球形MgCl_2负载钛催化剂催化苯乙烯等规聚合与产物分子量分布研究  

SYNTHESIS OF ISOTACTIC POLYSTYRENE WITH MgCl_2 SUPPORTED TITANIUM CATALYST AND STUDIES ON ITS MOLECULAR WEIGHT DISTRIBUTION

作　　者：王国成[1] 范志强[1] 徐君庭[1] 

机构地区：[1]浙江大学高分子科学研究所,杭州310027

出　　处：《高分子学报》2005年第4期600-605,共6页Acta Polymerica Sinica

基　　金：国家自然科学基金资助项目(基金号20274037)

摘　　要：采用球形高效负载ZieglerNatta催化体系(TiCl4MgCl2AlR3二苯基二甲氧基硅烷(DPDMS)合成等规聚苯乙烯(iPS),催化效率最高可达7.7×103gPSgTi·h.通过多个SchulzFlory最可几分布对产物的分子量分布曲线拟合分峰来研究iPS的分子量及分子量分布的变化,AlEt3能使产物中低分子量部分含量增加,Al(iBu)3则倾向于形成高分子量的活性中心.体系中加入氢气不仅能显著提高催化效率,而且使iPS的分子量分布显著增宽.The highest catalytic efficiency of styrene polymerization reached 7.7×10^3 gPS/gTi· h by using MgCl2 supported spherical Ziegler-Natta catalyst systems（TiCl4-MgCl2/AlR3/diphenyldimethoxry silane）. ^13C-NMR analysis showed that the products were isotactic. The influences of polymerization conditions on molecular weight and molecular weight distribution （MWD） were studied by fitting the GPC curves of isotactic polystyrene （iPS） with the Schulz-Flory “most probable” distributions. When triethylaluminium was used as cocatalyst, the produced iPS mayhave more low molecular weight fractions, iPS with narrow distribution was produced with triisobutylaluminium as cocatalyst. When molecular hydrogen was added in the system, the catalytic efficiency was increased and the MWD of iPS was strongly broadened.

关 键 词：等规聚苯乙烯 分子量分布 球形MgCl2 负载钛催化剂 ZIEGLER-NATTA 等规聚合 二苯基二甲氧基硅烷 

分 类 号：TQ325.2[化学工程—合成树脂塑料工业]