European bamboo fibres for composites applications, study on the seasonal influence

Four Phyllostachys species grown in Europe were analysed with the aim of extracting long bamboo fibres for composite applications. The morphological characteristics of the plant were determined and compared to the species grown in their native region. Though the species tend to grow smaller, the Phyllostachys vivax showed similar Young's modulus as the tropical Guadua angustifolia Kunth, i.e. 49 GPa versus 52 GPa. But the strength of all species was 16-44% lower. A chemical analysis of the fibres and an interface study of their composites was performed by analysing the wetting behaviour of the fibres and the chemical composition of their surface. All fibres showed a lignin rich surface, with minor differences in wetting behaviour; therefore difference in the fibre mechanical properties cannot be explained by interface differences. The chemical bulk composition of the fibres was determined as well, and the cellulose content of the fibres showed a linear correlation with the Young's modulus and strength of the fibres. Seasonal investigation, performed on one selected species, revealed that harvest in autumn or winter lead to higher fibre extraction yields with higher mechanical properties.