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.     

A novel durable photoactive nylon fabric using electrospun nanofibers containing nanophotocatalysts

This study explores new technique to produce a nylon fabric with durable self-cleaning property. Nylon fabric (polyamide 66) has been coated with electrospun nylon nanofibers containing nanoparticles (TiO₂, SrTiO₃ and ZnO). The coated samples were heat-setted in order to fixation of the nanofibers on surface of the nylon fabric. The self-cleaning property is tested by discoloration of the stained fabric with Direct Green 6 under UV irradiation. The scanning electron microscopy (SEM) images and X-ray diffraction (XRD) patterns were employed to characterize the treated nylon fabrics. The treated fabrics showed excellent photoactivity toward dye degradation. Moreover, the photoactivity of the treated fabrics stable after repeat laundering.     

Preparation and properties of microencapsulated octadecane with waterborne polyurethane

A series of microencapsulated blends of waterborne polyurethane (WBPU) as a matrix polymer and phase change material octadecane as a domain material were prepared in the presence of emulsifier. Nylon fabrics were coated with the coating materials formulated from microencapsulated blends, thickener, and hardener. The morphology and thermal behaviors of microencapsulated octadecane and WBPU/octadecane‐coated nylon fabrics were investigated using SEM, DSC, and KES‐F7. The size of octadecane microspheres increased with increasing octadecane contents. However, the size of microcsphere (1–6 μm) decreased with increasing emulsifier contents. ΔH_fusion, ΔH_{crystallization}, and their filling efficiencies of octadecane in film samples were found to increase with increasing microencapsulated blends, thickener, and hardener contents. Especially, thickener and hardener could function in trapping microencapsulated octadecane. Thermal characteristic Q_max (J/cm² s) values of WBPU/octadecane‐coated nylon fabrics are much higher than those of the control nylon fabric and WBPU‐coated nylon fabrics, indicating that the nylon fabrics coated with WBPU/octadecane blends have cooler touch sensation compared with nylon fabrics and WBPU‐coated nylon fabrics. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1596–1604, 2005     

Characterization of the draping behavior of jute woven fabrics for applications of natural‐fiber/epoxy composites

In this study, we investigated the draping behavior of jute woven fabric to study the feasibility of using natural fabrics in place of synthetic glass‐fiber fabrics. Draping behavior describes the in‐mold deformation of fabrics, which is vital for the end appearance and performance of polymer composites. The draping coefficient was determined with a common drapemeter for fabrics with densities of 228–765 g/m² and thread counts under different humidity and static dynamic conditions. The results were compared to glass‐fiber fabrics with close areal densities. Characterization of the jute fabrics was carried out to fill the knowledge gap about natural‐fiber fabrics and to ease their modeling. The tensile and bending stiffnesses and the shear coupling were also characterized for a plain woven jute fabric with a tensile machine, Shirley bending tester, and picture frame, respectively. As a case study, the draping and resin‐transfer molding of the jute fabric over a complex asymmetric form was performed to measure the geometrical conformance. The adoption of natural fibers as a substitute for synthetic fibers, where the strength requirements are satisfied, would thus require no special considerations for tool design or common practices. However, the use of natural fibers would lead to weight and cost reductions. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1453–1465, 2013     

Application of shear thickening fluid in ultra high molecular weight polyethylene fabric

An advanced stab‐resistant material composed of shear thickening fluid (STF) and ultra high molecular weight polyethylene (UHMWPE) fabric was investigated. STF was prepared by dispersing nanosilica (SiO₂) into ethylene glycol. The shear thickening behavior of STF with the increase of the shear rate was observed by PhysicaMCR301. STF/UHMWPE composite fabric was synthesized by impregnating UHMWPE fabric in STF dilution. Stab resistant experiment was conducted on a self‐made stab test machine with knife and spike as stab tool. The results demonstrate that the stab resistant property of the UHMWPE fabric is greatly improved by impregnating STF. The stab resistant property is greatly increased with the increase of mass fraction of silica in STF. Especially, when the mass fraction of SiO₂ in STF is 38%, the stab resistance force and energy absorption of STF/UHMWPE are optimal for knife and spike threats. With the same stab resistant properties, the flexibility of UHMWPE fabric impregnated with STF is higher than that of the neat fabric. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

