Flame-retardant treatment of silk fabric with sodium phytate and chitosan using the layer-by-layer padding technique

Abstract

Bio-based fl ame-retardant agents and layer-by-layer assembly have attracted a great deal of attention in the fl ame-retardant fi elds of textiles, composites and polymeric materials. In this study, the electrostatic layer-by-layer assembly of chitosan and sodium phytate on silk fabric was carried out using a padding technique. The eff ects of the concentration and assembled bilayer of chitosan and sodium phytate on the weight gain, fl ammability, surface morphology, whiteness, stiff ness, lustre, tensile strength, and washing durability of silk fabric were studied, and the heat release, thermal stability and fl ame-retardant mechanism of the coated fabric were analysed. The results revealed that at 10 to 15 assembled bilayers, the coated fabrics exhibited high limiting oxygen indexes and passed the vertical burning test, and their good fl ame retardancy was maintained even after 15 washing cycles. Moreover, the coated fabrics exhibited a signifi cant decrease in peak the heat release rate and a strong charring ability at high temperatures. The chitosan and sodium phytate system acted as fl ame retardants in the condensed phase. Given the high weight gain of silk fabric, the layer-by-layer assembly of chitosan and sodium phytate using a padding technique was more applicable to the fl ame-retardant treatment of furnishing fabrics.

Chitosan and nano-TiO2 coating improves the flame retardancy of dyed and undyed denim fabrics by increasing the charring

“…45 The authors recorded a 13.66% increase in fabric weight in the double-sided coating made using 0.5% chitosan by weight, whereas this increase was 24.81% when using 1.0% chitosan by weight. In this study, the observed weight gain was similar to the values reported by Lv et al 48 Since denim fabric is dyed, the amount of chitosan absorbed by the fabric was limited and chitosan could not penetrate into the fabric. In addition, the dense weaving of the denim fabric reduced the penetration of chitosan between the fibers.…”

“…Mass losses are due to the loss of water in the first stage, the thermal decomposition of the cellulosic fabric in the second stage and the further decomposition of the degraded products in the third stage. 48 The burning properties of cellulosic fibers vary significantly related to their chemical composition. 52 The results of this study also confirm the previous data.…”

“…The weight loss in the first stage is attributed to water evaporation, the weight loss in the second stage is ascribed to the formation of gas and charcoal due to the decomposition of chitosan and fabric by the effect of heat and the weight loss in the final stage is assigned to the thermal oxidation decomposition of the char residue produced in the previous stages. 48 The mass losses occurring at 625°C were 88.3% in the blue dyed denim fabric coated with crayfish chitosan, 65.7% in the raw denim fabric coated with crayfish chitosan, 86.4% in the green dyed calico fabric coated with crayfish chitosan and 66.0% in the crayfish chitosan and nano-TiO 2 -coated blue dyed denim fabric (Figure 8). The highest residue was observed in the undyed raw denim fabric (34.3%) coated with crayfish chitosan and in the blue dyed denim fabric coated with crayfish chitosan and nano-TiO 2 (34%).

Figure 8.Thermogravimetric analysis of chitosan and nanometal coated fabric samples: a) blue dyed denim fabric coated with crayfish chitosan, b) undyed raw denim fabric coated with crayfish chitosan, c) green dyed calico fabric coated with crayfish chitosan, and d) blue dyed denim fabric coated with crayfish chitosan and nano-TiO 2 .

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Flame retardant and anti-dripping polyethylene terephthalate fabric based on bio-based phytic acid/gelatine coating

“…With increasing public awareness of environmental issues, eco-friendly bio-based IFR coatings have been reported to construct on textiles. Phytic acid (PA), DNA and chitosan (CH) have been used for the construction of the bio-based IFR coating [30][31][32]. We have studied to construct IFR coating on PET fabrics by positively charged chitosan and negatively charged ammonium polyphosphate [33].…”

Construction of eco-friendly flame retardant and dripping-resistant coating on polyester fabrics

“…The coated polyester fabric achieved excellent dripping-resistance, while its flame retardancy was unsatisfactory. PA as a green, renewable, sustainable natural flame retardant has been reported to flame retardant treatment for cotton, silk and wool fabrics [27][28][29].…”