(730c) Co-Injection Molded Biodegradable Green Composites From Poly (3-hydroxybutyrate-co-3-hydroxyvalerate), Poly (butylene succinate) and Natural Fiber

To the best of our knowledge, this work reports the co-injection molding of bioplastics and natural fibers for the first time in the open literature. This approach opens up a novel method of manufacturing green composites for multitude of uses. To strike the stiffness-toughness balance of co-injection molded part,   poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and its composites with miscanthus were chosen as the core material while poly (butylene succinate) (PBS) was selected as the suitable skin material.  The process of co-injection molding of PBS and PHBV, and also co-injection of PBS and PHBV with miscanthus has been established. The mechanical properties of these co-injection molded parts were compared with those of neat polymers. As expected, the co-injection molded parts’ properties were found to be located between the properties of single injection molded skin and core materials.  The unnotched impact strength of coinjection molded green composite has drastically increased compared to the PHBV miscanthus injection molded composite. Thickness of the skin and core in the co-injection molded part was measured and flexural modulus was predicted using composite beam theory. SEM micrographs revealed good adhesion between the skin and the core layers. The deformed core confirmed the stress transfer from the core to the skin. These results suggest that co-injection molding technique has been very effective in improving the strength of the composites and the targeted stiffness-toughness balance was achieved.

This research is financially supported by Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)-2008 New Directions research Program Project number SR9211, the OMAFRA, Highly Qualified Personnel Program, Natural Sciences and Engineering Research Council (NSERC) NCE AUTO21 research program and the Ministry of Economic Development and Innovation (MEDI),  Ontario Research Fund - Research Excellence Round 4 program.