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

Abstract

The methacrylic monomer, 4-propanoylphenyl methacrylate (PPM) was synthesized by reacting 4-hydroxyl propiophenone dissolved in methyl ethyl ketone (MEK) with methacryloyl chloride in the presence of triethylamine. The homopolymer and various compositions of copolymers with glycidyl methacrylate (GMA) were synthesized using free radical polymerization in MEK solution at 70 ± 1 °C using benzoyl peroxide as initiator. The polymers were characterized by FT-IR, 1H NMR and 13C NMR techniques. The polydispersity indices of the copolymers determined using gel permeation chromatograph suggest that the chain termination by disproportionation predominates coupling when the mole fraction of GMA in the feed is high and radical recombination was predominant when the mole fraction of PPM was high in the feed. The glass transition temperature of the copolymer increases with increase in PPM content. The thermal stability of the copolymers increases with increase in PPM content. The copolymer compositions were determined using 1H NMR analysis. The monomer reactivity ratios were determined by the application of conventional linearization methods such as Fineman–Ross ( r 1=1.441: r 2=0.747), Kelen–Tüdös ( r 1=1.497: r 2=0.713), extended Kelen–Tüdös ( r 1=1.441: r 2=0.708) and a non-linear error-in-variables model (EVM) method using a computer program, RREVM ( r 1=1.264: r 2=0.653). These values suggest that PPM is more reactive than GMA and the copolymer will be richer in PPM units. The adhesives based on poly(PPM- co-GMA) were prepared for the application on leather and their peel strength were determined at 50 and 70 °C.