山梨醇醚存在下聚乙烯的光氧化降解特性研究

Study on Properties of Photo-Oxidation Degradation of Polyethylene Films in the Existence of Sorbitol Ether

通过特性粘度、凝胶含量、羧基含量及红外光谱测试,分析了山梨醇醚含量为0%、0.1%、0.3%、0.5%、1%、5%、8%的7种聚乙烯膜样品在人工加速老化实验下的光氧降解特性研究,并通过扫描电镜对山梨醇醚含量为1%的聚乙烯膜表面形貌进行了分析。结果表明,光照过程中,山梨醇醚在7种膜中引发自由基反应,致使聚乙烯分子交联、断链,并引入了羰基和羧基;当山梨醇醚含量为1%时,聚乙烯膜的降解效果最好,光照60 d后聚乙烯的特性粘度由67.46 Pa·s降为23.49 Pa·s,凝胶含量为0.92%,羧基含量为1.10%,羰基指数为5.08。

Experiments of intrinsic viscosity,the content of gel and carboxyl,and fourier transform infrared spectroscopy were assayed and analyzed properties of photo-oxidation degradation process of seven polyethylene films containing 0%,0.1%,0.3%,0.5%,1%,5%,8% sorbitol ether respectively in the photo-oxidation degradable duration of artificially accelerated climate,and the scanning electron microscopy（SEM） was used to analysis the morphology of polyethylene films containing 1% sorbitol ether.The results indicated that sorbitol ether in seven films produced free radical reactions in the euphotic process,and made Macromolecules of polyethylene occured chain cross linking and rupture,then led in carbonyl and carboxyl.Furthermore,when the content of sorbitol ether is 1%,polyethylene film has the best degradation effect,the intrinsic viscosity is decreased from 67.46 Pa·s to 23.49 Pa·s after irradiation 60 days,the content of gel,carboxyl and carbonyl index are 0.92%,1.10%,5.08,respectively.