Location: Dairy and Functional Foods ResearchTitle: Reinforcing and Toughening Effects of Bamboo Pulp Fiber on Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Fiber Composites. Author
Submitted to: Industrial and Engineering Chemistry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/19/2009
Publication Date: 2/1/2010
Citation: Jiang, L., Liu, L.S., Chen, F., Qian, J., Jijun, H., Wolcott, M., Zhang, J. 2010. Reinforcing and Toughening Effects of Bamboo Pulp Fiber on Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Fiber Composites. Industrial and Engineering Chemistry Research. 49:572-577. Interpretive Summary: Natural polymer reinforced biodegradable composites are environmentally friendly and have been studied as alternatives to petro-chemical engineering materials. How to improve the mechanical properties of the composites to match those of petroleum-based plastics remains as a key challenge. In this study, composites were prepared from bamboo fiber and suitable chemicals. The resultant composites have a tensile strength and toughness that match the values of high density polyethylene, a petroleum based polymer. The study highlights a new approach to further improve the mechanical properties of bamboo composites with proper chemical treatment.
Technical Abstract: Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/bamboo pulp fiber composites were melt-compounded and injection-molded. Tensile, impact and dynamic mechanical properties of the composites were studied. In contrast to many other short natural fiber reinforced biocomposites which demonstrate decreased strain-at-break, impact toughness and tensile strength, the PHBV/bamboo pulp fiber composites displayed increased tensile strength and impact toughness, and maintained/increased strain-at-break. Microscopic study of the fracture surfaces revealed extensive fiber pullout in both tensile and impact tests. The fiber pullout suggests insufficient interfacial adhesion between the fiber and the matrix. The pullout process in the impact testing dissipated a significant amount of energy and hence substantially improved the impact toughness of the composites. With the improved interfacial adhesion provided by coupling agent polymeric diphenylmethane diisocyanate (pMDI), the strength and modulus of the composites were further increased. However, the toughness was decreased due to the inhibition of the fiber pullout. An acoustic emission test revealed a significantly different process of structural change for the composites with/without pMDI during tension test.