Chemical modification of nylon 6 and polyester fabrics by ozone‐gas treatment

In a previous article, we reported on the ozone‐gas treatment of wool and silk fabrics in relation to the gas‐phase processing of textile fabrics. The treatment incorporated an oxygen element into the fiber surface and contributed to an increase in water penetration into the fabric. In this study, nylon 6 and polyester fabrics were treated with ozone gas in the same way as that of the wool and silk fabrics. The treatment incorporated much more oxygen into the fiber surface in the form of ? COH and ? COOH, as shown by electron spectroscopy for chemical analysis. Water penetration increased considerably with treatment, and the apparent dyeing rate and equilibrium dye uptake were also improved, especially for the polyester fabric, despite an increase in the crystallinity. Therefore, it seemed that the treatment brought about a change not only in the fiber surface but also in the internal structure of the fibers (the crystalline and amorphous regions) with regard to the dyeing behavior. Further, the mechanical characteristics of the ozone‐gas‐treated polyester and nylon 6 fabrics were measured with a Kawabata evaluation system apparatus. The shearing modulus and hysteresis widths increased with treatment, especially for the polyester fabric. Therefore, it was clear that the treatment caused a change in the fabric hand to crisp. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1344–1348, 2006     

Thermal behaviour of acrylamide and acrylonitrile grafted nylon 6

The thermal behaviour of nylon 6, 20 denier, monofilament (semi-dull) and the graft copolymers of nylon 6 with acrylamide and acrylonitrile was studied using dynamic thermogravimetry in air at a heating rate of 6°C/min. up to a temperature of 550°C. The thermal stabilities of the samples grafted with acrylamide and acrylonitrile to various percentages of grafting were computed from their primary thermograms by calculating the values of initial decomposition temperature (IDT), integral procedure decomposition temperature (IPDT) and activation energy (E). The results show that the thermal stability of the samples grafted with acrylonitrile increases with increase in graft-on percentage and the thermal stability of the samples grafted with acrylamide decreases with increase in graft-on percentage. The reduction is, however, not very significant.     

Some physical properties of acrylamide and acrylonitrile grafted nylon 6

Graft copolymerization of acrylamide and acrylonitrile on nylon 6 swollen in formic acid (60%) for 30 min was performed using ceric ions as initiator at 60°C. The optimum conditions to get highest percentage of graft-on were utilised to prepare the grafted samples with various amounts of polymer deposited inside the fibres. The mechanical properties, moisture regain, density, infrared studies, birefringence, dye uptake and dynamic mechanical properties were determined for the grafted samples and the results are discussed in relation to possible structural changes due to graft copolymerisation.     

Detection of hydroxyl radicals in photoirradiated wool, cotton, nylon and polyester fabrics using a fluorescent probe

Generation of hydroxyl radicals in the presence of buffered terephthalate solution produces flourescent 2-hydroxyterephthalate. Wool, nylon, cotton and polyester all generate hydroxyl radicals when irradiated with UVA light, and to a lesser extent with blue light, in terephthalate solution. Trace metal ions (particularly iron and copper) contribute to hydroxyl radical generation in wool and cotton. UVA irradation of wool in deuterated solution does not affect the concentration of hydroxyl radicals or the amount of yellowing observed relative to undeuterated solution. This suggests that 1O2 is not involved in the wet photoyellowing of wool. Although the photoinitiation stages are clearly different, it is likely that similar free radical processes are responsible for both hydroxyl radical production and wet photoyellowing in all four fibre types. This straight forward fluorescence technique has potential to correlate the free radical photodegeneration of fibres in the presence of various additives designed to improve performance.     

Mass coloration of polyester and nylon 6 using perylene pigments

The paper describes the mass coloration of polyester and nylon 6 using perylene-based pigments having groups structurally similar to the substrate. For this purpose, five perylene-based pigments were prepared by reacting 3,4,9,10-perylene tetracarboxylic acid dianhydride (PTDA) with methylamine, ethanolamine, glycine, 4-aminobutanoic acid and 6-aminocaproic acid. Structural characterisation of these pigments was carried out by elemental analysis, and electronic, i.r. and mass spectroscopy. The pigments were found to be stable up to 360d? C and started decomposing above this temperature. Mass-coloured polyester and nylon 6 fibres showed better pigment dispersion, darker shades and better fastness properties when compared with fibres produced by the chip coating method.     

