溶液聚合法合成低分子反式-1,4-聚异戊二烯蜡

以加氢汽油为溶剂，采用负载型TiCl4／MgCly-Al(i-Bu)，体系催化异戊二烯聚合，高压氢气调节相对分子质量，溶液聚合法合成出了低相对分子质量反式-1，4-聚异戊二烯蜡(LMTPIW)，并分别探讨了氢气压力和聚合温度对LMTPIW的相对分子质量、聚合物组成以催化效率的影响。结果表明：氢气压力由0．8MPa增加至4．0MPa，LMTPIW的特性粘数由0．391dL／g下降至0．1951dL／g，相应数均相对分子质量从1500降至1000以下，常温下汽油可溶物的质量分数由49．3％逐渐上升至77．6％，相对分子质量分布变窄。随聚合温度的升高，LMTPIW的相对分子质量有所增大，分布加宽。氢气压力及聚合温度的上升均使体系催化效率下降，但仍可保持在2500g／gTi以上。

Synthesis of low relative molecular mass trans-1,4-polyisoprene wax by solution polymerization with supported titanium catalyst

With high pressure hydrogen as relative molecular mass modifier, hydrogenation gasoline as solvent and supported TiCl_4/MgCl_2-Al(i-Bu)_3 system as catalyst, the low relative molecular mass trans-1,4-polyisoprene wax (LMTPIW) was synthesized. The effect of hydrogen pressure and polymerization temperature on relative molecular mass, content of LMTPIW and catalytic efficiency (CE) was discussed. The results showed that when hydrogen pressure increased from 0.8MPa to 4.0MPa, the intrinsic viscosity of the LMTPIW decreased from 0.391dL/g to 0.1951dL/g, accordingly its number-average relative molecular mass decreased from 1500 to 1000 below and the content of low molecular mass portion which could be dissolved by gasoline increased from 49.3% to 77.6%. The relative molecular mass distribution changed narrow. With increasing of polymerization temperature, the intrinsic viscosity of LMTPIW increased, and distribution was wider. The rise of hydrogen pressure and polymerization temperature resulted to the decreasing of CE,but the CE keep still over 2500g/g Ti.