Homopolymer of 4-benzoylphenyl methacrylate and its copolymers with glycidyl methacrylate: synthesis, characterization, monomer reactivity ratios and application as adhesives

The methacrylic monomer, 4-benzoylphenyl methacrylate (BPM) was synthesized by reacting 4-hydroxy benzophenone dissolved in methyl ethyl ketone (MEK) with methacryloyl chloride in the presence of triethylamine. The homopolymer and various copolymers of BPM with glycidyl methacrylate were synthesized by free radical polymerization in MEK solution at 70 ± 1 °C using benzoyl peroxide as initiator. The homopolymer and the copolymers were characterized by FT-IR, 1H NMR and 13C NMR spectroscopic techniques. The molecular weight (Mw¯andMn¯) and polydispersity indices of the copolymers determined using gel permeation chromatograph suggest that the chain termination by radical recombination was predominant when the mole fraction of GMA was high in the feed. The glass transition temperature of the copolymer increases with increase in BPM content. The thermal stability of the copolymers increases with increases in BPM content. The copolymer composition was determined using 1H NMR spectra. The monomer reactivity ratios were determined by the application of conventional linearization methods such as Fineman-Ross (r1 = 1.490; r2 = 0.824), Kelen-Tudos (r1 = 1.411; r2 = 0.712), Extended Kelen-Tudos (r1 = 1.437; r2 = 0.707) as well as by a non-linear error in variables model (EVM) method using a computer program, RREVM (r1 = 1.364; r2 = 0.69). The copolymer having 56%, 41% and 28% of GMA content were chosen for making adhesives by curing with diethanolamine in choloroform. The cured resins were tested for the adhesion properties on leather-leather bonding at 50 and 90 °C. It was found that the resin cured at 50 °C exhibited maximum peel strength of 0.73, 0.58 and 0.30 N/mm, respectively, revealing a good adhesive behaviour.