PLA-PHBHHx BLENDS: EFFECT OF WATER IMMERSION ON FILM TOUGHNESS

摘要

Poly(L-lactic acid) (PLA) - poly[(3-hydroxybutyrate)-co-(3-hydroxyhexanoate)] (PHBHHx) blend films comprising 90 wt% PLA showed a remarkable toughness improvement. Poly(acrylic acid) (PAA) and poly(acrylamide) (PAAm) were photopolymerized from the film surface to improve hydrophilicity. The resultant films were characterized using water contact angle goniometry, attenuated total reflectance (ATR) FTIR spectroscopy, and mechanical testing. Although these blend films were successfully surface modified, they significantly lost their toughness on surface modification. Further investigations using dynamic mechanical analysis (DMA) and wide-angle X-ray diffraction (WAXD) revealed solvent induced crystallization of blend films causing this toughness reduction.