Flame retardant finishing of the polyester/cotton blend fabric using a cross‐linkable hydroxy‐functional organophosphorus oligomer

Abstract

Summary Blend fabrics of cotton and polyester are widely used in apparel, but high flammability becomes a major obstacle for applications of those fabrics in fire protective clothing. The objective of this research was to investigate the flame retardant finishing of a 50/50 polyester/cotton blend fabric. It was discovered previously that N,N′‐dimethyloldihydroxyethyleneurea (DMDHEU) was able to bond a hydroxy‐functional organophosphorus oligomer (HFPO) onto 50/50 nylon/cotton blend fabrics. In this research, the HFPO/DMDHEU system was applied to a 50/50 polyester/cotton twill fabric. The polyester/cotton fabric treated with 36% HFPO and 10% DMDHEU achieved char length of 165 mm after 20 laundering cycles. The laundering durability of the treated fabric was attributed to the formation of polymeric cross‐linked networks. The HFPO/DMDHEU system significantly reduced peak heat release rate (PHRR) of cotton on the treated polyester/cotton blend fabric, but its effects on polyester were marginal. HFPO/DMDHEU reduced PHRR of both nylon and cotton on the treated nylon/cotton fabric. It was also discovered that the nitrogen of DMDHEU was synergistic to enhance the flame retardant performance of HFPO on the polyester/cotton fabric.

Advanced Flame‐Retardant Methods for Polymeric Materials

“…Although many works confirmed the water resistance (surviving after 10–50 washing cycles) of these surface treatments, some imperfections remain. [ 197 ] Firstly, high temperatures (>100 °C) and acidic conditions are often required to promote the reaction in the process of building covalent bonds, which will damage the mechanical properties of substrates (especially for cellulose‐based fabrics). Secondly, in the absence of formaldehyde, the covalent bonds formed by the polycondensation of these flame retardants and adhesives (or bridging agents) with substrates are still sensitive to water, resulting in a rapid decline in flame retardancy after multiple washing.…”

“…Inspired by the dye‐fixing process, a biomass coating without conventional elements (such as Cl, Br, P) was developed to impart long‐lasting flame retardancy to cotton fabrics. [ 197b ] In this coating, tannin used as a carbonization agent was fixed onto the fiber surface by tartar emetic through dye fixation, while the further coordinated Fe 2+ catalyzed the formation of graphited char from tannin and cotton fibers to achieve high flame retardance. The treated fabrics remained a high LOI of ≈27.0% and easily passed the horizontal flammability test even after 100 washing or friction cycles.…”

Design and study of multifunctional fabrics

“…In order to chemically attached this FR with cotton, two catalysts (commercial products "Freerez 900" and "Aerotex M-3") were added with heating treatment followed. Another inherent FR [16] was also involved with tedious synthesis and expensive reagents. Dicyandiamide was used as a catalyst, then synthesized FR could react with primary hydroxyl groups on C (6) at high temperature (170°C).…”