Property improvement and compatibilization mechanism of biodegradable polylactic acid/maleic anhydride-based/polypropylene spunbonded nonwoven slices

Abstract

Due to the increasing necessity for green and environmental protection, biodegradable polylactic acid (PLA)/polypropylene (PP) spunbonded nonwoven slices are gradually replacing the non-degradable PP counterparts. However, because of the poor compatibility of PLA with strong polarity and PP with weak polarity in the PLA/PP slice, its application is limited. Therefore, maleic anhydride (MAH) and maleic anhydride grafted polypropylene (PP-g-MAH) were selected as additives to prepare biodegradable PLA/additive/PP slices by melt blending. The effects of additives on the tensile and thermal properties, melt flow rate (MFR) and microstructure of these slices were investigated. Furthermore, the biodegradable PLA/PP-g-MAH/PP spunbonded nonwoven fabrics were prepared. The results show that the MFR of the slices increases with the increase of the additive content. The addition of MAH can reduce the glass transition temperature (Tg) of the blends and increase the thermal decomposition temperature. However, the addition of PP-g-MAH increases these two temperatures of the blends. Based on the results, the grafting reaction, ring-opening reaction and reduced interfacial tension might be the mechanism of additives to improve the performance of the slices. Their compatibility is improved due to the performance of MAH and PP-g-MAH, and the effect is better for PP-g-MAH than for MAH, because MAH has stable ring structure and low grafting proportion in PLA/MAH/PP slices.