Authors: Hun Sik Kim, Byung Hyun Park, Min Sung Kang, Hyoung Joon Jin, Jin San Yoon
881
Authors: Jia Chun Zhong, Jian Yang, Hai Long Tang, Xiao Bo Liu
Abstract: The kinetics of the thermal degradation of Polyarylene ether natriles (PEN) (crosslinked and uncrosslinked) were investigated by thermogravimetric analysis (TGA). The corresponding kinetic parameters of PEN were determined using Flynn–Wall–Ozawa method and Friedman method, respectively. Satava method was also used to discuss the probable degradation mechanisms of PEN. The results showed that the activation energy obtained from Flynn–Wall–Ozawa method was in good agreement with the value obtained from Friedman method. The solid-state decomposition mechanisms of PEN and crosslinked PEN were A2 type (nucleation and growth) and R2 type (phase boundary controlled reaction), respectively. The activation energy and initial decomposition temperature of crosslinked PEN were higher than that of PEN, which indicates that crosslinking treatment is effective to enhance the thermal stability of PEN.
1917
Authors: De Qiang Chang, Jing Xian Liu, Ning Mao, Bao Zhi Chen
Abstract: In order to study the thermal stability of PPS (polyphenylene sulfide) filter media, by means of thermogravimetry(TG), thermal degradation kinetics behavior of two kinds of PPS filter media were analyzed. The kinetic parameters of PPS filter media were obtained according to Flynn-Wall-Ozawa method. Thermal stability of PPS filter media was discussed. It was found that the initial decomposition temperature and activation energy of N3 sample are all higher than B1 sample, the thermal stability of N3 sample is better than B1 sample, and kinetic analysis can be used as an important method to evaluate the thermal stability of filter media.
1171
Authors: De Hui Guo, Xiao Wang, Hai Rong Jiang, Guo Chun Chen, Zhang Yan, Hui Xia Liu
Abstract: The pyrolysis kinetics parameters of material had an great importance on estimating material degradation during laser transmission welding. The PA66/CB was produced using a twin-screw extruder, and thermogravimetric experiment of PA66/CB was performed at different heating rate of 5, 10, 15 and 20 °C/min, then the pyrolsis behavior and pyrolysis kinetics parameters of material were investigated based on the Kissinger, Starink and Freeman-Carroll three methods. The results showed that the pyrolsis process of PA66/CB was one step reaction. With the increase of heating rate, the initial reaction temperature and final pyrolsis temperature of TG curve and the peak temperature of DTG curve were shift to higher temperature. Temperature hysteresis was appeared but the final pyrolsis rate was not affected by heating rate. The activation energy on the biggest pyrolsis rate was not affected by the addition of carbon black. The activation energy calculated using Starink method was increased by the increase of conversion rate. The activation energy calculated using Freeman-Carroll method was bigger than Kissinger and Starink methods. The activation energy was calculated using Freeman-Carroll method, then using the nth model, and the pyrolsis kinetic equation was expressed as: dα/dt=2.053×1019[exp (-245.32×103/RT)](1-α)2.22.
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