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 MgCl 2 ‐supported TiCl 4 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. Copyright © 2006 Society of Chemical Industry