Direct transesterification of poly(methyl acrylate) for functional polyacrylate syntheses

Post-polymerization modification is an important synthetic method to produce macromolecules with various chemical and physical properties. With this technique, functional groups of polymer molecules within the same structural scaffold can be varied, and thus, accurate research on structure-property relationships is possible. To add practicality, the direct post-polymerization of commodity polymers has been pursued, but only limited success has been realized. In this report, a study on various transesterification methods for the synthesis of functional polyacrylates beginning with a poly(methyl acrylate) (PMA), one common acrylate polymer, is presented. The Zn-based catalytic system, a combination of Zn₄(OCOCF₃)₆O and 4-dimethylaminopyridine with instant methanol removal, exhibited the highest reactivity among many catalysts and conditions. Assorted alcohols were reacted with PMA to produce the corresponding polyacrylates. This method was successfully extended to post-polymerization modification of a PMA-containing block copolymer, PS-b-PMA and synthesis of acrylate copolymers with functional group density control.