Flame Retardancy Of Cotton Fabrics Research Articles

Synergistic flame retardant effect of carbon nanohorns and ammonium polyphosphate as a novel flame retardant system for cotton fabrics

The development of environmentally friendly flame retardants that can achieve high efficiency for textiles at low addition levels is of great significance to human life and environmental protection. Halogen flame retardants have long dominated in flame retardant applications. However, there are increasing calls to ban its use because of the threat they pose to human health and the environment. Herein, this work investigated the potential of a novel carbonaceous nanomaterials-single-walled carbon nanohorns (SWCNHs) coating material for flame retardancy of cotton fabrics. The unique combination of SWCNHs and ammonium polyphosphate (APP) in a single halogen-free nanocoating has a synergistic effect, which endows cotton fabric with prominent fire resistance. When the addition amount of SWCNHs was 0.15 %, the limit oxygen index (LOI) could reach 27.5 ± 0.83 %, and the damage length decreased from 30 ± 0.01 % cm to 6.5 ± 0.06 % cm. SEM results showed that Cotton-APP/SWCNHs (0.15) still displayed well-preserved woven structure after the vertical flammability test. Additionally, the pHRR and THR of Cotton-APP/SWCNHs (0.15) were markedly decreased by 92.22 % and 58.44 %, respectively in the cone calorimeter test. Meanwhile, the flame retardant mechanism analysis confirmed that the incorporation of SWCNHs into the APP coatings promoted the formation of dense and stable graphitized carbon layer on the surface of the cotton fabric, and effectively prevented the generation of combustible volatiles, thus enhancing the flame retardant performance of cotton fabrics. This work provides a new insight into developing carbon nanomaterials for flame retardant polymeric materials and extending the application of SWCNHs.

Permanent P/N-rich polymeric coating capable of extinguishing flame on cotton fabrics

Although polyphosphazenes having attracted attention for use as flame-retardant coatings for textiles, nonetheless their add-on level is still far from ideal with regard to high-efficiency flame-retardant properties, wearing comfort and durability. Herein, for the first time, a cross-linkable phosphorus and nitrogen-rich polyphosphazene, poly(methoxy/allylphenoxy)phosphazene (PMAP), with mainly methoxy groups and an appropriate amount of unsaturated chemical bonds containing allylphenoxy side groups (ca. 8 %) was synthesized. Subsequently, the noncombustible, transparent, elastic crosslinked PMAP coating was coated on cotton fabrics through dipping and photoinduced cross-linking processes. The PMAP-coated cotton showed high-efficiency flame-retardant properties along with remarkably high durability. The intrinsic properties of cotton fabric, such as whiteness, gas permeability and bending rigidity, were highly reserved after being coated with PMAP. Interestingly, the flame-retardant properties of the 4.9 wt%-coated cotton increased, and the coated cotton obtained a self-extinguishing property and maintained >95 % of its initial mass after 60 rigorous laundry cycles. Moreover, the PMAP-coated cotton exhibited enhanced carbonization ability at lower temperatures, which was the key to the flame-retardant properties of cotton fabric. The PMAP-coated cotton also showed a lower peak heat release rate and total heat release values than the control cotton during combustion. Therefore, the comprehensive highly favorable properties of the PMAP coating make it a cutting-edge material for flame-retardant cotton fabrics and greatly expand its potential in practical applications.

Biobased coating derived from fish scale protein and phytic acid for flame-retardant cotton fabrics

The nitrogen-phosphorus flame-retardant coating was formed on the surface of cotton fabrics via strong electrostatic attraction and hydrogen bonds with layer-by-layer coating of protein extracted from fishery waste fish scales and phytic acid (PA) derived from plant seeds. The flame retardant property of the coated cotton fabrics demonstrated a significant improvement with a limiting oxygen index of 31.1%, meeting the flame retardant requirements of commercial fire-protection suit. Especially, noteworthy, due to the synergistic smoke suppression effect of fish scale protein and phytic acid, the total smoke emission was greatly reduced by 139%. Meanwhile, the charring of the cotton fabrics treated with FSP and PA was significantly enhanced. Scanning electron microscopy and Raman results of the residual char further reveal that the treatment of the combined coating facilitates the formation of dense and regular graphitized char residue during combustion or under high temperature. This waste-sourced, biomass-derived coating paves a new way towards sustainable flame-retardant fabrics and has great significance in civil, military, and industrial fields.

