PLA/chain‐extended PEG blends with improved ductility

Abstract

Melt blending of polylactic acid (PLA) and a chain-extended polyethylene glycol (CE-PEG) have been performed in an effort to toughen the PLA without significant loss of modulus and ultimate tensile strength. The chain-extended PEG was prepared with melt condensation of a low molecular weight PEG and 4,4 0 -methylenebis(phenylisocyanate) (MDI) for enhancement of the molecular weight of PEG. The thermal and mechanical properties, miscibility and phase morphologies of blends were investigated. By using thermal and fracture surface analysis, the blends were found to be a partially miscible system with shifted glass transition temperatures. The addition of CE-PEG leads to slight decrease in tensile strength and modulus, while the elongation at break is characterized by an important increase (540%), compared with neat PLA and PLA/PEG (low molecular weight PEG, M n ¼ 35,000). The relative ductility of PLA/CE-PEG is 40 times higher than that of neat PLA. The brittle fracture of neat PLA was transformed into a ductile fracture by the addition of CE-PEG.

Effect of poly(ethylene glycol) on the properties and foaming behavior of macroporous poly(lactic acid)/sodium chloride scaffold

“…When compared with neat PLA, the PLA/PEG/NaCl blends with different contents of NaCl (30 and 40 wt %), the tensile strength decreased from 54.9 MPa to 22.18 MPa and 16.62 MPa, whereas the average elongation at break increased from 6.86% to 26.34% and 11.27%. This result is consistent with the prior results from Sheth et al and Park et al The mechanical properties indicate that the addition of the PEG increases the flexibility of the blends system.…”

Fabrication of PLLA with High Ductility and Transparence by Blending with Tiny Amount of PVDF and Compatibilizers

“…The brittleness does hinder its applications ranging from packaging materials to medical implants . To improve the elongation at break and impact strength, various modifier polymers (e.g., rubber or other polymers with excellent flexibility) have been widely employed to blend with PLLA . The binary blend, however, always undergoes phase separation because of weak interfacial interaction and poor miscibility between PLLA and other polymers.…”

“…[3,4] To improve the elongation at break and impact strength, various modifier polymers (e.g., rubber or other polymers with excellent flexibility) have been widely employed to blend with PLLA. [5][6][7][8][9][10][11][12][13][14][15][16][17][18] The binary blend, however, always undergoes phase separation because of weak interfacial interaction and poor miscibility between PLLA and other polymers. Therefore, compatibilizers have been introduced to the blend system.…”

Fabrication of polylactic acid/polyethylene glycol (PLA/PEG) porous scaffold by supercriticalCO2foaming and particle leaching

“…Dorati et al investigated the degradation behavior of poly(ethylene glycol‐ co ‐ d , l ‐lactide) (PEG‐ d,l ‐PLA) multiblock copolymer. Park et al demonstrated that melt blend chain‐extended polyethylene glycol (CE‐PEG) with polylactic acid (PLA) could toughen the PLA matrix without significant modulus and ultimate tensile strength reduction. Moreover, as a plasticizer, many scaffolds based on PLA‐PEG block copolymer have been prepared to increase the flexibility and hydrophilicity of PLA .…”