Thermal studies

Nagashima H, Kato Y, Satoh H, Kamegashima N, Itoh K, 01 Kand Salto Y 1996 Thermal study of a silylmethylated fullerene leading to preparation of its vaouum deposited thin film Chem. Lett. 519-20... 

Thermal Properties. Spider dragline silk was thermally stable to about 230°C based on thermal gravimetric analysis (tga) (33). Two thermal transitions were observed by dynamic mechanical analysis (dma), one at —75° C, presumed to represent localized mobiUty in the noncrystalline regions of the silk fiber, and the other at 210°C, indicative of a partial melt or a glass transition. Data from thermal studies on B. mori silkworm cocoon silk indicate a glass-transition temperature, T, of 175°C and stability to around 250°C (37). The T for wild silkworm cocoon silks were slightly higher, from 160 to 210°C. 

The common side reaction in most thermal studies of fluorine-substituted cyclopropanes is difluorocarbene extrusion Increasing the number of fluonne substituents on the cyclopropane ring significantly increases the rate of difluorocarbene extrusion [135, 136, 137]... 

The thermal, mechanical, and morphological behaviors of two binary blends, HDPE-E-plastomer (Engage 8200) and iPP-E-plastomer (Engage 8200) have been investigated to compare the compatibility and molecular mechanistic properties of the blends. Both systems are thermodynamically immiscible but mechanically compatible. Thermal studies indicate that both blends exhibit two distinct melting peaks and there is depression of the HDPE melting peak in the blend with high... 

Industrial chemical syntheses are exo- or endothermic. Therefore, the thermal study aims at characterizing its performances according to the following two steps ... 

Thermal study is based on experiments which aim at cooling the process fluid. The process fluid temperature can, for instance, easily vary from 20 to 60 °C. Process fluid can be water at room temperature or heated with thermostat, whereas UF is water at 15 °C. Experiments with water are necessary since they allow the study of thermal performances of the reactor regardless of any other phenomenon (reaction, mass transfer, etc.). As a consequence, thermal study is an important preliminary step before performing chemical reactions. For each experiment, the operating protocol is as follows ... 

Decomposition studies confirmed that N-nitrosamides are much less stable than volatile N-nitrosamines such as NPYR and NDMA (79). Thermal studies utilizing heating conditions commonly encountered in the cooking of bacon and pork roasts indicated that N nitrosomethylpropionamide (NOMP) was degraded to the extent of 74-97% compared to 3-14% for NPYR and NDMA (Table V). It was tentatively concluded that the major... 

Teleb, S.M. (2004) Spectral and thermal studies of saccharinato complexes. The Journal of the Argentine Chemical Society, 92, 31. 

Infrared and thermal studies also add to our knowledge of these polymers. For example, the aromatic C-0 stretch of the Schiff-base ligands is shifted above 1300 cm-1 when coordinated, and coordinated carboxylate shows no CO stretch above 1600 cm-1 when bidentate. The... 

A typical synthetic route to the incorporation of pendent carboranyl units into a polymer chain is shown in scheme 3. Poly(o-carboranyl-organo-siloxane)s have been successfully prepared through hydrolysis of dimethyldichlorosilane in the presence of carboranedichloromethylsilane. The polymer has some of the elastomeric characteristics of the parent poly(siloxane) however, the thermal-oxidative cleavage of the o-carboranyl pendent group is reported to occurat lower temperatures than that for the thermooxidative cleavage of Si—O and Si—C bonds.10 Thermal studies have... 

Other supportive evidence for a specific water-solid interaction is available from thermal studies showing the amount of nonfreezable water [57-59], nuclear magnetic resonance [29,60-66], and diffusion studies [67,68]. The evidence is less clear, however, concerning whether there is distinct binding of water to... 

M. Zheng, A.M. Sarker, E.E. Giirel, P.M. Lahti, and F.E. Karasz, Structure-property relationships in light-emitting polymers optical, electrochemical and thermal studies, Macromolecules, 33 7426-7430, 2000. 

