Graft copolymerization modification of silk fabric with an organophosphorus flame retardant

This paper mainly deals with flame retardance of a silk fabric treated with a vinyl phosphate dimethyl 2‐(methacryloyloxyethyl) phosphate (DMMEP) onto silk fabric by a graft copolymerization technique. This paper also explores the relationship between limiting oxygen index (LOI) and weight gain of DMMEP treated silk fabric. The paper also investigates the whiteness, handle, tensile strength and laundering durability of treated silk fabric. Microscale combustion calorimetry (MCC) is applied to test the heat release rate of silk fabric. Thermal gravimetric analysis (TG) and differential thermal analysis (DTA) are carried out to investigate the thermal decomposition behavior of DMMEP treated silk fabric. The kinetic parameters, activation energy and pre‐exponential factor are determined using the Kissenger method. Copyright © 2009 John Wiley & Sons, Ltd.     

Improvement in the flame retardancy of cotton fabric by admicellar polymerization of 2‐acryloyloxyethyl diethyl phosphate using an anionic surfactant

The phosphorus‐containing acrylate monomer, 2‐acryloyloxyethyl diethyl phosphate (ADEP), was synthesized and applied to cotton fabric by using admicellar polymerization. Sodium dodecylbenzene sulfonate was used as the anionic surfactant. The film of polymerized monomer (PADEP) formed on the cotton surface was characterized by FTIR‐ATR spectroscopy and SEM. Thermal and flame retardant properties of PADEP‐coated cotton were investigated by TGA and flammability tests. Results showed that PADEP polymer film was successfully formed on the cotton fabric. The TGA and DTG analyses showed that the phosphorus‐containing PADEP lowered the decomposition temperature of the treated fabric resulting in a higher char yield than in the case of untreated cotton. The flammability tests showed that the treated cotton had much improved flame retardancy property after the treatment. The treated fabric also retained its good pliability and soft touch with good air permeability. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Surface photografting: New application for flame retardant finishing of polyamide6.6 (PA6.6) fabric

Surface photografting modification with maleic anhydride (MAn) under UV irradiation in association with a post reaction with triethanolamine has been used to improve the flame retardancy of polyamide6.6 (PA6.6) fabric in this study. The effects of irradiation time and monomer concentration on the fabric surface grafting were investigated. The flame retardancy and thermal decomposition behavior of the samples were characterized by limiting oxygen index test (LOI), thermogravimetric analysis (TGA), and differential scanning calorimetric (DSC), and the results indicate that flame retardancy of the treated PA6.6 fabric samples has been significantly improved. The chemical structures of the treated samples' surface were characterized by attenuated total reflection infrared spectroscopy (ATR‐FTIR), and the possible photochemical mechanisms were discussed. It is suggested that this could be the first time to use photografting technology to enhance the flame retardancy of PA6.6 fabric. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of methyl methacrylate on the properties of transparent flame retardant unsaturated phosphate ester copolymer

The effect of methyl methacrylate (MMA) on the properties of transparent flame retardant unsaturated phosphate ester copolymer (poly[UPE‐co‐MMA]) prepared by bulk polymerization technique was investigated. Fourier transform infrared spectra, gel fraction (G) test, and dynamic mechanical analysis revealed the structure and crosslinking density of poly(UPE‐co‐MMA) copolymers. The thermal degradation and flame retardancy of copolymers were indicated by thermogravimetric analysis, limiting oxygen index (LOI), and microscale combustion calorimeter (MCC) test. Besides, the mechanical properties and transparency were tested with testing machines and solid ultraviolet absorption spectra. As the MMA content increased to 50%, the copolymer contained 50 wt% MMA showed the maximal G (88.93%) and transmittance was up to 91.72%. From the poly(UPE‐co‐MMA) copolymers, the tensile strength increased from 14.62 to 26.95 MPa, assigned to the increase of crosslinking density of copolymers. The char yield of poly(UPE‐co‐MMA) was up to 21.18 wt%, which was a result of decomposition of phosphate groups, producing a phosphorus‐rich layer that increased the thermal stability of the residues. LOI and MCC results confirm that the introduction of MMA can retain the flame retardancy of copolymer remarkably. POLYM. ENG. SCI., 59:2103–2109, 2019. © 2019 Society of Plastics Engineers     

Flame retardancy finish with an organophosphorus retardant on silk fabrics

The 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 (600°C) 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. Copyright © 2006 John Wiley & Sons, Ltd.     

