Flame retardancy finish with an organophosphorus retardant on silk fabrics

Abstract

SUMMARYThe paper mainly deals with flame retardancy of silk fabrics treated with a commercial organophosphorus flame retardant [N-hydroxymethyl (3-dimethyl phosphono) propionamide (HDPP), also known as Pyrovatex CP], using the pad-dry-cure-wash method. The structures and properties of the treated and control sample are discussed. The Limiting Oxygen Index (LOI) value of the modified sample is above 30%. After 50 laundry cycles, it still has some flame retardancy left.HDPP and a cross-linking agent (HMM) were bound to silk fabrics which is confirmed by FT-IR spectra and amino analysis. The reaction degree of the flame retardant with silk is also high; almost all the tyrosine units have reacted, which can be confirmed by amino acid analysis. The reaction between flame retardant and silk only occurs in the amorphous region of silk fibre, which is confirmed by X-ray diffraction analysis and amino acid analysis. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis show that the flame retardant causes silk fabrics to decompose below its ignition temperature (6008C) and formed carbonaceous residue or char when exposed to fire. The char behaves as a thermal barrier to fire, so silk fabrics show good flame retardancy.The treatment has a little effect on the whiteness of the silk fabrics and the tensile strength of treated silk fabrics slightly decreased; both effects are negligible.

Flame‐retardant finishing in cotton fabrics using zinc oxide co‐catalyst

“…The rocking band of ACH 2 is a characteristic strong-medium intensity band for phosphonate structures having PACH 2 AR groups. 10,11 The spectrum confirmed the existence of flame-retardant agents on the treated specimens.…”

Polymer Degradation and the Matching of FR Chemistry to Degradation

“…This charring characteristic is probably largely influenced by the dehydrating and cross-linking tendency of the hydroxyl group within the serine -CH2OH -substituent. Charring can be increased by application of phosphoruscontaining species as might be expected given this assumed chemistry [53]. The natural fibre LOI value is 22-23 vol% reflecting this higher char-forming tendency than the simple aliphatic nylons which have LOI values of about 21 vol%.…”

The application of a novel flame retardant on viscose fiber

“…In the first stage, the initial pyrolysis temperature of samples treated with EP-MDPA is found to be about 240 • C, which below the initial pyrolysis temperature of control fiber (namely 283 • C). Before attaining its ignition temperature [23], the combustible gas produced during the stage of the fiber pyrolysis has escaped from the combustible system. That reduces the amount of fuel and the heat of combustion, at the same time prevents the decomposition of the residue.…”

“…The EP-MDPA is an effective flame retardant that can promote char formation by converting the fiber to a carbonaceous residue or char and hence reduces volatile formation. It also releases many kinds of non-flammable molecules like CO 2 , NH 3 , HCl and H 2 O during char formation [23]. In addition, the char behaves as a carbonized replica of the original fiber, which continues to function as a thermal barrier.…”

“…When the flame-retardant fiber was heated [20,21] HMM (crosslinking agent) will cause inflation of the melting carbon. The charred cellulosic fiber is similarly structured replicas of their former striated parents, with the control fiber having undergone considerably more reduction in width as a consequence of its higher cellulose content and hence greater loss in mass during pyrolysis [23]. The treated fiber char surfaces display numerous roughly hemispherical protrusions, which has the appearance of localized, surface blistering following volatile emissions [25,26].…”