Preparation of Ultra High Molecular Weight Polyethylene with MgCl2/TiCl4 Catalyst: Effect of Hydrogen and Cocatalyst on Molecular Weight and Molecular Weight Distribution
作者：ZHANG He鄄Xin1, ZHANG Hao1,3, ZHANG Chun鄄Yu1, HAO Xiu鄄Feng1,2*, ZHANG Xue鄄Quan1
關(guān)鍵字：Hybrid copolymer; Copolymerization; Nanocomposite; Ethylene; Polyhedral oligomeric silsesquioxane(POSS); bis(cyclopentadienyl) zirconium dichloride(Cp2ZrCl2) catalyst
論文來(lái)源：期刊
具體來(lái)源：CHEMICAL JOURNAL OF CHINESE UNIVERSITIES 2012 年 8 月Vol. 33 1850 ~ 1853
發(fā)表時(shí)間：2012年
An organic / inorganic hybrid copolymer was prepared with a bis ( cyclopentadienyl) zirconium dichloride ( Cp2ZrCl2 ) in conjunction with modified methylaluminoxane ( MMAO) cocatalyst. Two kinds of monovinyl substituted polyhedral oligomeric silsesquioxane(POSS) monomers were used to copolymerize with ethylene(E). The copolymers were characterized with 1H NMR, DSC, TGA and GPC to know the composition, thermal properties, molecular weight and its distribution, respectively. The comonomer content(POSS) was in the range of 0郾 01% —0郾 30% (molar fraction). With the increase of POSS content in copolymer, the melting temperature and heat of fusion decreased. Thermogravimetric analysis of E / POSS copolymers exhibited an improved thermal stability with a higher degradation temperature and char yields, demonstrating that the inclusion of inorganic POSS nanoparticles made the organic polymer matrix more thermal robust. Increasing the feed ratio of POSS, the molecular weight increased, while the molecular weight distribution broadened.