Water-dispersive PLA-based materials: from reactive melt processing to properties

Melt blending of poly(L-lactide) (PLLA) and water-soluble polymers was carried out through reactive melt processing with the objective to prepare water-dispersible PLLA-based materials. For this purpose, both polyvinyl alcohol (PVOH) and hydroxyethyl cellulose (HEC) were considered. Prior to melt blending, the preparation of plasticized PVOH and plasticized HEC was performed. The so-obtained blends have been characterized in terms of morphology and thermomechanical properties. The morphological analysis evidenced the possibility to prepare co-continuous PLLA/plasticized HEC blends. Nevertheless, their low melt strength did not allow producing monofilaments by melt spinning. Thus, PVOH was considered as an alternative to HEC. The results showed that using maleic anhydride-grafted polylactide as a compatibilizer for PLLA/plasticized PVOH 40/60 (w/w) blends allowed preparing co-continuous blends leading to tough monofilaments with high ultimate elongation. Moreover, the assessment of the water dispersiveness revealed that the monofilaments readily swelled in water and started to break up after 30 min. A full fragmentation of the monofilaments was observed within 1 hr. Copyright (C) 2015 John Wiley & Sons, Ltd.