In-situ reaction compatibilization modification of biodegradable poly (lactic acid)/poly (3-hydroxybutyrate-co-4-hydroxy-butyrate) blends by multifunctional epoxy compound

Thanks to their remarkable combination of good strength and high modulus, Poly (lactic acid) (PLA) is mixed with P34HB to enhance its strength, and the chain extender ADR-4370F is selected to modify PLA/P34HB blend via in-situ reaction compatibilization. The incorporation of 0.7 phr ADR into the 70/30 wt% PLA/P34HB blend results in a significant increase of 60%, 20% and 22% in Izod impact strength, tensile strength and modulus, respectively, compared with the 70/30 wt% PLA/P34HB blend. Rheological results demonstrate that storage modulus, loss modulus, and complex viscosity enhance evidently with the elevation of ADR dosage, indicating that the improvement of melt strength is beneficial to the processing and forming of the materials. The compatibilization mechanism is investigated by infrared spectroscopy, and the epoxy groups in ADR is the most important factor to improve the compatibility and the mechanical properties of the blends.