Preparations, characterizations, thermal and flame retardant properties of cotton fabrics finished by boron-silica sol-gel coatings

This work aims to improve the thermal stability and flame retardancy of cotton fabrics by using sol-gel processes. A hybrid sol was prepared by using silica sol, coupling agent of γ-Methacryloxypropyltrimethoxysilane (KH570) and flame retardant of sodium octaborate tetrahydrate (DOT) and then finished on the surface of cotton fabric. Fourier infrared spectroscopy (FTIR), X-ray electron spectroscopy (XPS), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), limiting oxygen index (LOI) and vertical burning test (VBT) were used to characterize the functional groups, surface element compositions, microscopic morphologies, thermal stability and flame retardancy of cotton fabrics, respectively. The results show that sols are successfully converted into gel coatings onto cotton fabrics. SiO2-KH570-DOT@Cotton shows the highest char residue rate (41.7%) and ΔLOI/Δm (6.0%/g) values. SiO2, KH570 and DOT coatings have shown some competitive but more synergistic effects in flame retardancy. The three-dimensional structure of SiO2 gel can provide structural support, effectively block heat transfer and transports of oxygen. KH570 has a significant coupling effect of increasing interfacial compatibility between sols and cotton fabrics. DOT is thermally decomposed to generate boric acid to accelerate the carbonization degrees of cotton fibers and thus improve the thermal stabilities of char layers.

Assembled hybrid films based on sepiolite, phytic acid, polyaspartic acid and Fe3+ for flame-retardant cotton fabric

Abstract To impart durable flame retardant property to cotton fabric, a kind of multilayered hybrid film based on environmentally friendly phytic acid, sepiolite, polyaspartic acid, and Fe3+ were deposited on the surface of cotton fabric by layer-by-layer and spraying method to form a dense protective layer. Compared with cotton fabric, hybrid film coated cotton showed excellent flame retardant property and low fire hazard, which can be demonstrated by vertical flame test, limiting oxygen index (LOI) and cone calorimeter test. After-flame time and after-glow time of hybrid film coated cotton is 1 s and 1 s, respectively. LOI value of hybrid film coated cotton increased by 44.4% compared with control sample. Cone calorimeter test revealed a total heat release rate reduction of 52.6% and peak heat release rate reduction of 73.6% for hybrid film coated cotton fabric. This work demonstrates that the hybrid film composed of phytic acid, sepiolite, polyaspartic acid, and Fe3+ could improve the durable flame retardant property of cotton fabric.

Durable flame-retardant cotton fabrics with tannic acid complexed by various metal ions

In this paper, a variety of metal ions (Ca2+, Fe2+, Co2+, Ni2+, and Zn2+) were used to coordinate biomass tannin (TA) and tartar emetic (TE) to prepare durable flame-retardant cotton fabrics. All the obtained TATEMe systems endowed cotton fabrics with highly durable flame retardancy, while different metal ions in the system contributed to different flame retardant effects. The Ca2+ and Zn2+ flame-retardant systems showed much better smoldering performances in comparison with Fe2+, Co2+, and Ni2+-containing coatings. Further, the catalytic carbonization process of different metal ions on biomass TA was tracked, the material pyrolysis process was revealed, and the durable flame-retardant mechanism of biomass TA-metal complexes was clarified. The Ca2+ flame-retardant system promoted the release of CO2 and the formation of graphitized carbon in both the gas phase and the condensed phase. And Zn2+ showed a better promotion effect on graphitized carbon in the condensed phase than those of Fe2+, Co2+, and Ni2+. This work provides a reference for the research of metal ion catalyzed carbonization flame retardancy.

