High trans-1,4-butadiene-isoprene copolymer rubber

摘要

The solution copolymerization of butadiene (Bd) and isoprene (Ip) in the presence of supported titanium catalyst TiCl4/MgCl2-Al(i-Bu)_3 system was investigated. In the copolymer conditions as follows: f_1~0=10%～20%, Ti/M=5 x 10~(-5)～10 x 10~(-5)(molar ratio), Al/Ti=50～100(molar ratio), amd polymerization temperature at 50℃, a random copolymer (TBIR) with high trans-1,4-unit con-tent(above 90%) were obtained. In its composition, the mole fraction F_1 was about 30%～60%, T_g of TBIR around -70℃, and T_m of TBIR about 30～40℃. Hydrogen was employed as an effective molecular mass regulator. The results showed that TBIR possessed good processing properties when its mooney value[ML(1+4)100℃] was about 30～50. The mechanical properties of vulcanizated TBIR is between that of NR and BR. The most outstanding property of TBIR is dynamic anti-fatigue performance. Its crack initiation and propagation resistance is 100 times as that of NR, 4 times as that of BR, and 10～20 times as that of BR/NR which is widely used in tire sidewall compound. The vulcanizated TBIR holds the promise of sidewall application for high performance tires in which good anti-fatigue performance is highly demanded.