A convenient,highly-efficient method for preparation of hydroxyl-terminated isotactic poly(propylene) and functional di-block copolymer

Both terminated functional isotactic polypropylene（iPP） and block copolymers containing iPP segment are desirable for commercial applications.This paper provides a convenient,highly-efficient method to prepare hydroxyl-terminated isotactic polypropylene（iPP-t-OH） and functional di-block copolymer containing the iPP segment through a combination of coordination polymerization and coupling reaction.The coordination polymerization was catalyzed by TiCl;4/MgCl;/AlEt;catalyst system using ZnEt;as chain transfer agent.Further,the Zn-terminated iPP was oxidized and subsequently hydrolyzed to provide iPP-t-OH.Soxhlet extraction and;C NMR were used to calculate the isotacticity of iPP-t-OH.The degree of polymerization and the number of hydroxyl groups at the chain end of iPP-t-OH were measured by GPC and;H NMR.Despite the high molecular weight and heterogeneous reaction,iPP-t-OH is effectively linked with PEG-t-NCO to produce di-block copolymers.DSC analysis of the di-block copolymer shows an obvious decrease in T;and T;,which indicated that PEG was successfully linked to the terminal end of iPP.