Synthesis, characterisation, investigation of flame retardancy properties and thermal stability of two new phosphoramides with cotton fabric

Phosphorus and nitrogen-containing compounds widely are used as flame retardant for cotton fabrics. In this paper, two new phosphoramides with the formula of (C6H5)2P(O)[N–C3H5N2O] (DIO) and (C6H5)2P(O)[N–C3H5N2S] (DIT) were synthesised and characterised using 1H NMR, 13C NMR, 31P NMR, IR, and MASS spectroscopy. Crystal structures of DIO were investigated using X-ray crystallography to confirm the proposed structure. Experimental analyses such as VFT, LOI, SEM-EDS, TGA-DTG and cone caloriometer, indicated these compounds are noteworthy because of their thermal and flame retardancy properties. According to the cone calorimetric results, DIT/ cotton owning THR (18.26) and HRR (183.37) is better flame retardant than DIO/ cotton. After treatment with DIO and DIT, the mechanical properties of cotton decreased and improved slightly, respectively. In order to understand the Structure-Flame retardancy Relationship (SFR) of synthesized compounds, the values of HOMO and LUMO energies, dipole moments, hardness, softness, and electrophilicity index were investigated computationally by density functional theory (DFT) method. These results were in good accordance with those of flame retardancy investigation.

Highly effective and durable P-N synergistic flame retardant containing ammonium phosphate and phosphonate for cotton fabrics

Cotton fabrics are widely used in everyday applications, which are flammable and present a fire hazard. Therefore, a phosphorus-nitrogen flame retardant, pentaethylenehexamine octamethylene tetraphosphonate dimethyl ester ammonium tetraphosphorus acid (APEHAP), was synthesized. The ammonium phosphate active group in APEHAP grafted with cotton fiber via P-O-C covalent bonds, and the phosphonate group prevented metal ions from degrading the flame retardancy of cotton fabrics during washing. The LOI value of the 30 wt.% APEHAP-treated cotton fabric reached 45.2% and remained at 33.6% after 50 laundering cycles (LCs) according to AATCC 61-2013 2A. This indicates that the APEHAP-treated cotton fabric obtained excellent flame retardancy and washing resistance. Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD) confirmed that the flame retardant APEHAP had little effect on the surface morphology and crystal structure of the cotton fabrics. Thermogravimetry (TG), cone calorimetry, and vertical combustion tests indicated that APEHAP promoted thermal degradation and charring of the cotton fabric during combustion and prevented flame spreading. The APEHAP-treated cotton fabrics maintained their mechanical properties.

A sustainable strategy for preparation of flame-retardant cotton fabric by phosphorylation of recycled cotton

The recycling and reutilization of cotton waste are in line with the sustainable development of society. Therefore, in this work, an environmentally friendly cellulose phosphate ammonium salt was synthesized by phosphorylation of cotton waste. Then the cotton fabrics were modified with cellulose phosphate ammonium salt by using the dip–dry–cure technique to obtain flame-retardant cotton fabric. The surface morphology, characteristic functional groups, and elemental components were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results indicated that the cellulose phosphate ammonium salt was immobilized onto the cotton fabric through a P–O–C chemical bond. Vertical combustion tests before and after washing showed that the treated cotton fabric had durable flame-retardant properties. Thermogravimetry demonstrated that the treated cotton fabric retained a large amount of residual char and the pyrolysis temperature was significantly earlier than that of the control sample. Compared with the blank sample, the peak of heat release rate and total heat release of the modified fabric was reduced by 90.8% and 84.1%, respectively. Thermogravimetric infrared of flame-retardant cotton fabric proved that cellulose phosphate ammonium salt acted both in the gas and condensed phase during the decomposition of the treated fabric.

