Flax fiber-based polymer composites: a review

Flax is one of the popular natural fibers used as a reinforcing agent for polymer composite. The raw flax fiber is hydrophilic in nature, and the chemical constituent of flax is mainly cellulose, hemicellulose, lignin, etc. To improve the interfacial adhesion between flax fiber and polymer matrix, the surface treatment is given to the fiber. The polymer matrix used for reinforcement is thermoplastic, thermosets, and polymers derived from natural resources. The composites can be made by various processing techniques such as extrusion, compression, hand lay-up, etc. The flax fiber improves the biodegradability and recyclability of the composite, and it shows better mechanical performance as compared to plain polymers. The reinforcement of flax fiber in polymer matrix improves its tensile properties, flexural properties, impact resistance, hardness, etc. The hybridization of fibers is another approach that combines two or more fibers in a polymer matrix and has a synergistic effect through more than one fiber. The flax fiber composite is more eco-friendly than corresponding petroleum-based fiber composites.