Flame Retardancy Of Cotton Fabrics Research Articles

Chemically modified wool waste keratin for flame retardant cotton finishing

Environmentally friendly flame retardant chemicals are being developed in recent studies as legislation for eco-sustainable textile production becomes more stringent around the world. Utilisation of waste generated by the wool spinning industry is a prime concern with present work. The extraction and modification of keratin from waste wool for flame retardant cotton has not been attempted previously. The research describes a unique method for using chemically modified keratin derived from wool waste as an environmentally acceptable nitrogen/phosphorus containing flame retardant for cotton fabrics. Melamine and sodium pyrophosphate were used as nitrogen and phosphorus sources, respectively, along with glyoxal as a cross-linking agent. The improved thermal stability of modified wool waste keratin and treated cotton fabrics was confirmed by TGA, while structural changes were established by FTIR and XRD analyses. Due to the synergistic impact of nitrogen and phosphorous, the modified wool waste keratin resulted in the formation of a continuous and intact layer of char that confers flame retardancy on treated cotton. The limiting oxygen index of cotton after application of the modified keratin showed a nearly 66.7% increase in flame retardancy compared to untreated cotton. Overall, the findings in the paper show a sustainable approach for the textile industry that combines waste utilisation from one textile sector (minimizing solid waste from the wool industry) with waste management elements to add value to another (multifunctional textile finishing agent for the cotton industry).

A biological reactive flame retardant for flame retardant modification of cotton fabric

A novel, high-efficiency, bio-based flame retardant ammonium salt of arginine hexamethylenephosphonic acid (AAHMPA) for cotton fabric was synthesized and grafted onto the cotton fabric by P–O–C and C–O–C covalent bonds. The flame retardancy and durability of treated cotton were improved obviously. The limiting oxygen index (LOI) value of 35 wt% AAHMPA-treated cotton reached 45.1%, and after 50 laundering cycles (LCs), the LOI value remained at 28.6%. The cone calorimeter, thermogravimetric and vertical flammability test indicated that treated cotton decomposed into phosphoric acid or polyphosphoric acid during combustion, which promoted the thermal degradation and charring of cotton fabrics and hindered the spread of flames. The mechanical properties of treated cotton fibers were slightly reduced. These results confirmed that AAHMPA treated cotton obtained excellent flame retardancy and high durability. • Flame-retardant cotton fabric was prepared by surface modification. • The treated cotton fabric has excellently durable flame retardant. • The flame retardant can form P–O–C and C–O–C covalent bonds with cotton fibers. • The raw materials of flame retardant are naturally-abundant. • Flame retardants will not produce harmful substances during use.

Superamphiphobic and flame-resistant cotton fabrics for protective clothing

Superamphiphobic and flame-retardant finishing of cotton fabric can significantly improve its protective properties to expand its applications, such as protective clothing. However, creating such materials is still a challenging issue. Herein, we present a facile strategy to fabricate superamphiphobic and flame-retardant cotton fabric (SFC) via step-by-step dip-coating and spraying technology. Ammonium polyphosphate (APP) endows cotton fabric excellent flame retardancy. The robust coating formed by the polymerization product of ethyl 2-cyanoacrylate and 1H,1H,2H,2H-perfluorooctyl trichlorosilane (FOCS) can not only protect APP from being damaged but also trap air to form "air plastron", which makes SFC have excellent antifouling, chemical repellence and self-cleaning. The resulting SFC exhibited superamphiphobicity and flame retardancy with water contact angle of 161°, oil contact angle of 158° and LOI of 30%. After UV irradiation, mechanical damage, 180 °C oven heating and ultrasonic washing, it still maintains excellent hydrophobicity without loss of flame retardancy. This study expands the potential applications of cotton and provides feasible technologies for improving the overall efficiency of cotton.Graphic abstract

Synthesis of Zinc Fluoroborate by Wet Method and Its Application as a Flame Retardant for Cotton Fabrics

In this study, zinc fluoroborate was synthesized by wet method using fluoroboric acid and zinc oxide as reactant and its usability as flame retardant for cotton fabrics was investigated. The wet method is economical, green, efficient and applicable for a large-scale. The maximum yield was determined related to the variation of reactant ratio, temperature, reaction period and stirrer rate. The characterization of the product was carried out by means of FTIR, BF4- ion selective electrode and XRD. The maximum yield of 97% was achieved at the reactant mole ratio (nZnO/nHBF4) of 1:3, temperature of 90 °C and reaction period of 90 minutes. The purity of the synthesized product was found as 98 %. Flame retardancy and high temperature resistance effects of zinc fluoroborate on cotton fabrics were investigated by LOI test and high temperature durability test method, respectively. Although LOI value of the untreated original fabric was determined as 16, this value increased above 55 by impregnating of fabric with 50 % zinc fluoroborate solution.

