【摘要】 研究了聚苯乙烯在超临界二甲苯介质中的解聚反应,温度为340~390℃,压力为5MPa、10MPa。产物用GC-MS分析表明解聚产物多达107种,含量最多的是苯乙烯的二聚物、丙基苯和对甲基苯乙烯二聚物。在实验取值范围内,主要产物苯乙烯二聚物及解聚转化率随温度升高而增加。在一级反应的基础上,由数据拟合求出了反应活化能、频率因子及反应速率常数的表达式,能较好地预测实验结果。更多还原

【Abstract】 Depolymerization of waste polystyrene (PS) in supercritical xylene was carried out in a stirred batch autoclave at temperature ranging 340~390℃, under different pressures of 5.0, 6.0, 8.0 and 10.0 MPa, respectively. The reaction products were examined by gas chromatography-mass spectrometry, high performance liquid chromatography and FT-IR spectrometry respectively. Total 107 components including isomers were identified by GC-MS in the liquid product. The main reaction products were dipolymer of styrene, isopropyl benzene and dipolymer of p-methyl styrene. Conversion rate and content of dipolymer of styrene in the liquid product increases with the increase of temperature under operating conditions respectively. The results of kinetic analysis showed that the depolymerization reaction rate is first order to the polystyrene concentration. The dependence of the rate constant on the reaction temperature was correlated by the Arrhenius relation, which shows that the activation energy is 47.6~41.9kJmol-1and frequency factor is 1.181~0.377 s-1.更多还原