Flame retardant properties of triazine phosphonates derivative with cotton fabric

The flame retardant behavior of cotton fabric treated with phosphorus-nitrogen containing triazine compound was evaluated. It was found that cyanuric chloride (2,4,6-trichloro-1,3,5-triazine) is an excellent starting material for the preparation of phosphonate flame retardants that interact well with cotton to improve flame resistance (FR) performance. Tetraethyl 6-chloro-1,3,5-triazine-2,4-diyldiphosphonate (TECTDP) has been prepared by a simple one-step reaction in high yield (98.0 %). Cotton fabrics treated with TECTDP result in covalent bond formation between TECTDP and hydroxyl groups in cotton fabrics. This FR system provides an efficient flame retardant for cotton textiles at low cost to meet government mandates. In this study, the FR material was synthesized and characterized by ¹H and ¹³C nuclear magnetic resonance (NMR), and LC-MS spectroscopy. The chemical structure of cotton twill fabric treated with TECTDP by pad-dry-cure method was analyzed by FT-MIR and SEM. Furthermore, the thermal and flammability properties were evaluated by thermogravimetric analysis (TGA), limiting oxygen index (LOI, ASTM D-2863-09), and a vertical flame test (ASTM D-6413-08).     

Highly flame retardancy of cotton fabrics with a novel phosphorus/nitrogen/silicon flame-retardant treating system

A novel reactive flame retardant (FR) containing phosphorus, nitrogen, and silicon was synthesized successfully, and its chemical structure was fully characterized by Fourier transform infrared spectrometry and nuclear magnetic resonance spectrometry (¹H-NMR and ³¹P-NMR). Then it was used to impart flame resistance to cotton fabrics. Vertical flammability and limiting oxygen index test were used to evaluate the flame retardancy of the cotton fabrics treated with FR. When the cotton treated with 150 g/l FR and 50 g/l sodium hypophosphite, the finished cotton can pass the vertical flammability test. Thermogravimetry (TG) was used to evaluate thermal behavior of FR and cotton fabrics. TG results demonstrated that the FR has good thermostability and char-forming ability. After treatment with FR, the thermal stability of the cotton fabrics was clearly improved, indicating that the FR can protect cotton fabric from fire to a certain degree. Furthermore, attenuated total reflection Fourier transform infrared spectroscopy was utilized to characterize the chemical structure of FR treated cotton fabrics. Finally, the surface morphology in different regions of the treated cotton was observed using scanning electron microscopy.     

Preparation and flammability properties of hybrid materials containing phosphorous compounds via sol-gel process

Organic-inorganic hybrid coatings containing phosphoric acid (PA) bonded to the organic-inorganic network were prepared from tetraethoxysilane (TEOS) using a sol-gel process. The effect of sol-gel phosphate-based flame retardant coating on polyacrylonitrile fabric properties (flammability, stiffness, and strength) was investigated. Sample characterization of the coated samples were investigated using differential thermal/thermogravimetric analysis (DTA/TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), and scanning electron microscopy (SEM). The results showed that hybrid coating on the polyacrylonitrile fabrics influenced fabric stiffness, strength, and flammability. And also, flammability of the coated samples after washing cycles was investigated, and the flame retardancy properties of the samples after 10 repeated washings were not completely lost.     

Encapsulation of phase change materials by complex coacervation to improve thermal performances and flame retardant properties of the cotton fabrics

