. Popescu, C.; Oprea. C.; Popescu, M.; Segal, E. Thermochim. Acta 1992. 249. .- - -, 797. .- . , . .. Ceipidor, U. B.; Bucci, R.; Magri, A. D. Thermochim. Acfa, 1992, 799, 77, 85; 1992,203, 137. Vyazovkin, S. V.; Lesnikovich, A. I.Thermochim. Acta, 1992,203, 177. Vyazovkin, S. V. Thermochim. Acta 1992,277,161. Vyazovkin, S.V.; Levchik, G. F.; Goryachko, V. I.; Vyazovkina, A. I.; Lesnikovich, A. I. Thermochim. Acta 1993,275,315. Kim, E. H.; Park, J. J.; Park, J. H.; Chang, I. S.;Choi, C. S. Thermochim. Acta 1992, 796,495. Orfao, J. J. M.; Figueiredo, J. L. Thermochim. Acta 1993,277, 151. Mianowski, A.; Radko, T. Thermochim. Acta 1992,204,281. Ozao, R.; Ochiai. M. Thermochim. Acta 1992,208, 161. Aggrawal, R. K. Thermochim. Acta 1992,203,93, 111. Malek,J.; Sestak, J.; Rouquerol, F.; Rouquerol, J.; Criado, J. M.; Ortega, A. J. Therm. Anal. 1992,38, 71. Criado, J. M.; Ortega, A.; Gotor, F. J. Thermochim. Acta 1992,203, 187. Zhengyuan, Y.; Rongzu, H.; Yi, X. Thermochim. Acta 1992, 795,157. Malek, J.; Criado, J. M. Thermochim. Acta 1992,203,25. Bezjak. A.; Tkaltec, E.; Ivankovic, H.; Eres, M. Thermochim. Acta 1993,227,23. Marcus, K.; Ball, A.; Allen. C. Wear 1991, 757,323. Gaffet. E.; Faudot, F.; Harmelin, M. OrderingandDisordering in Alloys (Proc.Eur. WorkshopOrderingDlswd.)Yaarl,A. R.. Ed.; Elsevier: London, 1992; p 423. Eckert, J.; Holzer, J. C.; Krill, C. E., 111; Johnson, W. L. J. Mater. Res. 1992, 7, 1751. Narasimharao,D.; Babu, S. V.; Rasmussen, D. H. J. Mater. Res. 1992, 7, 1104. Grynszpan, R. I.; Chassaing, E.; Harmelin, M. Mater. Sci. Forum IS92, 105-1 10 (Positron Annihilation, Pi 2), 1037. Mllmar, S.; Harmelin. M. Thermochim. Acta 1992,204,45. Mlbmar. S.;Bonneaux,J.; Harmelin, M. Thermochim. Acta 1993,277, 231. Mllmar, S.;Harmelin, M. J. Non-Cryst. Solids 1993, 753-154, 494. Gaffet, E.; Harmelin, M.; Faudot, F. J. Alloys Compd. 1993, 794,28. Faudot, F.; Gaffet, E.; Harmelin, M. J. Mater. Sci. 1993,26,2669. Clavaguera, M.; Surinach, S.; Baro, M. D.; Otero, A,; Ciavayuera, N. Thermochim. Acta 1992,203,379. Surinach, S.;Baro, M. D.; Diego, A.; Clavaguera, N.; Ciavaguera-Mora, M. T. Acta Metail. Mater. 1992, 40,37. Mukdeeprom-Burckel,P.; Edwards, J. G. Thermochim. Acta 1993,213, 47, Brown, M. E.; Galwey, A. K.; Po, A. L. W. Thermochim. Acta 1992,203, 221; 1993,220, 131. Tanaka, H.; Koga, N.; Sestak J. Thermochim. Acta 1992,203,203. Koga, N.; Tanaka. H. J. Therm. And. 1993,40, 1173. Koga, N.; Tanaka, H. Thermochim. Acta 1993,224, 141. Galwey, A. K.;Mohamed, M. A. Thermochim. Acta 1993,273,279. Mohamed, M. A.; Galwey, A. K. Thermochim. Acta 1993,217,263. Dollimore, D.; Evans, T. A.; Lee, Y. F. Thermochim. Acta 