Photopolymerization and thermal behavior of phosphate diacrylate and triacrylate used as reactive‐type flame‐retardant monomers in ultraviolet‐curable resins

Tri(acryloyloxyethyl)phosphate (TAEP) and di(acryloyloxyethyl)ethyl phosphate (DAEEP) were used as reactive‐type flame‐retardant monomers along with commercial epoxy acrylate and polyurethane acrylate oligomers in ultraviolet (UV)‐curable resins. The concentrations of the monomers were varied from 17 to 50 wt %. The addition of the monomers greatly reduced the viscosity of the oligomers and increased the photopolymerization rates of the resins. The flame retardancy and thermal degradation behavior of the UV‐cured films were investigated with the limiting oxygen index (LOI) and thermogravimetric analysis. The results showed that the thermal stability at high temperatures greater than 400°C and the LOI values of the UV‐cured resins, especially those containing epoxy acrylate, were largely improved by the addition of the monomers. The dynamic mechanical thermal properties of the UV‐cured films were also measured. The results showed that the crosslink density increased along with the concentrations of the monomers. However, the glass‐transition temperature decreased with an increasing concentration of DAEEP because of the reduction in the rigidity of the cured films, whereas the glass‐transition temperature increased with the concentration of TAEP because of the higher crosslink density of the cured films. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 185–194, 2005     

Graft copolymerization coating of methacryloyloxyethyl diphenyl phosphate flame retardant onto silk surface

This paper reports an efficient surface modification methodology to increase fire resistance properties of silk fabric performed by radio frequency (RF) plasma-induced graft copolymerization of vinyl phosphate ester as nanometer coating. Methacryloyloxyethyl diphenyl phosphate (MEDP) monomer was prepared and graft-copolymerized onto the surface of silk fabric by argon RF plasma at ambient temperature. Under optimum RF power (30 W), amounts of MEDP and N,N methylenebisacrylamide cross linking agent were varied to obtain optimum graft copolymerization conditions. Untreated and treated silk were characterized by attenuated total reflectance infrared (ATR-IR) spectroscopy to investigate their functional group characteristics. This showed a strong covalent attachment between the surface of silk and flame retardant material as the carbonyl functionality of the MEDP was clearly observed in the spectra. Scanning electron microscopic (SEM) analysis also showed grafted material as nanometer residue on silk surface. Thermogravimetric analysis (TGA) revealed that the decomposition of phosphorus compound which occurs at lower temperature than that of silk itself resulted in the formation of char which covers the surface of the fabrics. This protects the fabric surface from further burning, therefore, higher amounts of remaining materials were observed as char in all cases. Furthermore, the limiting oxygen index (LOI) increased from 25.5 for untreated to 28.0 (ca. 10%) for the MEDP-grafted silk. Higher amounts of char were also observed in the case of MEDP-treated silk. After 5 dry cleaning cycles, the LOI of the treated silk dropped only very slightly. Detailed analysis on structural and thermal properties as well as surface grafting efficiency are presented.     

