高结合苯乙烯含量且均匀无规分布的溶聚丁苯橡胶的合成(英文)

Synthesis of solution polymerized styrene-butadiene rubber with high bound styrene content and styrene uniform random distribution

采用负离子活性聚合的方法,以正丁基锂为引发剂、环己烷为溶剂、四氢呋喃为极性调节剂、叔戊醇钾为无规化剂,合成了结合苯乙烯质量分数为40%且均匀无规分布、1,2-结构质量分数为35%~40%的溶聚丁苯橡胶;考察了四氢呋喃用量和叔戊醇钾用量对产物的苯乙烯无规分布均匀性、1,2-结构含量等的影响。结果表明,四氢呋喃只能使苯乙烯-丁二烯无规共聚,苯乙烯的均匀无规分布主要受叔戊醇钾加入量的影响;当四氢呋喃和叔戊醇钾与正丁基锂的摩尔比分别为50和15.33×10^-3时,在整个大分子链的增长过程中结合苯乙烯含量都保持在设计值附近,表明苯乙烯在大分子链上基本为均匀无规分布;四氢呋喃对于产物1,2-结构含量的调节起主要作用,而叔戊醇钾基本无影响,二者对产物的相对分子质量及其分布和共聚组成基本无影响。

Adjusting bound styrene （St） content and its distribution, vinyl （By） content and the adaptation of St and By is the main means to improve the structure and properties of solution polymerized styrenebutadiene rubber（ SSBR）. According to the literature , compared with the conventional SSBR（ mass fraction of St 25% , Bv 60% ） used in making tire, the SSBR with 30%-40% of 1,2-unit mass fraction and 40% of St could significantly improve the wet skid resistance, nevertheless the rolling resistance increased not obviously, the mechanical properties were enhanced evidently. In anionic copolymerization of butadiene and St, the reactivity ratio of butadiene is much higher than that of St, so that a random copolymerization took place, and the distribution of St in the molecular chain is inhomogeneous, which was unfavourable to the properties of SSBR. Therefore, adjusting bound St in SSBR molecular chain to a high level and having its distribution uniform and random is an effective method to improve the performance of SSBR.