An efficient enzymatic-based process for the extraction of high-mechanical properties alfa fibres

Sabrine Hanana , Ahmed Elloumi , Vincent Placet (1) , Hajer Tounsi (2) , Hafedh Belghith (2) , Chedly Bradai

1 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)
2 CBS - Centre de Biotechnologie de Sfax

Alfa fibres, which are generally extracted from the leaf of a plant belonging to the Poaceae family(Stipa tenacissima L), originating from the center of Tunisia, are mainly used for pulp and paper applica-tions. Their potential use as reinforcement in polymer composites requires the understanding of theirmicrostructure and mechanical properties and a proper control of fibre extraction and transformationprocesses. This work investigates the morphology of the alfa plant (leaves and fibres) through opticaland electron microscopy. The extraction process combining mechanical, chemical and enzymatic stagesand the reaction time of the enzymes have been optimised to achieve the highest mechanical propertiesof fibres. The effect of enzymatic treatments (laccase, pectinases and xylanases) on the morphological,chemical composition and mechanical properties of alfa fibres was investigated and the effectivenessof enzymatic treatments has been evaluated. The chemical compositions of alfa are correlated with itsmechanical properties. The result indicates that the tensile properties of isolated fibres were greatlyimproved when an optimised enzymatic-based process is used to separate the fibres from the leaves.Using pectinase and xylanase activities, results show really high mechanical properties, with an averagerigidity and strength up to, respectively, 66 GPa and 1300 MPa, which make alfa fibre promising reinforcements for load-bearing composite materials. This work also showed that enzymes offer an attractive andeco-friendly approach to efficiently extract high-performance plant fibres.

Domaines: Mécanique [physics]

Sabrine Hanana, Ahmed Elloumi, Vincent Placet, Hajer Tounsi, Hafedh Belghith, et al.. An efficient enzymatic-based process for the extraction of high-mechanical properties alfa fibres. Industrial Crops and Products, 2015, 70, pp.190 - 200. ⟨hal-02963407⟩