The effects of weathering and atmospheric pollutants on cotton fabric and cotton fabric treated with selected flame retardants. I. Physical,chemical, and flammability properties

The effects of weathering and atmospheric pollutants on the physical, chemical, and flammability properties of cotton fabric treated with Pyrovatex 3805 and with THPOH-NH₃ flame retardant finishes and untreated controls were determined. The fabrics were exposed to SO₂, NO₂, and ozone singly and in combination for 50, 100, and 150 hr in a 2500-watt xenon arc Weather-Ometer using gas controls with and without light at a temperature of 35°C and a relative humidity of 90%. Excessive strength losses and large changes in D.P. for the untreated control occurred under all exposure conditions after 150 hr. Changes in the physical and chemical properties of the treated fabrics were moderated by the finishes, with Pyrovatex 3805 providing better protection to the cellulose than THPOH-NH₃. Elemental analysis and oxygen index measurements indicate that the Pyrovatex 3805 finish was severely degraded under these exposure conditions, with a resultant loss in flammability properties of the treated fabric after weathering. The THPOH-NH₃ finish was not appreciably affected by these exposure conditions and the treated fabric retained most of its flammability properties after weathering.     

Flame‐retardant finishing of cotton fabrics using polyamino carboxylic acids and sodium hypophosphite

The purpose of this research was to use polyamino carboxylic acids (PACAs) and their combination with sodium hypophosphite (NaH₂PO₂) as a flame‐retardant finishing system for cotton fabrics. Flammability of cotton fabric was evaluated by 45° flammability test, differential scanning calorimetry and measuring the char yield. The combination of polyamino carboxylic acids and sodium hypophosphite as a phosphorus‐containing catalyst reduces the flammability of cotton. The pyrolysis properties and the results of char yield of the finished cotton show that with increasing amount of catalyst, the flame retardancy increases. Fastness against multiple laundering, whiteness and tensile strength of the cotton finished with PACAs/NaH₂PO₂ to multiple standard laundering have been studied, too. The flame retardancy effect has an acceptable washing fastness. Whiteness and tensile strength of the finished cotton do not change significantly. Copyright © 2012 John Wiley & Sons, Ltd.     

阻燃型磷酸酯聚硅氧烷的合成与应用

该文以N-β-氨乙基-γ-氨丙基聚二甲基硅氧烷(ASO-1)、环氧氯丙烷、磷酸三丁酯为原料合成了阻燃型磷酸酯聚硅氧烷(PPSO),经红外光谱(IR)和核磁共振氢谱(1HNMR)证实了产物及中间体的化学结构,将PPSO进行乳化得到了透明乳液(PPSE),用马尔文纳米粒度仪及Zeta电位仪测出乳液平均粒径为62.5 nm,Zeta电位+53.71 mV.将所得硅乳应用于棉织物,探讨了阻燃剂用量对整理后织物性能的影响.结果表明,整理后的织物具有了阻燃性,最佳阻燃剂用量为200 g?L-1.为了进一步解释纤维阻燃的机理,通过热重分析研究了织物的热裂解过程,结果表明,阻燃剂对纤维起到了脱水、炭化作用,提高了剩炭率.     

A novel cyclic copolymer containing Si/P/N used as flame retardant and water repellent agent on cotton fabrics

A novel cyclic-shaped multifunctional copolymer named poly[tetra(tetramethylcyclosiloxyl-piperazin)-phosphinic acid methyl ether] (PNCTSi) was successfully synthesized. Its flame-retardant and hydrophobicity properties on cotton fabrics were investigated. The limited oxygen index (LOI) value of treated cotton fabrics with PNCTSi was up to 29.8%. By vertical burning test, it was found that the treated cotton fabrics have no after-flame and no after-glow. Apparently, more amounts of char were generated and hazardous volatiles distinctly reduce after combustion by thermogravimetric analysis. Besides, Treated cotton fabrics with PNCTSi can give a hydrophobic property, which reach a contact angle of 150°. The surface morphology of treated cotton fabric before and after combustion was analyzed by scanning electron microscopy, after burned, the surface morphology of cotton fiber exhibited more smooth and expanded feature. After washing the cotton fabric for 20 times, the LOI remains at above of 26.0%. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47280.     

