Flame-retardant finishing in cotton fabrics using zinc oxide co-catalyst

Impact of vitamin E in improving comfort, moisture management and mechanical properties of flame-retardant treated cotton fabric

The aim of this study is to analyze the use of vitamin E to enhance fabric's hand feel, moisture management and fabric strength which are affected due to flame retardant finish. Flame retardant treated fabrics typically become stiff, but the addition of Vitamin E along with emulsifier and binding agent through a vertical padding mangle by two times dipping and nipping results a soft fabric without impairing the flammability properties as determined by 45-degree flammability test. The samples were characterized by FTIR spectra, SEM images, and water contact angle. A new characteristics band is appeared at 1455 cm-1 for skeletal vibration of phenyl ring system of alpha tocopherol for Vitamin E measured by Fourier transform infrared spectroscopy (FTIR) that proves the effective attachment of vitamin E with fabric. Hydrophilicity of vitamin E containing sample is discovered after showing 37.629° as a water contact angle at optical tensiometer (Attension theta lite). Additionally, fabric comfort properties, moisture management properties, and mechanical properties were measured by fabric touch tester (FTT), moisture management tester (MMT) machine and tensile strength tester respectively that demonstrate significant affirmative change in almost all indexes of FTT, 43.5 % increase of overall moisture management capacity by MMT and 23 % increase of tear strength by tensile strength tester due to use of vitamin E that effectively compensate lower strength, poor fabric comfort, and low moisture management capability of flame retardant treated fabric.

Facile synthesis of a high efficiency and durability L-citrulline flame retardant for cotton

A novel flame retardant (FR), the ammonium salt of citrulline-penta (methylphosphonic acid) (ACPMPA) based on L-citrulline was synthesized, and its structure was characterized by ¹³C, ¹H, and ³¹P nuclear magnetic resonance (NMR) spectroscopy. The ACPMPA flame retardant molecule contains five ammonium salts of phosphorus acid and one ammonium salt of carboxylic acid, which allowed the covalent attachment of ACPMPA onto cellulose via -P=O(-O-C) and -COOC bonds. The results showed that the treated cotton fabrics had very high flame retardance and excellent durability. The limiting oxygen index (LOI) of cotton fabric treated with 35%-ACPMPA reached 49.2% and only decreased to 34.2% after 50 laundry cycles. Vertical flame tests also demonstrated that the treated cotton fabric acquired good flame retardance. The thermogravimetry (TG) and TG-IR results showed that the treated cotton left more residues and released almost no flammable volatiles at high temperatures. The cone calorimetry results showed that the treated cotton released less heat than pure cotton. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results demonstrated that the structure of the treated cotton fabric was almost unchanged, and no free formaldehyde was detected, indicating that the treated cotton was safe. The treated cotton fabric also retained good tensile strength and whiteness.

Surface Functionalization of Cotton and PC Fabrics Using SiO2 and ZnO Nanoparticles for Durable Flame Retardant Properties

In recent years, the use of functional textiles has attained attention due to their advantageous health and safety issues. Therefore, this study investigated the flame retardancy on cotton (COT) and polyester-cotton (PC) fabrics treated with different concentrations of silica and zinc nanoparticles through a sol-gel finishing technique. FTIR, SEM, and TGA were conducted for the characterization of coated fabric samples. The FTIR and SEM of Pristine and Treated Cotton and PC fabrics illustrated that the SiO2 (silica dioxide) and ZnO (Zinc oxide) nanoparticles were homogeneously attached to the fiber surface, which contributed to the enhancement of the thermal stability. The starting thermal degradation improved from 320 to 350 °C and maximum degradation was observed from 400 to 428 °C for the COT-2 cotton substrate. However, the initial thermal degradation improved from 310 to 319 °C and the highest degradation from 500 to 524 °C for the PC substrate PC-2. The outcomes revealed that the silica has a greater influence on the thermal properties of COT and PC fabric samples. Additionally, the tensile strength and flexural rigidity of the treated samples were improved with an insignificant decrease in air permeability.

ZnO Microstructures as Flame-Retardant Coatings on Cotton Fabrics

In this study, we report a unique strategy that utilizes ZnO and ZnS microparticles and rods as fire-retardant materials when coated onto cotton fabrics. ZnO and ZnO/ZnS microparticles or rods were grown or adsorbed to the surface of cotton fibers. Properties such as heat release rate, total smoke release, and mass loss rate of the materials were tested using a cone calorimeter. ZnO and ZnO/ZnS rods were able to reduce the heat release rate and total smoke release from 118 kW/m² and 18.3 m²/m² to about 70.0 kW/m² and 6.00 m²/m², respectively. The maximum average rate of heat emission and fire growth rate index, which is used to evaluate the fire spread rate, the size of the fire, and the propensity of fire development, were improved with these coatings and indicate that there are potential applications of these materials as fire retardants.