Facile access to functional polyacrylates with dual stimuli response and tunable surface hydrophobicity

Abstract

Magnetically separable and reusable Ni–Co alloy nanoparticles were employed to achieve ambient temperature reversible deactivation radical polymerization (RDRP) of methyl acrylate (MA), for the first time, yielding well-defined PMA (at least up to 124 500 g mol⁻¹) with a low dispersity (Đ ≤ 1.20). The controlled polymerization character of RDRP of MA was confirmed from the linear semilogarithmic plot exhibiting pseudo first order kinetics, a linear increase of the molecular weight of the polymer with monomer conversion maintaining low Đ and the synthesis of PMAs of varying molecular weights from 2200 to 124 500 g mol⁻¹ with low Đ. In addition, linear PMA-Br was used as a macroinitiator for the synthesis of several well-defined PMA-b-poly(M) block copolymers (where “M” stands for (2-dimethylamino)ethyl methacrylate (DMAEMA), tert-butyl methylacrylate (TBMA) and 2,2,3,3,4,4,5,5-octafluoropentyl acrylate (OFPA)), with acceptable Đs (≤ 1.24), demonstrating the high chain-end fidelity of the macroinitiator. The synthesized PMA-b-PDMAEMA demonstrated dual pH- and thermo-responsive properties. Upon hydrolysis, the synthesized PMA-b-PTBMA leads to the formation of unprecedented carboxylic acid-functionalized PMA derivatives. PMA-b-POFPA copolymers with varying OFPA mol% in the copolymer led to polymers with tunable surface hydrophobicity, as revealed by the water contact angle measurements.