Chemical reaction intumescent flame retardant cotton fabric with flame retardancy and UV resistance prepared from phytic acid, tannic acid and diethylenetriamine

PurposeIn this study, an eco-friendly cotton fabric (CF) treatment method was proposed to induce anti-ultraviolet and flame retardant properties, and a new application of tannic acid (TA) and phytic acid (PA) in ultraviolet protection and flame retardant fabric was put forward.Design/methodology/approachBy combining diethylenetriamine, PA and TA on CF, a chemical reaction intumescent flame retardant CF with anti-ultraviolet and anti-flame retardance was developed.FindingsThe flame retardant and ultraviolet resistance of CF were characterized by LOI, vertical combustion, cone calorimetry and ultraviolet resistance testing. SEM, XPS, FTIR and other tests were used to analyze the chemical composition, surface morphology and residual carbon after combustion of the CF, and it was confirmed that the modified CF has good ultraviolet resistance and flame retardant performance.Originality/valueIn this study, an eco-friendly CF treatment method was proposed to induce anti-ultraviolet and flame retardant properties, and a new application of TA and PA in ultraviolet protection and flame retardant fabric was put forward.

Fully bio-based flame-retardant cotton fabrics via layer-by-layer self assembly of laccase and phytic acid

With the ever-increasing attention to eco-friendly flame-retardant finishing of cotton fabrics (CF), bio-based flame retardants have been urgently required. For this end, laccase (QM) and phytic acid (PA) were fabricated on CF via layer-by-layer self assembly. The successful deposition of binary coating on CF was characterized by FTIR and SEM-EDS. With the aid of biomass coating, the LOI value of CF/QM/PA was largely elevated to 43.0% with an increment of 129% as compared to pristine CF. Moreover, CF/QM/PA displayed self-extinguishing phenomenon upon removing the fire during the vertical burning tests, and the peak heat release rate (PHRR) of CF/QM/PA was remarkably dropped to 36 W/g from 310 W/g of CF with a reduction of 88.4%. Thermogravimetric analysis (TG) revealed that although the maximum thermal degradation rate of CF/QM/PA significantly reduced as compared to CF, the final char residue reached up to 39.0%. More importantly, in combination of the analyses of the gaseous products generated during the combustion process and the residual chars after combustion, it was proposed that QM/PA coating exerted flame-retardant activities both in the condensed phase and gas phase. Generally, this work provides a feasible and eco-friendly method for the flame-retardant finishing of cotton fabrics.

Bio-based coating of phytic acid, chitosan, and biochar for flame-retardant cotton fabrics

A flame retardant coating containing phytic acid (PA), chitosan (CH), and biochar (BC) was prepared by the layer-by-layer assembly, and its flame retardancy after application to cotton fabrics was evaluated. The surface morphology, combustion properties, thermal degradation, and flame retardant behavior of untreated and coated cotton fabrics were investigated by scanning electron microscopy, cone calorimetry, and thermal gravimetric analysis coupled online with a mass spectrometer (TGA-MS). Results showed that the biochar was well dispersed in viscous chitosan and uniformly finished on the cotton fabric. Using the biochar, phytic acid, and chitosan (PA/CH/BC) coating significantly improved the char yield, protected the underlayer cotton fabric from degradation, and improved the thermal stability of the treated cotton through a condensed phase flame retardant mechanism. Cone calorimetry results confirmed that the PA/CH/BC-coated cotton fabric formed a thermally stable char layer during combustion, and this layer effectively inhibited oxygen and heat transfer. The peak heat release rate (pkHRR) and total heat release rate (THR) of PA/CH/BC-coated cotton fabric were significantly reduced compared with those of untreated cotton fabric. Compared to untreated fabric, cone calorimetry showed that cotton fabric treated with PA/CH/BC (7.5%) exhibited pkHRR and THR values that were decreased by 88.66% and 88.69%, respectively, and a limiting oxygen index that increased from 18.6% to 64.1%, indicating that the treated fabric has excellent flame retardant performance. Thermal degradation stability and thermal oxidation performance tests were conducted on treated materials subjected to ten laundering cycles to evaluate the durability of the flame retardant in practical application. TG analysis showed that the treated cotton exhibits favorable thermal degradation and thermal oxidation stability, and cone calorimetry suggested that approximately 60% of the flame retardant properties were retained after washing.

