Anal. Chem. 1996, 68, 63R-71R
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 Literature Cited
63R 64R 64R 65R 66R 67R 68R 68R
The publications that appear in Chemical Abstracts Thermal Analysis (CA Selects) from October 1993 to October 1995 are highlighted in this present review. The number of special publications, and the total number of publications on the topic, make it certain that some contributions to thermal analysis have escaped the present reviewer’s attention. Apologies for this type of omission are offered. It should also be remembered that however strict a discipline an author imposes upon himself, a certain bias in selection manifests itself and this must be true for the present article. An extremely useful textbook on thermal analysis has been authored by Haines (1). Other books include Calorimetry and Thermal Analysis of Polymers (2), Assignment of the Glass Transition (3), and Special Trends in Thermal Analysis (4). This latter book deals almost exclusively with the derivatograph and contains an appendix of almost all the publications in which the derivatograph is used. There have been several special publications in honor of the following people: Galway (5), Slade Warne (6), Wiedemann (7), and Lamprecht (8). Other journal publications present papers that formed part of various conferences and these include the NATAS conference at Denver (9), papers presented at the 13th International Conference on Chemical Thermodynamics (10), the 14th Nordic Symposium (11), the III Sino-Japanese Symposium (12), the symposium on Solution Chemistry, Thermodynamics, Thermochemistry and Thermal Analysis (13), the 6th Polish Conference on Calorimetry and Thermal Analysis (14). There are also special issues of journals devoted to certain aspects of the topic, such as pharmaceuticals (15), material science (16), and the environment (17), and on the application of thermal analysis and calorimetry in polymer physics (18). These special publications contain many significant research articles, and the reader interested in any particular topic is recommended to read the appropriate volume. Thermal analysis has been used to study artistic materials (19) and especially the binding media of samples from paintings (20). A microcalorimeter was used to study honey and wax which played an important role in ancient Egypt (21). Other historical studies deal with the details of the early commercial thermogravimetry balance in the U.K. (22), on the vacuum microbalance (23), and on gravimetric hygrometers (24). Thermal analysis is also finding application in studies concerned with space exploration. There are studies on Mars soil analogs (25). There is also S0003-2700(96)00006-6 CCC: $25.00
© 1996 American Chemical Society
a DSC study on the ammonia-water system in connection with problems in the outer solar systems (26). INSTRUMENTATION A new high-temperature differential thermal analysis unit (DTA) (27) and a differential scanning calorimeter (DSC) specially designed to study composite materials (28) are described. A new development is the reporting of DTA results using a single-pan, single-thermocouple signal (29). Contributions to the theory of power-compensated DSC come from Hohne and co-workers (30, 31), who make a rigorous effort to describe the heat flow as accurately as possible. This has led Schawe to propose a new method to estimate transition temperatures and heats from only one heating run (32). Temperature calibration of DSC units by the use of small quantities of added metals to the sample to serve as internal references is recommended by Tiers (33). One can sense however that alloying might cause a problem or that reaction might occur, so perhaps this method might not be universal in application. However, in DSC, there is a need to calibrate the unit for both heat and temperature. The recommendation of the GEFTA working group on calibration of DSC will remain as an example of a very detailed and reliable exposition (34). Wolf et al. (35) recommend the use of thin-layer platinum resistors to provide temperature sensing and both temperature and enthalpy calibration. Cammenga and Steer (36) make a further contribution to the GEFTA report by noting the influence of temperature, heating rate, mass, and heat capacity of samples on the temperature and heat calibration of DSC, making a comparison between metals and organic compounds for this purpose. Sabbah and Tan (37) propose 14 substances as being suitable for temperature and energy calibration of DTA and DSC in the temperature range 100-300 K. Modulated DSC, in which the usually linear temperature program is modulated by a sine wave and a mathematical treatment is applied to the resultant data to deconvolute the sample response to produce a signal that indicates the reversible processes and another that is due to irreversible processes, is finding considerable attention. It produces a convenient method of measuring heat capacity and the glass transition in polymers (38-43). A critique on modulated DSC is offered by Ozawa and Kanari (44). The principles for the interpretation have been outlined by Schawe (45). High-pressure cells continue to be used or designed for DSC. The usual effect of pressure increase is to cause an increase in the transition or dissociation temperature. In the latter case, this can drive the dissociation temperature up to a temperature beyond that of the maximum working temperature for the DSC unit. Equipment of this kind is described by Rein and Demas (46) in order to investigate liquid crystalline compounds and by Porowski et al. (47) to investigate crystal growth of R-HgS. Water or any other liquid adsorbed in the pores of an adsorbent solid will show a depression of the freezing point from which the pore size Analytical Chemistry, Vol. 68, No. 12, June 15, 1996 63R
distribution can be calculated. The method, using DSC, has been applied to silica gels (48-50). Thermogravimetry (TG) has produced some interesting technical innovations. In one technique, material was condensed onto a quartz crystal microbalance and then subjected to thermogravimetry (51). In another development, the gas is introduced directly to the sample cell (52). Pahlke and Gast (53) describe a new magnetic suspension coupling for microbalances which makes possible TG applications in high-vacuum or in highpressure environments. An economic solution to adapting existing thermobalances to constrained rate thermogravimetry is described (54). The adaptation of a TG balance to measure vapor pressures by noting the evaporation rate is also reported (55). Evolved gas analysis (EGA) is rarely a technique utilized on its own. Mass spectroscopy (MS) is the usual analysis device utilized. Its combination with TG is the subject of a review (56). McGhie (57) uses a heated capillary interface between the TA equipment and the MS unit. Barnes et al. (58) use a system capable of EGA at controlled transformation rate, with stepwise isothermal runs, and on samples subjected to a linear temperature program. Pan et al. (59) have combined TG with gas chromatography (GC), applying the unit to determine the composition of polymeric composites. The determination of evolved water is shown to be possible using a piezoelectric detector (60). Other combinations of techniques have used TG, thermomagnetometry (TM), and DTA techniques to study iron-containing pyrotechnic systems (61). Practical details and application of a TGA/DSC/FT-IR unit are provided by Akinade et al. (62). Other investigators have used FTIR coupled with TG (63, 64), and DSC has also been coupled with FTIR (65). DSC has in addition been successfully coupled with X-ray measurement systems and applied to phase transitions (66, 67). Thermal microscopy has been coupled with DSC by Wiedermann (68) in investigating organic compounds. Acoustic emission has been coupled with DSC or DTA to give information on dehydration (69) and phase transition (70). THERMODYNAMIC MEASUREMENTS The melting point determination in principle is endothermic (with increasing temperature) and is reversible, showing an exotherm (with decreasing temperature). A spread of the melting point endotherm on DSC may appear if the sample is impure. It is possible to determine the percent impurity by calculations based on the spread of the melting point. The method has been applied to pharmaceutical materials (71) such as nifedipine (72). A new method of purity determination is based on the shape of fusion peaks of eutectic systems (73). The DSC method is compared by Giron (74) with other methods of purity determinations. A correction procedure for thermal lag has been introduced (75). In a more general approach, Richardson (76) discusses the derivation of enthalpies, entropies, and free energies of fusion and transition from DSC curves. The melting and recrystallization behavior of quenched ethylene-propylene block copolymer cast film has been reported (77). Some high-temperature work on the fusion enthalpy of silver is reported (78). The use to which the boiling point may be investigated is associated with loss of material from the system. Paulik et al. (79) propose a new method for the microdistillation of liquids using quasi-isobaric thermogravimetry. 64R
Analytical Chemistry, Vol. 68, No. 12, June 15, 1996