1992, 194, 215. Selcuk, A.; Price, D. Thermochim. Acta 1992,209, 195. Masuda, Y.; Hirata, K.; Ito, Y. Thermochim. Acta 1992,203,289. House, J. E., Jr.; Goerne, J. M. Thermochim. Acta 1993,275,297. Strydom, C. A. Pretorius, G. Thermochim. Acta 1993,223,223. Allan, J. R.; McIoy, B.; Paton. A. D.; Smith, W. E.; Gerrard, D. L. Thermochim. Acta 1992, 798,219, 229; 205, 127. Allan, J. R.; Gardner, A. R.; McCloy, B.;Smith, W. E. Thermochim. Acta 1992,208,107, 115, 125. Allan, J. R.; McCioy, B. Thermochim. Acta 1992,271,85; 1993,274, 219. Ailan, J. R.; Beaumont, P. C.; Milburn, G. H. W.; Wood, I.Thermochim. Acta 1993,274,241; 1993,279, 159. Ailan, J. R.; McCloy, B.; Paton, A. D. Thermochim. Acta 1993,214,211. Allan, J. R.; Paton, A. D. Thermochim. Acta 1993,274,227, 235. Ailan, J. R.; McCoy, €3.; Gardner, A. R. Thermochim. Acta 1993,274, 249. Allan, J. R. Thermochim. Acta 1992,200,355. Peascoe, R.; Clearfield, A. J. Solid State Chem. 1991,95,289. Wang, J.; Tian, Y.; Wang, R. C.; Clearfield, A. Chem. Mater. 1992,4, 1276. Hall, G.; Sutcliffe, H. Thermochim. Acta 1992,205,323. Mingos, D. M. P.; Baghurst, D. R. Chem. SOC.Rev. 1991,20, 1. Moore, E. H.; Clark, D. E . Ceram. Eng. Sci. Proc. 1992, 73, 1081. Beck, D. D.; Siegel. W. S. J. Mater. Res. 1992, 7, 2840. Hua, D. W.; Smith, D. M. Langmuir 1992,8,2753. Kim, M. J.; Matijevib, E . J. Mater. Res. 1992, 7,912. Gaiwev, A. K.; Fakiha, S. A. A.: Abd El-Salaam, K. M. Thermochim. Acta 1992,206,297. Fagan, J G.; Amarahoon, V. R . W. Am. Ceram. SOC.Bull. 1993, 72, 69 (95)
Deb, K. K.; Hill, M. D.; Kelly, J. F. J. Mater. Res. 1992, 7, 3296. Dum, P. K.; Oallagher, P. K. Twu, J. Chem. Mater. 1992, 4, 647. Pfaff, G. J. Mater. Chem. 1992, 2, 591. Crlado, J. M.; Dianaz, M. J.; Gotor, F.; Real, C.; Mundi, M.; Ramos, S.; Del Cerro, J. F e r r w k t r . Len. Sect. 1992, 74, 79. Khabulla, F.; Phuie, P. P. Mater. Scl. €ng. B 1992, 872, 327. Selvaraj, U.; Rasadarao, A. V.; Komarnenl, S.; Brooks, K.; Kwtz, S. J. Mater. Res. 1992, 7, 992. Jondo, T. K.; Abraham, R.; Cohen-Adad, M. T.; Jorda, J. L. J. Alloys Compd. 1992, 766, 347. Dyer, A.; Saghal, M. A. Thermochlm. Acta 1992, 795, 105. Yu, B. L.; Dyer, A.; Enamy. H. The”.Acta 1992. 200, 299. Dyer, A.; Aminl, S.; Enamy, H.; El-Naggar, H. A,; Anderson, M. W. Zeolites 1993. 73. 281. Adrlan. F. J.; Cowan, D. 0. Chem. Eng. News. 1992, (Dec 21), 24. Izuml, T.; Nakamura, Y.; Sung, T.; Shiohara, Y. J. Mater. Res. 1992, 7, 801. Ward, T. L.; Kodas. T. T.; Carlm, A. H. J. Mater. Res. 1992, 7, 827. Rwlch, M. W.; Llu, Y. P.; Ibechem. J.: Hackev. J. P. J. M t e r . Res. 1993, 6, 1487. Yang. Y. X.; Howson, M. A.; Mllne, S. J. J. Non-Cryst. SdMs, 1992, 747, 715 .
