Plant cell walls to reinforce composite materials: Relationship between nanoindentation and tensile modulus

• Many different plant fibres were tested by tensile and nanoindentation tests.
• We evidenced a strong anisotropy between longitudinal and transverse fibre stiffness.
• An original correlation was established between tensile and nanoindentation modulus.
• Tensile modulus of softwood fibres was estimated.

Throughout this study, different plant fibres, used as polymer reinforcement, were tested by quasi-static tensile and nanoindentation tests to obtain their modulus using these two methods. Major differences of stiffness were found due to their different structures and morphologies. As example, tensile and nanoindentation moduli for sisal fibres were and 25.0±12.9 GPa and 10.2±1.7 GPa, respectively, whereas they were 52.4±13.2 GPa and 18.9±1.8 GPa for Eden flax fibres. A correlation between these two moduli was established; thus by an inverse method, we estimated the longitudinal stiffness of softwood fibre, for which the tensile test is delicate, mainly due to the short length of the fibre.