Grafting of Methacrylic Acid and Other Monomers onto Butadiene-Containing Polymers to Achieve Flame Retardancy

Abstract

Methacrylic acid has been grafted onto two styrene-butadiene block copolymers, SBS and K-resin, by the thermal decomposition of hydroperoxide generated by the anthracene sensitized formation of singlet oxygen. The sorption of anthracene at room temperature from a methanolic solution into the polymer film was affected by the heterogeneity of structure of the polymer. The effect of variables, such as time of irradiation, concentration of monomer and anthracene, reaction time and temperature, on the graft yield were investigated. The amounts of cross-likinkg and homopolymer in grafted polymer were also examined. The grafted methacrylic acid has been converted to its sodium salt by treatment with aqueous sodium hydroxide. The TGA residue that is obtained at 800 dedrees Celsius is greater than that expected based on the starting materials. Preliminary cone calorimetry results indicate that a graft layer of sodium methacrylate increases the time to ignition, decreases the peak heat release rate, and also decreases amount of smoke