Graft copolymerization of acrylic acid on to acrylonitrile-butadiene-styrene terpolymer and thermal analysis of the copolymers

The graft copolymerization of acrylic acid on to acrylonitrile-butadiene-styrene terpolymer (ABS) was studied by the use of the anthracene photosensitized formation of hydroperoxides in the butadiene portion of the polymer. The variables that were investigated include concentration of anthracene, concentration of acrylic acid, time of reaction, time of irradiation, and temperature. The grafting reaction proceeds quite similarly to previously reported work on methacrylic acid grafting. The thermal degradation of the copolymers has been studied by thermogravimetric analysis. The amount of non-volatile residue is always less than that expected for acrylic acid and is slightly greater than the expectation for sodium acrylate. In order for grafting to offer thermal protection, an adherent and thermally insulating layer is required. In the acrylic acid system, unlike the methacrylic acid system, the graft layer is not adherent and does not offer thermal protection.