This paper reports a study on the thermal stability and flame-retardant properties of microencapsulated phase change materials (PCMs) with clay nano-particles (Clay-NPs) doped gelatin/sodium alginate shell. The novel microcapsules were fabricated by the technique of complex coacervation using gelatin and sodium alginate as the shell and PCM n-eicosane as the core. Their flame retardant property as well as their practicable thermal performances when incorporated into woven cotton fabrics by pad-dry-cure were investigated. Thermal storage/release properties of the prepared microcapsules were analyzed using DSC instrument. Thermal gravimetry (TG) analysis was performed to measure the thermal stability and surface morphology of the microcapsules was observed by means of optical microscopy and SEM. The DSC results indicated that the latent heat storage capacity of prepared microcapsules changed in range of 97-114 J/g. The microcapsules had spherical shape with particle sizes between 1.37 μm and 1.6 μm. The PCM microcapsules (PCMMs) and nano-composite PCM microcapsules (NCPCMMs) with clay-NPs doped gelatin/sodium alginate shell were found to have good potential for developing thermal comfort in textiles. Comparing with conventional PCMMs, NCPCMMs have significantly better thermal stability. Nano-composite structure of the NCPCMMs, in which clay-NPs doped in the polymeric shell structure, attributed to increase the shell thermal stability. Improved flame retardant properties of the cotton fabrics treated with NCPCMs were declared as a result of flame retardant tests. Thermo-regulating properties of the fabrics were proved by thermal history (THistory) measurement results from releasing heat from microcapsules.     

Multifunctional,Hydrophobic and Flame-retarded Cotton Fabrics Modified with Liner Piperzine/Phosphorous/Polysiloxane Copolymer

α,ω-di[(4-butoxy-piperazin-1-yl)-phosphinic acid methyl ether]-terminated linear polysiloxane (PNPDMS) was synthesized and utilized as the flame retardant and hydrophobing agent. The flame retardance and thermal decomposition behaviors of cotton fabrics were systematically estimated by limiting oxygen index (LOI), thermogravimetric analysis and vertical burning test, respectively. It was found that the LOI of cotton fabric treated with PNPDMS enhanced to 29.82 % compared with cotton fabric without treatment, whose LOI was only 18.00 %. The treated cotton fabric showed a shorter char length, a shorter After-flame time, and no After-glow time as revealed in vertical burning test. The mechanical property in treated cotton fabric was slightly decrease. Furthermore, the grade of water repellency of treated cotton fabric reached to 90 and water contact angle (WCA) increased to 141.90° compared with cotton fabric without treatment whose WCA was 62.80°. The result showed that the cotton fabric treated with PNPDMS exhibited excellent flame retardance and hydrophobic properties.     

A novel DDPSi-FR flame retardant treatment and its effects on the properties of wool fabrics

A novel flame retardant monomer DDPSi-FR containing organophosphorus and silicon was prepared using 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), 4-hydroxybenzaldehyde (HBA), and 3-glycidoxypropyltrimethoxysilane (GPTMS). The chemical structure of DDPSi-FR was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Subsequently, after treating the wool fabrics, the effects of the monomer on the flame retardancy, thermal stability, and mechanical properties were studied. The flame retardant and thermal properties were evaluated by conducting vertical flame tests, limiting oxygen index (LOI) determination, and thermogravimetric analysis (TGA). The results showed that improved flame retardancy and thermal stability were achieved. Notably, the flame retardancy was retained even after 15 washing cycles. The mechanical properties were evaluated using the bursting strength, and the results indicated that DDPSi-FR treatment improved the breaking strength.     

Synthesis and flame-retardancy of UV-curable methacryloyloxy ethyl phosphates

Tris[2-methacryloyloxy ethyl] phosphate (TMEP), bis(2-methacryloyloxy) ethyl phosphate (DMEP), and 2-(methacryloyloxy ethyl) phosphate (MMEP) were synthesized from phosphorous oxychloride and 2-hydroxyethyl methacrylate, which can be used as flame retardant monomers for UV-curable coating systems. The characterization of the synthesized monomers was carried out by ¹H-NMR, FT-IR, thermo-gravimetric analysis, and the limited oxygen index (LOI) test. The thermal behavior of the cured films depended on phosphorous content and the methacrylate groups in the monomer. The UVcured films from TMEP, DMEP, and MMEP monomers showed LOIS of 28.5, 30.3, and 35.1 respectively. Also, LOI up to 25.4 was obtained for the UV-coated cotton fabrics, which presumably occur through a condensed phase mechanism as verified in the increased residue number. The higher performance of UV-coated cotton fabrics compared to PET was attributed to the facile dehydration and crosslinking of the cellulosic materials.     

