A Comprehensive Review on Bast Fibre Retting Process for Optimal Performance in Fibre-Reinforced Polymer Composites

Abstract

Natural fibres are a gift from nature that we still underutilise. They can be classified into several groups, and bast natural fibre reinforcement in polymer composites has the most promising performance, among others. However, numerous factors have reported influences on mechanical properties of the fibre-reinforced composite, including natural fibre retting processes. In this review, bast fibre retting process and the effect of enzymatic retting on the fibre and fibre-reinforced polymer composites have been discussed and reviewed for the latest research studies. All retting methods except chemical and mechanical retting processes are involving secretion of enzymes by bacteria or fungi under controlled (enzymatic retting) or random conditions (water and dew retting). Besides, enzymatic retting is claimed to have more environmentally friendly wastewater products, shorter retting period, and controllable fibre biochemical components under mild incubation conditions. This review comprehensively assesses the enzymatic retting process for producing high-quality bast fibre and will become a reference for future development on bast fibre-reinforced polymer composites.