Physical and dynamic mechanical properties of continuous bamboo reinforcement/bio-based epoxy composites

Abstract

Unidirectional bamboo reinforced cardanol-based epoxy composites were prepared by a close mould method. Two morphologies of reinforcements were used in this research: bamboo fibres and bamboo strips. The present article investigates the influence of bamboo reinforcements on the thermal and mechanical properties of the bio based matrix. Differential Scanning Calorimetry analyses showed that the introduction of bamboo does not modify the physical properties of the matrix. DMA analyses in shear mode showed an improvement of the shear conservative modulus that reaches 1.7 ± 0.1 GPa. This value that is independent from the morphology of reinforcements, indicates the existence of physical interactions. The continuity of matter between bamboo strips or bamboo fibres and the matrix observed by SEM confirms this result. Nevertheless, in tensile mode, the improvement of the tensile conservative modulus is specific to the used morphology. Indeed, for bamboo strips composites, it is 7.7 ± 0.8 GPa, while for bamboo fibres composites, it reaches 9.6 ± 0.8 GPa. This result is explained by the optimisation of stress transfer thanks to the specific morphology of bamboo fibres. A significant increase is also observed for the rubbery modulus due to entanglements specific of bamboo reinforcement.