Preparation and characterization of poly(ɛ-caprolactone)-b-polyacrylonitrile (PCL-b-PAN) and poly(l-lactide)-b-polyacrylonitrile (PLLA-b-PAN) copolymers by aluminum and lithium alkoxides containing double-headed initiators

Abstract Three new metal alkoxides, [(MMPEP)Al(μ-OCH 2 C 6 H 4 CH 2 Cl)] 2 ( 1 ), [(MMPEP–H)Li·(BnOH)] 2 ( 2 ) and [(MMPEP–H)Li·(HOCH 2 C 6 H 4 CH 2 Cl)] 2 ( 3 ) (MMPEP–H 2 : 2,2′-methylene-bis{4,6-di(1-methyl-1-phenylethyl)phenol}) have been synthesized and characterized. Complex 1 was prepared by the reaction of [(MMPEP)Al(CH 3 )(Et 2 O)] with p -(chloromethyl)benzyl alcohol. Followed by the reaction of MMPEP–H 2 with n BuLi, BnOH or p -(chloromethyl)benzyl alcohol was added to give complexes 2 and 3 , respectively. Complex 1 has shown excellent catalytic activity towards ring-opening polymerization (ROP) of ɛ-caprolactone. Both complexes 2 and 3 are active for ROP of l -lactide. Block copolymers of poly(ɛ-caprolactone)- b -polyacrylonitrile (PCL- b -PAN) and poly( l -lactide)- b -polyacrylonitrile can be synthesized by combining a technique of atom transfer radical polymerization (ATRP) and ROP using a double-headed initiator. Microphase-separated morphology of PCL- b -PAN has been observed by transmission electron microscopy, indicating the formation of self-assembled nanostructure.