Preparation, characterization and properties of poly(lactic acid)/poly(1,4-butylene adipate) blends for biodegradable packaging materials

Abstract

Poly(lactic acid) (PLA)/poly(1,4-butylene adipate) (PBA) blends with different PBA content were directly prepared via melt blending as potential biodegradable packaging materials. PBA with 1000 g/mol number average molecular weight was served as plasticizer to improve PLA properties. The morphological, thermal and mechanical properties of the blends were extensively investigated by scanning electron microscope (SEM), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), tensile and impact tests and thermogravimetry (TG). The results show that the degree of crystallinity of PLA increased with increasing PBA content. The addition of PBA (20 wt%) result in the positive effect on the elongation at break and toughness, which increased from 7.9% to 74.4% and from 3.9 kJ/m2 to 12.6 kJ/m2, respectively. Meanwhile, the migration tests indicate that PBA exhibits excellent lower migration ratio compared with citrate esters.