The baseline for the DSC experiment is determined by the heat capacity of the system. It is possible to use the DSC data to calculate the variation of the heat capacity with temperature. Flynn (80) has produced a very clear exposition of the methods available to make the calculation, advocating analysis of the heat capacity by integration. A measurement procedure for calculating the heat capacity has been published (81). The heat capacities of long-chain compounds (82), n-perfluoroakanes and poly(tetrafluoroethylene) (83), and cesium and rubidium salts (84) have all been studied using DSC. The glass transition temperature (Tg) is represented as a second-order transition. There are papers on Tg determinations using DSC for aqueous glucose-fructosewater systems (85), on nylon 6 (86), and on acrylic copolymers (87). Amorphous materials undergo exothermic irreversible transitions to a crystalline phase when subjected to suitable heat treatment. An example is to be found in studies on alloys (88). A brief introduction to DSC curves showing all the transitions that can be studied is very useful (89). A full review on thermal analysis and calorimetric methods used in the characterization of polymorphs and solvates has been drawn up by Giron (90). A detailed study of solid-solid phase transitions in lithium sulfate is provided by Tischler (91). The monoclinic-hexagonal phase transition in hydroxyapatite using X-ray studies and DSC (92), and on oxide systems involving crystallization (93), have been reported. There are numerous papers investigating the vapor pressure above a condensed phase by use of Knudren effusion and related studies. Edwards (94) finds that topological catastrophes in an effusion cell can make it difficult to achieve equilibrium in the cell. Materials investigated in these effusion cell techniques include thiourea and four of its dealkyl derivatives (95) and three isomers of iodobenzoic acid (96). The evaporation rate and saturated vapor pressures of various organic materials have been determined using a thermogravimetric balance capable of operating under vacuum conditions (97). A DTA cell suitable for systems with vapor pressures exceeding ambient has been described (98). A high-pressure DTA unit has been used to study phase behavior of pure and gas-saturated liquid crystals (99). DTA analysis finds many applications in constructing phase diagrams of binary systems. Typically, one may quote the study on the CuCl2-KCl system (100), the hydrogen-ice system (101), the p-dichlorobenzene-p-bromoiodobenzene system (102), and liquid gold-antimony alloys (103), but there are many more on this topic. There is a relationship between the peak shape of a DTA curve and the shape of a phase diagram (104). The application of DTA to measure phase changes in condensed systems may be extended to three-component systems. Again there are many papers published on the topic and typical studies include coppertin-lead mixtures (105), LiNO3-KNO3-Sr(NO3)2 (106), the water-glycine-sucrose system (107), and the water-sucroseNaCl system (108). REACTION KINETICS Reaction kinetics can be determined in a series of isothermal experiments. Reduced time plots of fraction decomposed (R) against reduced time (t/t0.5), where t0.5 is the time taken to reach a fraction of 0.5, can be used to identify the isokinetic nature of the isothermal series and the type of kinetic mechanism involved. However, Wilburn and Sharp (109) show that the plots may be
influenced by heat transfer. In a statistical approach to selecting appropriate kinetic equations, Mianowski (110) utilizes the compensation relationship
ln A ) a + bE where A is the preexponential factor and E is the activation energy in the Arrhenius equation (a and b are constants). The models for kinetic rate processes in the solid state were postulated many years ago, and the emphasis now seems to be on recognizing the equation that describes the process seen in the TG curve. Korobove (111) has contributed a significant discussion as to whether the analysis provides meaningful kinetic constants or whether they should be regarded as formal parameters. In any case, the majority of contributions relate to rising temperature methods and this invites the use of nonlinear parameter estimation procedures (112). The studies involving rising temperature kinetics are for some reason usually referred to as nonisothermal kinetics. There are two approaches, one involving the use of differential equations, the other an integral approach. Ceipidor et al. (113, 114) consider the effect of various experimental constraints, operational settings, and equipment features on the Arrhenius parameters. Chen and Dollimore deal with the effect of an inaccurate temperature (115). In a series of papers, Vyazovkin and Linert discuss the reliability of conversion-time dependences (116), the application of the isokinetic relationships (117, 118), the use of isoconversional methods (119), and the kinetic analysis of reversible thermal solid-state decompositions (120). Ozawa and Kanari (121) provide a method for kinetic analysis applicable to competitive reactions. Dollimore et al. (122) have introduced a method that is independent of the Arrhenius parameters and assesses solid-state reactivity on comparing R values of a sample (Rs) against a reference (Rr) value. It is illustrated by reference to sodium bicarbonate. Two methods are described to assess kinetic parameters from DTA and DSC data (123, 124). In controlled rate thermal analysis (CRTA), the rate is controlled while the temperature is varied in order to keep the rate constant. Criado et al. (125) describe a new TG unit capable of performing CRTA under controlled atmospheres at pressures ranging from vacuum to 1 bar. Criado et al. (126) also compare the effect of pressure on the TG and the CRTA trace. In another application of CRTA to the study of microporosity, the thermal desorption of water is described (127). The act of crystallization from an amorphous state is an exothermic irreversible process. It is a process where the crystallization can be measured as a rate process. The measurement of the rate of crystallization by thermal analysis has been applied to metals (128, 129), oxides (130), and polymers (131, 132). Others seek to establish models for the process (133, 134). INORGANIC COMPOUNDS The predominant interest in metal alloys seems to be the recrystallization phenomenon. This has already been mentioned. Other aspects of thermal analysis being applied to metals include a study on the effect of alloy elements and nodular graphites on austenite decomposition of ductile irons during isothermal holding (in the region 250-400 °C) (135), a study on Ag-Ag2O ultrafine particles prepared by sputtering (136), and a DSC study on the nucleation of the R-β and β-R transformations in unalloyed plutonium (137). Hayward et al. (138) used TG to study the
oxidation of uranium in steam. Voitovich et al. (139) used a combination of techniques which included TG to study the effect of impurities on the high-temperature oxidation of hafnium. DSC was used in a study of nanophase Ni3Fe and Fe3X (X ) Si, Zn, Sn) synthesized by ball milling at elevated temperature (140). DTA has been used to show that milling time can affect the activation energy for the reduction on cupric oxide by iron (141). An unusual application is the use of DTA to study reactive melt infiltration of silicon-molybdenum alloys into microporous carbons (142). A model describing the short-range-order anisothermal kinetics in metallic alloys was tested using DSC on R-Cu-Al alloys quenched from different temperatures (143). A study by Illekova et al. (144) on doped Se85Te15 glasses utilized DSC to determine specific heat, enthalpy release on annealing, glass transition, and kinetics of coordination short-range ordering, on the basis of first-order kinetics and a wide spectrum of relaxation times. A study on the solidification and microstructure of eutectic Pb-Sn microsolder beads is presented by Green et al. (145), who employed DSC experiments to reveal supercoolings up to 31 K before solidification. The preparation and properties of borides, carbides, and nitrides have become increasingly important over the last few years because of their commercial exploitation. Jayashankar and Kaufman (146) made a composite of MoS12-SiC by mechanical alloying and used DTA and TG to characterize their samples. A major concern is the oxidation of silicon carbide and a number of publications address this issue (147-150). In another study, Bushnell-Watson and Sharp (151) study the thermal behavior of polymeric precursors for silicon carbide fibers. There is a report of a thermal analysis study on the use of yttrium isopropoxide, utilized as a precursor for yttrium oxide, in aluminum nitride ceramic processing where the oxide acts as a sintering aid (152). In a study on oxy salts, the structure of cesium hydrogen sulfate existing in two phases was confirmed by the use of DSC (153). Lithium sulfate monohydrate, LiSO4‚H2O, has attracted much attention because it was suggested it might serve as a standard for kinetic analysis on thermal analysis equipment. It dehydrates in one step, but the accumulated opinion of many studies seems to be that it should not be regarded as a standard (154-156). The kinetics of the solid-state reduction of sodium sulfate with carbon is reported (157). There are kinetic and morphological studies on nickel sulfate hexahydrate (158), on aluminum sulfate hydrates (159), and on homogeneously precipitated Zr2(SO4)(OH)6‚6H2O (160). Kerridge et al. (161) use TG to study zirconium sulfate in molten alkali nitrates or nitrites. Double sulfates receive much attention. An exhaustive study of Tuttons salts [M12M11(SO4)2‚6H2O] shows two-stage melting with loss of water (162). Studies on KCr(SO4)2‚12H2O and KAl(SO4)2‚ 12H2O deal with the kinetics of dehydration (163). Donova and Koceva describe the synthesis and thermal decomposition of Na2Cd(SO4)2‚2H2O (164). Nitrates act as precursors for the preparation of lead zirconate titanate ceramic powders, and the synthesis involving the EDTAgel method has been investigated (165). Other studies involving nitrates include the combustion of Ti and Zr particles with KNO3 (166) and the thermal decomposition of KNO3‚6H2O (167). Sodium bicarbonate has been studied using various techniques of thermal analysis from a kinetic aspect (122), of kinetics combined with optical microscopy (168), and by a combination of electrical and thermal studies (169). Nickel carbonate precipiAnalytical Chemistry, Vol. 68, No. 12, June 15, 1996
65R