高强织物防穿刺作用特征与机制分析

高强织物广泛应用于防刺领域。为了研究高强织物防穿刺作用特征与机制,自行设计了可调重量与高度的自由落体式实验装置,选用单刃刀、三棱刀、锥对芳纶与超高分子量聚乙烯纤维织物进行刺入实验,考察了冲击能量、刀具截面形状、刺入角度对穿刺作用的影响,研究了织物纤维种类、结构、叠层密度与织物防穿刺作用的关系,分析了刀具对高强织物穿刺作用的机制。结果表明,穿刺效果主要由能量的大小决定,受其速度、质量的组成比例影响较小;刀具的截面形状决定其穿刺织物时的剪切破坏与排挤破坏的组成形式;防刺材料的结构是影响其防穿刺性能的关键因素,同种材料不同结构织物抗排挤能力越强。织物对锥和单刃刀的防穿刺能力越强。对三棱刀的防穿刺能力变化不明显。     

Electrospun ultrathin nylon fibers for protective applications

Electrospun nylon 6 fiber mats were deposited on woven 50/50 nylon/cotton fabric with the motive of making them into protective material against submicron‐level aerosol chemical and biological threats. Polymer solution concentration, electrospinning voltage, and deposition areal densities were varied to establish the relationships of processing‐structure‐filtration efficiency of electrospun fiber mats. A high barrier efficiency of greater than 99.5% was achieved on electrospun fiber mats without sacrificing air permeability and pressure drop. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Chemical treatments for improving adhesion between electrospun nanofibers and fabrics

Nanofiber‐coated fabrics have potential uses in filters and protective clothing. One major challenge is to ensure good adhesion of nanofibers to the fabrics achieving satisfactory durability against abrasion for practical use. This work is aimed to study adhesion mechanisms and their improvement between nanofibers and textile substrates; to achieve this goal cotton fabrics were treated with an alkali solution, while nylon fabrics were treated with ethanol. Adhesion of polyamide‐6 electrospun nanofiber layer to fabrics was evaluated by means of a peeling test. Treated fabrics showed improved bonding towards nanofibers: adhesion energy was ～0.58 J m^?2 for both untreated fabrics, and after treatments increased to 0.93 and 0.86 J m^?2 for cotton and nylon ones, respectively. Optical observations revealed that nanofibers deposited on fabrics are mainly linked to external protruding fibers (i.e., fabric hairiness). Therefore, surface hairiness seems to be the critical factor limiting adhesion. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39766.     

Electrically and thermally conductive nylon 6,6

Increasing the thermal and electrical conductivity of typically insulating polymers, such as nylon 6,6, opens new markets. A thermally conductive resin can be used for heat sink applications. An electrically conductive resin can be used in static dissipative and Electromagnetic Interference/Radio Frequency Interference shielding applications. This research focused on adding various carbon based conductive fillers and a chopped glass fiber to nylon 6,6. These materials were extruded and injection molded into test specimens. Tensile tests as well as in-plane electrical resistivity, in-plane thermal conductivity, and through-plane thermal conductivity tests were conducted. One successful formulation consisted of 10% 3.2 mm chopped E-glass fiber/15% Thermocarb (high quality synthetic powdered graphite)/5% carbon black/70% nylon 6,6 (all % in wt%). For this formulation, the in-plane electrical resistivity was reduced from 10¹⁵ ohm-cm (neat nylon 6,6) to 15 ohm-cm. The through-plane thermal conductivity increased from 0.25 W/mK (neat nylon 6,6) to 0.7 W/mK. The tensile elongation at failure was 1.4%.     

Nylon 6,6 copolyamides of bis(2-carboxyethyl) methylphosphine oxide

Copolyamides of nylon 6,6 with bis(2-carboxyethyl)methylphosphine oxide (CEMPO) were prepared by melt polycondensation of nylon 6,6 salt with CEMPO and hexamethylene diamine. The effect of CEMPO upon melting point, moisture regain, boiling water shrinkage, water wicking, tensile properties, thermal stability, static dissipation, and flammability of nylon 6,6 fibers and fabrics was determined. The fiber properties were greatly affected by the high water absorption and solubility characteristics of the phosphine oxide linkage. However, crystallinity and orientation were not greatly disturbed by up to 30–40M% CEMPO substitution in nylon 6,6. The copolyamides were of improved flame resistance compared to nylon 6,6 and were also found to give improved flame resistance in blends of the copolymer with various commercial plastics. In addition, CEMPO and the corresponding diamine, bis(3-aminopropyl)methylphosphine oxide were used to prepare a series of cycloaliphatic and aromatic ring-containing polyamides, but problems were encountered with moisture sensitivity and low melting points with some of these polymers.     

