Sucrose derivative as a cross-linking agent in enhancing coating stability and flame retardancy of polyamide 66 textiles

Abstract

A carbohydrate compound originated from plant species, namely oxidized sucrose (OS) was used as a cross-linking agent to stabilize the layer by layer (LbL) deposited flame retardant coatings developed onto the polyamide 66 textile surfaces. Here, the coating was constructed using some polyelectrolytes like chitosan (CS), sodium alginate (SA), phytic acid (PA) and montmorillonite (MMT) derived from green and mineral sources in a LbL assembly and subsequently, this coating was further treated with a polysaccharide binder like starch and a cross-linking agent like OS. In line, another bio-derived cross-linker, namely citric acid (CA) was used instead of OS and compared herewith. Obtained results showed that OS revealed superior coating stability over CA and in line, OS treated PA66 textiles exhibited better flame retardancy compared to the CA treated one. For example, OS treated fabrics attained a maximum limiting oxygen index (LOI) value by 23.5% along with a significant reduction in the peak heat release rate (pHRR) and total heat release rate (THR) by 36% and 15%, respectively. Meanwhile, OS could improve the stability of such coatings and offer extended durability in flame retardant performance. Thus, it was revealed that oxidized sucrose exhibited its potential to be considered as an effective green flame retardant alongside its cross-linking ability.