tated under different conditions forms an hydroxy carbonate and has been the subject of thermal analysis investigations in the pure form (170) and in the presence of doped materials (171). The technique of CRTA has been applied to copper hydroxy carbonate (172). It is reported that the decomposition of pure and rhodiumimpregnated cerium(III) carbonate hydrate gives different oxide products in different environmental atmospheres (173). Similar comments about products of thermal decomposition depending on the atmosphere may be made regarding ammonium uranyl carbonate (174). As expected, the water vapor pressure above manganese formate dihydrate decreased the rate of dehydration (175). Zinc formate complex compounds with urea, thiourea, and caffeine were studied using TG and DSC (176). Surface formate decompositions on Cu, CuCl, Cu2O, and CuO were correlated with structural properties (177). In a series of papers on ferric oxalate hydrate, ferrous oxalate dihydrate, and copper(II) oxalate, Mohamed and Galway studied kinetic and mechanistic aspects of the decompositions (178). A similar study is reported by Mansour on nickel oxalate dihydrate (179). It is shown that rare earth oxides have a catalytic effect on the decomposition of barium oxalate (180). It is reported that in the decomposition of calcium oxalate to calcium carbonate in vacuum about 47% of the CO disproportionates into CO2 and C (181). Calcium oxalate dihydrate is reported to be formed in spinach extraction and from urea media (182). Calcium oxalate trihydrate is formed by an homogeneous precipitation method (183). Hussein and co-workers (184, 185) used thermal analysis to study the decomposition of nickel acetate and ammonium ferric citrate hydrate. The kinetics of decomposition of caesium periodate is reported with an activation energy of 226 kJ mol-1 (186). The solid-state reaction between pyridinium chloride and aluminium chloride is reported (187). There are various reports from Allan and colleagues on thermal analysis studies of cobalt(II), nickel(II), and copper complexes of benzylmalonic acid (188), bis[dicarbonyl (πcyclopentadienyl)iron(II)] (189), dichlorohexa(anthranilamide)cobalt(II) and dichloro(anthranilamide)copper(II) (190), and chloro complexes of Co, Ni, and Cu with 3-phenylpyridine (191). All these experiments were tried in an atmosphere of static air. It would be of undoubted interest to investigate the same materials in an inert gassnitrogen or argon. The evaporation rate of oxides from undoped and Sb-doped Si melts under atmosphere of pure Ne, Ar, and Kr is achieved using a TG unit (192). The two steps in the oxidation of UO2+x and the reduction of U3O8 powders observed in DTA studies have been exploited to determine their surface areas (193). The R-β transition in quartz has been used to determine quartz using DSC (194, 195). Dilatometry and DSC were used in the characterization of sintered silica-yttria powders (196). TG and DTA were used to study laser-irradiated CeO2 powders (197) and copper oxides obtained by CO2 irradiation of copper salts (198). It has been shown by TG that manganese dioxides show (a) water loss, (b) dehydroxylation, and finally (c) oxygen release (199). Sulfated zirconia catalysts were characterized by TGA/DTA/MS (200). Microporous zirconia gels have been studied using thermal analysis and shown to possess an exothermic transition associated with the development of crystallinity (201). A finely divided crystalline BaTiO3 powder prepared by spray drying an aqueous solution of Ba(NO3)2, TiO(NO3)2, and alanine has been studied 66R
Analytical Chemistry, Vol. 68, No. 12, June 15, 1996
by TG (202). The melting points of MTiOAsO4, where M is K, Rb, or Cs have been correlated with the ionic radius of the M+ ion (203). ORGANIC AND POLYMERIC MATERIALS In the field of carbon chemistry, a tremendous impetus has resulted in many papers on fullerenes. These are the C60 molecule existing as a spherical moleculesthe aim of most of the work is to characterize the material in the hope of finding commercial use and then to simplify the synthesis and thereby bring the cost down. The reader is advised to read two reviews on fullerenes which put them into historical perspective and outline their synthesis and properties (204, 205). Other review articles deal with phase transitions (206), graphitic nanoparticles (207), carbon nanotubes (208), and shape of fullerenes and related carbon materials (209). Two transitions, at around 250 and 310 K are reported (210). In the lattice structure, there are interstitial volumes between the molecules of C60 and these serve to be locations where gases can be hosted, e.g., oxygen (211). When CO2 was absorbed on the C60 solid under supercritical conditions, there was a significant effect on phase transition at 250 K (212). The increase in mass on initial heating in oxygen of soots from aromatic species is taken to indicate the presence of fulleroid types in these materials on the basis of similar experiments on fullerene (213). It was found that a two-step oxidation in the production of polyacrylonitrile-based carbon fibers doped with 2% sodium acrylate improved the performance of the carbon fiber (214). Thermogravimetric analysis was used to characterize silica-coated carbon fiber used in ultramicroelectrodes (215). The use of a TG unit coupled with a mass spectrometer showed in the gasification of carbons derived from acenaphthylene treated with ammonia that nitrogen was released during the gasification (216). The oxidation of activated carbons by aqueous H2O2 has been studied using a thermobalance (217). It might be thought that simple organic compounds would simply show melting and boiling upon thermal analysis. However, the fusion can be manipulated into a temperature region for consideration as being suitable for energy storage as with p-chloroiodobenzene and p-bromoiodobenzene alloys (218). Howell and Liu (219) studied the thermal decomposition of 2-(4aminophenyl)- and 2-(2,4-diaminophenyl)malonic acids and derivatives using TG. Complexes between sulfathiazole and β-cyclodextrin have been investigated by a combination of X-ray structure studies and thermal analysis (220). The process of grinding in a vibrating mill can transform all or part of an organic system from the crystalline state into an amorphous condition, and DSC is a convenient tool to follow this phenomenon (221). It can also be shown that degradation of an organic material can be significantly altered if it is laid down as a thin film on a solid substrate (222). A TG analysis is suggested as a means of estimating the thermal stability of phenol stabilizers (223). The vast majority of studies on organic compounds involve polymers. There are a number of papers in which thermal analysis has been used to follow polymerization. The synthesis and mesophase characterization of liquid crystalline polyesters has been performed using DSC (224). Phase behavior and transreaction studies of model polyester/bisphenol-polycarbonate blends also involved thermal analysis (225). There are a series of papers by Pearce and co-workers in which DSC was used to identify Tg, crystallization, and the melting point (226, 229).
Khanna and co-workers make the point that the properties measured by thermal analysis are a reflection of the polymer’s processing history (230, 231). Jabarin (232) used DSC to study crystallinity and order development in oriented PVC. Crystal morphology and phase identifications in poly(aryl ether ketones) and their copolymers were made possible by a variety of techniques which included DSC (233). The same group of workers also used DSC to study liquid crystal transitions in poly(ester imides) (234) and thermoreversible gelation in a rigid-rod polyimide-m-cresol system (235). Liu and Harrison introduce a DSC method of measuring short-chain branching distribution in linear low-density polyethylene (236). Huglin and co-workers use DSC to determine bound water in hydrogels (237, 238). The variation in thermal properties of poly(ether sulfone) has been measured using DSC (239). Crighton and Luyt (240) consider methods of inhibiting the reordering of polypropylenes during programmed heating using DTA. The above are examples of using thermal analysis to characterize polymer materials. There are just as many dealing with the degradation of polymers. Two basic mechanisms are quite obvioussnamely, chain striping to a carbon residue or chain scission, i.e., depolymerization. Again only a representative set of examples can be cited. Chain scission has been observed in polypropylene tapes (241), on radiation-induced degradation of poly(3-hydroxybutyrate) and the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (242), and on poly(chlorotrifluoroethylene) and related polymers (243). Examples of chain stripping leaving a carbonaceous residue are the degradation of polyfuryl alcohol (244) and Kevlar Aramid fibers (245). A number of changes in polymers involve cross-linking, and this is generally observed as an exothermic process on DSC. The curing kinetics of a benzoxazine-based phenolic resin by DSC (246) and on epoxides of carbono-and thiocarbonohydrazones (247) are reported. Cross-linking of polychloroprene with ZnO and MgO upon programmed heating has been studied (248). Polymer composites have received some attention. Prof. Seferis, who received the Mettler Award in 1995 for his work in this field, has with his co-workers produced papers dealing with an epoxy alloy containing thermoplastics and a reactive rubber (249), autocatalytic-type thermoset prepreg cures (250), the toughening mechanism of a thermoplastic-modified aryl dicyanate (251), and of bismaleimide resins (252). Other examples of thermal analysis being used in composite study include a study on the compatibility of poly(vinyl alcohol)-silk fibroin blend films (253), and claypolymer nanocomposites formed from acidic derivatives of montmorillonite and an epoxy resin (254). BIOLOGICAL, MEDICAL, AND PHARMACEUTICAL STUDIES In the preparation of pharmaceutical dosage forms there is a need to know whether the drug is compatible with the excipients. Thermal analysis studies play an important role in such investigations. There are such studies on naproxen sodium suppositories (255), on bisoprolol hemifumarate (256), on indomethacin (257), and on ibuprofen and other drugs (258). Other studies involve the application of DSC and TG to assess components in atenolol tablets (259). There are also thermal analysis studies on single drugs and excipients. A detailed study on lactose has been made by Figura and Epple (260), who find an important transition in the dehydrated form of the lactose. Studies on stearic acid (261)
