Influence of Type and Content of Various Comonomers on Long-Chain Branching of Ethene/α-Olefin Copolymers

摘要: One polyethylene and nine ethene/α-olefin copolymers differing in amount (0.4−2.9 mol %) molar mass of the comonomer were characterized by NMR, SEC-MALLS, rheology. Samples polymerized using a [Ph2C(2,7-di-t-BuFlu)(Cp)]ZrCl2/MAO catalyst, with octene, octadecene, hexacosene as comonomers, resulting polymers Mw ≈ 190 kg/mol. The content was determined melt-state NMR. For homopolymer 0.37 0.30 LCB/molecule found NMR respectively. Rheological quantities, such zero shear rate viscosity (η0), increased LCB compared to linear samples same Mw. shape function steady-state elastic compliance ( ) showed dependence on length. These findings are used elucidate various long-chain branching architectures. highest behaved like typical rheological experiments, while those less contents be lo...