Fabrication and Properties of Poly (lactic acid) Hybrid Composites Synergistic Toughened by Ultra-fine Barium Sulfate and Light Calcium Carbonate

Abstract

The poly (lactic acid) (PLA) hybrid composites consisted of ultra-fine barium sulfate (BaSO4) and light calcium carbonate (CaCO3) inorganic particles were fabricated via molten blending and compression molding. The effect of BaSO4 mass fraction on the morphologies, mechanical properties, and melt flow rate (MFR) as well as thermal stability of hybrid composites were investigated, under the condition of fixed content of CaCO3. Results show that adequate BaSO4 is dispersed homogenously in the matrix and the inorganic particle-PLA interfacial adhesion is well. PLA is synergistically toughened significantly by BaSO4. With 15% content of BaSO4, the impact toughness and breaking elongation of the PLA hybrid composites are increased by 60.38% and 151.90%, respectively, compared to PLA/CaCO3 sample. As BaSO4 increases, the tensile strength decreases monotonically, while the elastic modulus of samples increases. On the whole, the melt flow rate of the composites is decreased with the presence of BaSO4. However, little effect of BaSO4 on the thermal behavior of PLA is observed.

Keywords

• poly (lactic acid)
• barium sulfate
• mechanical property
• thermal stability
• toughening