Effects of a novel compatible interface structure on the properties of starch–PCL composites

Abstract

Polycaprolactone (PCL)–starch composites were prepared in an intensive mixer using a PCL-based polyurethane (PCLPU) prepolymer as a compatibilizer. A multifunctional polyurethane layer (PCLPU layer) was then located at the interface between the starch granules and the PCL matrix. Good compatibility was shown between starch and the PCLPU layer, which was attributed to the urethane linkages. And the degradation experiment revealed that the urethane linkages between PCLPU and starch were stable. The PCL soft segments in the PCLPU layer could also interact with the PCL matrix through PCL crystallinity to improve the compatibility between the PCL matrix and PCLPU. The multifunctional PCLPU was thus deemed effective in improving the compatibility of starch–PCL composites. Additionally, the mechanical properties and thermal stability of the composites enhanced compared to starch–PCL composites. The novel multifunctional PCLPU layer therefore played an important role in improving the compatibility between the starch and PCL and the properties of starch–PCL composites.