Brian Condon

Flame retardant behavior of polyelectrolyte-clay thin film assemblies on cotton fabric.

Cotton fabric was treated with flame-retardant coatings composed of branched polyethylenimine (BPEI) and sodium montmorillonite (MMT) clay, prepared via layer-by-layer (LbL) assembly. Four coating recipes were created by exposing fabric to aqueous solutions of BPEI (pH 7 or 10) and MMT (0.2 or 1 wt %). BPEI pH 10 produces the thickest films, while 1 wt % MMT gives the highest clay loading. Each coating recipe was evaluated at 5 and 20 bilayers. Thermogravimetric analysis showed that coated fabrics left as much as 13% char after heating to 500 degrees C, nearly 2 orders of magnitude more than uncoated fabric, with less than 4 wt % coming from the coating itself. These coatings also reduced afterglow time in vertical flame tests. Postburn residues of coated fabrics were examined with SEM and revealed that the weave structure and fiber shape in all coated fabrics were preserved. The BPEI pH 7/1 wt % MMT recipe was most effective. Microcombustion calorimeter testing showed that all coated fabrics reduced the total heat release and heat release capacity of the fabric. Fiber count and strength of uncoated and coated fabric are similar. These results demonstrate that LbL assembly is a relatively simple method for imparting flame-retardant behavior to cotton fabric. This work lays the foundation for using these types of thin film assemblies to make a variety of complex substrates (foam, fabrics, etc.) flame resistant.

Intumescent All‐Polymer Multilayer Nanocoating Capable of Extinguishing Flame on Fabric

According to the National Fire Protection Association (NFPA), there were an estimated 1.3 million fi res in the United States in 2009, which resulted in 3010 civilian deaths (one every 175 minutes), 17 050 injuries (one every 31 minutes), [ 1 ] and direct property loss estimated at

Modern Applications of Nanotechnology in Textiles

12.5 billion. There were more than 40 000 deaths worldwide from fi re in 2006 and it cost every country an average of 1% of their gross domestic product in property loss, medical services for burn victims, etc. [ 2 ] Firerelated issues continue to drive the development of materials that can reduce fi re risk to save lives and protect property, but any fl ame retardants used to reduce that fi re risk have to meet various safety standards to reduce the deleterious effect on the environment or human health. Textiles in particular require effective anti-fl ammable performance combined with minimal enviornmental impact because they are often washed and fl ame retardant additives can leach out of the fabric and into the environment. [ 3 , 4 ] There are numerous strategies used to make textile fi bers fl ame retardant: surface treatment, fi re-retardant additives or co-monomers in synthetic fi bers, nanocomposite technology, heat-resistant and inherently fi re-retardant fi bers, and fi ber blending. [ 5 ] More recently, layer-by-layer (LbL) assembly has been used as a surface treatment to impart fl ame resistance to cotton fabric by coating each individual fi ber with a claypolymer nanobrick wall. [ 6 ]

Effect of water pressure on absorbency of hydroentangled greige cotton non-woven fabrics

Nanotechnology (NT) deals with materials 1 to 100 nm in length. At the National Nanotechnology Initiative (NNI), NT is defined as the understanding, manipulation, and control of matter at the above-stated length, such that the physical, chemical, and biological properties of the materials (individual atoms, molecules, and bulk matter) can be engineered, synthesized, and altered to develop the next generation of improved materials, devices, structures, and systems. NT at the molecular level can be used to develop desired textile characteristics, such as high tensile strength, unique surface structure, soft hand, durability, water repellency, fire retardancy, antimicrobial properties, and the like. Indeed, advances in NT have created enormous opportunities and challenges for the textile industry, including the cotton industry. The focus of this paper is to summarize recent applications of NT as they relate to textile fibers, yarns, and fabrics.

Advent of Greige Cotton Non-Wovens Made using a Hydro- Entanglement Process

A greige (non-bleached) cotton lint was used to fabricate non-woven fabrics on a Fleissner MiniJet, using different water pressures for the fiber entanglements. The greige cotton and its hydroentangled non-woven fabrics were primarily tested for their hexane extracts (waxes) and water-soluble (sugars) contents using the AATCC TM97 Standard Extraction Test. Tests have shown that a water pressure of 125 Bar or higher almost totally removed the greige cotton’s inherent hydrophobic waxes and water-soluble sugars. This discovery is a significant milestone in the development of greige cotton-based non-wovens because it could change the greige cotton’s native hydrophobic character into a desirable hydrophilic character for many end-uses. In fact, the AATCC Test Method 79-2007 has confirmed that the greige cotton non-wovens fabricated with high water pressure of 125 Bar are absorbent, as indicated by the 1-second time or less it took for the water drop to completely diffuse onto the fabric surface.

