Adjustion Of Microstructure Of Polylsoprene Prepared With Anionic Polymerization And Synthesis Of Block Copolymers

In this thesis, we synthesized polyisoprne with the method of anionic polymerization, mainly investigating the influence of the regulators, such as tri-isobutyl aluminum, diphenyl silane, triphenylphos-phine and2,2-di(2-tetrahydrofuryl)propane, on the polymerization rule of isoprene. And then, DTHFP/THF adjustment system was chosen as the discarboxylic modifier, with that we prepared styrene-isoprene block copolymers and styrene-butadiene-isoprene block copolymers, and studied their selective hydrogenation products’performance.Studies have shown that, the contents of1,4-PI prepared with the binary regulation system which contains tetrahydrofuran and another regulator,such as triisobuyl aluminum, was higher than that was prepared with single regulator THF. The ajunction of triisobutylaluminum can block the polymerization. Also, Ph3P and DDS with excessive amount can reduce the rate of reaction. DTHFP/THF adjustment system for adjusting the polymerization of isoprene with high reactivity can control the3,4-structure below12%, which have the advantage of industrial application.Cyclohexane as the solvent, two or three-stage method of addition, the molar ratio of2,2-di(2-tetrahydrofuryl)propane and n-butyllithium was DTHFP/Li=0.25, and the molar ratio of THF and butyllithium was THF/Li=4.2, we synthesized styrene-isoprene, styrene-butadiene-isoprene block copolymers and their selective hydrogenation product SEP, EPEBS. Comparing the performance of SEP and EPEBS, the study show that soft segment contains two polymer-units is more suitable than EPEBS as gelling agents used in thickeners.