Study On Composites Of Bioplastic P(3HB-CO-4HB)/Wood Flour

Melt grafting and microwave solid-phase grafting are used to prepared P(3HB-co-4HB)-g-MAH respectively. Poly(3-hydroxybutyrate-co-4-hydroxybutyrate)[P(3HB-co-4HB)]/wood flour compounds were prepared by melt extrusion. The structure of compatibilizer was characterized by infrared spectrometer and the effects of several additives on the rheological properties, processing performance, mechanical properties and morphology of compounds were characterized by contact angle measurement, polarizing microscopy, capillary rheometr, rheometer Huck, infrared spectroscopy, scanning electron microscopy and electronic universal testing machine, etc. Besides, adding poly(Lactic acid)(PLA) into composites to obtain P(3HB-co-4HB)/PLA/wood flour blends.The results show that (1) Aluminum zirconium coupling agent obviously improves the compatibility between wood flour and P(3HB-co-4HB) and increases the Notched impact strength of composites by43.4%. Light Lubricant significantly improves the appearance of surface with clear gloss as well as processing performance.(2) In the melt grafting technology, there is a maximum grafting ratio with the increase of MAH and BPO dosages. Under proper conditions, MAH monomer can be grafted onto P(3HB-co-4HB) by microwave grafting technology. Compared to pure P(3HB-co-4HB), P(3HB-co-4HB)-g-MAH significantly decreases in contact angle and spherulite size, and obviously improves thermal stability. The mechanical properties of P(3HB-co-4HB)-g-MAH/wood flour composite are better obviously than that of P(3HB-co-4HB)/wood flour composite., and one-step extrusion process significantly outweighs two-step extrusion process. As the compatibilizer, P(3HB-co-4HB)-g-MAH (BPO/MAH=0.3/4) significantly improves the mechanical properties of blends and reaches the optimum at5portion P(3HB-co-4HB)-g-MAH.(3) With the increasing poly(Lactic acid) content, the tensile strength of blends increases significantly and Notched impact strength decreased firstly and then increased, meahwhile, the thermal stability of the blends increases significantly; With the increasing wood flour content, the apparent viscosity of blends increases and processing performance decreases as well as mechanical performance.