Polymerization compounding composites of nylon‐6,6/short glass fiber

Nylon‐6,6 was grafted onto the surface of short glass fibers through the sequential reaction of adipoyl chloride and hexamethylenediamine onto the fiber surface. Grafted and unsized short glass fibers (USGF) were used to prepare composites with nylon‐6,6 via melt blending. The glass fibers were found to act as nucleating agents for the nylon‐6,6 matrix. Grafted glass fiber composites have higher crystallization temperatures than USGF composites, indicating that grafted nylon‐6,6 molecules further increase crystallization rate of composites. Grafted glass fiber composites were also found to have higher tensile strength, tensile modulus, dynamic storage modulus, and melt viscosity than USGF composites. Property enhancement is attributed to improved wetting and interactions between the nylon‐6,6 matrix and the modified surface of glass fibers, which is supported by scanning electron microscopy (SEM) analysis. The glass transition (tan δ) temperatures extracted from dynamic mechanical analysis (DMA) are found to be unchanged for USGF, while in the case of grafted glass fiber, tan δ increases with increasing glass fiber contents. Moreover, the peak values (i.e., intensity) of tan δ are slightly lower for grafted glass fiber composites than for USGF composites, further indicating improved interactions between the grafted glass fibers and nylon‐6,6 matrix. The Halpin‐Tsai and modified Kelly‐Tyson models were used to predict the tensile modulus and tensile strength, respectively.     

Coating of jute with natural rubber

Jute fabric was coated with natural rubber to develop double‐texture rubberized waterproof fabric and fabric‐reinforced rubber sheeting for hospitals. The vulcanization of such natural‐rubber‐coated flexible composites at 120°C for 3 h produced optimum effects. The jute/natural‐rubber composite was much superior to a conventional polyester/natural‐rubber composite for producing such double‐texture rubberized fabric with respect to the fabric‐to‐natural‐rubber adhesion, breaking strength, tear strength, abrasion resistance, puncture resistance, and biodegradability. For fabric‐reinforced rubberized sheeting, the jute/natural‐rubber composite was superior to a conventionally used cotton/natural‐rubber composite with respect to the fabric‐to‐natural‐rubber adhesion, breaking strength, tear strength, and abrasion resistance. However, for both applications, the jute‐based products were commonly found to be less extensible, heavier, and thicker. Unsaturation in the lignin fraction of jute established a chemical linkage with the unsaturation of natural rubber via sulfur at the jute/natural‐rubber interface. An examination of the surface morphology of uncoated and coated jute fabrics by scanning electron microscopy revealed a good degree of deposition and filling even in the intercellular regions of jute by a cohesive mass of natural rubber, which remained unseparated from the fiber, when mechanical force was applied. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 484–489, 2005     

Stab resisting behavior of polymeric resin reinforced p‐aramid fabrics

The stab resistant performance of p‐aramid fabrics reinforced with thermoplastic LDPE resin and thermoset epoxy resin was investigated by quasi‐static or drop tower stab resistance testing, and the stab resistance behavior against different shapes of impactors was also evaluated. The destruction behavior of LDPE reinforced p‐aramid fabrics against a knife impactor shows three distinctive steps; the initial penetration step with maximum strength, the cutting step by knife edge, and the destruction step of accumulated fiber bundles. On the other hand, epoxy resin reinforced p‐aramid fabrics against a knife impactor exhibit just two steps without the accumulation of fiber bundles. In the case of a spike impactor, the maximum stab resistant strength is observed from the initial penetration step; however, the stab resistant strength after initial penetration drastically decreased regardless of the reinforcing resins. It is also found that, even if the LDPE reinforced fabrics are multilayered, the performance improvement by resin reinforcement is observed only from the initial penetration step and the stab resistant strengths of the cutting step and the fiber accumulation step are not improved. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

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.     

结构参数对尼丝纺织物性能的影响

探讨了织物组织、纱线细度、织物紧度对尼丝纺织物的透湿性、抗紫外线性和折皱回复性的影响。结果表明,缎纹组织的尼丝纺织物的透气性、抗紫外线性和折皱回复性好于斜纹和平纹组织的织物;随着纱线细度的增大,尼丝纺织物的抗紫外线性和折皱回复性越好,透湿性越差;随着织物紧度的增加,尼丝纺织物的透湿性先变好后变差,抗紫外线性变好,折皱回复性变差。     

Ultrasound‐assisted coating of nylon 6,6 with silver nanoparticles and its antibacterial activity

A silver/nylon 6,6 nanocomposite containing 1 wt % metallic silver has been produced from an aqueous solution of silver nitrate in the presence of ammonia and ethylene glycol by an ultrasound‐assisted reduction method. The structure and properties of nylon 6,6 coated with silver have been characterized with X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, energy‐dispersive X‐ray, X‐ray photoelectron spectroscopy, Raman spectroscopy, and diffused reflection spectroscopy measurements. The nanocrystals of pure silver, 50–100 nm in size, are finely dispersed on the polymer surface without damaging the nylon 6,6 structure. This silver–nylon nanocomposite is stable to many washing cycles and thus can be used as a master batch for the production of nylon yarn by melting and spinning processes. The fabric knitted from this yarn has shown excellent antimicrobial properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1423–1430, 2007     

