Design of a novel bio-based inherent flame-retardant epoxy resin with anti-dripping, self-healing and reprocessability and its recycling in durable multifunctional Lyocell fabric

Traditional epoxy resins are manufactured from non-renewable fossil resources and suffer from several drawbacks, including poor flame retardancy, non-reprocessability and recycling difficulties, greatly affecting their wider applications. To address these issues, an inherent flame-retardant epoxy resin (L-Trp@PA/TPEP) was synthesized from biomass tea polyphenols, L-tryptophan, phytic acid and epichlorohydrin. L-Trp@PA/TPEP achieved a limiting oxygen index (LOI) value of 36.4%, with excellent anti-dripping, self-healing and reprocessability. Additionally, due to the limited number of reprocessable cycles, a versatile durable Lyocell fabric (L-Trp@PA/TPEP/Lyocell) was fabricated by finishing with the recycling of non-reprocessable L-Trp@PA/TPEP. L-Trp@PA/TPEP/Lyocell showed an LOI value of 34.5% and ultraviolet protection factor of 137.29. The elongation at break and tensile strength of modified Lyocell fabric increased by 19.2% and 33.6%. In addition, the modified fabric had favorable chemical resistance without mechanical deterioration within the pH range of 1 to 13. Besides, L-Trp@PA/TPEP/Lyocell displayed remarkable anti-fouling and self-cleaning capabilities. This work proposed a comprehensive and eco-friendly approach in terms of raw materials, application and recycling, which was significant for the development of sustainable novel materials and multifunctional textiles.