Influence of Dicumyl Peroxide Content on Thermal and Mechanical Properties of Polylactide

The aim of this article was to determine the effect of the dicumyl peroxide (DCP) content on thermal and mechanical properties of polylactide (PLA). Reactive extrusion of the PLA and DCP blends was performed. The DCP content varied from 0.2 to 1.0 wt.%. The extruded samples were characterized by the Fourier transform infrared spectroscopy (FTIR), analyses of gel content and swelling degree, thermogravimetry (TG), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and tensile and impact strength tests. It was found that DCP caused crosslinking of PLA as well as contributed to formation of low-molecular weight products of decomposition and degradation processes. These products caused plasticization of PLA, which led to a decrease in the glass transition temperature. An increase in tensile strength and decrease in impact strength were observed as the DCP content increased.