The recent syntheses of this compound have made it available for thermal studies (Wiberg and Lampman, 1963 Frey and Stevens, 1964 Srinivasan, 1963). Above 190° C, bicyclobutane isomerizes to butadiene. The reaction is predominantly homogeneous but there is some evidence for a small heterogeneous component of the reaction. The results of Srinivasan et al. (1965) yield the Arrhenius equation... 

Among the historic developments of studies on C—H activation, several methods and conditions have been used, from thermal studies to photochemical activation, with all of which have been mediated by derivatives of metals ranging from transition metals to lanthanides and actinides. Hence, given the importance that the chemistry surrounding the C—H activation process entails, several excellent reviews and monographs have already been published [6]. Unfortunately, in most of these cases the chemistry described has been devoted entirely to descriptions of the activation of a particular C—H bond in a given process, and consequently some division has arisen as to how the C—H activation process does in fact proceed... 

Complexes with Oxyanion Ligands. The zirconium-peroxo-oxalato-complex [Zr(02)(C204 )(H20)2],3—4H2O, has been assigned the trans-diaquo octahedral structure (28) from spectroscopic and thermal studies. ... 

Thermal studies of metal films prepared with oxygenated solvents (Cardenas et al., 1994)... 

Thermal studies on l,3-oxazetidin-2-ones, as expected, show the major pathway to be extrusion of carbon dioxide to give imines (70BAU1479,80S571). These systems are surprisingly stable for example, for (V-phenyl-l,3-oxazetidin-2-one AH = 128.9 kJ mol-1 and AS = 54.4 J K-1 mol . There is one report of fragmentation to give ketone and isocyanate... 

Hoshinq S., Mitsui T. Jona F. Pepinsky R. Dielectric and thermal study of tri-glycine sulfate and tri-glycine fmoberyllafce. Phys. Rev. 1957 107 1225. 

According to Stettbacher, mercuric azide develops the same vol of gas on deton as MF but it is 20 times more brisant. Wohler Krupko (Ref 3) observed that its sensitivity depended on the cryst size of the azide. Mercuric azide is considered to be more sensitive to impact and friction than MF and is so unstable that it frequently undergoes spontaneous deton at the slightest touch even under w (Refs 5 7). Hitch (Ref 4) noted this sensitivity expecially when the azide was prepd from mercuric nitrate and Na or K azide solns but by careful thermal studies he decompd it quanty into its elements without expln below 300°. Miles (Ref 8) reported that in every case when /3-crysts of Hg(N3)2 were present the material was likely to expl, and in w or more rapidly in mercuric nitrate soln, the /3-type was unstable being transformed to the o-type, as in the parallel case of LA,... 

Sherbon, J. W. 1968. Thermal studies of milk fat. In Analytical Calorimetry. R.S. Porter and J.F. Johnson (Editors). Plenum Press, New York, pp. 173-180. 

Nitric oxide is the simplest stable molecule with an odd number of electrons. Because of its unpaired electron, it is paramagnetic at room temperature (the lowest lying energy level, X2U/z, is diamagnetic), ionizes relatively easily, and is highly reactive with other paramagnetic species, such as NOz and Oa. It is an efficient scavenger of free radicals and triplet states and has been used frequently for this purpose in photochemical and thermal studies. 

Eubank R.W. VanDolah, Thermal Studies on TNT , NOTS 316, Naval Ordn Test Sta,... 

Sengupta, S. K. et al., Transition Met. Chem., 2000, 25(2), 150 Three to one lanthanum and praseodymium salts were prepared. They exploded on heating above 180 C, making thermal studies difficult. Analogues without the nitro-group decompose controllably. 

It may be concluded from thermal studies that the heat release due to decomposition attributed to the nitro group made a substantial contribution to the destructive power of the thermal explosion from 350-400 °C. 

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