Star High Vinyl Polybutadiene Synthesis

In this article, star-high vinyl content polybutadiene (S-HVBR) was prepared using a multi-functional organolithium anionic initiator by " one-step " process. On the basis of 250ml glassware experiment ,we improved the experiment in 2L metal kettle. The polymerization condition was got as follows: polymerization temperature : 50-60 ℃ , monomer content : 8-llg/100ml, polymerization time : 3~4 hours.Chracterizations were carried out by 'H-NMR, IR and GPC. It indicated the microstructure of S-HVBR as follows: the vinyl content: >70%, the number of arms : 2.5-4.5, molecular weight: l~4X105, molecular weight distribution : 1.3-2.5, the coupling efficiency: almost 100%, no linear polybutadiene.The factors affecting the microstructure of S-HVBR were discussed in the article. The species of polar additives and the content of polar additives as well as the temperature all had effect on the structure of S-HVBR, We also found the rules of unitary modifying system and duality modifing system.In order to solve the viscosity problem, we studied the factors that arised the viscosity of the system. We also analysized the themodynamics properties of S-HVBR by DSC and TG. Through testing the force properties, it showed that S-HVBR had better physical properties and dynamic properties.