Poly(lactic acid) Toughening with a Better Balance of Properties

Poly(lactic acid) (PLA) toughening is often associated with significant modulus and/or strength losses making it unsuitable for many consumer and biomedical applications. The major objective of this research was to toughen PLA without significant loss in modulus and strength and to introduce reactive acid groups using reactive blending of PLA with a combination of polymers. PLA was reactive blended with poly(acrylic acid) (PAA) followed by physical blending with poly(ethylene glycol) (PEG) in solution. The modified PLA was extruded into films using a co-rotating twin-screw extruder and characterized using tensile testing, differential scanning calorimetry (DSC), and dynamic mechanical analyses (DMA). This technology resulted in films with a ten-fold increase in toughness compared to neat PLA with little or no decrease in strength and modulus. [GRPHICS]