UC San Diego

Current building materials and practices in the construction industry cause the depletion of natural resources and simultaneously result in large amounts of waste material and green house gas emissions. In recent years, concerns over such economic and environmental problems have initiated research efforts into the development of materials derived from quickly renewable resources, such as biocomposites. Most of the research to date in the field of biocomposites has, however, been directed at applications involving non-structural elements. This is largely attributed to previous research efforts showing that these materials do not possess the properties necessary to make them useful for structural applications. Through the development and characterization of a novel biocomposite system, this project aims to overcome some of the challenges currently in place for biocomposite application. Unidirectional-aligned hemp fiber reinforced cellulose polymer composites were manufactured for this study using selected processing procedures to allow for efficient fiber reinforcement and an increase in overall composite performance. For composites with a fiber volume fraction of 0.51, tensile and flexural strengths of 224 and 133 MPa and elastic tensile and bending moduli of 25 and 22 GPa, respectively, were achieved. The experimental results of this study confirm the potential for biocomposites to be used as secondary structural elements; however, these properties were below the predicted values for the biocomposite system using the rule-of-mixtures and Halpin-Tsai methods. This discrepancy was attributed to high void content and poor adhesion between the fiber and matrix for both of which potential solutions were identified