PEG400存在下聚乙烯膜的光氧化降解特性研究

Study on Properties of Photo-oxidation Degradation of Polyethylene Films in Existence of PEG400

通过对聚乙烯的特性黏度、凝胶含量、羧基含量和红外光谱特征吸收的测定,研究了PEG400含量为8%(质量分数,下同),5%,1%,0.1%,0%的五种聚乙烯膜样品在人工加速老化实验下的光氧化降解特性,并利用扫描电镜对PEG400含量为1%的聚乙烯膜进行了表面形貌分析。结果表明:在实验条件下,PEG400明显加速了聚乙烯膜中的自由基反应,致使聚乙烯分子交联和断链,并在聚乙烯分子链中引入了羰基和羧基;当PEG400含量为1%时,聚乙烯膜的降解效果最为明显,光照60d后基体聚乙烯的特性黏度由67.6 Pa.s下降为34.9 Pa.s,凝胶含量为5.84%,羧基含量为1.29%。

With the analyses of the intrinsic viscosity, the content of gel and carboxyl, and fourier transform infrared spectroscopy, the photo-oxidation degradation process of five polyethylene films containing 8%, 5%, 1%, 0.1%, 0% （mass fraction） PEG400 were analyzed respectively in the artificial accelerated climate. The morphologies of polyethylene films containing 1 % PEG400 before and after degradation were studied with the Scanning Electron Microscopy （SEM）. The results showed that the photo-oxidation reactions process of the polyethylene in films were accelerated by the PEG400, it made the macromolecules of polyethylene chain cross linking or rupture and produced the carbonyl and carboxyl in the molecule chains. With the content of PEG400 at 1 %, the polyethylene film had the best degradation effect, the intrinsic viscosity of its polyethylene was decreased from 67.6 Pa · s to 34. 9 Pa · s after irradiation 60 days at the experiment condition, the content of gel and carboxyl were 5.84% and 1.29% respectively.