Structure and thermal behaviour of nylon 6 nanocomposites

In this article, nylon 6/clay nanocomposites with 5 wt % clay (NCN5) were prepared by a twin screw extruder. The effects of annealing including solid‐state annealing (170 and 190°C) and melt‐state annealing (240°C) on the polymorphic behavior and thermal property of NCN5 and nylon 6 have been comparatively studied as a function of annealing time using modified differential scanning calorimetry (MDSC) and wide‐angle X‐ray diffraction. It was demonstrated that NCN5 and nylon 6 exhibit a similar polymorphic behavior when they were annealed at 190°C for different time durations. As the annealing temperature was elevated to 240°C, significant differences in thermal behavior and polymorphism between NCN5 and nylon 6 could be found. For example, the α crystal became the absolutely dominating crystalline phase for NCN5 sample independent on the annealing durations, whereas the formation of γ crystal is greatly enhanced in neat nylon 6 with increasing annealing time. Moreover, a small endothermic peak is observed around 180°C in both nylon 6 and NCN5 samples annealed at 170 and 190°C, which might be related to the melting of microcrystals formed in the amorphous regions during annealing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3116–3122, 2006     

Microbial detection,surface morphology,and thermal stability of cotton and cotton/polyester fabrics treated with antimicrobial formulations by a radiation method

Cotton and cotton/polyester fabrics were treated with a proposed antimicrobial formulation based on zinc oxide (ZnO), Impron MTP (binder), and Setamol WS (dispersing agent) under the effect of γ irradiation. The effect of this treatment on the growth of certain bacteria (Bacillus subtilis) and fungi (Aspergillus niger) was studied. In general, it has been confirmed that ZnO ratio is an inhibitory factor on the growth of both microbes. As a result of treatment of cotton fabrics, as an example, the B. subtilis counts were decreased by 4 log cycles whereas the A. niger count was decreased by 2 log cycles. This finding was illustrated by observing the surface microstructure of the fabrics after they had been buried in a moist soil for two weeks. The deterioration in the weaving structure of the nontreated was so strong that it could not distinguish the strings forming the fabric. On the basis of microbial detection, it was found that the treatment with ZnO formulation causes a net reduction in the bacterial cells amounts to 78 and 62% in the case of treated cotton and cotton/polyester fabrics while the net reduction in the fungi was calculated to be 80.7 and 32%, respectively. However, it was found that the treatment with ZnO formulation caused a reduction in the thermal stability of the fabrics as indicated by thermogravimetric analysis. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2604–2610, 2003     

近年国内锦纶、聚酯帘子布生产发展现状

目前国内生产锦纶帘布的企业有30余家,帘子布产能约32万～35万吨,其中采用引进技术设备的中国神马集团实业股份有限公司、陕西九棉实业有限责任公司、青岛联创实业有限公司、岳阳巴陵公司鹰山石油化工厂4家企业的年产能为9万吨。另外,据初步了解,浙江、江苏、山东等27家企业新建和扩大年产能约8万吨,预计2005年底锦纶帘布生产将形成年产40万吨的生产能力。笔者在中国橡胶工业协会骨架材料专业委员会2003年帘子布企业生产发展情况统计的基础上,经过对江苏、浙江、上海、山东地区帘子布企业和相关织布机企业及浸胶机企业的调查了解,现对近年全…     

Airbag fabric material modeling of nylon and polyester fabrics using a very simple neural network architecture

