Toughening of polylactide with epoxy‐functionalized methyl methacrylate–butadiene copolymer

Glycidyl methacrylate‐functionalized methyl methacrylate–butadiene ( MB ‐ g ‐ GMA ) copolymers were prepared via an emulsion polymerization process. These functionalized copolymers were blended with polylactide ( PLA ). Dynamic mechanical analysis and differential scanning calorimetry results showed that the addition of MB ‐ g ‐ GMA did not result in a marked change in the glass transition temperature of PLA . With an increase of MB ‐ g ‐ GMA content, the tensile strength of the blends decreased; however, the elongation at break and impact strength increased significantly. From scanning electron micrographs, there was large plastic deformation (shear yielding) in blends subjected to impact tests, which was an important energy‐dissipation process and led to a toughened polymer. Rheological investigation demonstrated that there was a significant dependence of viscosity on composition. When the MB ‐ g ‐ GMA content increased, the viscosity began to increase.