Design and preparation of flame-retardant cellulose fabric with low strength loss using polycarboxylic acid as crosslinker

To decrease strength loss of flame-retardant cotton fabric using polycarboxylic acid as the crosslinker, a series of multi-amino phosphoramide (BPEI/DPn) was synthesized using branched polyethyleneimine (BPEI) and dimethyl phosphite (DP). The flame retardant coating was fabricated on cotton fabric with the assist of 1,2,3,4-butanetetracarboxylic acid (BTCA). The optimum multi-amino phosphoramide was obtained by investigate the effect of different BPEI/DPn on washing durability and flame retardancy of modified cotton fabrics. The results found that BPEI/DP4 (mole ratio of BPEI and DP was 1:4) coated cotton fabric presented superior flame retardancy with self-extinguishing action and 27.9% of LOI value. Also, this flame-retardant cotton fabric can withstand a certain number of standard washing cycles. The heat and smoke release of cotton fabric during the combustion were significantly inhibited after modification with BPEI/DP4, and HRR value decreased by 35.0% compared with the unmodified cotton. Additionally, BPEI/DP4 can greatly improve the mechanical capability of cotton fabric modified with BTCA, and almost 80% of breaking force can be remained owning to partially neutralizing the acidic circumstance of BTCA solution, which might provide an efficient method to prepare functional cotton fabric with high performance.

High-Efficiency and Durable Flame Retardant Cotton Fabric with Good Physical and Mechanical Properties by Layer-by-Layer Assembly Polyethylenimine/Phytic Acid Coating

ABSTRACT In this study, intumescent flame retardant coating of polyethylenimine/phytic acid (PEI/PA) with gradient structure was constructed on cotton fabric through a facile layer-by-layer (LBL) assembly method. The LOI value of coated cotton fabric reached over 40%, indicating excellent flame retardancy. Reasonable controlling the LBL assembly process of PEI/PA coating brought less influence to the physical properties of cotton fabrics. And the coated cotton fabric revealed good flame retardant washing durability. Thermogravimetric analysis results of coated cotton fabrics showed that PEI/PA flame retardant coating changed the thermal decomposition process and promoted char formation revealing the obviously condensed phase flame retardant action. SEM images of char residues revealed that PEI/PA flame retardant coating promoted to form the intumescent flame retardant (IFR) char layer showing obvious IFR action. This research provides novel strategy for the development of high-efficiency flame retardant cotton fabric with good durability and physical properties using a simple LBL assembly method.

Green P–N coating by mechanochemistry: efficient flame retardant for cotton fabric

Green P–N coating by mechanochemistry: efficient flame retardant for cotton fabric

Surface engineering for cellulose as a boosted Layer-by-Layer assembly: Excellent flame retardancy and improved durability with introduction of bio-based “molecular glue”

Layer-by-Layer (LbL) assembly was attractive as a versatile tool to address the flammability of cotton, while the washing fastness of LbL coating stayed an issue. Aiming to tackle this issue, LbL layers consisted of phenylphosphonic acid (PHA) and 3-aminopropyltriethoxysilane (APTES) was deposited on polydopamine (PDA)-coated cotton. The prepared cotton reached 31.4% of limiting oxygen index (LOI), and extinguished immediately after removing the ignitor. Peak of heat release rate (pHRR) attenuated around 36 % compared with pure cotton. A combined barrier and quenching mechanisms were proposed. Moreover, enhanced washing durability (24.1% of LOI) was achieved even after 50 detergent laundering cycles. A facile, boosted LbL approach with proposed π − π stacking interactions between PDA abundant aromatic structures and benzene ring in PHA from LbL layers, is first to put forward to construct durable efficient flame retardant (FR) cotton. This work attempted to enlighten more thoughts and design for durable FR cotton fabrics.