One Pot Facile Synthesis of Self-extinguishable Metal Based Flame Retardant for Cotton Fabric

ABSTRACT An efficient metal-based flame-retardant was prepared for cotton fabric (CF) by a convenient pad-dry-cure method, which involves the consecutive deposition of intumescent containing different combination of ammonium polyphosphate, melamine, pentaerythritol with Copper and Zinc metal ions. We studied different properties like thermal, mechanical, flammability, and laundering durability of treated CF samples. The intumescent-coated CF shows remarkable high-efficiency flame-retardant properties: (1) a self-extinguishing property (5 s) without lateral spreading of flame during the vertical flame test with a lower smoke release character; (2) the limiting oxygen index (LOI) values of coated CF are improved with increasing add-on level. The Zn-based samples exhibited a high limiting oxygen index value of 36%. Consequently, the resultant fabrics were observed to show great flame retardancy with high thermal stability as 35% of char yield at 600°C. The durability of modified cotton was tested after five laundering cycles, which showed that the coating maintains 84% of its initial mass. It is reported that in addition to durable flame retardancy, the mechanical properties of cotton were also enhanced. The present work provides eco-friendly one pot facile synthesis of intumescent-based flame retardant for CF which may be used in numerous applications. Abbreviations: ammonium polyphosphate; PER: pentaerythritol; MEL: melamine; LOI: limiting oxygen index; TGA: thermogravimetric analysis; DTG: derivative thermogravimetry; GSM: gram per square meter; FR: flame retardant; CP: plain cotton fabric; CT: twill cotton fabric; CF: cotton fabric; Int: intumescent; FTIR: Fourier Transformation Infrared; BEL: burn entire length; DNI: did not ignite; SE: self-extinguish; HGMs: hollow glass microspheres; CH/PA/Ba/PA: Chitosan/ Phytic Acid/Barium/Phytic Acid; DPPMA: diphenylphosphinic acid with melamine; PBS/30PA-GU: poly(butylene succinate/30 phytic acid-guanosine; PET: polyethyleneimine; Tri-HTAC: 2,4,6-tri[(2-hydroxy-3-trimethyl-ammonium)propyl]-1,3,5-triazine chloride; TA/B@PDA: tannic acid/Borax@polydopamine; P10H5: 5wt% HCCP(Hexachlorocyclotriphosphazene). ammonium polyphosphate; PER: pentaerythritol; MEL: melamine; LOI: limiting oxygen index; TGA: thermogravimetric analysis; DTG: derivative thermogravimetry; GSM: gram per square meter; FR: flame retardant; CP: plain cotton fabric; CT: twill cotton fabric; CF: cotton fabric; Int: intumescent; FTIR: Fourier Transformation Infrared; BEL: burn entire length; DNI: did not ignite; SE: self-extinguish; HGMs: hollow glass microspheres; CH/PA/Ba/PA: Chitosan/ Phytic Acid/Barium/Phytic Acid; DPPMA: diphenylphosphinic acid with melamine; PBS/30PA-GU: poly(butylene succinate/30 phytic acid-guanosine; PET: polyethyleneimine; Tri-HTAC: 2,4,6-tri[(2-hydroxy-3-trimethyl-ammonium)propyl]-1,3,5-triazine chloride; TA/B@PDA: tannic acid/Borax@polydopamine; P10H5: 5wt% HCCP(Hexachlorocyclotriphosphazene).