Synergistic UV-curable flame-retardant finish of cotton using comonomers of vinylphosphonic acid and acrylamide

While ‘Pyrovatex’ and’ Proban’ processes have been widely used for durable flame-retardant finishing of cotton, the flame retardants could release formaldehyde inevitably during or even after the finishing process, which is not environmentally compatible. As a new formaldehyde-free flame retardant and finishing process, the comonomers of vinylphosphonic acid (VPA) and acrylamide (AAm) can be in situ copolymerized upon LED-UV irradiation and impart excellent flame retardancy to the cotton. The increasing AAm addition enhanced fixation, flame retardancy effectivity and synergistic effectiveness by reducing the steric hindrance between the VPA monomers during the copolymerization. Also the multifunctional crosslinkers of either methylene bisacrylamide or triacryloylhexahydro triazine significantly improved the laundering durability of the finished fabrics. The increased char formation and residue number after pyrolysis indicated the solid-phase retarding mechanism of the synergistic VPA and AAm combination.     

Thermal performance and flammability of poly(ethylene terephthalate) fabrics grafted with different monomers followed by electron beam irradiation

Electron beam irradiation grafting of acrylic acid (AAc), acrylamide (AAm), and dimethyl vinylphosphonate (DMVP) onto poly(ethylene terephthalate) (PET) fabrics was performed using a high-energy electron accelerator. Parameters affecting the graft polymerization of PET fabrics, including absorbed dose and monomer concentration, were investigated. Fourier transform infrared spectroscopy analysis confirmed that the monomers were grafted onto the PET fabrics. The thermal behavior of the grafted PET fabrics was investigated with thermogravimetric analysis. Findings showed that grafting with AAm could improve the thermal stability of PET. The limiting oxygen index values and vertical flammability test results showed that PET fabric graft-polymerized with AAc could improve the flammability and prevent melt dripping. Grafting with AAm and DMVP could improve the flame retardation property of PET fabric. Scanning electron micrographs showed that the surface morphology of the PET fabric samples was significantly influenced by graft polymerization, and that grafting with AAc could promote the formation of residual char and impart an anti-dripping quality to PET fabrics.     

Effect of inorganic fillers and ammonium polyphosphate on the flammability,thermal stability,and mechanical properties of abaca-fabric/vinyl ester composites

In order to comply with the safety environment requirements, this research is being carried out for reinforcing inorganic additives to improve fire retardancy of composite. In the present study, abaca fabric/vinyl ester (AF/VE) composites were prepared by vacuum assisted resin transfer (VARTM) molding process. For improving flame retardant property of the composites, three different types of halogen free inorganic fillers, i.e. nano-clay (NC), halloysite nanotubes (HNT) and ammonium polyphosphate (APP) were used. The flammability, thermal stability and mechanical properties of composites have been investigated by Horizontal burning test, Thermogravimetric analysis (TGA), tensile, and flexural test respectively. FESEM was used to observe the morphology of the fractured surface of the tensile specimens. Taguchi method was used to optimize the process and minimize the number of experiments for fillers addition. The results showed that the flame retardancy and thermal stability increased with increasing percentage of fillers, but mechanical properties slightly decreased simultaneously.     

Influence of N-, P- and Si-based Flame Retardant Mixtures on Flammability,Thermal Behavior and Mechanical Properties of PA6 Composite Fibers

This research investigated the influence of two flame retardant (FR) mixtures consisting melamine cyanurate (MeCy) and aluminum diethylphosphinate (AlPi), and MeCy and sodium aluminosilicate (SASi) at different weight ratios, on the flammability, thermal behavior and mechanical properties of polyamide 6 (PA6) composite yarns produced by meltspinning. The morphological and chemical properties of PA6/FR filaments were investigated by scanning electron microscopy and Fourier-transform infrared spectroscopy, flame retardancy by vertical burning test UL-94, thermal behavior by thermogravimetric and differential scanning calorimetric analyses, and mechanical properties by tensile tests. The results indicate that within the UL 94 V2 rating, the composite yarns differed significantly from each other in their burning and dripping behavior. The incorporation of both mixtures, MeCy+AlPi and MeCy+SASi, into the PA6/FR yarns significantly decreased the afterflame time relative to pristine PA6, confirming a lower production of flammable volatiles. This phenomenon was attributed mainly to MeCy, which caused an immediate extinguishment of the flame after the withdrawal of the igniting flame. Compared to one component MeCy, the incorporation of the MeCy+SASi mixture enhanced the thermooxidative stability of the PA6/FR yarns because of their additive effect at higher concentrations. In contrast, an antagonistic effect was obtained for the MeCy+AlPi mixture, irrespective of the concentration. Since the incorporation of MeCy+SASi did not drastically reduce the tensile properties of filaments, this mixture enables the production of the PA6/MeCy+SASi composite yarns with the enhanced flame retardancy and thermo-oxidative stability.     

