丁苯接枝的高乙烯基聚丁二烯橡胶合成及其与丁苯橡胶的相容性研究

SYNTHESIS OF SB-GRAFTED HVPBR AND ITS COMPATIBILITY WITH SBR

以n-BuLi为引发剂,THF为结构调节剂合成一定分子量和苯乙烯结构单元含量的丁苯大分子(SB).在SB的加氢汽油溶液中用Mo-Al(正辛醇取代的MoCl5和Al(OPhCH3)(i-Bu)2)催化丁二烯配位聚合制备丁苯接枝的高乙烯基聚丁二烯橡胶(SB-grafted HVPBR).接枝结构是通过聚丁二烯活性链与SB分子上的双键反应生成.通过在HVPB主链上引入丁苯支链,使聚合物由线形变成含支链的聚合物,以此降低聚合物溶液的动力黏度,改善钼系催化丁二烯聚合溶液黏度大的缺点.采用FTIR、GPC、凝胶渗透色谱仪-激光光散射仪-在线黏度计联用系统、DSC等表征手段,研究SB用量和苯乙烯含量对SB-grafted HVPBR结构和聚合物溶液黏度的影响.通过差示扫描量热法(DSC)测试SB-grafted HVPBR与SBR不同共混比下硫化胶的玻璃化转变温度Tg,对SB-grafted HVPBR/SBR共混胶的相容性进行表征,初步探索SB-grafted HVPBR与SBR共混胶的共混比对两相相容性的影响.

Graft copolymers of high vinyl polybutadiene with butadiene-styrene copolymer（SB-grafted HVPBR） were synthesized by polymerization of butadiene in hydrogasoline solution of styrene-butadiene random copolymer（SB）（St% was 30%,Mn was 3.7×10-3） using a homogeneous MoCl3（OC8H16）2/Al（（OPhCH3）（i-Bu）2 catalyst.Graft copolymers were formed when the growing polybutadiene chains threaded through the double bonds of the dissolved SB,giving copolymers with proliferating chain structures.SB was synthesized by anionic polymerization with butyl-lithium as initiator and tetrahydrofuran as structural regulator.The effect of addition amount of SB on the structure and properties of SB-grafted HVPBR was studied by means of FTIR,GPC and GPC-MALLS-Viscometer Analysis System etc.Compared with HVPBR,the molecular weight of SB-grafted HVPBR and molecular weight distribution and the content of gel raised slightly.The solution dynamic viscosity of HVPBR was decreased to a great extent as a result of the presence of the SB graft chain.The graft efficiency was the highest when the SB＇s addtion was 3 wt%.Glass transition temperature（Tg） of SB-grafted HVPBR/SBR compounds at varying blending ratios were measured using differential scanning calorimetry（DSC）.The results of DSC confirmed that the compatibility of HVPBR and SBR was improved effectively by grafting SB onto HVPBR.