The effect of Poly(butylene succinate) on the structure and properties of Stereocomplex Polylactide

Abstract

Polylactic acid (PLA) is a recognized environmentally friendly and biodegradable green material, but its brittleness limits its wider application. This article investigates the effects of adding polybutylene succinate (PBS) as a toughening agent and epoxidized soybean oil (ESO) as a reactive compatibilizer on the properties of sterecomplex polylactic acid (PLLA/PDLA) composites. The results of mechanical performance testing, differential scanning calorimetry analysis, Fourier transform infrared spectroscopy testing, scanning electron microscopy, X-ray diffraction analysis, etc. show that scPLA has partial compatibility with PBS, and PBS can promote the formation of SC crystals. Non isothermal crystallization analysis further indicates that a lower cooling rate is conducive to the formation of SC crystals. This effect is particularly significant at a concentration of 30% PBS, where the trend is most pronounced, simultaneously, the elongation at break is higher.

ESO, as a compatibilizer, can promote the compatibility of PLLA/PDLA with PBS. FTIR testing shows that the formation of the blend is due to the ring opening reaction of ESO epoxy functional groups. DSC testing has shown that ESO can promote the crystallization of PLA stereocomplex (SC) crystals, forming 100% stereocomplex (SC) crystals at a content of 15%, improving the thermal processing performance of the material. The tensile test results indicate that ESO can be used as a plasticizer to enhance the elongation at break of PLLA/PDLA/PBS, but excessive ESO can lead to a decrease in elongation at break.

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