GMA改性磷酸腺苷的制备及其对棉织物的阻燃整理

为了提高磷酸腺苷单体在棉织物上的接枝改性程度及其阻燃效果,采用甲基丙烯酸缩水甘油酯（GMA）对一磷酸腺苷（AMP）、二磷酸腺苷（ADP）、三磷酸腺苷（ATP）进行改性,制得三种带有不饱和双键的阻燃单体AMP-m-GMA、ADP-m-GMA、ATP-m-GMA;然后通过紫外光接枝法将三种阻燃单体分别接枝到棉织物上,制备光接枝AMP-m-GMA、ADP-m-GMA和ATP-m-GMA阻燃棉织物;对三种阻燃单体进行了结构表征和热稳定性分析,并探究了三种阻燃单体光接枝阻燃棉织物的热稳定性、阻燃性能、燃烧行为和残炭结构。结果表明,三种磷酸腺苷通过GMA环氧基开环引入不饱和双键,且具有良好的热稳定性。相比于原棉织物,三种阻燃棉织物的最大热降解速率分别降低了60.0%、52.0%、60.0%,极限氧指数由16.1%分别提升到25.4%、27.4%、26.4%,织物热释放速率分别下降了15.09%、60.47%、37.82%,说明三种磷酸腺苷阻燃单体均有助于棉织物形成致密炭层,阻止热量扩散,获得良好的阻燃效果。其中,光接枝ADP-m-GMA阻燃棉织物的增重率可达22.4%,燃烧后损毁长度由30 cm缩短至14.2 cm,表现出更优异的阻燃性能。     

Flame retardancy in fabric consisting of cellulosic fiber and modacrylic fiber containing fine‐grained MoO3 particles

Flame retardancy of fabrics consisting of modacrylic fiber containing with various dispersed metal compounds and cellulosic fiber has been investigated by means of flame test (ISO15025 procedure A) and limiting oxygen index (LOI). It has been found that excellent flame retardancy is achieved by fine‐grained MoO₃ particles. The afterflame time in flame test and the LOI value are improved with decreasing particle size of MoO₃. The flame retardancy of MoO₃ (particle size; 0.1 µm) is comparable to that of Sb₂O₃. On the other hand, significant improvement in flame retardancy is not observed for other metal compounds although some metal oxides and a hydroxide in the present study are known as flame retardant or smoke suppressing agent in halogen containing polymer in previous studies. In order to clarify the mechanism of the observed flame retardancy by the addition of fine‐grained MoO₃, we have carried out X‐ray fluorescence spectrometry (XRF) measurement of the fabric specimen after the flame test and thermogravimetric analysis (TGA) of various types of samples. These analytical data indicated that MoO₃ works as halogen synergist in solid phase and the char of modacrylic fiber formed by addition of MoO₃ suppresses decomposition of the cotton blended in the fabric in the range of the ignition temperature. Copyright © 2015 John Wiley & Sons, Ltd.     

Performance of flame retardancy silk modified with water‐soluble vinyl phosphoamide

In this article, a water‐soluble flame retardant monomer dimethyl(methacryloyloxyethyl)phosphoramidate (DMMEPN) was synthesized and applied onto silk fabric via graft copolymerization technique initiated with potassium persulfate (KPS). The results of attenuated total reflection infrared spectroscopy (ATR), scanning electron microscope (SEM) and energy dispersive X‐ray spectroscopy (EDS) indicated that DMMEPN was successfully grafted onto silk fiber surface. X‐ray diffraction (XRD) patterns showed that grafting process didn't change the crystalline structure of silk fibers and the reaction mainly occurred at the amorphous region of silk fibers. DMMEPN grafted silk fabric exhibited self‐extinguish property when ignited with a candle like fire with LOI of 32.38% and could pass vertical flammability test with char length of 42 mm. Thermal gravimetric analysis showed that grafted silk fibers had different thermal decomposition mode with control silk fibers and tended to produce more char after combustion. This article also investigated the physical properties like whiteness index, hygroscopicity, and tensile strength of grafted silk fabrics. The results showed that physical properties had some loss but had no negative effect on final uses. Laundering durability test demonstrated treated silk fabrics still showed flame retardancy after enduring 30 hand wash cycles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis of a novel oligomeric intumescent flame retardant and its application in polypropylene

