New materials designed by coordination polymerization of omega-undecenyl macromonomers
Résumé
The major part of the present paper discusses the ability of well-defined omega-undecenyl polystyrene, polyisoprene or poly(styrene-block-isoprene) macromonomers to undergo coordination homopolymerization in the presence of selected titanium catalysts. Special emphasis is given to the influence of the nature of the catalyst, the polymerization temperature and the macromonomer molar mass and concentration on homopolymerization yield and average degree of homopolymerization (DPn). Titanium-based catalytic systems such as CpTiCl3/MAO and Cp*TiCl3/MAO only yielded dimers. The use of the homogeneous metallocene catalyst with constrained ligand geometry (CGC-Ti/MAO) having an open active site, significantly improved the degree of polymerization. increasing macromonomer molar mass, causes only a slight decrease of DPn whereas conversion increased moderately. The final section briefly discusses the copolymerization of omega-undecenyl polystyrene macromonomers with ethylene in the presence of Versipol (TM) catalysts.