摘要
以环己烷为溶剂、正丁基锂（n—BuLi）为引发剂、四氢呋喃（THF）和五甲基二乙基三胺（PMDETA）为微观结构调节剂、二乙烯基苯（DVB）为偶联剂，采用“臂先”和“核先”相结合的方法合成了星形杂臂畀戊二烯-丁二烯共聚橡胶[S-（PI）n-（PB）n]，并对其结构进行了表征。结果表明，最佳聚合工艺条件为单体质量浓度0．1g／mL、温度50～60℃、异戊二烯（Ip）聚合时间1h；在偶联反应时间为1h、[DVB]／[Li]（摩尔比）为1．0、聚异戊二烯的单臂数均分子量为6×10^4～10×10^4的条件下，采用Ip与DVB（摩尔比5：1）混合后的加入方式进行偶联反应，偶联效率可达70％，S-（PI）n-（PB）n的数均分子量为2．2×10^5～4．9×10^5，分子量分布可控制在1．80～2．10，PI和PB的平均臂数可达3—4，凝胶质量分数低于1．0％；当[THF]／[Li]（摩尔比）为0．5、[PMDETA]／[Li]（摩尔比）为1．0时，S-（PI）n-（PB）n中乙烯基质量分数可以达到63％。
Star miktoarm polyisoprene-co-poly-butadiene [ S-（PI） -（ PB ） n ] was synthesized by ＂arm-first＂ method and ＂core-first＂ method subse-quently with n-BuLi as initiator, tetrahydrofuran （THF） or pentamethyldiethyhriamine （PMDETA） as polar additive and divinylbenzene （DVB） as coupling agent. The results showed that the optimum polymerization conditions were mass concentration of monomer of 0. 1 g/mL, temperature of 50 - 60℃, polymerization time of isoprene of 1 h. The coupling efficiency could approach 70% when coupling time was 1 h, [ DVB]/[ Li] （mole ratio） was 1.0, single-arm number-average molecular weight of polyiso-prene was 6×10^4 - 10×10^4, and the isoprene and DVB（mole ratio 5：1 ） was mixed and then added. The number-average molecular weight of S-（ PI）n- （PB） n was 2.2×10^5 -4.9×10^5, its polydispersion index was 1.80 - 2. 10, average arm number of PI and PB was 3 - 4, and mass fraction of gel was less than 1.0%. The mass fraction of vinyl was 63% when [THF]/[Li] （mole ratio） was 0.5 and [ PMDETA]/[ Li] （ mole ratio）was 1.0.
出处
《合成橡胶工业》
CAS
CSCD
2010年第3期194-198,共5页
China Synthetic Rubber Industry
基金
国家自然科学基金资助项目(50773002)
关键词
丁二烯
异戊二烯
负离子聚合
偶联反应
星形杂臂橡胶
合成
表征
butadiene
isoprene
anionic poly-merization
coupling reaction
star miktoarm rubber
synthesis
characterization
