Epoxidized waste cooking oil enhancing the interfacial binding strength for fully bio-based flame retardant wool fabric with good wearability

Bio-based flame retardants have been widely studied for their eco-friendly, renewable and sustainable advantages. However, the durability of bio-based flame retardants is usually poor due to the weak combination with textile substrates. In this study, based on the strategy of constructing a covalent anchoring network between flame retardants and textile substrates, epoxidized waste cooking oil (EWCO) was used as the bio-based crosslinking agents to covalently bind with phytic acid (PA) and chitosan (CH) forming the fully bio-based intumescent flame retardant (IFR) system. The wool fabrics were treated by PA/EWCO/CH IFR system through simple pad-dry-cure finishing process, and a large cross-linking system between the flame retardants and wool fabrics could form during the finishing process anticipating to enhance the interfacial binding strength. The limited oxygen index (LOI) value of PA/EWCO/CH treated wool fabric reached 30.5%, its char length reduced to 96 mm showing excellent flame retardancy, and it still possessed good wearability. The LOI value of PA/EWCO/CH treated wool fabrics after 4 times washing was 27.5%, which was higher than that without EWCO (26.3%) showing good washing durability. This research provides a new strategy for solving the interfacial binding fastness between bio-based flame retardants and substrates to enhance the flame retardant durability by using bio-based waste plant oil derivatives crosslinking agent.