Environmental Hazards of Giant Reed (Arundo donax L.) in the Macaronesia Region and Its Characterisation as a Potential Source for the Production of Natural Fibre Composites.

This paper summarises the results obtained from the characterisation of giant reed (Arundo donax L.) plant and fibres. The research is part of a project developed in the Macaronesia region, of which the aim is to demonstrate the feasibility of using biomass from invasive plant species in the composites sector as a way of financing control campaigns and habitats conservation labours. An experimental procedure for the extraction of fibre bundles from this plant was developed, and the material obtained was characterised in terms of chemical composition, thermogravimetry and infrared spectra to evaluate its potential application in the production of polymeric composite materials as a strategy for the valorisation of residual biomass from this invasive species in Macaronesia. Thermoplastic matrix composites with fibre content up to 40 wt.% were produced and their mechanical properties under tensile, flexural and impact loading were determined. No references on the preparation of composite materials with polyolefin matrices and giant reed fibres have been found. Results obtained from mechanical tests show a good performance of the manufactured composites, with a significant increase in both flexural and tensile stiffness; the flexural modulus is almost tripled for PE-based composites and rises to 88% with respect to PP matrix. The ultimate flexural strength and the tensile and flexural yield strength are kept at acceptable values compared to neat polymer materials, although ultimate tensile strength and impact resistance are significantly affected when natural fibres are added.