Toughening Poly(lactic acid) by Melt Blending with Poly(ether-block-amide) Copolymer

Abstract

Melt blending with poly(ether-b-amide) copolymer (PEBA) was found to significantly enhance the toughness of poly(lactic acid) (PLA). The miscibility, morphology, thermal behavior, mechanical properties and rheological behavior of the blends were investigated. DMA and DSC analysis revealed that the PLA/PEBA blends were immiscible. A clear, phase-separated morphology was observed from SEM results. The addition of PEBA enhanced the cold crystallization of the PLA in the blends and accelerated the crystallization rate due to the interfacial function between PLA and PEBA phases. Significant enhancement of the toughness of PLA was achieved by the incorporation of PEBA copolymer. The optimum impact modification of the PLA was obtained by blending with 20 wt% PEBA, with an elongation at break of 300% as compared to 5% for pure PLA. The impact strength was ten times higher than that of the pure PLA. SEM results showed that the interfacial cavitation followed by a massive shear yielding of the matrix contributed to the increased toughening effect in the blends. The rheological measurement revealed an interaction between PLA and PEBA in the melt state.

Highly toughened poly(lactic acid) blends prepared by reactive blending with a renewable poly(ether‐block‐amide) elastomer

“…The viscoelastic response of PLA blends at low frequencies can be used to observe the interfacial interaction between different polymer components. Supposedly, at low frequencies, flow‐induced molecular orientation has little effect on the viscoelasticity 35,40 . It can be seen that PLA/PEBA blends had similar η * to neat PLA with increasing PEBA content from 0 to 30% in Figure 6(a), which exhibited Newtonian behavior with a zero shear viscosity plateau region at low frequencies, owing to its relatively linear structure.…”

“…Supposedly, at low frequencies, flow-induced molecular orientation has little effect on the viscoelasticity. 35,40 It can be seen that PLA/ PEBA blends had similar η* to neat PLA with increasing PEBA content from 0 to 30% in Figure 6(a), which exhibited Newtonian behavior with a zero shear viscosity plateau region at low frequencies, owing to its relatively linear structure. Among of them, the PLA/PEBA (80/20) blend showed the relatively high complex viscosity, which could be attributed to the compatibility provided by the soft block (polyether) of PEBA with PLA.…”

“…It is a segmented block copolymer made of flexible polyether and rigid polyamide (PA11) based on a vegetable resource-castor oil, which could decrease the fossil energy requirement as well as the CO 2 emission. 35 There are many kinds of PEBAs, they have good biocompatibility and can be widely used in a variety of medical applications, such as short-term implantation in humans and virus-proof surgical sheeting. In recent years, PEBAs have been widely used for toughening PLA, 36,37 but most PEBAs are not renewable.…”

“…Renewable poly(ether‐block‐amide) (PEBA) elastomer is the first bio‐based thermoplastic elastomer produced by Arkema Company. It is a segmented block copolymer made of flexible polyether and rigid polyamide (PA11) based on a vegetable resource‐castor oil, which could decrease the fossil energy requirement as well as the CO 2 emission 35 …”

Heterogenized Imidazolium-Based Ionic Liquids in Pebax®Rnew. Thermal, Gas Transport and Antimicrobial Properties

“…Pebax ® are thermoplastic block copolymers applied for medical uses (e.g., short-term implantation in humans and virus-proof surgical sheeting) [ 18 ]. These macromolecules include linear chains of hard polyamide (PA) blocks covalently linked to soft polyether (PE) blocks via ester groups.…”