Construction phosphorus/nitrogen-containing flame-retardant and hydrophobic coating toward cotton fabric via layer-by-layer assembly

Excellent flame-retardant cotton fabric with desired hydrophobic is of particular interests for both academia and industry. Herein, an effective multilayer coating consisting of phosphorylated polyethyleneimine (P-PEI) and hydrophobic modified ammonium polyphosphate (MAPP) was successfully constructed on cotton fabric through a facile layer-by-layer (LbL) assembly, which imparted high fire retardancy and desirable hydrophobic to the cotton fabric. Coated cotton fabric was characterized by Fourier infrared spectrometer, scanning electronic microscopy coupled with its energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy, conforming that a phosphorus- and nitrogen-containing multilayer coating was homogeneous and uniform increase on the surface of cotton fabric. The resultant cotton fabric achieved self-extinguishing in vertical burning tests and a desired hydrophobic with a water contact angle of 127.4° with only 4BL coating. Moreover, the coated cotton fabrics exhibited a slight delay of ignition accompanied by remarkably decrease of heat release and the fire growth rate index, suggesting the outstanding fire safety. The flame retardancy of coated cotton fabric was enhanced and even not ignited at the heat flux of 25 kW/m2, but the hydrophobic was almost not changed with the increase of bilayer number. Additionally, the relevant analysis of residues and volatile gases manifested that the multilayer coating contributed flame-retardant activities in both condensed- and gas-phase via forming thermally stable char residues and inhibiting the release of flammable gases. Taking advantage of the features, this high efficiency coating together with the facile finishing technique would have great potentials in application of multifunctional cotton fabrics.

Environmental and performance assessment of hydrophobic and flame-retardant cotton fabrics modified with functional integrated graphene

Environmental and performance assessment of hydrophobic and flame-retardant cotton fabrics modified with functional integrated graphene

Durable and high-efficiency casein-derived phosphorus-nitrogen-rich flame retardants for cotton fabrics

A casein derivative (CADP) was synthesized using casein, which is bifunctional containing both –P=O(O−NH4+)2 reactive groups and –P(=O)–O–C– groups, and the durable flame-retardant cotton fabrics were successfully prepared by CADP. The –P=O(O−NH4+)2 reactive groups allowed CADP to be firmly grafted onto cellulose. The –P(=O)–O–C– groups made flame-retardant cotton fabrics more resistant to soaping and improved its durability. The modification by 40% CADP increased the limited oxygen index value of cotton fabric from 17.4 to 41.6%, which maintained at 26.4% after 50 cycles of home machine washes. The results of TG, TG-FTIR, FTIR and SEM indicated that CADP increased the condensed components and decreased the flammable gaseous compounds, resulting the positive effect on char formation of cellulose. The whiteness, softness and tensile strength of cotton fabrics were retained well after modification, and the treated cotton fabrics didn’t have skin irritation.

Construction of biological flame retardant layer on cotton fabric via photografting of nucleotide/amino acid monomers

The adenine nucleotide (AMP-Na2) was modified to introduce unsaturated double bonds for photografting onto cotton fabrics together with l-Cysteine (l-Cys) monomer to prepare synergistic bio-based flame retardant cotton fabrics. The chemical structure of AMP-Na2/ l-Cys monomers, surface morphology, residual carbon morphology, thermal properties and flame retardant properties of photografted flame retardant cotton fabrics were analyzed. FT-IR and 1H NMR spectra verified the AMP-Na2 and l-Cys monomers with unsaturated double bonds. Scanning electron micrographs revealed the carbon residue of photografted fiber maintained a natural curled and fiber shape. TGA showed that the major pyrolysis temperature of cotton fabric declined by 51 °C and the weight loss reduced by 20.5%, proving good charring effect of flame retardant layer via photografting of AMP-Na2/l-Cys monomers. The afterflame and afterflow time of photografted cotton fabric were nearly decreased to 0 s. The LOI value of photografted cotton fabric was 27.34% and decreased by 7.9% after 20 washing times. The peak heat release rate and total heat release decreased from 198.05 kW/m2 and 9.94 MJ/m2 to 34.49 kW/m2 and 4.47 MJ/m2, respectively. The experimental results indicated that durable flame retardancy of cotton fabrics was achieved via facile photografting of AMP-Na2/l-Cys monomers.