and magnesium stearate (262, 263) are made more complex because the pharmaceutical industry allows the use of these materials under their chemical name when in fact they contain a significant proportion of palmitic acid and magnesium palmitate, respectively. Other studies deal with binary mixtures, such as the effect of shear rate in roll mixing of ibuprofen with β-cyclodextrin (264) and a study on the inclusion compound formed from emulsified cetostearyl alcohol with β-cyclodextrin in oil-in-water creams (265). There is a detailed report on thermal analysis of glassy pharmaceuticals in which it is pointed out that once heated above their melting point and rapidly cooled many materials exist in this metastable state (266). Poly(ethylene glycol)s (PEGs) find pharmaceutical use in a variety of fields and are provided commercially with a designation indicating their average molecular weight. The freezing and melting behavior of aqueous solutions of PEG is described in terms of nonfreezing water, freezable bound water, and free water (267). The nucleation and growth of ice crystals in concentrated solutions of ethylene glycol was investigated by DSC and the kinetics obeyed the Avrami equation (268). In other publications, the degradation behavior of poly(ethylene glycol)-poly(L-lactide) copolymer showed no exothermic crystallization peak on a first run but upon cooling to room temperature from 180 °C at 5 °C min-1 an exothermic recrystallization peak appeared at around 100 °C (269). Other studies on PEGs with average molecular weights of from 3000 to 20 000 show the effect of counterions in solid dispersions between the PEGs, griseofulvin, and alkali dodecyl sulfates (270, 271). There are several studies involving thermal analysis dealing with water in other systems. In a manner similar to the above observations regarding water in PEGs, DSC studies show nonfreezable water in hydroxypropyl cellulose and ethyl cellulose mixtures (272). There is a detailed review of pharmaceutical hydrates which describes the various ways in which water may be present and its effect on subsequent processing of the material (273). The dehydration of theophylline monohydrate is shown to be dependent upon particle size and sample weight (274). Data obtained on drying by use of TG have been compared with results obtained by the Karl-Fisher method (275). The subject of gallstones and associated calculi attracts attention from thermal analysts. It is shown using DSC that growth kinetics can be studied by growing crystals from melted gallstone (276). The interaction of cholesterol with dipalmitoylphosphatidylcholine bilayers has also been studied by DSC (277, 278), as also has its miscibility with cholesteryl hemisuccinate (279). A detailed study on human renal calculi using TG/ FT-IR is reported (280), in which TG curves of calcium oxalate dihydrate, uric acid, the sodium salt of uric acid, and alkaline earth phosphates are determined. DSC finds a wide application in the investigation of physicochemical properties of starch from specified sources (281) and at different water contents (282). Retrogradationsthe hardening of starch by association with amylopectinshas also been studied by DSC, especially with regard to the hardening of bread (283). The retrogradation was affected by food additives (284). In another study, it is concluded that high amylose starch should show slower physical aging than preparations from gelatinized normal starch (285). Yuun and Thompson state that the endotherm observed at 50 °C is proportional to the water content and is different from the aging peak associated with the glass transition Analytical Chemistry, Vol. 68, No. 12, June 15, 1996
67R
seen in many polymers (286). Samples stored at temperatures above the Tg point around -5 °C, were in the rubbery metastable state and showed evidence of retrogradation on storing (287). However, this was minimized by xanthen gum interaction. Starch heated with water undergoes gelatinization, observed as an endothermic peak with DSC from which the gelatinization kinetics can be derived (288). Svensson and Eliasson claim that gelatinization is a two-stage process (289). Other studies related to food, and employing DSC, include studies on metabolic properties of grape buds (290) and on cocoa butter and milk fat blends (291). An award-winning publication on the kinetics of hair reduction deals with the breaking of the keratin disulfide bond during the permanent waving process (292). In the thermal unfolding of azurin, DSC experiments showed an irreversible and complex unfolding path but the kinetic parameters were ascertained by repeat experiments at different heating rates (293). DSC was also used to determine interactions of certain amino acids and oligopeptides with hen egg white lysozyme (294). The kinetics and thermodynamics of thermal denaturation in acyl carrier protein is also reported (295). It is claimed that immobilization of nibonuclease A on silica beads improved the stability of the protein against thermal denaturation (296). MINERALS AND ENERGY-RELATED TOPICS Energetic materials have been studied by TA methods, but a limiting factor is the start of the branching process where the rate is both self-sustaining and too fast to follow. A simple method is detailed to determine the autoignition temperature for solid energetic materials using a DSC or DTA unit (297). Another method put forward determines critical temperatures of thermal explosions by use of DSC (298). Fifer and Morris note that the heat of explosion is defined as the difference between the energy of formation of the material and the energies of formation of the explosion products and they provide a method for its calculation (299). A kinetic evaluation of the Arrhenius parameters from TG data for composite propellants is provided by Rao et al. (300). Pyrotechnic mixtures receive attention with studies on the effect of moisture (301), the first reaction stage in the magnesiumsodium nitrate-alloprene system (302), and the zirconiumpotassium perchlorate-nitrocellulose system (303). Isothermal and rising temperature techniques based on TG, DTG, and DTA are presented for elucidating the kinetics and mechanism of the initial thermal decomposition of nitrocellulose (304). Studies on ammonium nitrate employ DSC to determine the effect of particle size (305) and TG to investigate the mass loss process in the molten state (306). There are thermal analysis studies on various energetic materials containing nitrogen such as diazodinitrophenol (307), poly(vinyl nitrate) (308), and feranzao[3,4-b]piperazine (309). Catalysts have a significant effect on the thermal decomposition of certain propellants (310). The sensitization of nitro compounds by amines can be measured using DSC (311). DSC measurements have also been used to investigate the thermal stability of four detection agents prescribed by the ICAO for incorporation into explosives (312). Studies on combustion involve TG measurements on tire and tire components (313) and the effect of additives and pretreatment on woods and cellulosic materials (314, 316). In gaseous combustion, it is the evolved volatile gases that catch fire, so studies on TG in nitrogen are important (317). There is a study on North Sea oil using high-pressure DSC to evaluate recovery 68R
Analytical Chemistry, Vol. 68, No. 12, June 15, 1996
of the oil by in situ combustion (318). The same kind of DSC cell has also been used to determine oxidative stabilities of engine oils contaminated by vegetable oil (319). The technique of proton magnetic resonance thermal analysis is advocated to determine the intrinsic softening temperature for coal-tar pitch (320). It is stated that reactive intermediate nitrogen is released during coal combustion (321, 323). The kinetic analysis of the hydration of 3CaO ‚Al2O3‚CaSO4 and the effect of adding NaNO3 arises because it is the main component of the sulpho-aluminate early-strength cements (324). The measure of hydration in cement as determined by thermal analysis is to follow the formation of Ca(OH)2. The most comprehensive kinetic and mechanistic model for the dehydroxylation of this material is that of Galwey and Laverty (325). The kinetics may be altered, however, by the environmental conditions, such as being deposited on a substrate (326) or by being formed in the hydration of calcium trisilicate (327). The influence of temperature and different storage conditions on the stability of supersulfated cement can be determined using TG (328). The hydration behavior of a sulfate-resisting portland cement was determined by thermal analysis in a detailed study involving many other techniques (329). Calcium carbonate is associated with the preparation of cement clinker. Its pretreatment can have a significant effect on the limestone’s decomposition rate (330). Decrepitation of certain limestones and dolomites is known to occur (331). There is also a bed-depth effect in the thermal decomposition of carbonates (332). There are also thermal analysis studies on various forms of calcium carbonate prepared from the Ca(OH)2-CH3OH-H2OCO2 system (333) and by continuous precipitation (334). The thermal analysis of dolomite has been studied by CRTA, and comparisons have made with conventional kinetic analysis (335). DSC can be used to determine gypsum and the hemihydrate in cement (336). Clays undergo dehydroxylation at moderate temperatures. The temperature range may be affected by grinding as in montmorillonite (337) and may serve to distinguish the clay from other minerals (338). ACKNOWLEDGMENT
