Durable flame retardant and anti-dripping of PET fabric using bio-based covalent crosslinking intumescent system of chitosan and phytic acid

Polyethylene terephthalate (PET) fabric is commonly used in people's daily life due to its excellent performance. However, PET is flammable and easy to produce dripping resulting in a potential fire hazard. It is of great significance to endow PET fabric with flame retardancy and anti-dripping simultaneously. Bio-based compounds have received more and more attention in flame retardant field for their eco-friendly, renewable and sustainable advantages. However, their poor durability restricts the industrial application. In this study, 3-glycidyloxypropyltrimethoxysilane (GPTMS) was used as the organic crosslinking agent, which was covalently binded with phytic acid (PA) and chitosan (CS) to endow PET fabrics with durable flame retardancy. The treated PET fabric with 20 bi-layers (BLs) CS/PA coating using layer-by-layer assembly method obtained a LOI value of 34 % and damage length of 6.5 cm, demonstrating that the excellent flame retardancy of treated PET fabric. After 4 times washing, its LOI value was higher than 26 %, indicating the good flame retardant durability of treated PET fabrics. This research provides a basis for durable flame retardant textile using bio-based flame retardants by forming covalent bonds through the crosslinking agent containing reactive epoxy groups.