聚异丁烯及其衍生物的结构分析与性能评价

STRUCTURE AND PROPERTY ANALYSIS OF POLYISOBUTYLENE AND ITS DERIVATIVES

聚异丁烯马来酸酐(PIBSA)作为制备无灰分散剂的中间产物,其结构和性质直接决定了后续胺化反应的成败。采用傅里叶变换红外光谱(FTIR)和核磁共振波谱(1H-NMR)分析两种催化工艺(BF 3和AlCl 3催化法)制备的不同活性的聚异丁烯和不同烃化工艺(氯化法和热合成法)制备的PIBSA的结构,探讨PIBSA的合成反应机理,对比分析了两种PIBSA进一步胺化制备的无灰分散剂的低温油泥分散性、高温清净性以及烟炱分散性能。结果表明:采用两种工艺制备PIBSA时,由于聚异丁烯的结构及反应原理不同,合成产物PIBSA的结构差异较大;热合成法PIBSA的末端以接枝的单五元环酸酐结构为主,氯化法PIBSA的末端主要以邻苯二甲酸酐结构为主,两种不同结构对无灰分散剂的性能产生较大影响。氯化法PIBSA制备的无灰分散剂DL和热合成法PIBSA制备的无灰分散剂DR的低温油泥分散性相当,DL的高温清净性优于DR,而烟炱分散性略差于DR。

As an intermediate in the preparation of ashless dispersant,the structure and properties of polyisobutylene succinic anhydride(PIBSA)were the critical factor of subsequent amination reactions.The structures of polyisobutylenes with different activities prepared by two catalytic processes(BF 3和AlCl 3)and of PIBSA prepared by different alkylation processes(chlorination and thermal addition)were characterized by IR and 1H NMR to study the systhetic reaction mechanism.The ashless dispersants were prepared by further amination of two PIBSAs.The dispersity of low temperature sludge,high temperature cleanness and soot dispersability of the ashless dispersants were compared and analyzed.The results indicated that the structures of PIBSAs prepared by two alkylation processes were great different due to the difference of polyisobutylene structures and reaction principles.The end of PIBSA prepared by thermal addition method was mainly composed of grafted monopentacyclic anhydride structure,while at the end of PIBSA prepared by chlorination method,phthalic anhydride structure was predominant.Two different structures had a great influence on the performance of ashless dispersants.The ashless dispersant DL prepared by chlorination of PIBSA and the ashless dispersant DR prepared by thermal addition of PIBSA had a similar low-temperature oil sludge dispersibility.The high temperature detergency of DL was better than that of DR,while the soot dispersibility was slightly worse than that of DR.