不同单体质量比合成TBIR的结构与性能

Structure and properties of trans-1,4-butadiene-isoprene copolymerized rubber with different monomer mass ratios

研究了不同单体比例反式-1,4-丁二烯-异戊二烯共聚橡胶(TBIR)的结构及性能。结果表明,采用溶液聚合方法合成TBIR,在控制转化率保持一致的条件下,随着丁二烯/异戊二烯(Bd/Ip)单体质量比增加,其聚合催化效率逐渐增大;Bd和Ip结构单元均以反式-1,4-结构(>95%)为主,产物中Ip反式-1,4结构含量略有降低,Ip链段长度减小,Bd反式-1,4含量逐渐增加;随着Bd单体质量增加,玻璃化转变温度降低,结晶能力逐渐下降,TBIR为具有一定结晶性的无规共聚物;数均相对分子质量逐渐增加,相对分子质量分布变宽。当Bd/Ip单体质量比为10/100时,与纯天然橡胶(NR)相比,10份TBIR替代NR,硫化胶耐磨耗性能提高了11%;Bd/Ip单体质量比为2/100时,Ip反式-1,4结构摩尔分数最高达到96%以上,1,4-反式聚异戊二烯(TPI)链段较长,10份TBIR替代NR,硫化胶具有优异的物理机械性能,耐屈挠疲劳寿命提高了81%。

The structure and properties of trans-1,4-butadiene-isoprene copolymerized rubber(TBIR)with different monomer properties were studied.The results showed that the conversion rate increased with the increase of Bd/Ip ratio.TBIR were synthesized by solution polymerization under the condition of the same polymerization efficiency.Both Bd and Ip structural units were mainly composed of trans-1,4-structure(>95%).The content of Ip trans-1,4 structure decreased slightly,the length of Ip chain segment decreased,and the content of Bd trans-1,4 gradually increased.The glass transition temperature and crystallization capacity decreased,TBIR is a random copolymer with crystallinitywith M n increased and M w/M n widened gradually.Wear resistance got better with the increase of Bd content,and the Bd/IP mass ratio was 10/100.When 10 parts TBIR replaced natural rubber(NR),the wear resistance increased by 11%compared with pure NR.When the mass ratio of Bd/Ip was 2/100,Ip trans-1,4 structure mass fraction reached more than 96%,and TPI chain segment was longer.When 10 phr TBIR replaced NR,vulcanization had excellent mechanical properties,and flexure fatigue life increased by 81%.