Synthesis of propylene diblock copolymers via metallocene and borane chemistry

An isotactic chain end unsaturated polypropylene was prepared by the homoge neous metallocene catalyst Et(Ind)(2)ZrCl2 with MAO. Herein, the chain end unsaturated polypropylene proceeded the hydroboration reaction to prepare b orane-containing polypropylene. The borane-containing polypropylene could b e transformed to hydroxyl-terminated polypropylene, PPOH. And then the poly propylene-nylon 6 diblock copolymer, PP-b-NY6, was synthesized from teleche lic PPOH by converting this prepolymer with toluene diisocyanate and using the resulting materials as macroactivators for anionic caprolactam polymeri zation. Meanwhile, this investigation used borane-containing polypropylene and oxygen to produce free radicals at the chain end on the polypropylene. Experimental results indicate that the free radical is an effective initiat or for the polymerization of methyl methacrylate to produce diblock PP-b-PM MA. The block copolymers are characterized by IR, NMR, and DSC analyses. Th e diblock copolymer is a good compatibilizer for polymer blends.