Synthesis of a graft-functionalized flame retardant based on DOPO and its application on the surface of terylene/cotton fabrics

Terylene/cotton (TC) fabrics are widely used in the textile industry because of their superior softness and durability. In addition, its high combustibility leads to a great safety hazard, and the droplet phenomenon during combustion is particularly serious. 9-oxa-10-phospha-9,10-dihydrophenanthrene 10-oxide (DOPO) and its derivatives are frequently used as eco-friendly flame retardants in large quantities in substrates. It would be difficult to apply to the surface of the fabric, and the addition of large amounts would lead to a decrease in the mechanical properties. Therefore, it is necessary to design a strategy for graft-functionalized flame retardants that can be applied to surfaces. Here, this study reported a washing-fastness flame-retardant coating (DOPO-p) synthesized from DOPO and p-hydroxybenzaldehyde (p-HBA), coatings with a low weight growth and high flame-retardant efficiency are prepared by the strategy of dissolving with organic solvents. Water and dry-cleaning tests showed excellent washing fastness of TC fabrics. In the limiting oxygen index (LOI) test, the finished fabric achieved a LOI value of 22.9%. In the cone calorimetry test, the peak of heat release rate of the finished fabric is decreased by 27% and CO₂ release is reduced by 29% when the coating weight growth was only 3.3 wt%.     

Novel application of partial carboxymethylation in the wet processing of linen fabric

Scoured linen fabrics were treated with NaOH at different concentrations (1–7N). Unscoured (gray) linen fabrics were modified via partial carboxymethylation under different conditions, including monochloroacetic acid concentration (1–4N), sodium hydroxide concentration (0.5–3.5N), reaction time (30–180 min), and reaction temperature (30–90°C). Alkali treated and partially carboxymethylated linen fabrics were bleached using H₂O₂ (20 g/L), sodium silicate (3 g/L), and nonionic wetting agent (1 g/L) at pH 10 for 150 min at 95°C. The unbleached and bleached linen fabrics (alkali treated and partially carboxymethylated) were assessed for technical properties, namely, whiteness index (W.I.), loss in fabric weight, copper number, carboxyl content, and H₂O₂ decomposition percent. A comparison was made between the properties of the two substrates. It indicates that the properties of partially carboxymethylated linen fabric were comparable, if not superior, to alkali treated linen fabric. Hence it is advantageous to introduce partial carboxymethylation in the wet processing of linen fabrics since scouring and alkali treatment can be omitted. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 996–1001, 2007     

PET pyrolysis and hydrolysis mechanism in the fixed pyrolyzer

In the conventional polyethylene terephthalate (PET) pyrolysis process, the formation of char by excessive pyrolysis is mainly due to the dehydration mechanism, so water is considered an auxiliary agent that can effectively inhibit excessive pyrolysis. The preparation of terephthalic acid (TPA) by steam-assisted pyrolysis of PET is an effective method to achieve closed-loop recycling of waste PET. To ensure that the reaction is mild enough to reduce excessive cracking products such as char and benzoic acid and thus increase the yield of TPA, it is critical to reduce the reaction rate while maintaining a sufficient excess steam coefficient. Under the optimal operating conditions, when the temperature rise rate was 0.5 °C min⁻¹ and the excess steam coefficient was 150, the yield of TPA was 72.5 wt.%, and the purity was 85.5%. Noticeably, the steam-assisted pyrolysis system is a heterogeneous reaction system whose reaction mechanism is different from the conventional hydrolysis and pyrolysis reactions and has a unique reaction path. The mechanistic study indicates that, in addition to the thermal cracking of PET molecules occurring in conventional pyrolysis, hydroxyl attack and transfer, and supplementation of benzene ring hydrogen also occur between water and intermediate molecules. Meanwhile, it has also been proven that the intermolecular hydrogen transfer between intermediate molecules and water molecules is the key to reduce the intensity of the reaction and inhibit the formation of char. This discovery illustrates the mechanism of the reaction between water and PET in the steam-assisted pyrolysis process in the fixed pyrolyzer and justifies the distinction between it and the pyrolysis and hydrolysis processes of PET. It provides a theoretical basis for optimizing the pyrolysis process of PET, which is essential for the industrialization of TPA preparation from PET steam-assisted pyrolysis.     