Moiseev. G. K.; Zaltseva, S. I.; Sestak, J.; Vatolln, N. A. ThermOChlm. Acta 1993, 276, 301. Ponnosamy, D.; RavKhandar, K. J. Mater. Res. 1992, 6, 268. Pecina. A.; Haerdtl, K. H. Mater. Len. 1993, 76, 61. Krauns, C.; Krebs, H. U. Z. physlca B 1993, 92, 43. Keto, M.; Kojima, N.; Yoshlmura, K.; Ueda, Y.; Nakayama, N.; Sosuge, K. J. SolM State Chem. 1993, 703. 253. Won@@,W.; Chlang, C. K.; Frelman, S. W.; Cook, L. P.; Hili, M. D. Am. Ceram. Soc. Bull. 1992, 77, 1261. Gallagher. P. K.; Zhong, 2.; Twu, J.; Kane, S. M. Trends Anal. Chem. 1991, 70, 279. Wiedemann, H. 0.; Bayer, G. Thermochlm. Acta 1993, 274, 214. Saxby, J. D.; Chatfield, S. P.; Palmlseno, A. J.; Vassaib, A. M.; Wilson, M. A.; Pang, L. S. K. J. phys. Chem., 1992. 96, 17. Gallagher, P. K.; Zhong, Z. J. Therm. Anal. 1992, 36, 2247. Putlvlskll, V. V.; Mllner, A. A.; Zapoiskii, A. K. Svedrhtverd. Mater. 1992, 30. Sun, Q.; Alam, M. J. Elstrochem. SOC. 1992, 139, 933. Sbirrazzuoli, N.; Glrault, Y.; Elegant, L. 7lWmochlm. Acta 1992, 202, 233; 270, 223. Gonthler-Vassal, A.; Szwarc, H.; Romain, F. Themrochim. Acta 1992, 202, 87. Hammami, A.; Mehrotra, A. K. Thermochlm. Acta 1992, 277, 137. Briehl, H.; Butenuth, J. Themchlm. Acta 1990, 787, 249. Caira, M. R.; Nassimbeni, L. R.; Schubert. W.4.; Toda, F. Thennochlm. Acta 1992, 206, 205. Rodante, F.; Marrosu, 0.; Catalanl, G. Themrochlm. Acta 1992, 794, 197. Couture, A.; Grandclaudon, P.; Ivan, L.; Harasim. I.; Segal, E. Thermochlm. Acta 1992, 796, 247. Lu. S.; Pearce, E. M.; Kwel, T. K. Macronwkubs 1993, 26, 3514. Hurley, S. L.; MMleman, M. L.; Wilkle, C. A.; Polym. Degrad. Stab. 1993,
-0.9-, .Id5 - .-.
Fawcett, A. H.; Surgenor, A. E.; Bashlr. 2.; Lltchfleld, R. E.; Todd, N. G. Polymer 1992. 33, 5282. Allen, N. S.; Hurley, J. P.; Rahman, A.; Follows, G. W.; Weddell, I Eur. Polvm. J. 1903. 29. 1155. ciGng,s. z. D.:HSU, s. L. c.; ~ e e c. , J.; arris. F. w.; ~ a u s. , F. pdymer 1992, 33, 5179. Barlkanl. M.;Babe-Naalbandi, A.; Ahmadl, A. IranJ. Polym. Scl. Techno/. (Pefsian Ed.) I99 1, 4, 186. FillpovlE, J. M.; Petrovk-Djakov. D. M.; Vrhovac, L. P.; Velickovic, J. S. Thermhim. Acta 1992, 205, 139. Scheirs, J.; Peletyckl,0.; Bigger, S.W.; Billingham, N. C. Polym. Degrad. Stab. 1992, 36, 23. Karbashewski.E.; Kale, L.; Rudin, A.; Tchir, W. J.; Cook, D. G.; Pronovost, J.O. J. Appl. Polym. Scl. 1992, 44. 425. Nalrn, K. M.; Waliers. R. L.; Simon, G. P.; Hill, A. J. Mater. Forum 1992, 76, 167. Wel, Y.; Jang, G. W.; Hsueh, K. F.; Scherr, E. M.; MacDlarmld, A. C.; Epstein, A. J. Polym. 1992, 33, 314. Prime, R. B. Polym. Eng. Scl. 1992, 32, 1286. Compan, V.; Lopez, M. L.; Monferrer, L. Polymer 1993, 34, 2971. Jabarln. S. A. Polym. Eng. Scl. 1992, 32, 1341. Howell, B. A.; Delney, M. F.; Rajaram, C. V. Thefmochlm. Acta 1992, 272. 115. McNelli, I. C.; Llggat, J. J. Polym. m a d . Stab. 1992, 36, 291. Rincon, A.; McNeili, I. C. Polym. &grad. Stab. 1993, 40. 125, 343. Nam, J. D.; Seferis, J. C. J. Polym. Scl., Parl B Polym. phys. 1992, 30, 455. Richardson, M. J. Pwe Appl. Chem. 1992, 64, 1789. Jackson, M. 6.; Edmond, L. N.; Varley, R. J.; Warden, P. G. J. Appl. Polym. Scl. 1993. 46, 1259. Peters, 0. A.; Stili, R. H. Pofym. -rad. Stab. 1993. 42, 41, 49. Kruger. F. W. H.; McGiil, W. J. J. Appl. Polym. Scl. 1992, 44, 581, 45, i KAK ,171.
