苯乙烯-对叔丁基苯乙烯-间戊二烯三元共聚物制备及表征

The Synthesis and Characteristic of Poly(styrene-co-p-tbutyl-styrene-co-pentadiene)Terpolymer

相对于异戊二烯和丁二烯传统二烯烃,新型间戊二烯单体可以通过阴离子共聚合实现特殊序列结构共聚物,如交替共聚物。本文以间戊二烯、苯乙烯和对叔丁基苯乙烯为共聚单体,通过丁基锂引发聚合合成系列二元及三元共聚物,重点考察了共聚动力学和共聚物的微观结构。实验结果表明:(1)聚合动力学显示共聚合符合经典一级反应特征,共聚单体可以转化完全;(2)核磁氢谱在线分析表明共聚单体等摩尔消耗,核磁氢谱和碳谱证明了二元交替共聚结构;(3)二元及三元共聚均具有明显的活性可控聚合特征,分子量与理论值高度吻合,分子量分布D均小于1.20;(4)示差扫描量热(DSC)结果显示交替共聚物是一类特殊的半结晶聚合物,玻璃化转变温度Tg可以通过调控共聚单体比例微调,Tm在100~120℃范围;(5)基于间戊二烯特殊的二元交替共聚,推测了可能的聚合机理。

In contrast to conventional isoprene and butadiene,1,3-pentadiene monomer can undergo anionic copo-lymerization to afford special sequence controlled copolymers,such as alternating copolymers.In this paper,a series of binary and ternary copolymers were synthesized using 1,3-pentadiene,styrene and p-tert-butylstyrene comonomers and initiated by n-butyllithium.Focusing on the copolymerization kinetics and microstructure of copolymers,some interesting results were obtained:(1)kinetics analysis indicated that copolymerization conformed to the characteristics of classical primary reactions,and all comonomers can be converted completely;(2)the real-time NMR analysis showed the equal consumption of pentadiene and its comonomer,and~1H-NMR/13C-NMR spectra all proved the binary alternating sequence structure;(3)binary and ternary copolymerization had obvious living and controllable polymerization characteristics,the molecular weight was highly consistent with the theoretical value,and the molecular weight distribution D was less than 1.20;(4)the DSC results showed that copolymers were a special class of semi-crystalline polymers,and the glass transition temperature Tgcan be fine-tuned by regulating the proportion of comonomers,and Tmis in the range of 100-120℃;(5)Based on dual-alternating copolymerization strategy of pentadiene,we proposed the possible alternating polymerization mechanism.