A durable coating constructed by metal-organic framework and polyphosphazene for flame retardant cotton fabric with enhanced mechanical properties

• Published in: Next materials 2024-04, Vol.3, p.100143, Article 100143
• Main Authors: Bi, Xue, Cheng, Xianwei, Zhang, Zeqi, Huang, Yaxuan, Pan, Ye-Tang, Guan, Jinping, Ardanuy, Mònica, Yang, Rongjie
• Format: Article
• Language: English
• Subjects: Flame retardant; Metal organic framework; Polyphosphazene; Starch; Wearability
• ISSN: 2949-8228; 2949-8228
• DOI: 10.1016/j.nxmate.2024.100143

The extremely flammable cellulose macromolecules in cotton fabrics seriously affect their application in the field of flame retardancy. In this paper, the surface of cotton fabric was modified with citric acid, and then metal-organic framework (UiO-66), cationic starch (St) and polyphosphonitrile (PZS) microspheres containing the transition metal element Zr were sequentially deposited to prepare an efficient and economical cotton fabric. St-PZS double-impregnated cotton fabrics have better thermal stability, flame retardancy and mechanical properties. And the coating does not affect the whiteness and stiffness of the cotton fabric. The results of thermogravimetric analysis showed that cotton/UiO-66/2St-PZS had a higher residual char rate (25.34%) under N2 atmosphere, which was 200.1% higher than that of control cotton (8.28%). In addition, cotton/UiO-66/2St-PZS had a 46.6% reduction in peak heat release, a 31.7% reduction in total heat release, and a 35.3% reduction in the peak of CO2 production compared to control cotton. It is worth noting that the average gross calorific value is 63.3% lower than that of the control cotton, indicating that flame retardant cotton fabrics can effectively inhibit the production of flammable gases. In addition, the tensile strength and elongation at break of cotton/UiO-66/2St-PZS are 458.79 N and 11.04%, respectively. After 20 laundering cycles, the mechanical properties remained almost unchanged. [Display omitted] •UiO-66 is successfully anchored to the surface of cotton fabric to improve its flame retardant properties.•The flame retardancy and mechanical properties of Cotton/UiO-66/2St-PZS are significantly enhanced.•The loading of the coating does not affect the whiteness and color of the cotton fabric.•The mechanical properties of cotton fabrics are hardly affected after 20 laundering cycles.