Copolymerization of 4-acetylphenyl methacrylate with ethyl methacrylate: Synthesis, characterization, monomer reactivity ratios, and thermal properties

Abstract

Methacrylates have high glass transition temperature (T g) values and high thermal stability. A new methacrylate copolymer, poly(4-acetylphenyl methacrylate-co-ethyl methacrylate) (APMA-co-EMA), was synthesized. The thermal behaviors of copolymers were investigated by differential scanning calorimetry and thermogravimetric analysis. They behaved as new single polymers with single T g 's and the thermal stability of the copolymers increased with increasing 4-acetylphenyl methacrylate (APMA) fraction, leading to the manufacture of copolymers with desired T g values. Structure and composition of copolymers for a wide range of monomer feed ratios were determined by Fourier transform infrared (FT-IR) and 1H-nuclear magnetic resonance ( 1H-NMR) spectroscopic techniques. Copolymerization reactions were continued up to 40% conversions. The monomer reactivity ratios for copolymer system were determined by the Kelen-Tüdös (r a (APMA) = 0.81; r b (EMA) = 0.61) and extended Kelen-Tüdös (r a = 0.77; r b = 0.54) methods and a nonlinear least squares (r a = 0.74; r b = 0.49) method. © 2014 Gamze Barim and Mustafa Gokhun Yayla.