Effect of carbon fabric type on the mechanical performance of 2D carbon/carbon composites

A stabilized PAN fabric was carbonized and graphitized from 800°C to 2500°C. Two-dimensional (2D) carbon/carbon composites were made using the stabilized PAN fabric, carbonized fabrics, and a resol-type phenol-formaldehyde resin. These composites were heat-treated from 600°C to 2500°C. The influence of different heat-treated fabrics and heat treatment on the fracture and flexural strength of these composites was also studied. The composite reinforced with higher heat-treated fabrics showed a lower weight loss than that with lower heat-treated fabrics. When the composites were graphitized at 2500°C, the loss was 49.7 wt% for the composite made with stabilized PAN fabric and 26 wt% for that with carbonized fabric at 2500°C. Those composites also have a higher density than composites produced by other methods. Composites made with stabilized PAN fabric exhibited a strong bonding in the fiber/matrix during pyrolysis. This composite showed catastrophic fracture and a smooth fracture surface with no fiber pullout. Composites made with higher carbonized fabrics exhibited a weak interface bonding. These composites showed a pseudo-plastic fracture pattern with fiber pullout during pyrolysis. Composites made with carbonized fabrics at 2000°C and 2500°C showed the highest flexural strength at the prolysis temperature of 1000°C. Composites made with carbonized fabric at 1300°C showed the highest flexural strength above 1500°C to 2500°C. The composite made with stabilized PAN fabric exhibited the lowest flexural strength during pyrolysis.     

Thermal decomposition of zinc oxalate dihydrate: Kinetics of dehydration and pyrolysis in various atmospheres

Thermogravimetric analysis has indicated that a convenient range for the study of Zn(COO)₂.2H₂O dehydration is 120–300 °C, while for pyrolysis it is 320–400 °C. Kinetics of isothermal dehydration and pyrolysis were studied as two consecutive steps in various atmospheres, namely in constant water vapour pressure of 4.8 and 8 mm Hg, in air saturated with water vapour at 25 °C and in vacuo. The kinetic data indicated that dehydration is a pseudo-first order reaction, which is highly dependent on the surrounding atmosphere. The mechanism of dehydration is either activated diffusion (alternatively surface diffusion) for dehydration in vacuo or in low water vapour pressures, or activated desorption for dehydration in presence of high water vapour pressure. On the other hand pyrolysis is independent of the prevailing atmosphere, and the energy of activation is of the order of the enthalpy change of the reaction. Earlier studies have involved contact of the dehydrated oxalate with air, or have obscured the influence of the prevailing atmosphere, by dehydrating the sample material at the pyrolysis temperature. These conditions are considered in the present investigation.     

The effects of weathering and atmospheric pollutants on cotton fabric and cotton fabric treated with selected flame retardants. II. Spectroscopic studies

Spectroscopic studies of weathered flame retardant cotton fabrics were conducted. The weathering conditions included combined and independent exposure to xenon arc light and low concentrations of SO₂, NO₂, and O₃ gases. Multiple internal reflectance infrared analysis of weathered Pyrovatex 3805-treated fabric showed that the finish removed after 150 hr of weathering exposure had the same structure as the original finish. Interferometer spectra of Pyrovatex 3805 and THPOH-NH₃ finishes on the fabric indicated no significant changes in the structure for both finishes after exposure to the various weathering conditions.     

Microstructure evolution of ammonia‐catalyzed phenolic resin during thermooxidative aging

The thermooxidative aging of ammonia‐catalyzed phenolic resin for 30 days at 60–170°C was investigated in this article. The aging mechanism and thermal properties of the phenolic resin during thermooxidative aging were described by thermogravimetry (TG)–Fourier transform infrared (FTIR) spectroscopy, attenuated total reflectance (ATR)–FTIR spectroscopy, and dynamic mechanical thermal analysis. The results show that the C? N bond decomposed into ammonia and the dehydration condensation between the residual hydroxyl groups occurred during the thermooxidative aging. Because of the presence of oxygen, the methylene bridges were oxidized into carbonyl groups. After aging for 30 days, the mass loss ratio reached 4.50%. The results of weight change at high temperatures coincided with the results of TG–FTIR spectroscopy and ATR–FTIR spectroscopy. The glass‐transition temperature (T_g) increased from 240 to 312°C after thermooxidative aging for 30 days, which revealed the postcuring of phenolic resins. In addition, an empirical equation between the weight change ratio and T_g was obtained. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