Flame-Retardant and Wear Comfort Properties of Modacrylic/FR-Rayon/Anti-static PET Blend Yarns and Their Woven Fabrics for Clothing

This study examined the flame retardant, anti-static, and wear comfort properties of woven fabrics from two types of yarns composed of modacrylic, FR-rayon, cotton, and anti-static PET fibers. The FR-rayon-blended modacrylic fabric mixed with anti-static PET fibers exhibited better flame-retardant and anti-static properties than those of the cotton-blended modacrylic fabric. In addition, the absorption and drying properties of the FR-rayon-blended modacrylic fabric were superior to those of the cotton-blended modacrylic fabric. The thermal conductivity of the FR-rayon-blended fabric was lower than that of the cotton-blended one, whereas the water vapor permeability was slightly higher than that of the cotton-blended one. These wear comfort properties of the FR-rayon-blended fabric were attributed to the micro-pores and longer fiber length of the FR-rayon fibers, as well as their yarn and fabric structural parameters. This study suggests that FR-rayon-blended modacrylic fabric has better flame-retardant and anti-static properties in both twill and rip weaves with good warmth keepability, and higher water and vapor transmission properties than cotton-blended one. In addition, the FR-rayon-blended modacrylic clothing exhibited a better wear comfort feel than the cotton-blended one due to the lower microclimate humidity. This means that FR-rayon-blended modacrylic fabric makes it more comfortable to wear than cotton-blended one.     

Dimensional,physical and thermal properties of plain knitted fabrics made from 50/50 blend of modal viscose fiber in microfiber form with cotton fiber

In this study, the dimensional, physical and thermal comfort properties of the plain knitted fabrics made from 50/50 blend of modal viscose fiber in microfiber form with cotton fiber are compared with those of the similar fabrics made from 50/50 blend of conventional modal viscose fiber with cotton fiber and made from 100 % cotton fiber. All the fabric types are produced in three different stitch lengths. The slight differences among the fabric types are observed in terms of the stitch density results and the dimensional constants calculated in the fully relaxed state. In the fully relaxed state, the dimensional K values of the modal microfiber blended knitted fabrics are found to be more closely resemble those of the cotton fabrics rather than those of the conventional modal fiber blended fabrics. The lowest fabric thickness and bursting strength results are obtained for the modal microfiber blended fabrics. The modal microfiber blended fabrics reveal lower air permeability than the conventional modal fiber blended fabrics and higher air permeability than the cotton fabrics. It is also observed from the thermal comfort results that the modal microfiber blended fabrics have the lowest thermal resistance and the highest thermal absoptivity values. The thermal conductivity results of the modal microfiber blended fabrics are lower than those of the cotton fabrics and higher than those of the conventional modal fiber blended fabrics. Because of the highest thermal absorptivity values, the modal microfiber blended fabrics provide the coolest feeling when compared with the other two fabric types.     

