【摘要】 用δ-Ticl₈-Et₂AlCl作催化剂,合成了含长乙烯序列的无规乙丙共聚物。影响乙烯丙烯共聚合产率的主要聚合参数是[Ti]、[Al]/[Ti]比和聚合温度,在55℃左右聚合产率呈现极大值;影响共聚物组成的主要参数是乙丙混合气中单体C₂的含量,当其在60克分子％以上,有利于生成长乙烯序列无规乙丙共聚物;[Ti]、单体C₂含量和聚合温度对共聚物的分子量有显著影响。用沉淀分级方法证明了共聚物组成的不均一性;用DSC,扭摆和TEM等方法对共聚物和与其组成相同的共混物进行对比,发现共聚物的T_m,T_c和X_c％均小于共混物;共聚物的T_g随C₂含量的增加向低温方向迁移,而共混物的T_g则随C₂含量增加移向高温;共聚物与共混物的形态结构均呈两相体系,前者PE片晶堆砌疏松,后者堆砌紧密;共聚物的常温断裂强度高达140公斤/厘米²,与钒催化剂制备的序列型AP447的强度（135公斤/厘米²）相近。更多还原

【Abstract】 Random ethylene-Propylene copolymers with long C2-sequences were synthesized with δ7-TiCl3-Et2AlCl since Ti catalysts have longer activity and tend to give long monomer esq-uences than vanadium catalysts. Results showed that [Ti] , [Al] / [Ti] and polymerization temperature were the main factors affecting polymerization yieli. Molecular weight of the copolymers was chiefly affected by [Ti] , monomer mixture composition and polymerization temperature.Structure and morphology of the copolymers were studied with DSC, dynamic mechanical spectrum and transmission electron microscope. By comparing the copolymers with EPR/PE blends, it was found that while Tg of the copolymers shifted to low temperature direction with increase in C2%, Tg of blends shifted to higher temperatures,One sample had a breaking strength of 140 kg/cm2,更多还原