The help given by the Chemical Abstract Service in providing CA Selects to aid in the literature search is gratefully appreciated. A debt of gratitude is made to Ms. Supaporn Lerdkanchanaporn for help in arranging the text and selection of the abstracts noted in this review. D. Dollimore received his B.S. (1949), Ph.D. (1952), and D.Sc. (1976) degrees from London University. He has been a Professor of Chemistry at the University of Toledo since 1982, 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 Chairman of the British Thermal Methods Group (1969-1971). He is the author of several books and editor of various Conference Proceedings. In 1988, he received 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. LITERATURE CITED (1) Haines, P. J. Thermal Methods of Analysis; Blackie: London, 1995. (2) Mathot, V. B. F. Calorimetry and Thermal Analysis of Polymers; Hanser: Cincinnati, OH, 1994. (3) Seyler, R. J., Ed. Assignment of the Glass Transition; ASTM Publication STP 1249; ASTM: Philadelphia, 1995. (4) Paulik, F. Special Trends in Thermal Analysis; Wiley: Chichester, U.K., 1995. (5) Brown, M. J., Ed. J. Therm. Anal. 1994, 41. (6) Yariv, S., Keattch, C. J., Eds. J. Therm. Anal. 1993, 39. (7) Reller, A., Ed. Thermochim. Acta 1994, 234. (8) Kemp, R. B., Schaarschmidt, B., Eds. Thermochim. Acta 1995, 250, 215-377.
(9) Riga, A. T., Patterson, G. H., Eds. Thermochim. Acta 1994, 243, 109-300. (10) Wilhelm, E., Ed. Thermochim. Acta 1995, 259. (11) Seiersten, M., Stolen, S., Eds. Thermochim. Acta 1995, 256. (12) Yen, W.-H., Suga, H., Ozawa, T., Eds. Thermochim. Acta 1995, 253. (13) Wentising, Y.; Rullin, L.; Halke, Y.; Fu, T.; Rongzu, H. J. Therm. Anal. 1995, 45. (14) Piekarski, H., Ed. J. Therm. Anal. 1995, 45, 597. (15) Ford, J. L., Ed. Thermochim. Acta 1995, 248. (16) Sestak, J., Stepanek, B., Eds. J. Therm. Anal. 1995, 43, 371544. (17) Kettrup, A. A. F., Ed. Thermochim. Acta 1995, 263. (18) Mathot, V. B. F., Ed. Thermochim. Acta 1994, 238. (19) Chan, A.; Odlyha, M. Life Chem. Rep. 1994, 269. (20) Odlyha, M.; Scott, R. P. W. Thermochim. Acta 1994, 234, 165. (21) Lamprecht, I. Thermochim. Acta 1994, 234, 179. (22) Keattch, C. J. J. Therm. Anal. 1995, 44, 1211. (23) Robens, E.; Eyraud, C.; Rochas, P. Thermochim. Acta 1994, 235, 135. (24) Robens, E.; Massen, C. H.; Hardon, J. J. Thermochim. Acta 1994, 235, 125. (25) Banin, A.; Ben-Shlomo, T.; Margulies, L.; Blake, D. F.; Mancinelli, R. L.; Gehring, A. U. J. Geophys. Res., [Planets] 1993, 98 (e11), 20831; Chem. Abstr. 1994, 120, 34995q. (26) Yarger, J.; Lunine, J. L.; Burke, M. J. Geophys. Res., [Planets], 1993, 98 (e7), 13109. (27) Roger, J.; Ganteaume, M. H. R. Fr. Demande FR 2704948, (Cl. GOIN25/48), 10 Nov 1994, Appl. 93/5540, 03, May 1993. (28) Kailagin, V. I. Zzmer Tekh. 1994, 41. (29) Chen, D.; Dollimore, D. Thermochim. Acta 1995, 249, 259. (30) Hohne, G. W. H.; Schawe, J. E. K. Thermochim. Acta 1993, 229, 27. (31) Schawe, J. E. K.; Schick, C.; Hohne, G. W. H. Thermochim. Acta 1993; 229, 37; 1994, 244, 33; 1994, 244, 49. (32) Schawe, J. E. K. Thermochim. Acta 1993, 229, 69. (33) Tiers, G. V. D. Thermochim. Acta 1993, 226, 249. (34) Sarge, S. M.; Gmelin, E.; Hohne, G. W. H.; Heiko, K.; Hemminger, W.; Eysel, W. Thermochim. Acta 1994, 247, 129. (35) Wolf, G.; Schmidt, H.-G.; Bohmhammel, K. Thermochim. Acta 1994, 235, 23. (36) Cammenga, H. K.; Steer, A. G. Thermochim. Acta 1993, 229, 15. (37) Sabbah, R.; Tan, Z.-C. J. Therm. Anal. 1994, 41, 1577. (38) Reading, M. Trends Polym. Sci. 1993, 1, 248. (39) Sauerbrunn, S. R.; Crowe, B. S.; Reading, M. Polym. Mater. Sci. Eng. 1993, 68, 269. (40) Gill, P. S.; Sauerbrunn, S. R.; Reading, M. J. Therm. Anal 1993, 40, 931. (41) Reading, M.; Luget, A.; Wilson, R. Thermochim. Acta 1994, 238, 295. (42) Reading, M.; Jones, K.; Wilson, R. Netsu Sokutei 1995, 22, 83. (43) Wunderlich, B.; Jin, Y.; Boller, A. Thermochim. Acta 1994, 238, 277. (44) Ozawa, T.; Kanari, K. Thermochim. Acta 1995, 253, 183. (45) Schawe, J. E. K. Thermochim. Acta 1995, 260, 1; 1995, 261, 183. (46) Rein, C.; Demus, D. Thermochim. Acta 1994, 237, 133. (47) Porowski, S.; Jun, J.; Krukowski, S.; Bockowski, M.; Tedenac, J. C.; Record, M. C. AIP Conf. Proc. 1994, 309 (High Pressure Science and Technology, 1993, Pt. 1), 485. (48) Ishikiriyama, K.; Todoki, M.; Motomura, K. J. Colloid Interface Sci. 1995, 171, 92. (49) Ishikiriyama, K.; Todoki, M. J. Colloid Interface Sci. 1995, 171, 103. (50) Sarikaya, Y.; Ceylan, H.; Bozdogan, I.; Akine, M. Turk. J. Chem. 1993, 17, 119. (51) Bargeron, C. B.; Phillips, T. E.; Benson, R. C. Proc. SPIE-Int. Soc. Opt. Eng. 1994, 2261 (Optical System Contamination: Effects, Measurements and Control IV), 188. (52) Yamaguchi, M.; Sayama, S.; Nishikawa, Y.; Kamide, M.; Matsuda, H. Hokkaido Kogyo Gijutsu Kenkyusho Hokoku 1994, 60, 23. (53) Pahlke, W.; Gast, Th. Thermichim. Acta 1994, 233, 127. (54) Richarson, R. T. J. Therm. Anal. 1994, 42, 771. (55) Gueckel, W.; Kaestel, R.; Kroehl, T.; Parg, A. Pestic. Sci. 1995, 45, 27. (56) Isa, K.; Hasegawa, H.; Arii, T. Netsu Sokutei 1995, 22, 160. (57) McGhie, A. Thermochim. Acta 1994, 234, 21. (58) Barnes, P. A.; Parkes, G. M. B.; Charsley, E. L. Anal. Chem. 1994, 66, 2226. (59) Hutchison, E. J.; Bowley, B.; Pan, W.-P.; Nguyen, C. Thermichim. Acta 1993, 223, 259. (60) Kristof, J. Talanta 1994, 41, 1083. (61) Brown, M. E.; Tribelhorn, M. J.; Blenkinsop, M. G. J. Therm. Anal. 1993, 40, 1123. (62) Akinade, K. A.; Campbell, R. M.; Compton, D. A. C. J. Mater. Sci. 1994, 29, 3802. (63) Wilkie, C.; Mittleman, M. L. Adv. Chem. Ser. 1993, No. 236 (Structure-Property Relations in Polymers), 677. (64) Marini, A.; Berbenni, V.; Capsoni, D.; Riccardi, R.; Zerlia, T. Appl. Spectrosc. 1994, 48, 1468. (65) Compton, D. A. C.; Johnson, D. J.; Powell, J. R. Adv. Chem. Ser. 1993, No. 236, (Structure-Property Relations in Polymers), 661. (66) Bras, W.; Derbyshire, G. E.; Devine, A.; Clark, S. M.; Cooke, J.; Komanschek, B. E.; Ryan, A. J. J. Appl. Crystallogr. 1995, 28, 26.
(67) Yoshida, H.; Kinoshita, R.; Teramoto, Y. Thermochim. Acta 1995, 264, 173. (68) Wiedermann, H. G. J. Therm. Anal. 1993, 40, 1031. (69) Shimada, S.; Furuichi, R. Bull. Chem. Soc. Jpn. 1990, 63, 2526. (70) Vassilev, Ts.; Velinov, Ts.; Avramov, I.; Surnev, S. Appl. Phys. A: Mater. Sci. Process. 1995, A61, 129. (71) Giron, D.; Goldbronn, C. J. Therm. Anal. 1995, 44, 217. (72) Zheny, J.; Yang, L.; He, Y.; Li, G. Shenyang Yaoke Daxue Xuebao 1995 12, 10. (73) Bader, R. G.; Schawe, J. E. K.; Hohne, G. W. H. Thermochim. Acta 1993, 229, 85. (74) Giron, D. Bull. Chim. Farm. 1994, 133, 201. (75) Wang, G.; Harrison, I. R. Thermochim. Acta 1993, 230, 309. (76) Richardson, M. J. Thermochim. Acta 1993, 229, 1. (77) O’Kane, W. J.; Young, R. J.; Ryan, A. J.; Bras, W.; Derbyshire, G. E.; Mant, G. R. Polymer 1994, 35, 1352. (78) Callanan, J. E. J. Therm. Anal. 1995, 45, 359. (79) Paulik, F.; Gal, S.; Mezaros, S.; Zeacseanyi, K. J. Therm. Anal. 1994, 42, 425. (80) Flynn, J. H. Thermochim. Acta 1993, 217, 129. (81) Lowen, B.; Schulz, S.; Seippel, J. Thermochim. Acta 1994, 235, 147. (82) Nakasone, K.; Takamizawa, K.; Shiokawa, K.; Urabe, Y. Thermochim. Acta 1994, 233, 175. (83) Jin, Y.; Wunderlich, B.; Lebedev, B. V. Thermochim. Acta 1994, 234, 103. (84) Kohli, R. Thermochim. Acta 1994, 237, 247. (85) Arvanitoyannis, I.; Blanshard, J. M. V.; Ablett, S.; Izzard, M. J.; Lillford, P. J. J. Sci. Food. Agric. 1993, 63, 177. (86) Khanna, Y. P.; Kuhn, W. P.; Sichina, W. J. Macromolecules, 1995, 28, 2644. (87) Gupta, M. K. J. Coat. Technol. 1995, 67, 53. (88) Otero, A.; Diego, J. A.; Surinach, S.; Baro, M. D.; Clavaguera, N.; Clevaguera-Mora, M. T. Key Eng. Mater. 1993, 81-83, 233. (89) Perrenot, B.; Widmann, G. Thermochim. Acta 1994, 234, 31. (90) Giron, D. Thermochim. Acta 1995, 248, 1. (91) Tischler, M. Thermochim. Acta 1994, 231, 87. (92) Suda, H.; Yashima, M.; Kakihana, M.; Yoshimura, M. J. Phys. Chem. 1995, 99, 6752. (93) Kramer, M. J.; Margulies, L.; Araasmith, S. R.; Dennis, K. W.; Lang, J, C.; McCallum, R. W. J. Mater. Res. 1994, 9, 1661. (94) Edwards, J. G. Thermochim. Acta 1994, 242, 223. (95) Tenenzi, L.; Piacente, V. Thermochim. Acta 1994, 234, 61. (96) Tan, Z-C.; Sabbah, R. Thermochim. Acta 1994, 231, 109. (97) Yase, K.; Takahashi, Y.; Ara-Kato, N.; Kawazu, A. Jpn. J. Appli. Phys. Part I 1995, 34 (2A), 636. (98) Grande, T.; Aasland, S.; Julsrud, S. Thermochim. Acta 1995, 256, 33. (99) Krombach, R.; Schneider, G. M. Thermochim. Acta 1994, 231, 169. (100) Zurowski, K. J. Therm. Anal. 1995, 45, 437. (101) Dradin, Yu. A.; Aladko, E. Ya. J. Inclusion Phenom. Mol. Recognit. Chem. 1994 (Pub. 1995), 20, 115. (102) Oonk, H. A. J.; Calvet, T.; Cuevas-Diarte, M. A.; Tauler, E.; Labrador, M.; Haget, Y. Thermochim. Acta 1995, 250, 13. (103) Hayer, E.; Castanet, R. Z. Metallkd. 1995, 86, 8. (104) Chen, S.-W; Huang, G.-C.; Lin, J-C. Chem. Eng. Sci. 1995, 50, 417. (105) Paulin, A.; Spaic, S. Metall (Heidelberg) 1994, 48, 766. (106) Dibirov, M. A.; Gasanaliev, A. M.; Gamataeva, B. Yu. Zh. Weorg. Khim. 1995, 40, 341. (107) Shalaev, E. Yu.; Kanev, A. N. Cryobiology 1994, 31, 374. (108) Shalaev, E. Yu.; Franks, F. Thermochim. Acta 1995, 255, 49. (109) Wilburn, F. W.; Sharp, J. H. J. Therm. Anal. 1994, 41, 483. (110) Mianowski, A. Thermochim. Acta 1994, 241, 213. (111) Korobov, A. J. Therm. Anal. 1995, 44, 187. (112) Madarasz, J.; Pokol, G.; Gael, S. J. Therm. Anal. 1994, 42, 539. (113) Ceipidor, U. B.; Bucci, R.; Magri, A. D. Thermochim. Acta 1994, 231, 287. (114) Ceipidor, U. B.; Brizzi, E.; Bucci, R.; Magri, A. D. Thermochim. Acta 1994, 247, 347. (115) Chen, D.; Dollimore, D. Thermochim. Acta 1994, 239, 115. (116) Vyazovkin, S.; Linert, W. Anal. Chim. Acta 1994, 295, 101. (117) Vyazovkin, S.; Linert, W. J. Chem. Inform. Comput. Sci. 1994, 34, 1273. (118) Vyazovkin, S.; Linert, W. Chem. Phys. 1995, 193, 109. (119) Vyazovkin, S.; Linert, W. J. Solid State Chem. 1995, 114, 392. (120) Vyazovkin, S.; Linert, W. Int. J. Chem. Kinet. 1995, 27, 73. (121) Ozawa, T.; Kanari, K. Thermochim. Acta 1994, 234, 41. (122) Heda, P.; Dollimore, D.; Alexander, K. S.; Chen, D.; Law, E.; Bicknell, P. Thermochim. Acta 1995, 255, 255. (123) Luo, K.-M. Thermochim. Acta 1995, 255, 241. (124) Vyazovkin, S. Thermochim. Acta 1994, 236, 1. (125) Alcala, M. D.; Criado, J. M.; Gotor, F. J.; Ortega, A.; Perez Maquedo, L. A.; Real, C. Thermochim. Acta 1994, 240, 167. (126) Criado, J. M.; Ortega, A.; Rouquerol, J.; Rouquerol, F. Thermochim. Acta 1994, 240, 247. (127) Torralvo, M. J.; Grillet, Y.; Rouquerol, F.; Rouquerol, J. J. Therm. Anal. 1994, 41, 1529. (128) Graydon, J. W.; Thorpe, S. J.; Kirk, D. W. Acta Metall. Mater. 1994, 42, 3163. (129) Baburaj, E. G.; Prasad, G. E.; Banerjee, S.; Raghu, T.; Patni, J. J. Therm. Anal. 1995, 44, 345. (130) Zhang, P.; Zhitong, S. Scand. J. Metall. 1994, 23, 244. (131) Zhang, Z.; Chin, J. Polym. Sci. 1994, 12, 256.