Azizl, J. A.; Dolllmore, D.; Dollimore, P. J.; Heel, G. R.; Maniey, P.; Kneller, W.A.; Yong, W. J. J. Therm. Anal. 1993, 40, 831. Ahn. K. J.; Peterson, L.; Seferis, J. C.; Nowacki. D.; Zachmann, H. G. J. Appl. Polym. Scl. 1992. 45, 399. Sichlna, W. J. Am. Lab. 1993, 45. Mehl, P. M. Thermochlm. Acta 1992, 203, 475; 1993, 273. 177. Stephen, A.; Issard, M. J.; Lllltord, P. J. J. Chem. Soc.. Farahy Trans. 1992, 66, 789.
Yuasa, H.; Ozekl, T.; Kanaya. Y.; Olshi, K. Chem. Fhafm. BuU. 1992, 40, 1592. Qupchup, 0.; Alexander, K.; Dolllmore, D. ?lhsmo&lm. Acta 1992, 796, 267. Lamparski, H.; Lee, Y. S.; Se1ls.T. D.; O M e n , D. F. J. Am. Chem. Soc. 1993, 775, 8096. Weldmann, T. S.; Cheng, S. M. J. CcflMInterfece Sci. 1991, 747,531. LaRosa, C.; &asso, D.; Fresta, M.; Venture, C.; Pugiisl, G. Thennochm. Acta 1992, 195, 139 798, 181. Alexander,K.S.;DoYirore,D.;Dunn,J.G.;Gao,X.;Patel,D.~, Acta 1993, 275, 171. Campanella, L.; Cardarelll, E.; Cwninl. R.; DAscenzo, 0.; Tomaaseltl, M. J. Therm. Anal. 1992, 36, 2707. Wada, Y.; Igiml, H.; Uchida, K. Thermochkn. Acta 1992, 270, 233. Maicolmson. R. J.; Beswlck, P. H.; Highinboltham, J.; Prlvat, P. 0.; Saunler, L. Blochem. Soc. Trans. 1992, 20, 3495. Hatley, R. H. M.; Franks, F. FaradayD&cuss. 1992, 93, 249. Tanaka, A.; Kbmura, S. Sebutsu Buts& 1992, 32, 110. Johnson, C. M.; Cooper, A.; Stockley, P. 0. Bbchemkby 1992, 37, 9717. Tanaka, A.; Flanagan, J.; Sturtevant, J. M. Froteln Sd. 1998, 2, 507. Tullszka. M.; Jaroszyk, F. nmwnochhn. Acta 1992, 794, 67. Lipkowksi, J.; Kuilkov. 0. V.; Zlelenklewicz, W. W.Chem. 1992, 7, 73. Kulikov. 0.V., Zlelenkiewicz, W.; Utzig, E.; Krestov, G. A. Thermodlm. Acta 1993, 273, 103. Milczarek, P.; Zlellnski, M.; Garcia, M. L. Col/o&fPo&m. Scl. 1992,270, 1106. Fuehrer, C.; Welssbarth, M. Parfwm, Kosmet. 1992, 73, 220, 226. Wakasa, K.; Yamaki, M. J. Mater. Scl.: Mater. Med. 1992, 3, 141. Hill, J. 0.; Korce, S.; Lim, S.; Scollary, G. R. Thermhlm. Acta 1992, 209, 30 1. D’Souza, V.; DeMan, J. M.; DeMan, L. J. Am. Oil Chem. Soc.1992, 69, 1198. Gorinstein, S.; Lii. C. Starch/Staeuke 1992, 44, 461. Kowalskl, B. Pol. J. Food N&. Scl. 1992, 7, 51. Rensch, H.