星型SIBR合成中偶联反应的研究

Study on coupling reaction in synthesis of star type SIBR

以n -BuLi为引发剂 ,环己烷为溶剂 ,SnCl4为偶联剂 ,在不同极性添加剂存在下合成了苯乙烯、异戊二烯和丁二烯的偶联星型无规共聚物SIBR。研究了聚合阶段不同极性添加剂 (THF、THF -2G和 2G)、偶联温度、偶联剂用量及偶联方式对偶联效果的影响。研究结果表明适宜的工艺条件为 :极性添加剂THF或THF -2G ;偶联温度 70℃ ;偶联剂用量n(SnCl4) /n(Li) =0 .40～ 0 .45 (THF作极性添加剂 )或 0 .3 5 (THF -2G作极性添加剂 ) ;二次偶联、偶联前加入适量极性添加剂及丁二烯戴帽 。

The star random copolymer SIBR was synthesized by anionic polymerization of styrene,isoprene and butadiene using SnCl 4 as coupling agent,n BuLi as initiator,cyclohexane as solvent with the existence of different modifiers,The effects of modifier amount in the polymerizing period,the coupling temperatute,the amount of coupling agent and the coupling methods on the coupling reaction were investigated.It was found that suitable technological conditions are:THF or THF 2G as polar modifiers;70℃ as coupling temperature;[SnCl 4]/[Li] was about 0.40～0.45(THF as polar modifier) or 0.35(THF 2G as polar modifier);the difference of coupling methods also effects the coupling reaction. [WT5HZ]