Analytical Chemistry, Vol. 68, No. 12, June 15, 1996
69R
(132) Campoy, L.; Arribas, J. M.; Zaporta, M. A. M.; Mario, C.; Gomez, M. A.; Fatou, J. G. Eur. Polym. J. 1995, 31, 475. (133) Chan, T. V.; Shyu, G. D.; Isayev, A. I. Polym. Eng. Sci. 1995, 35, 733. (134) Hammami, A.; Spruiell, J. E.; Mehrotra, A. K. Polym. Eng. Sci. 1995, 35, 797. (135) Chang, C. H.; Shih, T. S. Trans. Am. Foundrymen’s Soc. 1994, (Pub. 1995), 102, 357. (136) Li, J.; Liu, C.-Y.; Liang, Y.-P.; Ren, H.-X.; Deng, Z.-J.; Liu, C.-X. Wuli Xuebao 1994, 43, 1876. (137) Cost, J. R.; Johnson, K. A. J. Nucl. Mater. 1995, 223, 267. (138) Haywood, P. J.; Evans, D. G.; Tayler, P.; George, I. M.; Duclos, A. M. J. Nucl. Mater. 1994, 217, 82. (139) Voitovich, V. B.; Laurenko, V. A.; Golovko, E. I.; Adejev, V. M. Oxid. Met. 1994, 42, 249. (140) Hong, L. B.; Bansal, C.; Fultz, B. Nanostruct. Mater. 1994, 4, 949. (141) Forester, J. S.; Schaffer, G. B. Metall. Mater. Trans. A 1995, 26A, 725. (142) Singh, M.; Behrendt, D. R, Mater. Sci. Eng. A 1995, A194, 193. (143) Varschavsky, A.; Pilleux, M. E. Mater. Lett. 1993, 17, 364. (144) Illekova, E.; Clavaguera-Mora, M. T.; Baro, M. D.; Surinach, S. Mater. Sci. Eng. B 1994, B22, 181. (145) Green, N. R.; Charles, J. A.; Smith, G. C. Mater. Sci. Technol. 1994, 10, 977. (146) Jayashankar, S.; Kaufman, M. J. J. Mater. Res. 1993, 8, 1428. (147) Upila, E, J. Am. Ceram. Soc. 1995, 78, 1107. (148) Vaben, R.; Stoever, D. J. Mater. Sci. 1994, 29, 3791. (149) Kaiser, A.; Vassen, R.; Stover, D.; Buchkremer, H. P. Nanostruct. Mater. 1994, 4, 795. (150) Shimoo, T.; Takemura, M.; Okamura, K.; Kurachi, Y.; Kajiwara, M. J. Ceram. Soc. Jpn. 1995, 103, 470. (151) Bushnell-Watson, S. M.; Sharp, J. H. Thermochim. Acta 1994, 240, 11. (152) Dweck, J.; Franco, A.; Shanefield, D. J. J. Therm. Anal. 1995, 44, 3. (153) Lipkowski, J.;Baranowski, B.; Lunden, A. Pol. J. Chem. 1993, 67, 1867. (154) Brown, M. E.; Galway, A. K.; Po, A. L. W. Thermochim. Acta 1993, 220, 131. (155) Masuda, Y.; Takeuchi, H.; Yahata, A. Thermochim. Acta 1993, 228, 191. (156) Rouquerol, F.; Laureiro, Y.; Rouquerol, J. Solid State Ionics 1993, 63-65, 363. (157) Li, J.; van Heiningen, A. R. P. J. Pulp. Pap. Sci. 1995, 21, J165. (158) Koga, N.; Tanaka, H. J. Phys. Chem. 1994, 98, 10521. (159) Moselhy, H.; Madarasz, J.; Pokal, G.; Gal, S.; Pungor, E. J. Therm. Anal. 1994, 41, 25. (160) Chang-Wei, L.; Jian-Lin, S.; Tong-Geng, X.; Xue-Hua, Y.; YunXian, C. Thermochim. Acta 1994, 232, 77. (161) Al Raihani, H.; Durand, B.; Chassagneux, F.; Kerridge, D. H.; Inman, D. J. Mater. Chem. 1994, 4, 1331. (162) Voigt, W.; Goring, S. Thermochim. Acta 1994, 237, 13. (163) Galway, A. K.; Guarini, G. G. T. Proc. R. Soc. London A 1993, 441, 313. (164) Donova, I.; Koceva, D. J. Therm. Anal. 1995, 44, 597. (165) Wang, H. W.; Hall, D. A.; Sale, F. R. J. Therm. Anal. 1994, 41, 605. (166) Miyata, K.; Kubota, N. Proc. Int. Pyrotech. Semin. 1994, 20TH, 729. (167) Mansour, S. A. A. Thermochim. Acta 1993, 228, 173. (168) Guarini, G. T.; Dei, L.; Sarti, G. J. Therm. Anal. 1995, 44, 31. (169) Abdel-Kader, M. M.; Abutaleb, M.; El-Tanahy, Z. H.; Eldehemy, K.; Ali, A. I. Phys. Scr. 1995, 52, 334. (170) Mansour, S. A. A. Thermochim. Acta 1993, 228, 155. (171) Fried, D.; Dollimore, D. J. Therm. Anal. 1994, 41, 323. (172) Reading, M.; Dollimore, D. Thermochim. Acta 1994, 240, 117. (173) Padeste, C.; Cant, N. W.; Trimm, D. L. Catal. Lett. 1994, 24, 95. (174) Kim, E. H.; Choi, C. S.; Park, J. H.; Chang, I. S. Yoop Hak Hoechi 1993, 30, 289. (175) Masuda, Y.; Iwata, K. J. Therm. Anal. 1995, 44, 1613. (176) Gyoryova, K.; Balek, V.; Zelenak, V. Thermochim. Acta 1994, 234, 221. (177) Lin, J.; Neoh, K. G.; Teo, W. K. J. Chem. Soc., Faraday Trans. 1994, 90, 355. (178) Mohamed, M. A.; Galway, A. K. Thermochim. Acta 1993, 213, 269, 279; 1993, 217, 263. (179) Mansour, S. A. A. Thermochim. Acta 1993, 230, 243. (180) Bose, S.; Sahu, K. K.; Bhatta, D. J. Therm. Anal. 1995, 44, 1131. (181) Wang, J.; McEnaney, B. Fenxi Ceshi Xuebao 1993, 12, 19. (182) Amin, Z. M.; Rohani, A. J. Phys. Sci. 1993, 4, 1. (183) Nishikawa, Y.; Takahashi, K.; Mitsuru, Y.; Okabe, M.; Yoshida, M.; Ohota, M. Nippon Kagaku Kaishi 1994, 661. (184) Hussein, G. A. M.; Nohman, A. K. H.; Attyia, K. M. A. J. Therm. Anal. 1994, 42, 1155. (185) Hussein, G. A. M. Powder Technol. 1994, 80, 265. (186) Strydom, C. A.; Prinsloo, L. C. Thermochim. Acta 1994, 241, 43. (187) Newman, D. S.; Rosinski, J. Proc.-Electrochem. Soc. 1994, 9413 (Molten Salts), 633. (188) Allan, J. R.; Dalrymple, J. Thermochim. Acta 1994, 231, 129. (189) Allan, J. R.; Paton, A. D. Thermochim. Acta 1994, 231, 333. (190) Allan, J. R.; McCloy, B.; Paton, A. D. Thermochim. Acta 1994, 231, 121. 70R
Analytical Chemistry, Vol. 68, No. 12, June 15, 1996