A novel oligomeric phosphorous‐nitrogen containing intumescent flame retardant, poly (4,4‐diamino diphenyl methane‐O‐bicycli pentaerythritol phosphate‐phosphate) (PDBPP), was synthesized and characterized. Thermal stability and flammability properties of polypropylene (PP)/PDBPP composites with various PDBPP loading were investigated by thermogravimetric analysis (TGA), limited oxygen index (LOI), and cone calorimeter, respectively. The results showed that the incorporation of PDBPP could improve both the thermal stability and flame retardancy of PP considerably. PP/30%PDBPP system had a LOI value of 28 and its peak heat release rate was reduced by 60% relative to pure PP. Infrared spectrum and field emission scanning electron microscope measurements revealed that PDBPP and PP/PDBPP composites would form a continuous multicellular char layer containing phosphoric acid when exposed to elevated temperature. It was suggested that the very char layer was responsible for the enhanced thermal stability and improved flame retardancy. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Synergism between hydrotalcite and silicate‐modified expandable graphite on ethylene vinyl acetate copolymer combustion behavior

Influence of independent Mg–Al‐layered double hydroxide (LDH), silicate modified expandable graphite (EG), mixture of LDH and EG at various ratios on ethylene vinyl acetate copolymer (EVA) combustion behavior and thermal stability was detected in sequence through the limiting oxygen index (LOI), vertical combustion (UL‐94) level, microscale combustion calorimeter (MCC) tests and thermal gravimetric/differential thermal gravimetric (TG/DTG) analysis. Results show that the 30 wt % LDH can improve the LOI of 70EVA/30LDH to 27.0%, but the combustion accompanies with serious melt‐dropping. While, the same amount of the EG can increase the LOI, UL‐94 level to 28.5%, V‐0 respectively. However, the combination of LDH and EG can further enhance the 70EVA/20LDH/10EG flame retardancy, it presents the LOI of 29.7%, UL‐94 level of V‐0, and total heat release of 29.5 kJ g^?1. The excellent flame retardancy is attributed to its compact residue. Compared with residue mass, the residue compactness plays a more important role in improving flame retardancy. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44634.     

聚乳酸/苯基次膦酸铈复合材料的制备及性能

采用简单方法合成苯基次膦酸铈(CeP),并将其作为阻燃剂加入聚乳酸(PLA)中,通过熔融共混技术制备聚乳酸/苯基次膦酸铈(PLA/CeP)复合材料。通过热重(TG)、极限氧指数(LOI)、UL-94垂直燃烧(UL-94)、微型量热(MCC)研究复合材料的热稳定性、阻燃性能和燃烧性能。通过阻燃测试发现,CeP能够提高复合材料阻燃性能,PLA/CeP20极限氧指数能达到24.3%并通过UL-94 V-2级别。热重分析的结果表明,CeP显著提高了PLA/CeP复合材料初始分解温度和成炭率。MCC测试结果表明,CeP能明显降低PLA/CeP复合材料火灾危险性。PLA/CeP20热释放速率峰值(PHRR)和总热释放(THR)分别为397 W/g和13.6 kJ/g,与纯聚乳酸相比,分别下降了13.9%和28.0%。因此,苯基次磷酸铈对聚乳酸具有良好的阻燃效果。     

磷酸腺苷对蚕丝织物的生物阻燃耐久整理

为了满足对蚕丝织物生态阻燃的需求，以1-(3-二甲氨基丙基)-3-乙基碳二亚胺 (EDC)和 N-羟基琥珀酰亚胺(NHS)为催化剂将磷酸腺苷(AMP)引入蚕丝织物。采用FTIR、SEM、EDS等对改性前后丝织物的化学结构、表面形貌和元素含量进行表征，采用极限氧指数仪、垂直燃烧测试仪、锥形量热仪和热重分析仪对其阻燃性能和热稳定性进行测试，同时对改性前后丝织物的拉伸断裂性能和织物风格等物理机械性能进行测试。结果表明，改性丝织物表面呈现颗粒状覆盖物，且均匀分布着磷元素。改性丝织物增重率达13.3%时，极限氧指数达30.10%，相比于原丝织物失重率降低13.1%，热释放速率降低30.6%，损毁长度减少11.1 cm，并出现明显炭层。经50 次洗涤后，改性丝织物极限氧指数仍能达到25%以上，说明改性丝织物具有较好的耐洗性能。     