CO2 gasification of wood charcoals derived from vacuum and atmospheric pyrolysis

The gasification of biomass derived char obtained via vacuum and atmospheric pyrolysis of Populus tremuloides has been studied in the ranges of 725–960°C and 0.1 to 6 MPa. CO₂ was used as the oxidizing gas. The results show that char reactivity is influenced by the preheating rates and that pressure effects are significant between 850°C and 950°C. A correlation based on the expression: df/dt = k₀{exp(-E/RT)}(1 - f)^af^βP^yCO₂ was used to fit the experimental data. In general, vacuum pyrolysis derived char showed a higher reactivity than atmospheric pyrolysis chars. An explanation based on a higher oxygen content of the vacuum pyrolysis char is suggested.     

Electron spectroscopy for chemical analyses (ESCA)—A tool for studying treated textiles

Electron spectroscopy for chemical analysis (ESCA) has been successfully used to determine the location of flame-retardant polymers or reagents and crosslinking and oil/water-repellent reagents in relation to fiber surfaces of chemically modified cotton fabrics and cotton/polyester blends. Changes in intensity of characteristic ESCA element signals were followed as the particle size of the treated fabric varied. Dimethyloldihydroxyethyleneurea (DMDHEU) and the flame-retardant polymer formed from tetrakis(hydroxymethyl)phosphonium chloride (Thpc) and urea penetrate and are homogeneously deposited throughout cotton fabrics. The oil/water-repellent finish, FC-218, and the flame retardants from the THPOH/NH₃ reaction and tris(dibromopropyl) phosphate are deposited on the surfaces of both cotton and polyester fibers.     

Bi-phase flame-retardant effect of hexa-phenoxy-cyclotriphosphazene on rigid polyurethane foams containing expandable graphite

The flame-retardant rigid polyurethane (PU) foams with hexa-phenoxy-cyclotriphosphazene/expandable graphite (HPCP/EG) were prepared through box-foaming in our laboratory. The flame retardancy of PU foams was characterized using the limiting oxygen index and cone calorimeter. The results show that the incorporation of HPCP into the PU foams containing EG enhanced flame retardancy. The main degradation process of HPCP in PU foams was investigated by pyrolysis gas chromatography/mass spectroscopy. HPCP during combustion generated phenoxyl and PO₂ free radicals, which could quench the flammable free radicals produced by the matrix and hamper the free radical chain reaction of combustion. This observation shows that HPCP produced a gas-phase flame-retardant effect in this specimen. Additionally, micro-morphology, elemental composition and content of residual char of the flame-retardant PU foams after the cone calorimeter test were also characterized using scanning electron microscope and energy dispersive X-ray microanalyser. The results exhibit that the partial phosphorus from HPCP remained in the residual char, and HPCP significantly enhanced the strength and compatibility of the char layer formed by the PU foams containing EG. These results indicate the important function of HPCP in condensed phase. Thus, HPCP exhibited gas-phase and condensed-phase flame-retardant effects on the PU/EG foams.     

Influence of pregrafting cotton fabrics on kinetics of DMEU finishing

Cotton fabrics were pregrafted with a mixture of N-methylolacrylamide and methacrylic acid at mixing molar ratio of 4/6. The influence of pregrafting on the kinetics of finishing with 1,3-dimethylolethylene urea was studied. The results shows that pregrafting can increase the rate constants. Values of E_a ΔH^*, ΔS^*, and ΔG^* suggest that the pregrafting of cotton fabric not only affects the reaction action state, but also is beneficial for the reaction between cellulose and the finishing agent. © 1996 John Wiley & Sons, Inc.     

Characteristic properties of polypropylene cationic fabrics and their derivatives

Polypropylene fabrics were modified with 2N‐morpholino ethyl methacrylate by electron beams and grafting. Then, the modified fabrics were quaternized with different alkylating agents, such as benzyl chloride, monochloroacetic acid, chlorosulfonic acid, and chloroethanol. The reaction completion was calculated from the increase in the fabric weight. The modified polypropylene fabrics were characterized by microanalysis and IR spectroscopy. The moisture regain was measured at 20°C and 65% relative humidity. The modified fabrics were sufficiently hydrophilic to adsorb the metal ion Cu²⁺ from a CuSO₄ solution. Their antimicrobial properties were evaluated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2917–2922, 2003     

