溶聚丁苯橡胶结构与加工应用性能的关系

针对聚合方法、微观组成、生胶门尼黏度相同的线型、两臂、三臂、四臂结构的溶聚丁苯橡胶(SSBR),及采用不同偶联剂四氯化硅(SiCl 4)和四氯化锡(SnCl 4)制备的四臂SSBR,考察SSBR的结构与加工应用性能的关系。结果表明,随着偶联臂数的增加,SSBR的玻璃化转变温度无明显变化,分子量分布逐渐加宽,对温度的敏感性逐渐下降。支化SSBR较线型SSBR具有更好的开炼机加工性、增强填料分散性及较弱的填料网络。随着支化臂数的增加,出口膨胀率增加。相对于SiCl 4,SnCl 4偶联的SSBR加工性能更佳。线型SSBR较支化SSBR具有更快的硫化速率,支化SSBR的动态力学性能更佳。

门尼黏度对SIBR性能的影响

以正丁基锂(n-BuLi)为引发剂,环己烷为溶剂,四氢呋喃(THF)为结构调节剂,四氯化锡(SnCl_4)为偶联剂,采用阴离子聚合法合成普通门尼黏度和高门尼黏度的无规溶聚苯乙烯-异戊二烯-丁二烯橡胶(SIBR)样品。对不同门尼黏度的SIBR样品进行了基本性能评价并与国内溶聚丁苯橡胶产品SSBR-C进行对比研究。

The application study of polycarboxylates water-reducing admixture in passenger dedicated line engineering

Polycarboxylate water-reducing admixture possesses the capability which could meet with the comprehensive performance of high performance concrete used in passenger dedicated line engineering.The problems of polycarboxylates water-reducing admixtures existed in the engineering application of were analyzed.At present the key for polycarboxylates application was to settle the compatibility between the water-reducing admixture and the cement and to keep the quality retention of this admixture.