Construction of novel silicon‐phosphorus linear polymers with DDSQ and DOPO derivatives for effective flame retardancy of PC/ABS

Two kinds of novel silicon‐phosphorus linear polymers were synthesized by the hydrosilylation reaction of double‐decker‐shaped silsesquioxane (DDSQ) and 9,10‐dihydro‐9‐oxa‐10‐ phosphaphenanthrene‐10‐oxide (DOPO) derivatives and characterized using ¹H NMR, ³¹P NMR, and ²⁹Si NMR. Flame‐retardant polycarbonate/acrylonitric‐butadiene‐styrene (PC/ABS) blends were prepared with different contents of silicon‐phosphorus linear polymers. The flame‐retardant properties of silicon‐phosphorus linear polymers as well as the morphology were investigated in detail by using thermogravimetric analysis (TGA), limiting oxygen index (LOI), (Underwriters Laboratory) UL‐94, microscale combustion calorimetry (MCC), and scanning electron microscopy (SEM), respectively. The silicon‐phosphorus linear polymers containing DDSQ and DOPO units can synergistically improve the flame retardancy and thermal stability of PC/ABS blends. Flame‐retardant polymers with different linkers between DDSQ and phosphate units show comparable effect on the flame retardancy of PC/ABS.     

Gamma-induced polymerization and grafting of a novel phosphorous-, nitrogen-, and sulfur-containing monomer on cotton fabric to impart flame retardancy

Diethyl (acryloyloxy) ethylthiophosphoramidate (DEAETPN), a novel phosphorus-, nitrogen-, and sulfur-containing monomer, was synthesized in a two-step reaction. The monomer was polymerized and grafted onto cotton fabric by gamma radiation method. Effect of methyl methacrylate (MMA) on percentage grafting (Pg) of DEAETPN on cotton fabric was studied, and it was found that small amount of MMA increases Pg on cotton fabric. The monomer, polymer, and the grafted cotton fabric were characterized by spectroscopic and thermogravimetric techniques. Flame retardant property of the modified cotton fabric was studied by the Shirley Manual Flammability Tester. The flame retardancy of cotton-g-DEAETPN by gamma radiation method and living radical polymerization method was compared. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis,characterization and flame retardancy of methacrylated phosphate/diphosphate

Methacrylated phosphate (MAP) and diphosphate (MADP) and were synthesized using diethylphosphoric acid and glycidyl methacrylate, and were characterized by FTIR, NMR and elemental analysis. The thermostability and combustion behaviours of UV‐cured MAP, MADP and their blend films were investigated by thermogravimetric analysis, limiting oxygen index (LOI) and cone calorimeter tests. The results obtained have shown that the samples containing a higher percentage of MAP exhibit relatively lower thermostability at lower temperatures while higher thermostability at elevated temperatures and more char was formed compared with those containing lower percentage of MAP. The average heat release rate (HRR), the smoke extinction area (SEA) and the total smoke production (TSP) during combustion decreased by increasing the MPA content in the films. The LOI values increased from 26.8 to 28.5 by increasing the content of MADP, which depended on the increasing gel content of the UV‐cured films. Compared with MADP, MAP was better in a real fire as it displayed lower HRR, SEA and TSP values, although the LOI was lower than that of MADP. These new compounds can effectively improve flame retardancy if used as components in UV‐curing formulations. Copyright © 2004 Society of Chemical Industry     

