LAUSR

This study describes an investigation into the variation of the tensile strength of maize stem fibres at different growth stages of the plant. In this context, the fibres were all extracted manually, and in some cases preceded by a water retting process for 10 days. The variation of the tensile strength and chemical functional groups among four common maize varieties were determined. The fibres were characterised by performing tensile test, density & linear density tests, Fourier Transform infra-red spectroscopy (FTIR), X-ray diffraction, Thermo-gravimetric analysis and surface morphology (SEM image analysis). The thermal analysis, FTIR and X-ray results showed that, in general, the fibres from the different maize varieties and from the different growth stages are semi-crystalline in nature. Furthermore, the SEM micrographs revealed the presence of equi-spaced fibre‑nodes along the fibre, that are believed to be due to the growth stresses induced in the plant stem. This fibre inter-node distance varied in relation to the growth stage of the plant, and yielded a good correlation (coefficient of 0.91) with the tensile strength of the fibres. Finally, a better fibre yield was obtained from the stem at the senescence stage of the maize plant.