Effect of graphite on the thermal behavior of benzyl methacrylate and styrene copolymers

In this study, homopolymers of benzyl methacrylate (BzMA) and styrene (St) and P(BzMA0.17, 0.33, 0.64-co-St) copolymers were synthesized by free radical polymerization method at 65°C in the presence of BPO initiator in 1,4-dioxane solvent. The structure of the copolymers was characterized by 1H-NMR, FT-IR, TGA and DTA techniques. Composites of the synthesized P(BzMA0.33-co-St) copolymer with graphite at 1%, 5% and 10% by mass were prepared by solvent casting method. Thermal stability and glass transition temperatures of copolymers and composites with TGA-DTA binary system were investigated comparatively. The glass transition temperatures of the copolymers were found to be between the glass transition temperatures of the homopolymers. Glass transition temperatures of the composites increased with increasing graphite ratio. The thermal degradation kinetics of P(BzMA0.33-ko-St) copolymer and P(BzMA0.33-ko-St)/G %5 composite were examined and their average activation energies were determined by FWO and KAS methods. While the activation energy of the P(BzMA0.33-ko-St) copolymer was determined according to the FWO and KAS method as 148,898 and 146,431 kJ/mol, respectively, this value was determined as 186.545 and 185,668 kJ/mol for the P(BzMA0.33-ko-St)/G %5 composite. Dielectric properties of copolymers and composites were investigated. Keywords: Benzyl methacrylate; Graphite; Composite; thermal property; Activation ener