胺基铪茂催化乙烯/1-辛烯无规共聚合的研究

COPOLYMERIZATION OF ETHYLENE WITH 1-OCTENE CATALYZED BY HAFNOCENE DIAMIDE

在亚乙基双（ 茚基） 二胺化茂铪（ｒａｃＣ２Ｈ４（Ｉｎｄ）２Ｈｆ（ＮＭｅ２）２ ，简称１ ，Ｉｎｄ ＝ 茚基，Ｍｅ＝ 甲基） 催化作用下，对乙烯（Ｅ） 与１辛烯（Ｏ） 无规共聚合进行了研究．作为比较，利用异亚丙基（ 环戊二烯基）（１芴基） 二甲基锆茂催化体系（（ＣＨ３）２Ｃ（Ｆｌｕｏ）（Ｃｐ）ＺｒＭｅ２ ，简称２ ，Ｆｌｕｏ ＝ 芴基，Ｃｐ ＝ 环戊二烯基） 对乙烯／１辛烯在相同共聚合条件下进行了共聚合．结果表明，在单体浓度比［Ｏ］／［Ｅ］ 较小时共聚合速率随单体浓度比增加而增加，进一步增加单体浓度比则导致共聚合速率降低．催化体系１／Ａｌ（ｉＢｕ）２Ｈ／［Ｐｈ３Ｃ］［Ｂ（Ｃ６Ｆ５）４］（３） 催化共聚活性比２／ ＭＡＯ高得多．共聚物中辛烯含量随反应单体１辛烯含量的增加而增加，两单体竞聚率乘积（ ｒＥ×ｒｏ） 小于１ ，表明聚合物为无规共聚物．相同共聚单体浓度比下１／Ａｌ（ｉＢｕ）２Ｈ／３ 催化共聚物中辛烯含量比２／ ＭＡＯ 共聚物中辛烯含量高，表明前者具有更强的共聚合能力．所得无规共聚物熔点温度、结晶度、本体粘度及密度随共聚物中辛烯含量的增加而显著降低．辛烯含量较高时共聚物呈现明显无结晶行为．差示扫描量热分析显示，同乙烯均聚?

Copolymerization of ethylene with 1 octene is reported based on metallocene, rac \|C 2H 4(Ind) 2Hf(NMe 2) 2 (1) (Ind=η 5\|indenyl) and (CH 3) 2C(Fluo)(Cp)ZrMe 2 (2) (Cp=η 5\|cyclopentadienyl,Fluo=η 5\|fluorienyl).The result shows that the copolymerization rate increases with the increase of comonomer molar ratio ([O]/[E]).Further increase of [O]/[E] reduces copolymerization rate.The activity of 1/Al(\%i\%Bu) 2/[Ph 3C][B(C 6F 5) 4](3) is much higher than that of 2/MAO.System 1/Al( \%i\% Bu) 2/3 also shows higher incorporation ability of 1\|octene into copolymer than that of 2/MAO.The values of the product r E× r O are below 1 for all the resulting copolymer,which correspond to random copolymer structures with a more alternating structure.The melting point( T m),crystallinity ( X C),intrinsic viscosity ([η]) and density ( D ) of the 1\|octene/ethylene copolymers decreased markedly with an increase in the 1\|octene content,regardless of the type of catalytic system.High comonomer contents of the products show clearly amorphous behavior.All the copolymers show melting within a broad temperature range,duplicate peaks or with shoulder.The copolymers produced by 1/Al( i Bu) 2H/3 have much higher molecular weight than that of 2/MAO,and have a wider range of density from 0 965 to 0 84 g/cm 3.