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1.
L. Matisová-Rychlá J. Rychlý P. Ambrovič M. Vavreková I. Paška 《European Polymer Journal》1980,16(7):631-635
From measurements of weight losses of samples of isotactic polypropylene (IPP) with triphenylphosphonium cyclopentadienylide (TPCP) under various conditions and from the measurements of time courses of chemiluminescence, kinetic parameters of the process were determined. At concentrations of TPCP >1 wt%, the rate of loss of weight changes with the additive concentration. Compensation of the values of activation energy and pre-exponential term, determined from thermo-oxidation of IPP alone and IPP with TPCP, indicates that interaction of TPCP with oxidized polymer is complex. 相似文献
2.
Secondary multiple cool flame appearing under certain conditions during thermooxidation of polypropylene was interpreted on the basis of oxidation of the polymer surface being influenced by changes in the direction of the temperature gradient. The average period of the oscillation process, directly proportional to the amplitude of the first oscillation, expresses the effect on the oscillation process of all important factors such as the oxygen concentration, rate of delivery of volatile oxidation products and temperature of a cool flame in the gas phase. 相似文献
3.
Jozef Rychlý Martina Hudáková Lyda Rychlá 《Journal of Thermal Analysis and Calorimetry》2014,115(1):527-535
The burning of polyethylene in the mixture with aluminium hydroxide, aluminium oxide, cellulose and Irganox 1010 has been examined by cone calorimeter under non-standard sizes of the sample. The time to ignition of pure polyethylene decreases with decreasing initial amount of polyethylene powder. The subtraction of the mass of water released from the total mass lost for polyethylene with aluminium hydroxide give the same values of effective heats of combustion as for pure polyethylene up to the load about 50 mass% of aluminium hydroxide. The mean heats of combustion determined from the cone calorimeter software are higher than those determined from the total oxygen consumed and mass lost multiplied by the factor 13.1. The additivity rule was found for effective heat of combustion and total smoke released for polyethylene with cellulose. The free radical scavenger Irganox 1010 does not show a significant effect on the flammability of polyethylene except for the increase of the total smoke released. The equation describing the heat release rate evolution in time has been proposed showing a good fit to the experimental runs. 相似文献
4.
Jozef Rychlý Aysegul Kocer Fathy Tanis Lyda Matisová-Rychlá Ivica Janigová Katarína Csomorová 《Chemical Papers》2009,63(4):471-478
Difference in the kinetics of chemiluminescence (CL) and differential scanning calorimetry records for decomposition of originally
solid benzoyl peroxide continuing as a melt reaction was outlined. While the main portion of heat measured by DSC is released
in the spontaneous decomposition of benzoyl peroxide starting as a homolytic scission of peroxidic bonds, the CL light emission
in oxygen comes presumably from the subsequent disproportionation reaction of polyphenyl peroxyl radicals and monitors the
induced decomposition of peroxide. Thermogravimetry revealed that oxygen remains partially bound to the products of benzoyl
peroxide decomposition. 相似文献
5.
A significant retardation effect by PbO on the formation of volatile products from isotactic polypropylene (IPP) was found at temperatures up to 380°C. The effect is explained by the formation of a surface active form of PbO (possibly Pb3O4) which is formed by interaction of PbO with peroxy radicals. Primary and secondary alkyl radicals terminate effectively on the active surface and the kinetic length of the degradation reaction is thus decreased.A compensation effect exists between the Arrhenius parameters ln A and E for both inhibited and uninhibited formation of volatile products. 相似文献
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J. Rychly A. A. Dalinkevich I. Janigová L. Rychlá 《Journal of Thermal Analysis and Calorimetry》1994,41(1):115-124
The decomposition of polyethylene and ethylene-vinyl acetate copolymers in composites with Al(OH)3 and Mg(OH)2 (60% by wt.) has been estimated from the aspect of the extent of synchronization of the two fundamental processes, the release of water and flammable volatiles from a polymer and the effect of this on the resulting polymer flammability. An attempt has been made to implement the peculiarities of decomposition observed for each system to the fire behaviour of these materials. 相似文献
8.
L. Rychlá J. Rychlý J. Svoboda J. Šimonik 《Journal of Thermal Analysis and Calorimetry》1984,29(1):77-85
The decomposition of azodicarbonamide (Genitron AC-2) in the solid state was investigated by DSC. It was found that the decomposition under non-isothermal conditions can be described by the autocatalytic reaction scheme $$X\xrightarrow{{k_1 }}Y,X + Y\xrightarrow{{k'_2 }}2Y$$ where the following dependences hold for the rate constants: $$k_1 = 4.8 \times 10^{19} e - {{243 600} \mathord{\left/ {\vphantom {{243 600} {RT_s - 1}}} \right. \kern-\nulldelimiterspace} {RT_s - 1}}$$ and $$k'_2 = 1.0 \times 10^{13} e - {{133 500} \mathord{\left/ {\vphantom {{133 500} {RT_s - 1}}} \right. \kern-\nulldelimiterspace} {RT_s - 1}}$$ The first pre-exponential factor includes the thermal history of the sample, especially the quick heating to a certain temperature, from which normal slow heating starts. Due to this fast heating, the decomposition reaction of AZDA may be understood as the collapse of its crystal lattice into nucleation centres with critical dimensions. 相似文献
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