Keywords: Hydrophilic polymer, copolymer, methacrylic acid, butyl acrylate, emulsion polymerization

Abstract

Copolymerization of methacrylic acid (MAA) and butyl acrylate (BuA) monomers to produce copolymer nanoparticles of poly(methacrylic acid-co-butyl acrylate), p(MAA-co-BuA) was successfully synthesized via emulsion polymerization technique. Homopolymers of poly(methacrylic acid), p(MAA) and poly(butyl acrylate), p(BuA) were also successfully prepared via a similar method, which acted as control for comparison. The emulsion polymerization composed of MAA and BuA monomers, sodium dodecyl sulphate (SDS) (surfactant), potassium persulfate (KPS) (initiator) and water as dispersion medium. The effects of different molar ratios of MAA and BuA towards the formation, morphology, thermal stability and solubility of copolymer nanoparticles were thoroughly studied. The formation of copolymer nanoparticles was confirmed by the absorption peaks from Fourier transform infrared spectroscopy (FTIR). The particle size and morphology of the copolymer nanoparticles were obtained by using scanning electron microscope (SEM). Irregular shapes of the polymer nanoparticles were observed in the range of 200 – 900 nm. Thermogravimetric analysis (TGA) was utilised to compare the thermal degradation of the copolymer nanoparticles of different monomer ratios. Solubility test of the copolymer nanoparticles was performed and p(MAA-co-BuA) of the ratio of 4:1 was found to be the optimum ratio that showed improved hydrophilicity among the copolymer nanoparticles.