Analysis of 2-Acetyl-1-Pyrroline in Rice by HSSE/GC/MS

Using greige (scour/bleach-less) cotton, non-woven fabrics have been successfully produced by adopting conventional fiber opening, cleaning and (modified) carding machines followed by cross-lapping, pre/light needling, and hydro-entanglement (HE) on modern commercial machinery and equipment. Using standard test methods and procedures, the fabrics were evaluated for their weight, thickness, burst strength, tensile and tear failures in both machine (MD) and cross (CD) directions, and absorbency. Dimensional characteristics of the fabrics were determined before and after an ordinary wash. Microscopic examinations of the fiber/fabric surfaces before and after various conditions/degrees of H-E were conducted. Results of these preliminary research investigations have shown that a run-of-the-mill greige cotton, processed on a conventional cotton cleaning and preparatory system, can indeed be efficiently processed on the downstream non-wovens production equipment. In addition, it has been shown that different processing conditions, especially the high-pressure (HP) hydraulic energy of the H-E system, have a considerable influence on properties of the fabrics produced. At the nominal fabric production rates deployed in the research trials, pressure greater than 100 bar (at the system’s two HP jet-heads) produces a fabric that is partially hydrophilic: a desirable attribute for many end-use applications of cotton non-wovens. Based on a previous in-house investigation, it seems that the HP (hydraulic energy) at certain levels partly removes some of the greige cotton fiber’s natural hydrophobic defensive membrane (outer-surface barrier) of heavy hydrocarbons, such as waxes, pectins, etc., thus making the fiber/fabric partially hydrophilic. Further, it has been observed that the high water pressures (HP), under otherwise similar processing conditions, tend to fracture some cotton fibers into tiny fibrils, as evidenced by scanning electron microscopy (SEM) images. These ruptured fibers, by way of exposing their inner (hydrophilic) walls, could also partly contribute to the fabric’s improved absorbency at elevated hydraulic energy levels. Furthermore, a rather unique fabric structure, comprising certain well-defined fibrous “strands and channels,” observed at elevated (HP) pressures is also deemed to partly contribute to the greige fabric’s improved wickability.

Decreased immunoglobulin E (IgE) binding to cashew allergens following sodium sulfite treatment and heating.

ABSTRACT An extremely sensitive method for the analysis of 2-acetyl-1-pyrroline (2AP) in rice, employing stir bar sorptive extraction (Twister) was studied. The Twister stir bar is placed in the headspace of a 20-mL vial containing 1 g of rice kernels, 7.5 mL of 0.1M KOH, and 2.2 g of NaCl, along with a second Teflon-coated stir bar for mixing. Analytes are adsorbed onto the Twister for 4 hr at 40°C and then desorbed at 270°C into a GC column while cryofocusing at –80°C. The headspace sorptive extraction (HSSE) method was able to detect 10%) was not as good as the GC/FID method (≈6%). Using HSSE, 2AP was observed in all samples generally considered to be aromatic and was not observed in any nonaromatic samples. Additionally, a modified method for the synthesis of 2-acetyl-1-pyrroline was studied and the presence of a tautomer of 2-acetyl-1-pyrroline was confirmed.

Processing and Characterization of Flame Retardant Cotton Blend Nonwovens for Soft Furnishings to Meet Federal Flammability Standards

Cashew nut and other nut allergies can result in serious and sometimes life-threatening reactions. Linear and conformational epitopes within food allergens are important for immunoglobulin E (IgE) binding. Methods that disrupt allergen structure can lower IgE binding and lessen the likelihood of food allergy reactions. Previous structural and biochemical data have indicated that 2S albumins from tree nuts and peanuts are potent allergens, and that their structures are sensitive to strong reducing agents such as dithiothreitol. This study demonstrates that the generally regarded as safe (GRAS) compound sodium sulfite effectively disrupted the structure of the cashew 2S albumin, Ana o 3, in a temperature-dependent manner. This study also showed that sulfite is effective at disrupting the disulfide bond within the cashew legumin, Ana o 2. Immunoblotting and ELISA demonstrated that the binding of cashew proteins by rabbit IgG or IgE from cashew-allergic patients was markedly lowered following treatment with sodium sulfite and heating. The results indicate that incorporation of sodium sulfite, or other food grade reagents with similar redox potential, may be useful processing methods to lower or eliminate IgE binding to food allergens.

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

Effective from July 1, 2007 it is mandatory that all mattress sets meet the federal flammability standard CFR 1633. It is necessary to impart flame resistance that would provide at least 30 min for occupants to escape fire. Changes in the flammability laws are expected on other soft furnishings of sleep products like comforters and pillows. Generally these products are often the first to be engulfed by the fire. Currently many inherently flame retardant (FR) fibers and chemicals are available in the market. We have developed barrier fabrics with FR properties by incorporating these fibers in blends with cotton that either meet or exceed the standard. Results from this ongoing research are discussed in this article.

Enhanced thermal and combustion resistance of cotton linked to natural inorganic salt components

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 5–21 wt% add-ons had high LOI values of 30–40 vol%, while fabrics treated with CN-1 at 5–19 wt% add-ons had low to high LOI value of 20–36 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.