A facile strategy to achieve efficient flame-retardant cotton fabric with durable and restorable fire resistance

Novel, durably flame-retardant cotton fabrics with fascinatingly restorable fire resistance were prepared by simple grafting of phosphate and melamine, which contributed to a phosphorous-nitrogen (P/N) synergism. During the preparation process, phosphate was grafted with the hydroxyl groups of cellulose to form P-O-C bonds; subsequently, melamine reacted with the aldehyde groups of cellulose generated from phosphorylation to form P/N modified fabrics (P/N-Cotton). The P/N synergistic effect endowed cotton fabric with prominent fire resistance and durability. The Limit oxygen index (LOI) was as high as 51.1 ± 0.3% and was maintained at 32.7 ± 0.8% after 50 laundering cycles (LCs). The total heat release (THR) and peak values of heat release rate (pHRR) of P/N-Cotton were significantly reduced by 70.11% and 64.19%, respectively. Amazingly, the modified cotton fabrics exhibited restorable fire resistance once immersed into the acetic acid solution due to the ion exchange between Na+ from detergent and H+ from acetic acid. The LOI of P-Cotton and P/N-Cotton after 50 LCs can be restored to 32.4 ± 0.7% and 35.7 ± 0.7% from 20.8 ± 0.7% and 32.7 ± 0.8%, respectively. The analysis of gas-phase products and residual char demonstrated that the incorporation of phosphate and melamine facilitated cellulose fibers to convert to dense and stable graphitized carbon layers and carbon-nitrogen heterocycles, effectively protecting the fabric from decomposing to flammable gases.

Properties of flame-retardant cotton fabrics: Combustion behavior, thermal stability and mechanism of Si/P/N synergistic effect

A novel silicon, phosphorus and nitrogen synergistic flame retardant, aminoethylpiperazine phosphoric acid methyl ester modified siloxane (EPSO-P) was synthesized, the structure of EPSO-P was confirmed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The limiting oxygen index (LOI) value of cotton fabrics treated by EPSO-P increased to 31.4 %, and passed the vertical flammability test (VFT) with a residual char length of 6.3 cm. The thermal stability of samples is obviously improved after processing, and the char residue maintained 43 % at 700 °C in nitrogen atmosphere. The burning behavior of cotton fabrics showed that the peak heat release rate decreased from 232.1 kW/m2 to 74.5 kW/m2, and the total heat release decreased from 6.3 MJ/m2 to 2.8 MJ/m2 after flame retardant treatment. The flame retardant mechanism of the samples was analyzed by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and thermogravimetric analysis coupled with fourier transform infrared analysis (TG-FTIR). The results indicated that the EPSO-P can prevent the fabrics from burning in gas phase and condensed phase. This work proved that EPSO-P is enlightening for the production of flame retardant cotton fabrics with considerable properties.

Superhydrophobic and phosphorus‑nitrogen flame-retardant cotton fabric

In recent years, various functions including electrical conductivity, superhydrophobicity, magnetism, flame retardancy and antibacterial activity have been considered to allow cotton fabric (CF) a wider the application range. A new strategy for the preparation of superhydrophobic and flame-retardant CF is described here. Phytic acid (PA) and 1-[3-(trimethoxysilyl)propyl]urea (UPTMS) were firstly coated on CF to provide phosphorus‑nitrogen flame retardancy. Then silica particles grafted with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) for the construction of surface roughness and further improvement of flame retardancy and low-surface-energy polydimethylsiloxane (PDMS) were covered on the surface of CF, and the superhydrophobic and flame-retardant CF (SFR-CF) was obtained after thermal curing. The SFR-CF displayed a high water contact angle of 155.9° and excellent anti-adhesion properties and self-cleaning capabilities. In addition, the SFR-CF could be used to efficiently separate oil-water mixtures with a separation efficiency of up to 96.1%. Moreover, the SFR-CF possessed outstanding flame retardancy. The damage length in vertical burning test was only 5.2 cm. This was attributed to not only the release of non-flammable gases such as NH3 and H2O to dilute the concentration of the flammable gas and retard the combustion speed, but also the formation of a dense protective char layer promoted by the presence of poly-phosphoric acid from PA and DOPO-silica. The method used is facile and efficient, and the fabricated superhydrophobic and flame-retardant CF has great potential in a wide range of applications such as oil-pollution treatment, firefighter clothing, outdoor tents and fold-top cars.

