Monomer composition effects on thermal properties of transparent poly(methyl methacrylate-co-isobornyl methacrylate-co-cyclohexyl maleimide) terpolymers

Terpolymers based on methyl methacrylate (MMA), isobornyl methacrylate (IBOMA) and N-cyclohexyl maleimide (ChMI) were synthesized by conventional free-radical solution copolymerization. The mole fraction of all polymers was characterized by elemental analysis and H-1 NMR spectroscopy. The thermal and thermomechanical properties of all polymer series having different comonomer compositions were investigated by DSC, TGA, DMTA and TMA. The results showed improved heat resistance characteristics, in which both the glass transition and decomposition temperatures of the terpolymers were heightened with increasing IBOMA and ChMI comonomer content, due to their bulky pendent group and rigid imide ring structure. Furthermore, the dynamic mechanical properties as well as dimensional stability of the terpolymers increased with a higher IBOMA and ChMI content without sacrificing a high transparency of pure PMMA. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.