宽峰聚乙烯催化合成及其性能

Polymerization, Morphology and Rheological Properties of Polyethylene with Broad MWD via Bimetallic Catalysts Supported by MgCl2

研究了ＭｇＣｌ２负载的双金属催化剂ＭｇＣｌ２／Ｔｉ（ＯＢｕ）Ｃｌ３／Ｃｐ２ＺｒＣｌ２和ＭｇＣｌ２／Ｔｉ（ＯＢｕ）Ｃｌ３／Ｅｔ（Ｉｎｄ）ＺｒＣｌ２催化乙烯聚合，得到了相对分子质量呈宽分布的聚乙烯．结果表明，相对分子质量分布宽度易受聚合条件影响，呈现随ｎ（ＡｌＥｔ３）／ｎ（Ｔｉ）增加，ｎ（ＭＡＯ）／ｎ（Ｚｒ）减少，峰宽增加的规律；分析了所得聚乙烯的形态；测定了宽峰聚乙烯的加工流变性能，在整个切变频率范围内，该类聚乙烯的储能模量和损耗模量变化不大。

The polyethylene with broad molecular weight distribution was synthesized using bimetallic catalysts supported by MgCl2, e.g. MgCl2/Ti(OBu)Cl3/CpZrCl2Cl2 and MgCl2/Ti(OBu)Cl3/Et(Ind)ZrCl2. The molecular weight distribution of polyethylene was affected sensitively by polymerization condition, especially the molar ratio of Et3Al to Ti(OBu)Cl3 and the molar ratio of MAO to metellocenes. Dynamic measurements in a plateplate system were presented for broad MWD polyethylene. The morphology of the PE was showed with SEM. The rheological behavior of the PE obtained is different from conventional commercial PE. The PE carried out by the MgCl2supported bimetallic catalytic system is highly elastic.