One-step green synthesis of eco-friendly novel N–P synergistic flame retardant for cotton fabric

A novel N–P ammonium salt 1,3-propylene glycol diphosphate ester (APGDPE) flame retardant was tersely synthesized under solvent-free condition to lower cotton fabric fire hazard. The APGDPE structure was characterized by 1H NMR, 13C NMR, 31P NMR and IR spectroscopy. The reactive P = O(NH4+)2 and PO(OH)2 groups of APGDPE were successfully grafted into cotton fabric to form P–O–C covalent bond. The limiting oxygen indexes (LOI) of treatment cotton with weight gain rate of 14.7%, 17.2% and 20.8% reach 40–44.5%. After 50 laundering cycles (LCs), the LOI value of treatment cotton with weight gain rate of 20.8% still maintains 27.3%. These results verified that the treated cotton has obtained outstanding flame retardancy and prominent durability. TG test indicates that the thermal stability and thermal oxidative stability of treated cotton are much higher than those of control cotton. TG-IR test displayed that treated cotton released less flammable volatile gases than those of control cotton. Cone calorimetry revealed that the PHRR and THR values of treated cotton decreased by 5.57% and 26.8%, respectively. XRD results suggest that the crystallization zone of cotton fabric before and after treatment hardly change. TG-IR and cone calorimetry tests verified the APGDPE condensation phase mechanism for treated cotton.

A superhydrophobic and flame-retardant cotton fabric fabricated by an eco-friendly assembling method

A novel eco-friendly and durable superhydrophobic and flame-retardant cotton fabric with fluorine-free, halogen-free was prepared via step-by-step dip-coating and spraying technology. At first, common cotton fabric was impregnated in the flame-retardant ethoxysilane-terminated phosphate polyurethane. Afterwards, methanol mixture containing silica nanoparticles, methyl triethoxysilane, and dihydroxy-terminated polydimethylsiloxane was sprayed on the surface of the cotton fabric. Finally, a flame-retardant cotton fabric with micro-nano rough surface and low surface energy was formed. The resulting superhydrophobic and flame-retardant cotton fabric exhibited superamphiphobicity with the contact angle and sliding angle of 160° and 6°, respectively, while flame retardancy with limited oxygen index of 28.1%. and flame self-extinguishing. Furthermore, this superhydrophobic and flame-retardant cotton fabric showed robust superhydrophobicity and flame-retardancy after undergoing 1000 cycles of abrasion, 60 min of ultrasonic washing and 50 standard machine washing cycles, in sequence, indicating its potential as a multifunctional protective textile fabric. Additionally, the method proposed in this study can effectively solve durability and environmental problems currently faced by the coated fabric with superhydrophobicity and flame-retardancy.

High-Efficiency Flame Retardants of a P-N-Rich Polyphosphazene Elastomer Nanocoating on Cotton Fabric.

Modification by intumescent flame retardants is an effective way to impart antiflame properties to fabric materials. Polyphosphazene elastomers contain all three elements required by intumescent flame retardants: an acid source, a gas source, and a carbon source, making them all-in-one integrated intumescent flame retardants. In this work, halogen-free poly(dimethoxy)phosphazene (PDMP) loaded with 29.0 wt % phosphorus and 13.1 wt % nitrogen is shown to be an ideal flame retardant for fabric materials. For the first time, transparent and elastic PDMP was applied as an intumescent flame retardant for cotton fabric. The PDMP-coated cotton shows remarkable high-efficiency flame-retardant properties: (1) a self-extinguishing property during the vertical flame test is obtained when the add-on level reaches 5.3 wt %, with a lower smoke release character; (2) the limiting oxygen index (LOI) values of coated cotton are improved with increasing add-on level, and the thickness of the coating is measured to be at the nanolevel, 2540 nm when 10.9 wt % PDMP is coated. The coated cotton shows enhanced carbonization ability at lower temperatures, which is the key to imparting flame-retardant properties to cotton, and the PDMP-coated cotton shows remarkably lower peak heat release rate and total heat release compared to the control cotton during combustion. The durability of modified cotton was tested after 50 laundering cycles, which showed that the coating maintains 80% of its initial mass, and the after-laundering sample preserves the characteristics of self-extinguishing and a high LOI. Thus, the PDMP nanocoating-modified flame-retardant cotton fabric is sufficiently durable for practical application.