(191) Carson, B. R.; Kenessey, G.; Allan, J. R.; Liptay, G. J. Therm. Anal. 1995, 45, 369. (192) Huang, X.; Terashima, K.; Tokizaki, E.; Kimura, S.; Whitby, E. Jpn. J. Appl. Phys. Part I 1994, 33(7A), 3808. (193) Rao, Y. B.; Yadav, R. B.; Swamy, R. N.; Gopalan, B.; Syamsundar, S. J. Therm. Anal. 1995, 44, 1439. (194) Norton, G. A. Thermochim. Acta 1994, 237, 295. (195) Sheffield, G. S. Anal. Chim. Acta 1994, 286, 125. (196) Glesche, H.; Matijevic, E. J. Mater. Res. 1994, 9, 436. (197) Popescu, C.; Fatu, D.; Alexandrescu, R.; Voicu, I.; Morjan, I.; Popescu, M.; Jianu, V. J. Mater. Res, 1994, 9, 1257. (198) Segal, E.; Andrei, A.; Parvulescu, V. J. Therm. Anal. 1994, 41, 1063. (199) Giovanoli, R. Thermochim. Acta 1994, 234, 303. (200) Srinivasan, R.; Keogh, R. A.; Milburn, D. R.; Davis, B. H. J. Catal. 1995, 153, 123. (201) Ragai, J.; Selim, S.; Sing, K. S. W.; Theocharis, C. Stud. Surf. Sci. Catal. 1994, 87 (Characterizatin of Porous Solids III), 487. (202) Zhong, Z.; Gallagher, P. K. J. Mater. Res. 1995, 10, 945. (203) Zhong, Z.; Gallagher, P. K.; Loiacono, D. L.; Loiacono, G. M. Thermochim. Acta 1994, 234, 255. (204) Dresselhaus, M. S.; Dresselhaus, G.; Eklund, P. C. J. Mater. Res. 1993, 8, 2054. (205) Miller, G. P. Chem. Ind. 1993, 226. (206) Rao, C. N. R.; Seshadri, R. MRS Bull. 1994, 19, 28. (207) Ugate, D. MRS Bull. 1994, 19, 39. (208) Iijima, S. MRS Bull. 1994, 19, 43. (209) Kroto, H. W.; Hare, J. P.; Sarkar, A.; Hsu, K.; Terrones, M.; Abeysinghe, J. R. MRS Bull. 1994, 19, 51. (210) Yang, H.; Zheng, P.; Chen, Z.; He, P.; Xu, Y.; Yu, C.; Li, W. Solid State Commun. 1994, 89, 735. (211) Myers, S. A.; Assink, R. A.; Schirber, J. E.; Loy, D. A. Mater. Res. Soc. Symp. Proc. 1995, 359 (Science and Technology of Fullerene Materials), 505. (212) Nagano, Y.; Kiyobayashi, T. Chem. Phys. Lett. 1994, 217, 186. (213) Madarasz, J.; Pokol, G.; Keki, S.; Beck, M. T. Carbon 1994, 32, 1023. (214) Ogawa, H. Nippon Kagaku Kaishi 1994, 560. (215) Zhao, G.; Giolando, D. M.; Kirchhoff, J. R. Anal. Chem. 1994, 66, 2592. (216) Grant, K. A.; Zhu, Q.; Thomas, K. M. Carbon 1994, 32, 883. (217) Gomez-Serrano, V.; Acedo-Ramos, M. A.; Lopez-Peinado, A. J.; Valenzuela-Calahorro, C. Thermochim. Acta 1995, 254, 249. (218) Tauler, E.; Labrador, M.; Cuevas-Diarte, M. A.; Calvet. T.; Estop, T.; Mondieig, D.; Haget, Y. Mater. Res. Bull. 1994, 29, 293. (219) Howell, B. A.; Liu, M. Thermochim. Acta 1994, 243, 181. (220) Caira, M. R.; Griffith, V. J.; Nassimbeni, L. R.; Van Oudtshoorn, B. J. Inclusion Phenom. Mol. Recognit. Chem. 1994, 17, 187. (221) Tsukushi, I.; Yamamura, O.;Matsuo, T. Solid State Commun. 1995, 94, 1013. (222) Clark, J. H.; Tavener, S. J.; Barlow, S. J. J. Mater. Chem. 1995, 5, 827. (223) Nikulicheva, O. N.; Fadeeva, V. P.; Logvinenko, V. A. J. Therm. Anal. 1995, 44, 329. (224) Khan,N.; Price, D. M.; Bashir, Z. J. Polym. Sci., Part B: Polym. Phys. 1994, 32, 2509. (225) Kollodge, J. S.; Porter, R. S. Macromolecules 1995, 28, 4089. (226) Lu, S.; Pearce, E. M.; Kwei, T. K. J. Polym. Sci., Part A: Polym. Chem. 1994, 32, 2597. (227) Shih, H.-Y.; Kuo, W. F.; Pearce, E. M.; Kwei, T. K. Polym. Adv. Technol. 1995, 6, 413. (228) Zhuang, H.; Pearce, E. M.; Kwei, T. K.; Polymer 1995, 36, 2237. (229) Zhuang, H.; Pearce, E. M.; Kwei, T. K. Macromolecules 1994, 27, 6398. (230) Khanna, Y. P.; Kuhn, W. P.; Macur, J. E.; Messa, A. F.; Murthy, N. S.; Reimschuessel, A. C.; Schneider, R. L.; Sibilia, J. P.; Signorelli, A. J.; Tayler, T. J. J. Polym. Sci., Part B: Polym. Phys. 1995, 33, 1023. (231) Murthy, N. S.; Khanna, Y. P.; Signorelli, A. J. Polym. Eng. Sci. 1994, 34, 1254. (232) Jabarin, S. A. Annu. Tech. Conf. Soc. Plast. Eng., 52nd 1994, 1464. (233) Ho, R.; Cheng, S. Z. D.; Itsiao, B. S.; Gardner, K. H. Polym. Prepr. (Am. Chem. Soc., Div. Polym. Chem.) 1995, 36, 338. (234) Pardey, R.; Wu, S. S.; Chen, J.; Harris, F. W.; Cheng, S. Z. D.; Keller, A.; Aducci, J.; Facinelli, J. V.; Lenz, R. W. Macromolecules 1994, 27, 5794. (235) Kyu, T.; Yang, J.-C.; Cheng, S. Z. D.; Hsu, S. L. C.; Harris, F. W. Macromolecules 1994, 27, 1861. (236) Liu, T. M.; Harrison, I. R. Thermochim. Acta 1994, 233, 167. (237) Ahmad, M. B.; O’Mahong, J. P.; Huglin, M. B.; Davis, T. P.; Ricciardone, A. G. J. Appl. Polym. Sci. 1995, 56, 397. (238) Liu, Y.; Huglin, M. B. Polym. Int. 1995, 37, 63. (239) Mehmet-Alkan, A. A.; Biddlestone, F.; Hag, J. N. Thermochim. Acta 1995, 256, 123. (240) Crighton, J. S.; Luyt, A. S. J. Therm. Anal. 1994, 41, 583. (241) Horrocks, A. R.; D’Souza, J. A. Polym. Degrad. Stab. 1994, 46, 181. (242) Mitomo, H.; Watanabe, Y.; Ishigaki, I.; Saito, T. Polym. Degrad. Stab. 1994, 45, 11. (243) Zulfigar, S.; Zulfigar, M.; Rizvi, M.; Munir, A.; McNeill, I. C. Polym. Degrad. Stab. 1994, 43, 423. (244) Bandosz, T. J.; Putyera, K.; Jagiello, J.; Schwarz, J. A. Carbon 1994, 32, 659. (245) Mosquera, M. E. G.; Jamond, M.; Martinez-Alonso, A.; Tascon, J. M. D. Chem. Mater. 1994, 6, 1918.
