Structure and Property of Polylactide/Polyamide Blends

Abstract

In order to explore a potential method for improving the toughness of polylactide (PLA), polyamide (PA) with high strength and toughness as an engineering plastic was used to prepare PLA/PA blends suitable for a wide range of applications of PLA as general-purpose plastics. The structure and properties of PLA/PA blends were studied in terms of the mechanical, morphological, and thermal properties. The results indicated that the blends are a partially miscible system due to the hydrogen bonding between the molecules of PA and PLA. Addition of PA reduced the PLA spherulite size in the blends, and the crystallinity of the PA phase increased with increasing PA content while it decreased for the PLA phase. The spherical particles of PA dispersed homogeneously in the PLA matrix. The fracture surface of the blends was covered with fiber-like PA phase and showed strong interfacial adhesion of the two phases which led to a remarkable increase of the elongation at break, without an obvious drop in the tensile strength, for the blends with 15–20 wt% PA.