Novel phosphorus/nitrogen-rich oligomer with numerous reactive groups for durable flame-retardant cotton fabric

Novel phosphorus/nitrogen-rich oligomer with numerous reactive groups for durable flame-retardant cotton fabric

A novel ε-polylysine-derived durable phosphorus‐nitrogen‐based flame retardant for cotton fabrics

A novel biomass-based, phosphorus-nitrogen-based, halogen-free flame retardant, ammonium salts of polylysine methylphosphonate glycerol ester (PLUEG), was successfully synthesized based on e-polylysine and glycerol, used to prepare highly efficient and durable flame-retardant cotton fabrics. The large number of –P=O(O−NH4+)2 reactive groups improved the binding between flame retardants and cotton fabrics, making it harder for flame retardants to be washed off from cotton fabrics. During the synthesis process, some of the –P=O(OH) groups on flame retardants were esterified in advance with glycerol, to reduce the effect of metal ions on the flame retardancy of cotton fabrics during washing process. And cotton fabrics were pretreated with sodium hydroxide to partly break the crystalline region of cellulose and increase the number of reacting sites in cellulose for flame retardants. After the pretreatment with sodium hydroxide and treatment with PLUEG, cotton fabrics with high flame retardancy and durability was prepared. The limiting oxygen index value of cotton fabrics increased to 42.7%, which remained at 28.6% after 50 laundering cycles (LCs) of home machine washes. Analysis by Fourier-transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectroscopy revealed that PLUEG were bound to cotton fabrics by –P(=O)–O–C bonds, and the flame retardancy of treated cotton fabrics decreased during washing process because of the replacement of NH4+ in unreacted –P=O(O−NH4+)2 groups by the metal ions in washing liquid. Also, analysis by thermogravimetric (TG), TG-FTIR spectroscopy and scanning electron microscopy indicated that PLUEG was mainly effective in the condensed phase. The whiteness and mechanical properties of treated cotton fabrics were retained well.

Correction to “Ecofriendly Flame-Retardant Cotton Fabrics: Preparation, Flame Retardancy, Thermal Degradation Properties, and Mechanism”

Correction to “Ecofriendly Flame-Retardant Cotton Fabrics: Preparation, Flame Retardancy, Thermal Degradation Properties, and Mechanism”

Eco-friendly and efficient flame-retardant cotton fabric based on a multi-hydroxyl hyperbranched phosphoramidate

A kind of multi-hydroxyl containing hyperbranched phosphoramidate (HPAE) was successfully synthesized and characterized by FT-IR, 1H-NMR, 31P-NMR, and GPC. With the crosslinking of butane tetracarboxylic acid (BTCA), the flame-retardant cotton fabrics were prepared, and the combustion behavior and thermal degradation properties were investigated by limiting oxygen index (LOI), vertical flammability test, cone calorimetry test and thermogravimetric analysis. After treating with 300 g/L HPAE, good flame retardancy was obtained with LOI value of 29.0% and treated cotton fabrics can pass the vertical flammability test without afterflame and afterglow. The peak heat release rate was decreased from 255 to 93 kW/m2 and the total heat release after treatment was reduced by 37%. The thermal stability was greatly improved and over 40% of char residues maintained at 800 °C in N2. The washing durability of HPAE-BTCA treated cotton fabrics was also investigated and LOI value decreased from 29.0 to 25.2% after 25 washing cycles. Besides, the tensile strength, wrinkle recovery angle, and whiteness of cotton fabric after treatment were examined. Overall, our research provides a facile and effective approach to prepare durable flame-retardant cotton fabric, which has great potential in friendly flame-retardant textiles.

