The Preparation of Self-Reinforced Sisal Fiber Composites

To prepare self-reinforced sisal composites, sisal fibers were cleaned, treated with NaOH solution, and then benzylated with benzyl chloride. In this way, the skin layers of the fibers were converted into thermoplastic material while the core of the fiber cells remained unchanged. Under the circumstances of hot pressing, self-reinforced all-plant fiber composites of sisal can be prepared, in which plasticised sisal serves as matrix and the unplasticised cores of the fibers as reinforcement. In this work the effect of the reaction conditions, such as alkalinity, temperature and the extent of benzylation, was studied in detail. The roles of quaternary ammonium salts and γ-ray irradiation treatment on the efficiency of benzylation were also taken into account. In addition, structural characteristics, melt flow and mechanical properties of the modified sisal and their composite sheets were analysed. It was found that a balance between melt processability and the reinforcing effect of the benzylated sisal fibers was required.