Homo-and Copolymerization Of1-octene Catalyzed By Palladium(Ⅱ)-α-diimine

The palladium（Ⅱ）--diimine catalyst [（ArN=C（An）-C（An）=NAr）Pd（CH₂）₃C（O）OMe]（BAr’4） was synthesized. The homo-polymerization of1-octene was catalyzed in CH2Cl2by the Palladium（Ⅱ）-based catalyst tostudy the performance of the catalyst. When synthesizing the catalyst,we introduced a small amount of water to improve catalyst properties.The structure of the two catalysts were characterized by IR, EA, DSC,NMR, etc. The homo-polymerization of1-octene and copolymerization of1-octene with methyl acrylate （MA） were carried out using thepalladium（Ⅱ）--diimine including bound water [（ArN=C（An）-C（An）-=NAr）-Pd（CH₂）₃C（O）OMe]（BAr’4）·H₂O as the catalyst adopting fourmethods: CH₂Cl₂, water, emulsion and bulk polymerization. The chemicalstructure of product such as diameter of particles, melting point,molecular weight and morphology were revealed through light scattering,GPC, DSC, NMR, etc. We furtherly study the emulsion polymerizationsystem using different types of emulsifiers under different temperatures.The results suggested the polymerization was carried out throuth fourmethod of CH₂Cl₂, water, emulsion and bulk polymerization successfully, resulting poly（1-octene） and poly（1-octene and MA） with themolecular weight of2.310⁴⁶10⁴. In general, the degree ofbranching in the polymers are high, in which the degree of branching ofthe polymers synthetized by aqueous polymerization are higher and thedegree of branching of the polymers synthetized in CH2Cl2is the lowest.The polymers synthetized in emulsion and bulk polymerization arebetween aqueous polymerization and CH2Cl2polymerization. Thecatalytic activity in emulsion system is the lowest （homopolymerizationis2.71kg/mol and copolymerization is2.6kg/mol） and the others arehigher than it. The catalytic activity in CH₂Cl₂is highest （homopolymeri-zation is17.51kg/mol and copolymerization is16.7kg/mol）. The particlesize is200⁴00nm in water and emulsion polymerization, the state ofthe polymerization systems is stable respectively. The temperature on theimpact of trends in the emulsion polymerization system is that thepolymer molecular weight increased when the temperature rised, but thecatalytic activity declined slightly, the polymers in CH₂Cl₂areamorphous polymers with only glass transitiontransition temperature Tg（homopolymer the Tg:-45.6oC, the copolymer Tg:-47.5oC） withoutmelting point Tm. The polymers in the aqueous system and the emulsionsystem are crystalline polymers with Tg and Tm. The Tg and Tm ofhomopolymer synthetized in aqueous polymerization are-54.7℃and74.8℃. The Tg and Tm of copolymer synthetized in aqueous polymerization are-34.8℃and32.3℃. The Tg and Tm of homopolymersynthetized in emulsion polymerization are-54.5℃and50.3℃. The Tgand Tm of copolymer synthetized in emulsion polymerization are-57℃and83℃.