Study On The Synthesis Of Highly Reactive Polyisobutylene

Highly reactive polyisobutylene (HRPIB) is widely used as potential green product in internal combustion engine oil additives, fuel detergents and so on. The demand for HRPIB brisks both in domestic and foreign markets, however, the synthesis technology is just at the beginning stage in China, and the potential market is enormous. Nowadays, the synthesis of HRPIB mainly uses boron trifluoride (BF3) as initiation system in industry.BF3 initiation system was used in the thesis. The influence of the type of coinitiator, solvent, dosage of initiator, polymerization temperature and initial monomer concentration on the yield and molecular weight of polymer were studied. Thus, the optimum initiation system and synthesizing conditions were obtained, and it paved the way for the kinetic study of polymerization of isobutylene.Then, the kinetic study of the synthesis of highly reactive polyisobutylene was mainly researched in this thesis. The methylene chloride was used as solvent and methyl tert butyl ether (MTBE) and BF3 as initiation system for the polymerization process of isobutylene, a certain creative mechanism of polymerization of isobutylene was proposed through theoretical analysis and experimental research, and the kinetic equation of polymerization of isobutylene was presented according to the mechanism. The rationality of mechanism was verified by a list of experiments, for example, the change in concentration, the change in ratio of initiator to coinitiator, the active centre transfer without monomer and the change in temperature etc.. Then the kinetic parameters of polymerization of isobutylene in MTBE/BF3 initiation system were worked out.The isomerization process in which active centre transferred to the middle of the polymer chain was further researched at last.1H-NMR was used as the main method for end-group structures inspection. The influence of different factors such as the type of coinitiator, dosage of initiator, polymerization temperature on the active centre transfer casing isomerization were studied. The above experimental results can be explained by the theory knowledge. This research further supplemented and verified the mechanism of polymerization of isobutylene.