Mechanical Properties and Morphology of Polylactide Composites with Acrylic Impact Modifier

Polylactide (PLA) composites with acrylic impact modifier BPM, i.e., PLA/BPM composites, were produced by the melt blending method. The effects of BPM on the thermal properties, melting behaviors, and dynamic mechanical properties of the PLA/BPMs were investigated by thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. Tensile strength, flexural strength, and modulus of the injection molded specimens were measured by an Instron tensile machine. The influence of BPM on the impact strength of injection molded PLA/BPM composites was examined using an impact tester. The morphology of cryofractured surfaces and fracture surfaces of the composites after the tensile and impact testing was also investigated using scanning electron microscope. The test results show that the composites with BPM possess better flexibility when compared with neat PLA. However, the notched Izod impact strength showed improvement only when the BPM content was higher than 15 wt%.