首次研究了一种添加剂——过氧化苯甲酰(BPO)对高密度聚乙烯在超临界水中降解行为的影响。对使用添加剂和未使用添加剂的实验产物采取多种方式检测对比,得到结论:在降解反应的前30 m in内,聚乙烯降解效率最高;温度是影响降解反应的重要因素;在反应温度较低和反应时间较短的情况下,添加BPO可以有效促进聚乙烯的降解,达到与未添加BPO实验中高温和长时间反应相比拟的效果。同时本文讨论了聚乙烯在超临界水中降解反应机理,对BPO在反应中的促进作用也进行了分析。
The effect of benzoyl peroxide (BPO) on polypropylene (PP) degradation in supercritical water was investigated with the aim of developing a process for recycling of waste plastics. A series of experiments with and without BPO were carried out at temperatures of 653 K and 673 K under pressure about 26 MPa for 30, 75 and 120 min respectively. Products were analyzed by an Ostward-type viscometer, gas chromatography and spectrometry (GC/MS) etc. The results indicated that mean molecular weight of the samples decreased greatly along with the time elapsing or with the temperature increasing, and PP was decomposed to aliphatic and cycloparaffinic hydrocarbons but a few benzenoid hydrocarbons. By comparing the experiments with and without BPO, it was made clear that BPO is an effective additive on PP degradation in supercritical water.
