Multiple morphologies of a poly(methyl methacrylate)‐<i>block</i>‐poly(<i>N,N</i>‐dimethyl aminoethyl methacrylate) copolymer with pH‐responsiveness and thermoresponsiveness

Abstract

ABSTRACT We successfully prepared a series of pH‐responsive and thermoresponsive poly(methyl methacrylate) (PMMA)‐ block ‐poly( N,N ‐dimethyl aminoethyl methacrylate (PDMAEMA) copolymers via reversible addition–fragmentation chain‐transfer polymerization with PMMA as a macro chain‐transfer agent. Control over the chain length of PDMAEMA allowed the morphological transformation of PMMA‐ b ‐PDMAEMA. The critical water content and critical micelle concentration also depended on the length of the PDMAEMA block. UV–visible and fluorescence spectrum analyses indicated that the PMMA‐ b ‐PDMAEMA copolymer exhibited a lower critical solution temperature type phase transition in water. The particle size of PMMA‐ b ‐PDMAEMA was dominated by the pH value, as evidenced by dynamic light scattering and transmission electron microscopy. In addition, the PMMA‐ b ‐PDMAEMA copolymers exhibited good reversible thermoresponsive behavior between 33 and 38°C. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47972.