Polyp ropylene-graft-poly(methyl methacrylate) Graft Copolymers: Synthesis and Compatibilization of Polypropylene/Polylactide

Polypropylene-graft-poly(methyl methacrylate) (PP-g-PMMA) graft copolymers, possessing different compositions and branch lengths, were synthesized using 2-bromoisobutyrate group containing PP (PP-g-Br) as a macroinitiator for the metal-catalyzed living radical polymerization of MMA. The polypropylene/polylactide (PP/PLA) binary blends and the PP/PLA/PP-g-PMMA ternary blends were prepared by melt-blending and compression molding. From the results of the tensile and flexural tests, the strength and modulus of the PP/PLA blends were significantly improved by addition of the PP-g-PMMA. On the other hand, the PP-g-PMMA was ineffective in improving the elongation at break and the Izod impact strength of these polymer blends. TEM observations suggested that the ternary blends had a well-dispersed morphology compared with the binary blends and the PP-g-PMMA worked as a compatibilizer for the PP/PLA blends.