【摘要】 针对润滑油用乙丙共聚物粘度指数改进剂的应用需求,设计一系列乙丙橡胶的热氧化降解体系,系统考察反应条件对乙丙橡胶热氧化降解的影响规律。采用乌氏粘度计、凝胶色谱仪和红外光谱分别对样品特性粘数、分子量及其分布和链段结构进行测定和表征,并分析探讨其热氧化降解机制。结果表明,引发剂A、B对乙丙橡胶降解均有促进作用,随着时间的延长降解程度增大;一定范围内引发剂浓度增加降解程度增大;降解体系胶油质量比1∶6的降解程度比1∶9大;金属铜离子能明显提高降解程度。采用0.3%~0.5%引发剂A和胶油质量比1∶6~1∶9的反应体系可制备出适当的分子量和较窄分子量分布的降解产物乙丙共聚物,经红外光谱分析其链段结构未出现异常变化。更多还原

【Abstract】 To meet the application needs of the ethylene-propylene copolymer viscosity index improver for lubricating oil,a series of thermo-oxidative degradation reaction systems with ethylene-propylene rubber were designed,and the effect factors on the reaction product of the thermo-oxidative degradation were analyzed.The molecular weight and its distribution,intrinsic viscosity and structure of the product were characterized by GPC,ubbelohde viscometer and FTIR spectra,and the mechanism of thermo-oxidative degradation was discussed.It is shown from the experimental results that the degradation degree of ethylene-propylene rubber can be improved and increased by appending initiator A or B,adding its concentration,prolonging reaction process or containing copper ion,and the degradation degree in the system with the ratio 1∶6 of rubber to oil is higher than that in the system with 1∶9.The product of the appropriate molecular weight and its distribution can be prepared with 0.3%~0.5% initiator A and 1∶6~1∶9 mass ratio of the rubber to the oil.There are little differences between the chain segment structures of the ethylene-propylene rubber before and after reaction.更多还原