Study On The Catalysts For Polyisobutylene With A Terminal Double Bond

The properties of different catalysts for polyisobutylene with a terminal double bond in isobutylene were studied. The Mn of polyisobutylene was measured using VOP method and the amount of a-olefins was determined by NMR. Polyisobutylene was prepared in the kettle reactor. Besides, the experiment of polymerization had gotten together in succession , the catalyst comprising BF3 as the main catalyst , MTBE for catalyst-accelerators compound and hydrocarbon chloridized for the solvent.The effect of the composition of catalyst, the kind and content of the catalyst-accelerators and the kinds of solvents in lower than ambient temperature on the molecular weight of polyisobutylene and the amount of a-olefins was discussed. Besides, the proportion of main catalysts /catalyst-accelerators, the temperature catalysts prepared, the store temperature and the period kept in ambient temperature also were considered This text involved the effect of raw materials kinds, and the conditions of raw materials pretreated, and the temperature and time, and the total amount of catalyst used and the kinds and the proportion of halts. The best process conditions for the preparation of catalysts and for the reaction of polymerization were defined. The process conditions for the polymerization in succession were studied on the basis of reaction in batches, and the temperature and time for the reaction of polymerization in succession were discussed.The results of the experiment show that the activation of catalyst was affected by the purity of the main catalyst and the kind of the catalyst-accelerators. The activation of catalyst comprising MTBE for catalyst-accelerators and the amount of a-olefins were both high and the color of the polymer is better. The purity of the main catalyst requested by the active of catalyst can be satisfied with 99.6%. Solvent have remarkable function on changing viscidity and dispersibility of BF3-MTBE catalyst, which can be found in experiment. The activation catalyst comprising CHCl3 for the solvent was high, The shelf life of catalyst can be extended by adding solvents of CHCls, CH2Cl2- The order adding solvent influenced the performance of complexing catalyst, which is higher before than after finishing preparing catalysts. The conditions and results of polymerization also were affected by raw materials. Butadiene remainder, C4 of catalytic hydrogenation of heavy oil and C4 of wax oil catalysis for raw material for polymerization, the yield of polymer and the amount of alpha-olefins were heavily affected by the different ratio catalyst to isobutylene. The yield of polymer and the amount of a-olefins were both high when the ratio catalyst to isobutylene was large, and the two targets were both gratifying when the content of isobutylene is low. The activation of catalyst was affected by the content of butadiene in raw materials, and the quantity of the catalyst consumed and the time for reaction had a little effect on the molecular weight, but the yield increased with extending reaction time. With heightening temperature, the molecular weight of the polymer was reduced gradually, and the yield changed little. The molecular weight and yield of product also influenced by the proportion of catalyst/isobutylene in raw materials. The yield of polyisobutylene was lower at catalyst/isobutylene lower than 1.2‰ . The molecular weight of the polymer increased and the yield reduced when catalyst dropping time became long. With the proportion of catalyst/ethanol increasing, alcohol as the halt, the yield of product increased and the amount of a-olefins also increased but the amount reduced with halt temperature increasing. The best process conditions were defined by method of perpendicularity designing.The changing rule of reaction temperature in fitting in succession was discussed. Under the same processconditions, it was lower than intermittent reaction to get the molecular weight and the yield of the products ,and the molecular weight was influenced by the changing of time in succession greater t...