Synthesis and Application of Phosphorus-containing Flame Retardant Plasticizer for Polyvinyl Chloride

A novel phosphorus-containing flame retardant plasticizer (PFRP) derived from castor oil acid methyl ester (COME) was synthesized to substitute dioctyl phthalate (DOP) for plasticizing polyvinyl chloride (PVC) products. The chemical structures of PFRP were confirmed by fourier transform infrared spectroscopy (FTIR) and ¹H nuclear magnetic resonance (¹H NMR). Meanwhile, the plasticizing effect, flammability and thermal stability of plasticized PVC films were investigated by dynamic mechanical analyzer (DMA), limiting oxygen index (LOI) test, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). As the PFRP content increasing from 0 wt% to 50 wt% amount of plasticizers, the plasticizing efficiency and the mechanical properties showed a slightly decreasing tendency compared with that of DOP, while the LOI value of plasticized PVC increased remarkably from 21.5 % to 25.2 %, showing a combined plasticizing efficiency and flame retardancy. SEM and TGA analysis indicated that PFRP had little effect on thermal stability but was effective to promote the formation of compact carbon residue.     

New insight into compressive shrinkage finishing in a garment company: The effects on physical,mechanical and colorimetric properties of cotton woven fabrics

Compressive shrinkage or compressive shrinkage finishing is one of the most important finishing procedures in the textile industry to improve the dimensional stability of cotton fabrics. Study of the physical and mechanical properties of compressive shrinkage finished fabrics could be useful for optimizing the treatment conditions. This research was carried out in a production line of a recognized garment company on cotton woven fabrics with two different woven patterns (twill and plain). The samples were first dyed with reactive and sulfur dyes in a jigger dyeing machine and finished with a silicone softener. The dried fabrics were then processed in a compressive shrinkage machine. Several physical and mechanical properties of the samples were evaluated including area shrinkage, crimp percentage, thickness, abrasion resistance, drapeability, mechanical and colorimetric properties. The results showed that the thickness of all treated samples increased due to compressive shrinkage. The fabrics were analyzed with a Martindale Abrasion Tester to determine the abrasion resistance. Interestingly, we noted an increase in the abrasion resistance. After the compressive shrinkage process, the strength of the plain woven fabrics decreased in the warp direction, but increased for twill woven cotton fabrics. On the contrary, the strength of all samples increased in the weft direction. Colorimetric evaluation of the samples showed that the effect of compressive shrinkage on the color of all samples was negligible.     

Effect of ultrasonic laundering on thermophysiological properties of knitted fabrics

The paper focuses on the application of ultrasonic energy in textile laundering. In recent years, there has been an increasing interest in ultrasonic energy application in textile industry; however, the effect of ultrasonic laundering on the thermophysiological properties of knitted fabrics has not been studied yet. This study was conducted by using polylactic acid (PLA), cotton, polyethylene terephthalate (PET), and poly acrylic (PAC) fibres containing yarns and their blends. Knitted fabrics, single pique, were made from these yarns by using weft knitting machine. The fabrics were washed ten times for 15 and 60 minutes under 40 °C by using conventional and ultrasonic washing methods. The main aim was to determine the effect of washing methods on the thermophysiological properties of the fabrics. It is also aimed to analyse and evaluate the thermophysiological properties of the PLA fabrics. The incorporation of 100 % PLA and cotton/PLA yarns into single pique knitted fabrics has been attempted to produce for the first time and studied their thermal comfort properties. The results show that the washing processes have a critical importance for the tested fabrics in terms of thermal conductivity, thermal resistance, thermal absorbtivity, water vapour permeability, and heat loss. It has been also demonstrated that the fabric cleaning by using ultrasonic method enhanced the properties of tested fabrics such as thermal conductivity and % recovery. It was also noted that 15 minutes ultrasonically washed fabrics had significantly lower thermal resistance as compared to conventionally washed fabrics.     

Synthesis of a novel flame retardant containing phosphorus-nitrogen and its comparison for cotton fabric

