ABC Triblock Copolymers Prepared Using Atom Transfer Radical Polymerization Techniques

Triblock copolymers (or, alternatively, terpolymers) of the type ABC, where A, B, and C represent distinct blocks based on different monomers, have been prepared using atom transfer radical polymerization (ATRP) techniques. Various macroinitiators, including mono- and difunctional poly( tert -butyl acrylate), difunctional poly(styrene), and trifunctional p(St), were prepared and used for block copolymerizations with different monomers, including methyl acrylate, methyl methacrylate, and vinylpyridine. The block copolymers were characterized by gel permeation chromatography to determine chain end functionality and by 1 H NMR to measure the final composition of the block copolymers. Additionally, guidelines are presented for preparing block copolymers using ATRP techniques. Topics addressed include approaches to retaining the chain end functionality, achieving a high blocking efficiency, as well as strategies to maintain control over the ATRP reaction.