Super-tough poly (l-lactide) materials: Reactive blending with maleic anhydride grafted starch and poly (ethylene glycol) diacrylate

Abstract

Super-tough poly (l-lactide) (PLLA) without compromising its biodegradability and biocompatibility was fabricated by reactive blending with PLLA and maleic anhydride grafted starch (MS)/poly (ethylene glycol) diacrylate (PEGDA). PEGDA as reactive compatibilizer exhibits higher compatibilization efficiency and significant plasticization effect in PLLA matrix. Fourier transform infrared spectroscopy (FT-IR) confirmed that PEGDA monomer successfully located at the molecules of MS and some interesterification reactions occurred between PEGDA and PLLA. The ductility of PLLA materials were significantly improved, for example, the elongation of break increased to 298% at the optimum PLLA/MS/PEGDA content. Dynamic mechanical thermal analysis (DMTA) demonstrated the glass transition temperature of blends decreased with the contents of MS/PEGDA increasing. The differential scanning calorimeter (DSC) results revealed that cold crystallization temperature and melting temperature of blends were decreased with the augment of the contents of MS/PEGDA. Wide angle X-ray diffraction (WARD) and DSC certified that a high crystalline article was obtained through practical extrusion process, which could propagate shear yielding deformation to dissipate energy during tensile fracture. Scanning electron microscope (SEM) demonstrated that the blends with PEGDA did not exhibit a visible phase-separated morphology from cryogenic fractured surfaces compared with the blend without PEGDA.