Study of the thermo-oxidative degradation behavior of isotactic polypropylene with the varying ethylene content
Study of the thermo-oxidative degradation behavior of isotactic polypropylene with the varying ethylene content
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不同乙烯含量等规聚丙烯热氧化降解行为研究
DOI：
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发表时间：
2007
影响因子：
0.5
通讯作者：
M. Moniruzzaman
中科院分区：
文献类型：
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作者：
M. S. Alam;S. Razzaque;G. M. A. Khan;A. Chakraborty;M. Moniruzzaman
采用凝胶渗透色谱法（GPC）研究了等规聚丙烯的热氧化降解行为随乙烯和氧浓度变化的函数。研究了平均分子量和分子量分布（Mw/Mn）相似的三种等规聚丙烯iPP、ePPI、ePP2的热稳定性。iPP、ePPI、ePP2的乙烯含量分别为0、0.5、2.7 wt%。在此条件下，等规聚丙烯样品的分子量和分子量比随乙烯含量的增加而减小。每个样品的降解速率也随着氧浓度的增加而增加。研究了时间效应对GPC曲线变化的影响。随着降解时间的延长，iPP、epppi和epp2中较长链的断裂更有利于GPC曲线的改变。结果表明，等规聚丙烯的热氧化稳定性显著取决于乙烯掺入量的变化。
The thermo-oxidative degradation behavior of isotactic polypropylene is studied as a function of varying ethylene and oxygen concentration effects by means of gel permeation chromatography (GPC) measurement. The thermal stability of three types of isotactic polypropylene viz. iPP, ePPI, ePP2 which contains 0, 0.5, 2.7 wt% of ethylene, respectively having similar average molecular weights and molecular weight distribution (Mw/Mn) is studied in solution at 453 K. Under this condition, the changes of molecular weight and M w/M n in isotactic polypropylene samples arc decreased with the increase of ethylene. The rate of degradation has also been increased with the increase of oxygen concentration for each sample. The variation of time effect on changing of GPC curve is also studied. GPC curves are changed preferably by the scission of longer chain in iPP, ePPI and ePP 2 with the increasing degradation time. The results reveal that the thermo-oxidative stability of isotactic polypropylene significantly depends upon the varying ethylene content incorporation.