Photoinduced grafting of vinyl benzyl trimethyl ammonium chloride on polyester nonwoven fabric with surfactant coating and its anion‐exchange properties

Vinyl benzyl trimethyl ammonium chloride (VBTAC) could be efficiently and stably grafted onto polyester fiber coated with a surfactant polyester (PET) by a photoirradiation‐induced graft polymerization with benzophenone as the photoinitiator without any cografting monomer required. The degree of VBTAC grafting could be controlled simply by the irradiation time and concentration of VBTAC in the monomer solution. The anion‐exchange capacity (AEC) of the PET‐g‐VBTAC fabrics increased with increasing degree of grafting up to 80 ± 5% and then leveled off. The maximum AEC of PET‐g‐VBTAC was 2.2 mequiv/g; this was similar to that of a commercial anion‐exchange resin (2.16 ± 0.04 mequiv/g) and much higher than those of nylon‐g‐VBTAC–2‐hydroxyethyl methacrylate fabrics (≤1.0 mequiv/g) prepared with a conventional cografting system. The grafted fabric was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy studies, and the sorption selectivity for anions and regeneration efficiency were estimated. The results suggest that the grafting system, in which VBTAC alone was grafted onto PET fiber coated with surfactant, was more practical and effective for the preparation of the VBTAC‐containing anion exchanger, and the resulting PET‐g‐VBTAC fabrics could be used as an effective anion exchanger. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41674.     

Improving the colour fastness of dyed nylon‐6 fabric by graft copolymerisation and curing of acrylic acid

The influence of grafting and grafting–curing of acrylic acid on the colour fastness of nylon‐6 fabric dyed with an acid dye of low wash fastness was investigated. The variables involved in grafting were initially optimised for pristine nylon‐6 fabric prior to grafting the same monomer onto the dyed fabrics. The highest graft yield achieved for the pristine and dyed nylon‐6 fabrics was 44 and 14% respectively. Grey scale testing and colorimetric analysis revealed that the highest colour fastness and the smallest drop in colour strength belonged to the dyed–grafted–cured nylon‐6 fabric. The colour components were measured, and the total colour difference of each sample after five washing cycles was computed. The specific colour difference showed that the implementation of either grafting or grafting–curing processes will alter the reference colour of the dyed fabric. The tensile strength of the grafted and grafted–cured fabrics was respectively 2.7 and 6.3% lower than that of dyed nylon‐6.     

Morphology and crystallization behavior of nylon 6‐clay/neat nylon 6 bicomponent nanocomposite fibers

Nylon 6‐clay hybrid/neat nylon 6, sheath/core bicomponent nanocomposite fibers containing 4 wt % of clay in sheath section, were melt spun at different take‐up speeds. Their molecular orientation and crystalline structure were compared to those of neat nylon 6 fibers. Moreover, the morphology of the bicomponent fibers and dispersion of clay within the fibers were analyzed using scanning electron microscopy and transmission electron microscopy (TEM), respectively. Birefringence measurements showed that the orientation development in sheath part was reasonably high while core part showed negligibly low birefringence. Results of differential scanning calorimetry showed that crystallinity of bicomponent fibers was lower than that of neat nylon 6 fibers. The peaks of γ‐crystalline form were observed in the wide‐angle X‐ray diffraction of bicomponent and neat nylon 6 fibers in the whole take‐up speed, while α‐crystalline form started to appear at high speeds in bicomponent fibers. TEM micrographs revealed that the clay platelets were individually and evenly dispersed in the nylon 6 matrix. The neat nylon 6 fibers had a smooth surface while striped pattern was observed on the surface of bicomponent fibers containing clay. This was speculated to be due to thermal shrinkage of the core part after solidification of the sheath part in the spin‐line. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39996.     

纬编双轴向多层衬纱织物增强复合材料的弯曲性能研究

本文主要对高性能纤维的纬编双轴向多层衬纱织物增强复合材料的弯曲性能进行研究分析.本文所用的增强纤维为玻璃纤维和高强聚乙烯纤维两种,增强织物包括玻璃纤维织物、高强聚乙烯纤维织物及玻璃纤维/聚乙烯纤维层间混合织物三种,基体为乙烯基酯树脂,文中着重对几种复合材料的弯曲性能进行测试和分析比较.分析结果表明,该类复合材料有很好的弯曲性能,含有玻璃纤维的横向弯曲破坏有其特点,玻璃纤维为脆性破坏,而聚乙烯纤维表现为屈曲破坏.