Fracture mechanism of plant fibres

Abstract

This paper, which describes work from an extensive study of various plant species, is aimed at presenting the best common physical description of the mechanism of failure in tension of cellulose-based fibres. A correlation coefficient of r=0.69 was observed between the mean tensile strengths and Young's moduli of fibres extracted from leaves, stems, and other miscellaneous sources. This observation is attributed to increases in Young's modulus and tensile strength with decreasing microfibril angle and increasing cellulose content. A cylindrical cell model was applied to the mean tensile strengths of fibres preconditioned at 24 to 27° C and 60% relative humidity. A modification of the resulting expression was used to produce the best correlation coefficient of r=0.89 between predicted and measured mean tensile strengths. However, the importance of cellulose content for strength which is presently illustrated for various plant species is not reflected in terms of mean fracture strain, which was increased by increasing microfibril angle showing why high works of fracture can be obtained from different species.