Enhancing interfacial interaction of immiscible PCL/PLA blends by in-situ crosslinking to improve the foamability

The immiscible between poly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA) significantly hinders the properties and application of the blends. In this work, the use of benzoyl peroxide (BPO) is an effective methods to improve the compatibility and foamability of immiscible PCL/PLA blends. The tensile test results showed a 41% increase in yield tensile strength and a 632% increase in elongation at break of the crosslinked PCL/PLA/0.6%BPO film compared to the pristine PCL/PLA blends, which demonstrate the enhancement of PCL/PLA interfacial interaction. The melt strength of the blends was gradually increased due to the improvement of interfacial interaction, which led to the decrease of average cell size and the increase of cell density of the PCL/PLA foam. Moreover, the open-cell structure was altered to a highly close-cell structure with increasing BPO content. Consequently, structural-tunable foams can be obtained by varying degrees of interfacial interaction.