摘要
端基官能化橡胶在改善填料分散性,增加橡胶与填料之间相互作用力,进而影响橡胶复合材料性能方面发挥重要作用.本文采用非均相TiCl_(4)/MgCl_(2)型Ziegler-Natta催化剂,以二环己胺(DCHA)为链转移剂,通过配位链转移聚合法一步合成了组成和结构可控的胺端基官能化的高反式-1,4-丁二烯-异戊二烯共聚橡胶(F-TBIR).研究了DCHA和助催化剂三乙基铝(AlEt_(3))的用量对催化活性、胺端基官能化效率(CE,%)和F-TBIR链微观结构的影响.结果表明,DCHA不改变催化剂的定向能力,DCHA用量增加时,催化活性及聚合物的分子量降低,CE显著提高;随着AlEt_(3)用量增加,催化活性先增加后降低,CE与聚合物分子量均逐渐降低.计算得到本文实验条件下DCHA的链转移常数为0.0537,AlEt_(3)的链转移常数为0.016.结合密度泛函理论(DFT)模拟,讨论了DCHA和AlEt_(3)在非均相Ziegler-Natta催化剂催化二烯烃配位聚合中的链转移机理,为制备端基官能化的合成橡胶提供了一种简便可行的策略.
The chain-end functionalized rubbers play important roles in improving the filler dispersion and increasing the interaction force between rubbers and filler particles,both of which affect the properties of the final products.In this paper,amine-capped trans-1,4-poly(butadiene-co-isoprene)copolymers(F-TBIR)with con⁃trollable composition and micro-structure were synthesized through one-step coordination chain transfer polymerization by using heterogeneous TiCl_(4)/MgCl_(2)type Ziegler-Natta catalyst with dicyclohexylamine(DCHA)as chain transfer agent.The effects of the amount of DCHA and co-catalyst triethylaluminum(AlEt_(3))on the the catalytic efficiency,amine-capped efficiency(CE,%)and chain micro-structure of the F-TBIR were investigated.The results indicated that DCHA did not change the stereo-regularity of the catalytic species.With the increase in DCHA dosage,the catalytic efficiency and molecular weight of the copolymers decreased,while CE increased significantly.With the increase in the amount of AlEt_(3),the catalytic efficiency initially increased then subsequently decreased,and the molecular weight of polymer and CE gradually decreased.Under the specified experimental conditions,the chain transfer constants of DCHA and AlEt_(3)were 0.0537 and 0.016,respectively.Combined with density functional theory(DFT)simulation,the chain transfer mechanism of DCHA and AlEt_(3)in the diene coordination polymerization catalyzed by heterogeneous Ziegler-Natta catalyst was discussed.This work provides a straightforward and feasible strategy for developing chain-end functionalized synthetic rubber.
作者
罗淑芳
赵远进
王硕
周润川
杨霞
贺爱华
LUO Shufang;ZHAO Yuanjin;WANG Shuo;ZHOU Runchaun;YANG Xia;HE Aihua(Shandong Key Laboratory of High Performance Polyolefin Materials and Recycling,Key Laboratory of Rubber-plastics(Ministry of Education),School of Polymer Science and Engineering,Qingdao University of Science and Technology,Qingdao 266042,China;Research Center for Computer and Chemical Engineering,College of Chemical Engineering,Qingdao University of Science and Technology,Qingdao 266042,China)
出处
《高等学校化学学报》
北大核心
2025年第8期136-145,共10页
Chemical Journal of Chinese Universities
基金
国家重点研发计划项目[批准号:2022YFB3704700(2022YFB3704702)]
山东省重大科技创新工程项目(批准号:2021CXGC010901)
泰山学者工程资助.
