Biodegradable blends of thermoplastic waxy starch and poly(ε-caprolactone) obtained by high shear extrusion: Rheological, mechanical, morphological and thermal properties

The aim of this work was to develop polymer blends of plasticized thermoplastic waxy starch (TPS) and poly(epsilon-caprolactone) (PCL) using the largest amount of TPS possible to obtain a biodegradable material motivated by sustainability issues and to replace petrochemical-based polymers with alternatives based on biopolymers. Addition of TPS to other polymers has been used to obtain cheaper and increasingly biodegradable final products. However, TPS presents limited mechanical proper-ties, and mixing with other polymers such as PCL is necessary to overcome these limitations and improve its processability. TPS was processed by extrusion and thermo-compression using 30 wt% glycerol. The blends were suitably processed by extrusion and further injected. The TPS/PCL blends were studied by varying the amount of PCL in a range of 10 wt% in increasing order of addition. Thermal analysis showed that introducing PCL in TPS increased T-onset because of the higher thermal stability of the former, and that the obtained blends presented a behavior intermediate to that of neat polymers.