Homopolymer and copolymers of 4-cyanophenyl acrylate with glycidyl methacrylate: Synthesis, characterization, thermal properties, and determination of monomer reactivity ratios

The acrylic monomer, 4-cyanophenyl acrylate (CPA), was synthesized by reacting 4-cyanophenol dissolved in methyl ethyl ketone (MEK) with acryloyl chloride in the presence of triethylamine as a catalyst. The homopolymer and copolymers were synthesized by using free-radical techniques. Characterization by FTIR, ¹H NMR, and ¹³C NMR spectroscopic analysis confirms the chemical structure. The solubility of the polymers was tested in various polar and nonpolar solvents. The polydispersity index values of polymers suggest a strong tendency for chain termination by disproportionation in all cases, and the tendency increases with the increasing GMA content in the feed. The initial decomposition temperatures for poly(GMA) (188°C), poly(CPA-co-GMA) (280°C), and poly(CPA) (290°C) reveal that the thermal stability of the copolymer increases with an increase in CPA content. DSC analysis showed Tg for poly(CPA) (25°C), poly(GMA) (74°C), and copolymer (0.4007 : 0.5993) (39°C) indicates that Tg of the copolymers decreases with the increase in CPA content. The copolymer composition was determined using ¹H NMR spectra. The monomer reactivity ratios were determined by the application of linearization methods such as Fineman-Ross (r₁ = 0.5806, r₂ = 0.6651), Kelen-Tudos (r₁ = 0.5442, r₂ = 0.6472), and extended Kelen-Tudos methods (r₁ = 0.5372, r₂ = 0.6352). The reactivity ratio values indicate that the copolymerization has a tendency to alternation.