The material properties of engineering fabrics that are used to manufacture airbags can not be modeled easily by the available nonlinear elastic–plastic shell elements. A nonlinear membrane element that incorporates an elaborate tissue material model has been widely used by the auto industry for the airbag simulation studies. This model is highly computation intensive and does not differentiate between the various physical properties of the fabrics like fiber denier, the polymer fiber, and weave pattern. This paper introduces a new modeling technique that uses artificial neural networks. Experimental permeability data for fabrics under biaxial strain conditions were obtained through a blister-inflation technique and were used to train the proposed network architecture. In this training environment, various properties of the fabric can be incorporated and the network can be trained to generalize relative to the environment. Once trained, the cause–effect pattern is assimilated by the network with approprate weights to produce a desired output. Fabrics tested in this study included nylon 66 fabrics with three different fabric deniers: 420, 630, & 840 and two types of weave, and two 650-denier polyster fabrics having different calendering effects. The predictions obtained from this neural network model agreed very well with the experimental data. This indicates that neural nets can be considered as a serious design tool use in determining permeability and biaxial stress–strain relationships for textile fabrics used in airbags. © 1996 John Wiley & Sons, Inc.     

Compatibility of nylon 6 and PMMA–oligoamide graft copolymer

PMMA–oligoamide graft copolymers, which were prepared by reacting poly(methyl methacrylate-co-methacryloyl chloride) with oligoamide, were blended with nylon 6. The compatibility was examined by measuring thermal properties such as melting point and crystallization temperature. It was observed that the melting point was significantly depressed as the grafted PMMA was added to nylon 6, suggesting that the blend is a miscible system. It was concluded that hydrogen bonding between amide groups of the two polymers enhanced the miscibility.     

Solvent induced phase separation in a nylon 6-b-polyimide-b-nylon 6 triblock copolymer

A series of new nylon 6-b-polyimide-b-nylon 6 (triblock) copolymers have been synthesized via condensation polymerization of the polyimide component and anionic polymerization of the nylon 6 component. The polyimide component is prepared from bisphenol-A dianhydride (BisA-DA) and bisaniline-P diamine (BisP) with end-capped functional groups. After the polyimides are dissolved in caprolactam, the nylon 6 anionic polymerization is initiated by the functional groups of the polyimides. The triblock copolymers can be dissolved in both m-cresol and 1,6-hexanediol. Of the two components present in the copolymers, nylon 6 crystallizes partially and BisA-DA/BisP is amorphous. Based on differential scanning calorimetry, dynamic mechanical analysis, wide angle X-ray diffraction, small angle X-ray scattering and transmission electron microscopy experiments, the copolymer films prepared from the 1,6-hexanediol solution are phase separated. The BisA-DA/Bis P and the nylon 6 components show little miscibility in the inter-lamellar amorphous region. However, in the films prepared from the m-cresol solution both components are largely miscible in the inter-lamellar amorphous region. This is due to the different solvation power of the two solvents with respect to the polyimide and nylon 6.     

Hydrophobicities and antibacterial activities of silicone polyester/titanium dioxide composites on nylon fabrics after argon plasma treatment

To be more biocompatible, poly(N-isopropyl acrylamide) (PNIPAM) hydrogel, as a typical temperature-sensitive hydrogel, is expected to be linked with other materials of excellent biocompatibility. For this propose, poly(N-isopropyl acrylamide)-block-poly(3-O-allyl-α-D-glucose) (PNIPAM-b-POAG), a new diblock copolymer, was successfully synthesized from N-isopropyl acrylamide (NIPAM) and 3-O-allyl-1,2:5,6-di-O-isopropynylene-α-D-glucose (OAIG) via reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of cumyl dithiobenzoate (CDB). PNIPAM-b-POAG was characterized byFourier transform infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (¹H NMR) spectroscopy, and gel permeation chromatography (GPC). The critical micelle concentration (CMC) of the copolymer was 0.045 mg/ml measured by fluorescence spectroscopy. The copolymer solution exhibited a reversible sol-gel phase transitions with the increase or decrease of temperature. An in situ gel formed rapidly after subcutaneously injecting the copolymer solution into a Sprague Dawley (SD) rat, which indicated the copolymer has a good injectable property. The in vitro release result showed that methylene blue (MB) as a model was sustainably released by the temperature-sensitive PNIPAM-b-POAG diblock copolymer at 37 °C within 120 h. The copolymer showed no apparent cytotoxicity on L929 cells by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The novel temperature-sensitive hydrogel is a promising candidate for drug delivery.     