Effect of Silicone Nano,Nano/Micro and Nano/Macro‐Emulsion Softeners on Color Yield and Physical Characteristics of Dyed Cotton Fabric

The study of silicone nano‐emulsions and softeners to alter physical properties of undyed cotton fabric has recently gained a substantial interest. However, systematic investigation of silicon nano‐emulsion softeners on dyed cotton fabric has not so far been conducted. This paper deals with the application of silicone nano‐, micro‐, and macro‐emulsion softeners, and combinations of nano/micro and nano/macro, on dyed cotton fabric. We report the effect of silicon nano/micro‐ and nano/macro‐emulsion softeners on color yield and physical characteristics of dyed cotton fabric. All bleached fabrics were dyed with CI Reactive Black 5 and then treated with known concentrations of silicone softeners by the pad‐dry method. The silicone nano‐emulsion was combined with micro‐ and macro‐emulsion softeners using blending ratios of nano/micro (1:1) and nano/macro (1:1). Treated fabrics were compared in terms of physical properties such as fabric handling, wrinkle recovery angle, bending length, abrasion resistance and tensile strength. The color changes were evaluated by color yield (K/S) values and total color difference (ΔE_cmc). The results revealed that the silicon nano‐emulsion had better physical properties than micro‐, macro‐ and combination nano/micro‐ and nano/macro‐emulsion softeners. Among all treated samples, nano‐emulsion softeners showed better ΔE_cmc values. Scanning electron microscopy analysis suggests that the fiber morphology of treated fabrics was very smooth and uniform.     

Layer‐by‐layer assembly of halogen‐free polymeric materials on nylon/cotton blend for flame retardant applications

Thin films of environmentally safe, halogen free, anionic sodium phosphate and cationic polysiloxanes were deposited on a Nyco (1:1 nylon/cotton blend) fabric via layer‐by‐layer (LbL) assembly to reduce the inherent flammability of Nyco fabric. In the coating process, we used three different polysiloxane materials containing different amine groups including, 35–45% (trimethylammoniummethylphenythyl)‐methyl siloxane‐55‐65% dimethyl siloxane copolymer chloride salt (QMS‐435), aminoethylaminopropyl silsesquioxane‐methylsilsesquioxane copolymer oligomer (WSA‐7021) and aminopropyl silesquioxane oligomers (WSA‐991), as a positive polyelectrolyte. Thermo‐gravimetric analysis showed that coated fabric has char yield around 40% at 600 °C whereas control fabric was completely consumed. The vertical flame test (VFT) on the LbL‐coated Nyco fabric was passed with after flame time, 2 s, and the char length of 3.81 cm. Volatile and nontoxic degradation products of flame retardant‐coated fabric were analyzed by pyrolysis gas chromatography mass spectroscopy (Py‐GCMS). Surface morphology of coated fabrics and burned fabric residues were studied by scanning electron microscopy. Copyright © 2014 John Wiley & Sons, Ltd.     

阻燃涤纶汽车座套面料的研究和开发

采用阻燃涤纶和普通涤纶作为原料,研究了阻燃涤纶和普通涤纶交织混合时,混用的比例对织物阻燃性能的影响;并根据汽车座套面料的要求设计了不同层数的织物,研究其对使用性能和舒适性能的影响。从织物的阻燃性和使用性能综合分析,得出普通涤纶与阻燃涤纶比例为1∶2的双层织物为最佳方案。     

Novel phenyl acetylene terminated poly(carborane‐silane): Synthesis,characterization, and thermal property

Phenyl acetylene terminated poly(carborane‐silanec) (PACS) was synthesized by the couple reaction of methyldichlorosilane with 1,7‐dilithio‐m‐carborane and lithium phenylacetylide. The structure was characterized using FTIR, ¹H‐NMR, ¹³C‐NMR, ²⁹Si‐NMR, and gel permeation chromatography. PACS exhibits solubility in common organic solvents. Thermal and oxidative properties were evaluated by thermogravimetric analysis (TGA). Thermoset exhibits extremely thermal and oxidative property and TGA curves show that the temperature of 5% weight loss (Td₅) is 762°C and char yield at 800°C is 94.2% in nitrogen. In air, surprisingly, both Td₅ and char yield at 800°C show slight increase, which is greater than 800°C and 95.6%, respectively. After pyrolysis, the char has no additional weight loss up to 800°C in air. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2498–2503, 2007