Properties of PLA/PMMA blends with high polylactide content prepared by reactive mixing in presence of poly(styrene‐co‐glycidyl methacrylate) copolymer

ABSTRACT Polylactide/poly(methyl methacrylate) blends with high polylactide content (100/0, 95/5, 90/10, 85/15, and 80/20 wt %) were prepared in presence of poly(styrene‐co‐glycidyl methacrylate) copolymer by reactive melt‐blending. The behavior of these blends was studied by torque monitoring while blending and the thermal properties, mechanical properties, and the morphological study of the produced blends was carried out by differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, tensile test, impact test, and scanning electron microscopy. In situ torque monitoring during blend preparation suggested no reactivity between the copolymer and poly(methyl methacrylate), while it proved reactivity with polylactide. It was observed that a higher copolymer‐to‐polylactide weight ratio lead to an increase in the slope of the torque‐time curve. At least around 15 wt % of poly(methyl methacrylate) was required to achieve interesting properties. Polylactide/poly(methyl methacrylate) blended at 80/20 wt % containing 3 pph of copolymer showed a huge enhancement of elongation at break value and improved impact resistance compared with neat polylactide, while keeping the tensile modulus and strength over 3 GPa and 60 MPa, respectively. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46825.