-P.; Riedl, B. Thermochlm. Acta 1992, 205, 39. Saikla, C. N.; Dutta, N. N.; Borah, M. Thennochlm. Acta 1993, 279, 191. O h , R. Thermochlm. Acta 1992, 272, 255. Willlams, R. J. Thermochlm. Acta 1992, 272, 105. Birch, W. D.; Prlng, A.; Reller, A.; Schmalle, H. Natvwlssenschaften 1992, 79, 509. Wiedemann, H. G.; Reller, A. Naturwksenhften 1992, 79, 172. DaCosta, 0. M.; DeJesus Filho, M. F. J. M a w . Scl. 1992, 27, 6116. Dunn, J. G.; Gong, W.; Shl, D. Thermochlm. Acta 1992, 208, 293. Dunn, J. G.; Mackey, L. C. J. Therm. Anal. 1991, 37, 2143. Jaworska-Galas, 2.;Janlak, S.; Mista, W.; Wrzyszcz, J. Zawadzki, M. J. Mater. Scl. 1993, 26, 2075. Mlbsevlc,S.; Tomasevlccanovic, M.; Dlmlbijedc, R.; Petrov, M.; DjulEIC, M. Ceram. Bull. 1992, 7, 771. Aglietti. E. F.; Porot, L.; Jose, M. Mater. Res. Bull. 1992, 27, 1205. LaIgbsia, A. Clay Mlner. 1993, 26, 311. Baumer, A.; Ganteaume. M.; Gernat, M. Thennochlm. Acta 1993,227, 255. Peric, J.; Kristulovic R.; Feric, T.; Vucak, M. Thennochm. AcM 1992, 207, 245. Watanabe, T.; Hayashl, M.; Matsude, H.; Hasatanl, M. Kageku Ko&u Ronbunshu 1993, 79, 91. Luehr, J.; Janowskl, F. Angew. Makromol. Chem. 1993, 205, 1. Sheila, D. J. Mlner. Process 1993, 37, 73. Ochiai, M.; Ozao, R. Thernwchlm. Acta 1992, 796, 279. Sledel, H.; Hempel, S.; Hempel. R. Cem. Concr. Res. 1993, 23, 453. Ramachandran, V. S.; Lowry, M. S. 7?wmocMm. Acta 1992, 795,373. Justnes, H.; SellevoM, E. J.; LundevaH, 0. Am. Concf. Inst., SP 1993, SP- 732(Fly Ash, Silica Fume, Slag, Net. PozzolansConcr., Voi. 2), 873. Simard, M. A.; Nkinamubanzi, P. C.; Joiicoew. C.; Penaton, D.; Aitcln, P. C. Cem. Concr. Res. 1993, 23, 939. Chen, D. Feng, X.; Long, S. Thennochim. Acta 1992, 796,313 1993, 275, 143, 157. Yasue, T.; Kojlma, Y.; Kishimoto, Y.; Arai, Y. m u m L l m 1992, 239, 230. Olmez, H.; Icbudak, H.; Yiimax, V. T. Turk. J. Chem. 1992, 76. 128. Krishnan, S. V.; Sotlrchos, S. V. Can. J. Chem. Eng. 1993, 77, 244. Norton, G. A. Thermochlm. Acta 1993, 274, 171. Munoz-Guillena, M. J.; Linares-Solano. A.; Sallnaa-Martlnez de Le-, C. Fuel 1992, 77, 579. Yun, Y.; Suuberg, E. M. Fuel 1993, 72, 1245. Bergner, M. K.; Albeno, C. Anal. Chem, 1993, 65, 204. Sakurovs, R.; Lynch, L. J.; Barton, W. A. A&. Chem. Ser. 1993. No. 229 (Magnetic Resonance of Carbonaceous Soilds), 229. Riga, A. T. Thennochlm. Acta 1992, 206, 95. Lege, P. 0.;Rose, D. J.; Taylor, N. Thmmxhlm. Acta 1992, 206, 95. Mllllngton, A.; Price. D.: Hughes, R. J. Therm. Anal. 1903, 40. 225. Oxley, J. C.; Kaushik, S. M.; Qilson, N. S. 7h”ochlm. Acta 1992,272, 77. Drennan, R. L.; Brown, M. E. Ttwnwchim. Acta 1992,206,201, 223, 247. Emmott, P.; Grifflths, T. T.; Queay. J.; Charlsey, E. L.; Warrlngton. S. B. Roc. Int. Pyrotech. Semln. 1992, IM, 221.
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