Polyimide and nylon 6 blend film: Preparation,characterization and thermal behavior

A polyimide blend system has been prepared from a base polyimide of BTDAODA by adding ε‐caprolactam at the poly(amic acid) stage where ε‐caprolactam undergoes polymerization to form nylon 6 during the thermal cyclodehydration of poly(amic acid). The blend has been characterized by elemental analysis. IR, ¹³C CPMAS NMR, XRD and simple chemical methods. The thermal analysis study (TGA and DTA) shows that the stability of the blend systems is more in the lower temperature region (up to 300°C) in comparison to the control polyimide system. The isothermal study at 400°C in inert atmosphere shows that the blend system is equally stable but the isothermal study in air at 400°C shows that the thermooxidative stability of the blend films (except BB 4) is higher. Also, isothermal study in air at 500°C shows more than 90% weight loss for all the films within 3 h, but in an inert atmosphere, the blend films show lower weight loss compared to the control film. Although the XRD pattern of all the blend and control films shows an amorphous character, the films developed some crystallinity when treated with boiling NMP where the blend films developed higher crystallinity.     

Preparation of chelating fabrics by radiation‐induced grafting of itaconic acid and acrylonitrile onto polypropylene nonwoven fabrics and subsequent amination of graft copolymer

A mixture of acrylonitrile (AN) and itaconic acid (IA) was cografted onto polypropylene (PP) nonwoven fabrics by preirradiation method. The effects of graft polymerization conditions such as temperature, reaction time, Mohr's salt concentration, solvent mixture ratio, and comonomer composition on the total grafting yield were investigated. The addition of AN as a comonomer increased the amount of IA that reacted with PP fabrics. An increase in the temperature from 40 to 60°C increased the grafting rate, but the final grafting yield decreased at high temperature. The addition of 0.01 wt % Mohr's salt to the reaction medium leaded to a sharp increase of grafting yield. The accelerative effect of solvent medium on the grating yield was higher in dimethylformamide (DMF) and methanol mixtures, when compared with DMF or methanol. Chelating fabrics was synthesized by subsequent amination of grafted fabric with ethylene diamine (EDA) and phenylhydrazine (PH). The conversion yield reached maximum value at about 90% for 80% PP‐g‐AN‐IA fabrics at 90°C. At same amination conditions, the conversion yield is higher when PP‐g‐AN‐IA fabrics react with EDA compared with PH. FT‐IR data indicate that amine groups were introduced onto PP‐g‐AN‐IA fabric through amide linkage between grafted AN or IA and EDA or PH. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

A realistic comparison of biaxial performance of nylon 6,6 and nylon 6 fabrics used in passive restraints—airbags

Nylon has been the material of choice for airbag construction because of its specific strength and dimensional stability during deployment. Of the nylons, nylon 6,6 has been widely used in airbag construction. In this article, we attempted to compare the performance of several commercial nylon 6,6 and nylon 6 fabrics offered, for use, to the auto industry. The performance of four traditional nylon 6,6 fabrics are compared with identical fabrics made from nylon 6 fibers. We used a test procedure championed by Chrysler but was developed in our laboratory called the blister-inflation. This test mimics the biaxial deformation of airbag fabric in a manner similar to the deformation of airbag fabric during actual deployment. Several other engineering properties of interest in airbag application are also addressed in this article for comparison purposes. © 1996 John Wiley & Sons, Inc.     