A new charring agent, a derivative of cyanuric chloride, mono-substituted, dimethyl (4,6-dichloro-1,3,5-triazin-2-yloxy)methylphosphonate (CN), was synthesized in good yield and characterized. Its flame retardant and thermogravimetric properties were compared to those of the di-substituted compound, tetramethyl (6-chloro-1,3,5-triazine-2,4-diyl)bis(oxy)bis (methylene)diphosphonate (CN-1), which was prepared in previous work. All untreated fabric showed limiting oxygen index (LOI) values of about 18 vol% oxygen in nitrogen. Fabrics treated with CN at 5?C21 wt% add-ons had high LOI values of 30?C40 vol%, while fabrics treated with CN-1 at 5?C19 wt% add-ons had low to high LOI value of 20?C36 vol%. In 45° angle flammability tests, all treated fabrics with CN and CN-1 were passed and some fabrics were not igniting at all. Thermal degradation revealed that onset of degradation and the char yield of CN compound is higher than that of CN-1. Treated fabric with CN, 21 wt% add-on, had an onset of degradation of 240 °C, while fabric treated with CN-1, 19 wt% add-on displayed an onset of degradation of 230 °C. Despite the differences in onset temperature, the two samples provided almost the same char yield at 600 °C, 35 and 36 %. With Fourier transform infrared (FTIR), samples of treated/unburned and treated/burned of CN and CN-1 showed the same functional groups and revealed the disappearance of triazine group and P-O-methyl after burning. Additionally, scanning electron microscopy (SEM) showed that both CN and CN-1 acted as flame retardants by the same mechanism and characterized the surface morphology of the flame retardant treated twill fabrics.     

Flame resistant modification of silk fabric with vinyl phosphate

The flame resistant finishing of silk fabric is still a challenge because most of the available treatment methods usually result in insufficient laundering durability. In this paper, a vinyl phosphorus-based monomer diethyl-2-(methacryloyloxyethyl) phosphate (DEMEP) was applied onto silk fabrics by graft copolymerization technique using potassium persulfate as an initiator. FT-IR spectra and amino analysis showed the evidence of the reaction between DEMEP and silk. The silk fabrics treated with DEMEP have excellent self-extinguishing property when the DEMEP add-on is over 50 % wt of silk fabrics. The LOI of treated samples is at least 28 % when the weight gain is 10 %. After being subjected to 30 hand wash cycles, DEMEP treated silk fabric can still pass the vertical flammability test. Thermal gravimetric (TGA) and differential thermal analysis (DTA) were applied to explore the thermal decomposition of silk fabrics treated with DEMEP. The initial decomposition temperature of silk fabric treated with DEMEP was shifted to a lower temperature. And at the end of decomposition at 700 °C, the char residue of silk fabric treated with DEMEP was higher than that of the control sample.     

Optimum manufacturing conditions of activated carbon fiber absorbents. I. Effect of flame retardant reagent concentration

In this paper, viscose rayon-based knitted fabrics were utilized as the precursor to produce activated carbon fiber absorbents (ACFA). To obtain better pore characteristics and higher weight yield of ACFA, the effect of flame retardant reagent concentration was studied. Experimental results revealed that both BET surface area and micropore volume increased with increasing flame retardant reagent concentration. On the other hand, both weight yield and micropore volume ratio (V_mic/V_tot) decreased as the flame retardant reagent concentration increased. It was therefore concluded that controlling the flame retardant reagent concentration at 30% not only could obtain better absorption property of ACFA but also helped maintain its production efficiency.     

Antibacterial finishing of cotton fabrics using biologically active natural compounds

The paper discusses a method to functionalize cotton fabrics using biologically active natural compounds to achieve the antibacterial characteristics required for medical application. The biologically active natural compounds include propolis, beeswax, and chitosan. Three 100 % cotton knitted fabrics with different degrees of compactness were impregnated in the emulsions containing the active ingredients and fabric variant G3 with the highest degree of impregnation was considered for the evaluation of the antibacterial properties and comfort characteristics. The results show that the treated cotton fabric had high antibacterial activity against both gram positive bacteria Staphylococcus aureus and Streptococcus β haemolytic, and gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The presence of the biologically active natural compounds on the cotton substrates modified the surface of the textile fibers as seen in the SEM images. The treatment also improved fabric comfort properties, the cotton substrates became less air permissive and more hygroscopic after the treatment. The experimental results indicated that propolis, beeswax and chitosan can be applied as an emulsion to functionalize cotton textile materials. The antibacterial performance of the functionalized fabrics suggested that the cotton fabrics treated with those biologically active natural compounds have the potentials to be used in medical fields.