Construction of durable eco-friendly biomass-based flame-retardant coating for cotton fabrics

Inspired by the classic dye-fixing process, a novel eco-friendly biomass-based coating that neither used traditional elements such as Cl, Br, P nor toxic organic solvents was first developed to endow cotton fabrics with durable flame retardancy from biomass tannin (TA), tartar emetic (TE), and Fe2+. In this coating system, TA used as a charring agent was fixed onto the fiber surface of cotton fabric by TE in water via the action like dyestuff fixing, while Fe2+ coordinated with the hydroxyl of TATE can catalyze TA and cotton fibers to form graphited stable carbon residues for achieving high flame retardance. Consequently, the resultant fabrics showed great flame retardance with excellent durability. Even after 100 laundering or friction cycles, their limiting oxygen index values of ~27.0% hardly changed. And the washed flame-retardant cotton fabrics still easily passed the horizontal flammability test with an extremely low destroy spread speed. Moreover, scanning electron microscopy, confocal laser scanning microscope, and cone calorimeter test results all confirmed the durability of the coating. The flame-retardant mechanism analysis demonstrated that the coating could promote the cotton fibers to form dense and regular graphitized carbon layers and effectively protect the matrix from decomposing to flammable gases under high temperatures. In addition to durable flame retardancy, the mechanical properties and hydrophilicity of cotton were slightly influenced by the flame-retardant coating. This eco-friendly biomass-based flame-retardant coating provides a new strategy for fabricating green flame-retardant systems without using hazardous compounds.

Comparison of differences in the flame retardancy of cotton fabrics caused by the introduction of cyclic polysiloxane into P/N organic coatings

Cyclic polysiloxane was introduced into P/N flame retardant coating to prepare Si/P/N synergistic FRs (ASPP-Si), which can improve the heat release and smoke release of cotton fabric and enhance the tensile strength of fiber.

Effect of Relative Humidity Condition on Electrical Heating Textile Coated with Graphene-based on Cotton Fabric

The objective of this study was to determine effects of relative humidity on electrical heating textile properties. Relative humidity (RH) is a factor to determine clothing comfort. Electrical heating textile is used in close contact with human skin in winter or under extreme environments. Graphene/polymer composite was coated with flame retardant cotton fabric with a horseshoe-pattern. The relative humidity was controlled through water-sulfuric acid method. Samples were stored in external environment with different RH (25-% RH, 35-% RH, 45-% RH, 55-% RH, 65-% RH, and 90-% RH). With increasing RH, weight change rate also tended to increase due to increase amount of moisture absorbed by cotton fabric. Regarding surface resistivity under dry and each RH condition, it was found that surface resistivity change rate tended to decrease from 25% RH to 55% RH and then started increasing upto 90 % RH. Surface temperature and current of samples with various RH conditions were linearly increased with increasing applied voltage. When a voltage between 5 V and 6 V was applied to samples with various RH conditions, surface temperature was about 50 °C. Differences in surface temperature and current change rate tended to increase from under 25 % RH to 55 % RH conditions. However, they started decreasing from 65 % RH condition and the decline continued upto 90 % RH condition. These results confirmed that 55 % RH condition could improve electrical and electrical heating properties of samples. This condition could be expected to improve electrical properties of electrical heating textiles for wearable electronic applications.

An eco-friendly and effective method to fabricate flame retardant cotton fabrics

To reduce the flammability of cotton fabrics, an environmentally benign, simple and effective method was proposed. Coatings composed of phosphoguanidine/ATMP/alginate were deposited on the surface of the cotton fabrics through layer-by-layer (LbL) assembly. FTIR spectra indicate that the layer-by-layer deposition process is successfully carried out on the surface of cotton fabrics. TGA suggested that LbL coating can significantly increase the char residue. The results of MCC and vertical flame tests showed that the LbL coatings can remarkably enhance the fire safety properties of the cotton fabrics and a higher concentration of ATMP (2 wt%) can bring better effect of flame retardancy.

A study on coating with nanoclay on the production of flame retardant cotton fabrics

In this study, flame retardant properties of 100% cotton fabrics were tried to be improved by using commercial nanoclay (Cloisite 20A) which is a clay based montmorillonite. Flame retardancy and thermal decomposition behavior of the samples were characterized by the vertical burning test, limiting oxygen index (LOI), and thermogravimetric analysis (TGA). The surface morphology of untreated and treated fabric was examined using a scanning electron microscope (SEM). Fourier-transform infrared spectroscopy (FTIR) analysis was carried out for Cloisite 20A, untreated and coated fabrics. The results of the tests showed that the coating treatment even at low nanoclay concentration is enough to have a considerable flame retardant effect. This result was attributed to the barrier effect of the nanoclay.