Electrical properties and EMI shielding characteristics of polypyrrole–nylon 6 composite fabrics

Polypyrrole (PPy) was polymerized both chemically and electrochemically in sequence on nylon 6 woven fabrics, giving rise to polypyrrole–nylon 6 composite fabrics (PPy–N) with a high electric conductivity. The stability of the composite prepared by electrochemical polymerization (ECP) on chemical oxidative polymerization (COP) fabric was better than that of the composite prepared solely by the COP process, since the AQSA dopant was able to strongly interact with the PPy main chain and had a large molecular structure. The temperature dependence of the conductivity of the composites was verified over four heating and cooling cycles. The change in conductivity over these four repeated heating and cooling cycles was affected by the interaction between the thermal stability of the dopant and the rearrangement of the PPy main chain. The electromagnetic interference shielding efficiency (EMI SE) values were in the range 5–40 dB and depended on the conductivity and the layer array sequence of the conductive fabric. The composites with a high conductivity represented reflection‐dominant EMI shielding characteristics, which are typical of the EMI shielding characteristics of metals. However, composites with low conductivity showed absorption‐dominant EMI shielding characteristics. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1969–1974, 2003     

Alteration of the mechanical and thermal properties of nylon 6/nylon 6,6 blends by nanoclay

Nylon 6 [N(6)], nylon 6,6 [N(6,6)], and their blends at different clay loadings were prepared. The mix was melted and injected into strip‐shaped samples. Mechanical and thermal analyses were performed to investigate the effect of blending and the incorporated clay on the mechanical and thermal properties. Enhancements in the Young's modulus and hardness were obtained for all of the nanocomposites, with a 55% increase in Young's modulus after the addition of 6 wt % nanoclay, although the improvement in tensile strength depended on the blend ratio, with greatest effects on the 50% N(6)/50% N(6,6) blend with increases of 44 and 59% for 2 and 4% clay loadings, respectively. Thermogravimetric analysis showed an enhancement in the thermal properties in the 50% N(6)/50% N(6,6) blend at 2% clay loading, and the blend exhibited ductile behavior at this loading. Increases in the crystallization peak temperatures of 10–15° in N(6,6) and the two blends 30% N(6)/70% N(6,6) and 50% N(6)/50% N(6,6) were observed after the addition of the clay. The nanoclay enhanced the γ‐/β‐form crystals in N(6) and N(6,6) neat polymers and also in the blends. Fourier transform infrared spectroscopy FT‐IR revealed the formation of hydrogen bonding and the possible formation of ionic bonds between the polymers and the nanoclay, which resulted in enhancements in the mechanical properties of the blends. The distribution of the nanoclay in the blend was well dispersed, as shown by X‐ray diffraction analysis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Influence of non-ionic surfactant on the stability of styrene—acrylonitrile copolymer latices

Styrene–acrylonitrile copolymer latices were prepared by emulsion polymerisation using sodium lauryl sulphate as emulsifier and potassium persulphate as initiator. The effect of polyoxyethylene nonyl phenyl ether on the stability of these copolymer latices has been investigated using magnesium chloride as a flocculating agent by measuring the rates of flocculation in the presence of various concentrations of surfactant. The values of the critical coagulation concentration (c.c.c.) were found to increase with increasing surfactant concentration for all latices. The rates of increase in c.c.c. with increasing surfactant concentrations were found to increase uniformly with increase in the content of acrylonitrile. The electrophoretic behaviour of these latices in the presence of surfactant has also been investigated. The values of mobilities at c.c.c. were found to decrease with increasein concentration of surfactant.     

Synthesis of nylon 6-g-poly(ethylene glycol) copolymer and its compatibilizing effect in nylon 6/poly(ethylene glycol) blends

Summary A graft copolymer of poly(ethylene glycol) onto nylon 6 was prepared by two-step reactions; poly(ethylene glycol) (PEG) was chlorinated with thionyl chloride in carbon tetrachloride and the chlorinated PEG was then grafted onto nylon 6 by reacting each other with triethylamine and tin chloride in o-chlorophenol. Blends were also prepared from the graft copolymer with nylon 6 or PEG. The thermal properties and crystalline structure of the graft copolymer and the blends were studied using differential scanning calorimeter and X-ray diffractometer. It was found that the grafting of PEG onto nylon 6 changed the crystal structure of nylon 6. It was observed that compatibilization of the nylon 6/PEG blend of 50/50 composition by weight was achieved in the presence of the graft copolymer.