Synthesis of polypropylene graft copolymers from a hydroxyl-groups-containing polypropylene precursor via atom-transfer radical polymerization

Isotactic polypropylene graft copolymers, isotactic[polypropylene-graft-poly(methyl methacrylate)] (i-PP-g-PMMA) and isotactic[polypropylene-graft-polystyrene] (i-PP-g-PS), were prepared by atom-transfer radical polymerization (ATRP) using a 2-bromopropionic ester macro-initiator from functional polypropylene-containing hydroxyl groups. This kind of functionalized propylene can be obtained by copolymerization of propylene and borane monomer using isospecific MgCl2-supported TiCl4 as catalyst. Both the graft density and the molecular weights of i-PP-based graft copolymers were controlled by changing the hydroxyl group contents of functionalized polypropylene and the amount of monomer used in the grafting reaction. The effect of i-PP-g-PS graft copolymer on PP-PS blends and that of i-PP-g-PMMA graft copolymer on PP-PMMA blends were studied by scanning electron microscopy. (c) 2006 Society of Chemical Industry.