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71.
E. A. Sokolov S. D. Babenko N. P. Piven’ A. N. Ponomarev 《Russian Chemical Bulletin》1997,46(4):826-828
Experimental results related to the transition of spontaneous polymerization of acrylamide complexes with metal nitrates to
the “explosive” regime at room temperature are presented. It is suggested that the “explosion” has a thermal nature.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 859–861, April, 1997. 相似文献
72.
Wieczorek-Ciurowa K. Gamrat K. Paryło M. Shirokov Ju. G. 《Journal of Thermal Analysis and Calorimetry》2002,70(1):165-172
The physical mixtures of hydroxocarbonates of Cu and Ni with aluminium were activated using a laboratory planetary mill. The
chemical reactions and alloy formations as the effects of grinding were followed by the phase analysis of solid products based
on the thermogravimetry and X-ray diffractometry. Experimental evidence indicates that the nature of reactions and products
of mechanical activation was dependent on the amount of aluminium and time of grinding.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
73.
Reduced charge montmorillonites (RCM) were prepared by the thermal treatment of lithiumsaturated montmorillonite. Samples prepared by mild thermal treatment with lithium contained more water sorbed than the original montmorrilonite. When RCMs were prepared, part of the lithium cations reacted with hydroxyl groups in the octahedral sheet and released protons, which reacted with the structure. Acid treatment probably enhanced the surface area. which was reflected in the amount of water sorbed. Deprotonation of hydroxyl groups was proved by the measurements of the ignition loss. The heating of lithium saturated montmorillonite at higher temperatures brough about the collapse of the interlayers and a decrease in the amount of water sorbed. 相似文献
74.
A new method for the analysis of thermal desorption spectra is presented, based on the experimental peak maximum functions
for temperatureT
m(β) and pressureP
m(β) and a rigorous mathematical treatment. The resonant heating rate βr is determined, satisfyingT
m(βr)=T
r, whereT
r is the resonant temperature defined byA exp(−E
d/(RT
r))=1. Desorption energyE
d and frequency factorA can be determined simultaneously with relatively high robustness towards statistical experimental errors as demonstrated
by computer-simulated thermal desorption spectra. 相似文献
75.
Mixtures composed of amides and electrolytes exhibit interesting properties such as viscoelastic behaviour and a megavalue of the dielectric constant. In order to improve the dielectric properties, the authors are investigating a large number of molten mixtures of CF3COONa with different types of amides, including the ternary system sodium trifluoroacetate-chloroacetamide-acetamide. The experimental measurements showed that the ternary mixtures are thermally unstable. A yellow oily product is formed; this was purified and tested by means of IR and NMR techniques. The formula and the kinetic mechanism are proposed. 相似文献
76.
D. Radic L. H. Tagle A. Opazo A. Godoy L. Gargallo 《Journal of Thermal Analysis and Calorimetry》1994,41(5):1007-1018
Poly(monoitaconates) containing octyl, decyl and dodecyl groups and random monoalkylitaconate-co-vinylpyrrolidone copolymers were studied by thermogravimetric analysis. Copolymers of mono-n-octylitaconate (MOI), mono-n-decylitaconate (MDI), and mono-n-dodecylitaconate (MDoI), respectively, with N-vinyl-2-pyrrolidone (VP) of different compositions were studied by dynamic thermogravimetric analysis. The thermal stability of the copolymers depends on the structure of the monoitaconate comonomer and on the composition of the copolymer The kinetic analysis of the degradation data shows that the thermal decomposition of these copolymers can be described by several kinetic orders depending on the copolymer and on the composition. The relative thermal stability of the copolymers increases as the VP content increases and as the length of the side chain of the itaconate increases, following the same trend as the flexibility of the copolymers in solution. 相似文献
77.
Near-field thermoelastic imaging is a simple way to investigate the thermal and coupled thermoelastic properties of materials. A few microscopes, deriving from the atomic force microscope, have been used to observe and to quantify the samples observed. But the main problem is the absolute measurement of the temperature, because surface topography and thermal expansion contributions are not easily discernible. In the proposed SThEM (scanning thermoelastic microscope), the tip is excited at the resonance frequency of the cantilever and the sample is periodically heated by the Joule effect. Thus the static contributions (drift, topography) are reduced. Moreover, a radiometric sensor, operating in the far field, has been added in order to quantify the temperature. This multi-acquisition microscope enables one to investigate small objects at the nanoscale with complementary information at the micrometric scale. 相似文献
78.
L. Barral J. Cano A. J. López J. López P. Nogueira C. Ramírez 《Journal of Thermal Analysis and Calorimetry》1995,45(5):1167-1174
Using dynamic mechanical analysis (DMA) we have studied thermal degradation for a system containing a diglycidyl ether of bisphenol A (DGEBA) and 1,3-bisaminomethylcylohexane (1,3-BAC). The changes of dynamic mechanical properties during thermal degradation indicated a shift of the glass transition temperature (T g) to higher temperatures and a decrease in the peak value of the dynamic loss factor (tan δ) with an increasing of aging time. The value of dynamic storage modulus (E′) at the rubbery state showed an increase with aging time, whiteE′ at the glassy state only underwent a moderate change with increased thermal degradation. From these results it can be argued that thermal degradation during the stage prior to the onset of the severe degradation involves structural changes in the epoxy system, as further crosslinking and loss of dangling chains in the crosslinked network. 相似文献
79.
A new method is presented for spatially resolved thermal lensing measurements using multiple narrow probe beams and a two-dimensional array detector. The method is applied to an Er, Tm, Ho: YAG laser rod. No significant deviation from a parabolic temperature profile has been found although there is extraordinarily strong thermal lensing in the crystal. Thermo-optical constants of the material are reported. 相似文献
80.
Thermal diffusivity, heat capacity, and density of polyvinyl chloride/polycaprolactone (PVC/PCL) blends were measured by the laser flash method, DSC, and pycnometry, respectively. The thermal conductivity of the PVC/PCL blends was determined from the results. The miscibility of the blend and crystallinity of PCL were determined by DSC. The effect of blend structure on thermal conductivity is discussed. The phase compositions of the PVC/PCL blends are of three types depending on PCL content: i.e., up to 33%, from 33 to 70%, and above 70% PCL by weight. Thermal conductivity, thermal diffusivity, and heat capacity of the PVC/PCL blends are strongly affected by the phase composition of the blend, which changes in a complicated way with PCL content. © 1994 John Wiley & Sons, Inc. 相似文献