Study On The High Trans Butadiene-Isoprene Copolymer

With the development of automobile industry and express high way,higher demands for tires have been brought about.To develop high-performance tires,which have low rolling resistance,high grip ability and superior abrasion resistance,is an important subject of state advance of science and technology.High performance of tires is,on the one hand,to produce radial tires,and on the other hand,to synthesize high performance rubber.High trans-1,4 butadiene-isoprene eopolymer(TBIR) is an ideal material for high performance radial tires due to its low heat build-up,outstanding fatigue durability,good wear characteristics and low temperature performance.BaDEGEE and BAT were synthesized in this paper at first.And then polyisoprene, TBIR and block TBIR were synthesized with organic barium/TIBA/n-BuLi compound initiator system and cyclohexane as the solvent.The effect on polymerization reaction and polymer with the initiator system was systematacially studied in this paper.The polymerization kinetics,mierostructure,Tg,Tm,molecular weight and molecular weight distribution were studied.From the summary the full thesis,it came to the conclusions,as follow:1.In the organic barium/TIBA/n-BuLi compound initiator system,both organic barium and TIBA played a very impotant role in forming complexes with n-BuLi to increase the content of trans 1,4-structure of polyisoprene,and neither was dispensable. BaDEGEE/TIBA/n-BuLi initiator system was better than BAT/TIBA/n-BuLi initiator system in regulating the content of trans 1,4-structure of polyisoprene.The polymerization rate was linear with monomer concentration.The apparent rate constants and activation energy for propagation of different polymerization conditions were obtained.2.TBIR having the content of high trans Bd units more than 70%was synthesized with BaDEGEE/TIBA/n-BuLi initiator system.There was no melting peak in the DSC curves.So the Ip units had a strong influence in the crystallinity of high trans Bd units.This copolymerization was fist order reaction.When the value of Ba/Li was 1/4,the copolymerization was dose to the constant polymerization with increasing the dosage of A1.3.Block TBIR with different block ratios was synthesized with BaDEGEE/TIBA/n-BuLi initiator system.There was only one peak in the GPC chromatogram.So it indicated that the polymer was block polymer but not blend polymer.