(246) Ishida, H.; Rodriguez, Y. Polymer 1995, 36, 3151. (247) Thangamathesvaran, P. M.; Jain, S. R. J. Appl. Polym. Sci. 1994, 53, 1339. (248) Mallon, P. E.; McGill, W. J.; Shillington, D. P. J. Appl. Polym. Sci. 1995, 55, 705. (249) Woo, E. M.; Bravenec, L. D.; Seferis, J. C. Polym. Eng. Sci. 1994, 34, 1664. (250) Nam, J. D.; Seferis, J. C. J. Appl. Polym. Sci. 1993, 50, 1555. (251) Woo, E. M.; Shimp, D. A.; Seferis, J. C. Polymer 1994, 35, 1658. (252) Salin, I. M.; Seferis, J. C.; Loechelt, C. L.; Rothschilds, R. SAMPE Q. 1992, 24, 54. (253) Tsukada, M.; Freddi, G.; Crighton, J. S. J. Polym. Sci., Part B: Polym. Phys. 1994, 32, 243. (254) Wang, M. S.; Pinnavaia, T. J. Chem. Mater. 1994, 6, 468. (255) Santus, G.; Giordano, F.; Gazzaniga, A.; Bruni, G.; Paiotti, S. Eur. J. Pharm. Biopharm. 1994, 40, 243. (256) Lyer, E. K.; Tipnis, H. P. Indian Drugs 1995, 32, 25. (257) Venkataram, S.; Khohlokwane, M.; Wallis, S. H. Drug. Dev. Ind. Pharm. 1995, 21, 847. (258) Al-Meshol, M. A. Alexandria J. Pharm. Sci. 1994, 8, 51. (259) Pyramides, G.; Robinson, J. W.; Zito, S. W. J. Pharm. Biomed. Anal. 1995, 13, 103. (260) Figura, L. O.; Epple, M. J. Therm. Anal. 1995, 44, 45. (261) Lin, H.-H.; Huang, Y.-B.; Hsu, L.-R.; Tsai, Y.-H. Int. J. Pharm. 1994, 112, 165. (262) Wada, Y.; Matsubara, T. Powder Technol. 1994, 78, 109. (263) Phadke, D. S.; Collier, J. L. Drug Dev. Ind. Pharm. 1994, 20, 853. (264) Nozawa, Y.; Suzuki, K.; Sadzuka, Y.; Miyagishima, A.; Hirota, S. Pharm. Acta Helv. 1994, 69, 135. (265) Preiss, A.; Mehnert, W.; Froemming, K.-H. J. Inclusion Phenom. Mol. Recognit. Chem. 1994, 18, 331. (266) Kerc, J.; Srcic, S. Thermochim. Acta 1995, 248, 81. (267) Yamauchi, T.; Murakami, K. Kami Parupu Kenkyu Happyokai Koen Yoshishu, 61st 1994, 100. (268) Bronshteyn, V. L.; Steponkus, P. L. Cryobiology 1995, 32, 1. (269) Hu, D. S.-G.; Liu, H.-J. J. Appl. Polym. Sci. 1994, 51, 473. (270) Alden, M.; Lyden, M. Tagenfeldt, J. Int. J. Pharm. 1994, 110, 267. (271) Wulff, M.; Alden, M. Thermochim. Acta 1995, 256, 151. (272) Aoki, S.; Ando, H.; Ishii, M.; Watanabe, S.; Ozawa, H. J. Controlled Release 1995, 33, 365. (273) Khankari, R. K.; Grant, D. J. W. Thermochim. Acta 1995, 248, 61. (274) Agbada, C.; York, P. Int. J. Pharm. 1994, 106, 33. (275) Komatsu, H.; Yoshii, K.; Okada, S. Chem. Pharm. Bull. 1994, 42, 1631. (276) Kumar, S.; Burn, S. J.; Blanton, T. J. Mater. Res. 1995, 10, 216. (277) McMullen, T. P. W.; McElhaney, R. N. Biochim. Biophys. Acta 1995, 1234, 90. (278) Borochov, N.; Wachtel, E. J.; Bach, D. Chem. Phys. Lipids 1995, 76, 85. (279) Bach, D.; Borochov, N.; Wachtel, E. J.; Shinitzky, M. Chem. Phys. Lipids 1995, 76, 123. (280) Materazzi, R.; Curini, G.; D’Ascenzo, G.; Magri, A. D. Thermochim. Acta 1995, 264, 75. (281) Davydova, N. I.; Leont’ev, S. P.; Genin, Ya. V.; Sasov, A. Yu.; Bogracheva, T. Ya. Carbohydr. Polym. 1995, 27, 109. (282) Yuryev, V. P.; Nemirovskaya, I. E.; Maslova, T. D. Carbohydr. Polym. 1995, 26, 43. (283) Kweon, M. R.; Park, C. S.; Auh, J. H.; Cho, B. M.; Yang, N. S.; Park, K. H. J. Food Sci. 1994, 59, 1072. (284) Ward, K. E. J.; Hoseney, R. C.; Seib, P. A. Cereal Chem. 1994, 71, 150. (285) Shogren, R. L.; Jasberg, B. K. J. Environ. Polym. Degrad. 1994, 2, 99. (286) Yuan, R. C.; Thompson, D. Carbohydr. Polym. 1994, 25, 1. (287) Ferrero, C.; Martino, M. N.; Zaritzky, N. E. Starch/Staerke 1994, 46, 300. (288) Zanoni, B.; Peri, C.; Bruno, D. Food Sci. Technol. (London) 1995, 28, 314. (289) Svensson, E.; Eliasson, A.-C. Carbohydr. Polym. 1995, 26, 171. (290) Gardea, A. A.; Moreno, Y. M.; Azarenko, A. N.; Lombard, P. B.; Daley, L. S.; Criddle, R. S. J. Am. Soc. Hortic. Sci. 1994, 119, 756. (291) Ali, A. R. M.; Dimick, P. S. J. Am. Oil Chem. Soc. 1994, 71, 299. (292) Evans, T. A.; Ventura, T. N.; Wayne, A. B. J. Soc. Cosmet. Chem. 1994, 45, 279.
(293) La Rosa, C.; Milardi, D.; Grasso, D.; Guzzi, R.; Sportelli, L. J. Phys. Chem. 1995, 99, 14864. (294) Sabulal, B.; Kishore, N. J. Chem. Soc., Faraday Trans. 1995, 91, 2101. (295) Horvath, L. A.; Sturtevant, J. M.; Prestegard, J. H. Protein Sci. 1994, 3, 103. (296) Giovanni, R.; Battistel, E. Proteins Struct. Funct. Genet. 1994, 120. (297) Huang, C. C.; Wu, T. S. Thermochim. Acta 1994, 239, 105. (298) Zhang, T. L.; Hu, R. Z.; Xie, Y.; Li, F. P. Thermochim. Acta 1994, 244, 171. (299) Fifer, R. A.; Morris, J. B. Thermochim. Acta 1994, 237, 375. (300) Rao, V. K.; Bardon, M. F.; Stowe, R. A. Combust. Flame 1995, 102, 219. (301) Matsuzawa, T.; Sakata, K.; Hoh, M.; Arai, M.; Hatanaka, S.; Miyahara, A.; Tamura, M.; Osada, H. Kayaku Gakkaishi 1994, 55, 46. (302) Griffiths, T. T.; Queay, J.; Charsley, E. L.; Warrington, S. B. Proc. Int. Pyrotech. Semin., 19th 1994, 716. (303) Berger, B.; Charsley, E. L.; Rooney, J. J.; Warrington, S. B. Thermochim. Acta 1995, 255, 227. (304) Makashir, P. S.; Mahajan, R. R.; Agrawal, J. P. J. Therm. Anal. 1995, 45, 501. (305) Kestila, E.; Valkonen, J. Thermochim. Acta 1994, 233, 219. (306) Nobuyoshi, K.; Tanaka, H. Thermochim. Acta 1994, 240, 141. (307) Kaiser, M.; Ticmanis, U. Thermochim. Acta 1995, 250, 137. (308) Mishra, S. C.; Pant, J.; Pant, G. C.; Dutta, P. K.; Durgapal, U. C. Propellants, Explos. Pyrotech. 1995, 20, 91. (309) Patil, D. G.; Brill, T. B. Thermochim. Acta 1994, 235, 225. (310) Chang, F.-M.; Huang, C.-C.; Shen, S.-M.; Chen, S.-I. J. Therm. Anal. 1995, 44, 405. (311) Constantinov, P.; Chaudhri, M. M. J. Therm. Anal. 1995, 44, 1301. (312) Jones, D. E. G.; Augsten, R. A.; Feng, K. K. J. Therm. Anal. 1995, 44, 533. (313) Williams, P. T.; Besler, S. Fuel 1995, 74, 1277. (314) Ponder, G. R.; Richards, G. N. Energy Fuels 1994, 8, 705. (315) Julien, S.; Chornel, E.; Overend, R. P. J. Anal. Appl. Pryolysis 1993, 27, 25. (316) Khaltab, M. A.; Gad, A. M.; El-Samanoudi, A. H. J. Appl. Polym. Sci.; Appl. Polym. Symp. 1994, 55 (Degradation and Stabilization of Materials), 87. (317) Zeriouh, A.; Belkbir, L. Thermochim. Acta 1995, 258, 243. (318) Lukyaa, A. B. A.; Hughes, R.; Millington, A.; Price, D. Chem. Eng. Res. Des. 1994, 72 (A2), 163. (319) Kowalski, B. Thermochim. Acta 1995, 250, 55. (320) Cao, J.; Buckley, A. N.; Lynch, L. J. Carbon 1994, 32, 493. (321) Gonzalez, de Andres, A. I.; Thomas, K. M. Fuel 1994, 73, 635. (322) Jones, M.; Harding, A. W.; Brown, S. D.; Thomas, K. M. Carbon 1995, 33, 833. (323) Hindmarsh, C. J.; Varey, J. E.; Thomas, K. M. Prepr. Pap.sAm. Chem. Soc. Div. Fuel Chem. 1994, 39, 747. (324) Hu, S.; Yang, H.; Liu, S.; Chen, D.; Dollimore, D. Thermochim. Acta 1994, 246, 129. (325) Galwey, A. K.; Laverty, G. M. Thermochim. Acta 1993, 228, 359. (326) Sawada, Y.; Ito, Y. Thermochim. Acta 1994, 232, 47. (327) Chen, D.; Dollimore, D. J. Therm. Anal. 1995, 44, 1001. (328) Grounds, T.; Nowell, D. V.; Wilburn, F. W. J. Therm. Anal. 1994, 41, 687. (329) Gollop, R. S.; Taylor, H. F. W. Cem. Concr. Res. 1994, 24, 1347. (330) Wang, Y.; Thomson, W. J. Thermochim. Acta 1995, 255, 383. (331) Dollimore, D.; Dunn, J. G.; Lee, Y. F.; Penrod, B. M. Thermochim. Acta 1994, 237, 125. (332) Wilburn, F. W.; Sharp, J. H. J. Therm. Anal. 1993, 40, 133. (333) Ueda, Y.; Komatu, K.; Shimizu, S.; Nishioka, H.; Hanazaki, M.; Minayoshi, S. Gypsum Lime 1994, 249, 105. (334) Chakraborty, D.; Agarwal, V. K.; Bhatia, S. K.; Bellare, J. Ind. Eng. Chem. Res. 1994, 33, 2187. (335) Ortega, A.; Akhouayri, S.; Rouquerol, F.; Rouquerol, J. J. Therm. Anal. 1994, 235, 197; 1994, 247, 321. (336) Masaru, H. Ceram. Trans. 1994, 40 (Cement Technology), 123. (337) Fajnor, V. S.; Kuchta, L. J. Therm. Anal. 1995, 45, 481. (338) Weissenborn, P. K.; Dunn, J. G.; Warren, L. J. Thermochim. Acta 1994, 239, 147.
A1960006P
Analytical Chemistry, Vol. 68, No. 12, June 15, 1996
71R
72R
Analytical Chemistry, Vol. 68, No. 12, June 15, 1996