The flame retardant effect of aluminum phosphinate in combination with zinc borate,borophosphate, and nanoclay in polyamide‐6

The effect of zinc borate (ZnB), borophosphate (BPO₄), and organoclay were studied to improve the flame retardancy of polyamide‐6 composites containing organic phosphinates. The flame retardancy of polyamide‐6 composites was investigated using limiting oxygen index (LOI), Underwriters Laboratories (UL‐94) standard, thermogravimetric analysis, Fourier transform infrared spectroscopy, and mass loss calorimeter. The addition of 15 wt% aluminum phosphinate (AlPi) increased the LOI value from 22.5 to 29.5, and V0 rating was obtained from UL‐94 test. The addition of organoclay, ZnB, and borophosphate does not change the predominant gas phase mechanism of AlPi during LOI and UL‐94 tests. The addition of organoclay increased the condensed phase mechanism of AlPi physically by the protective effect of layered silicate, whereas the addition of ZnB increased the condensed phase mechanism of AlPi chemically by the formation of boron aluminum phosphate species deducted from mass loss calorimeter studies. Copyright © 2012 John Wiley & Sons, Ltd.     

Aqua-mediated in situ synthesis of highly potent phosphorous functionalized flame retardant for cotton fabric

Flame retardancy in various materials is becoming an increasingly important performance feature. In the textile industries, fire-related problems have become an important concern over the decade. Herein, the polyvinyl alcohol (PVA) and graphene-supported material were functionalized with trimethyl phosphate (TMP) for the synthesis of flame retardant (FR) composite material [graphene polymer functionalized trimethyl phosphate (GPTMP)] in the aqueous medium, which improves the stability of cotton fabric against flame. Graphene and PVA fabricated with phosphorus functional groups make the fabric more comfortable against fire and help to avoid further spreading of fire. The composite-coated fabric sustains for a long time on continuous flame with maintaining its initial shape and size. The GPTMP-coated fabric shows flame retardancy for up to 540 s on constant flame exposure, whereas control samples such as PVA-, graphene oxide-, and TMP-coated fabrics resist for up to 15, 20, and 14 s, respectively. The limiting oxygen index (LOI) and vertical flammability test (VFT) for synthesized composites were performed to confirm and support the flame retardancy property of GPTMP. The GPTMP shows the 35% LOI value and forms the char length of 2.6 cm during VFT. This work provides a simple and eco-friendly method to obtain novel GPTMP, which has a high potential as a FR for different fabrics, including cotton.     

Click chemistry‐assisted preparation and properties of phosphorus and nitrogen synergistic flame retardant optical resin with a high refractive index

In this study, halogen‐free flame retardant tri(acryloyloxyethyl) phosphate (TAEP) was prepared using 2‐hydroxyethyl acrylate and phosphorus oxychloride. The chemical structure of TAEP was characterized by Fourier transform infrared and proton nuclear magnetic resonance spectrometers. The mixture of TAEP, acrylamide, and pentaerythritol tetrathioglycolate with different P, N, and S content were used to prepare flame retarding optical resin via the click chemistry curing. The curing performance, thermal stability, and flame retardant performance of the optical resins were measured by differential scanning calorimeter, thermogravimetric analyzer, vertical burning tester, and limiting oxygen index test, respectively. Additionally, the morphology of the burned residual was investigated by scanning electronic microscopy, and the refractive indices of the optical resins were measured by an Abbe Refractometer. The results strongly indicated that increasing sulfur content in resins improved their refractive indices, but deteriorated their flame retardancy. Meanwhile, the nitrogen element was helpful for the flame retardancy of the optical resin. With S N, and P contents of 3.00%, 1.00%, and 6.70 wt %, respectively, the refractive index of the optical resin reached up to 1.4987, and its flame retardancy achieved the UL‐94 V‐0 level and the LOI value of 29.3%. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46648.