Improving the flame retardant and antibacterial performance of polyester/cotton blend fabrics with organic-inorganic hybrid coating

Construction of composite self-assembly coating based on chitosan for enhancing the flame-retardant and antibacterial performances of cotton fabric

In this work, the step-by-step dip-coating (SBS) method was used to effectively improve the drawback of LBL by reducing the construction of a multilayer polyelectrolyte. Bio-based flame retardants, phytic acid (PA), and chitosan (CS) were further self-assembly on the surface of cotton fabric treated by epichlorohydrin-modified aramid nanofibers (AEP), ionic liquid (IL), and Cu ion. The pure cotton fabric was immersed in each dipping liquid only once, improving fire safety and antibacterial performance. The treated cotton self-extinguished with a 59 mm char length in the vertical flammability test, and the limiting oxygen index (LOI) value increased from 18.5 % to 38.5 %. The result of the cone calorimeter test (CCT) revealed that the fire hazard of flame-retardant cotton noteworthy declined (e.g., ~44.1 % and 55.4 % decline in peak heat release rate (pHRR) and total heat release rate (THR)). Conspicuously, the treated cotton exhibited a remarkably inhibiting effect on E. coli and S. aureus activity. The cotton fabric after flame-retardant finishing exhibited excellent fire safety and antibacterial performance.

Eco-friendly multifunctional coating for polyester-cotton blended fabrics with superior flame retardancy and antibacterial properties

Since the fire hazards of polyester-cotton blended (PTCO) fabrics and the hidden dangers of bacterial infection concerns caused by the contained cotton fiber, the design of flame retardant and antibacterial PTCO fabrics has received considerable attention. In this work, flame-retardant PTCO fabrics with satisfactory antibacterial properties were fabricated via a convenient and eco-friendly impregnation treatment involving guanidine phosphate (GP) and polyethylenimine (PEI). The prepared PTCO fabrics demonstrated excellent flame retardancy with a high limiting oxygen index value of 30.5 % and self-extinguishing capability, the damaged length was only 34 mm in the vertical flammability test. Furthermore, the peak heat release rate and the total heat release of coated PTCO fabrics were reduced significantly by 49 % and 38 %, respectively, indicating a substantial enhancement in fire safety. According to the analysis of the char residues and volatiles, GP presented great catalytic carbonization property, and PEI assisted the formation of the dense and stable carbon layer. The stable carbon layer effectively restricted mass and oxygen transfer between the PTCO fabrics and the environment. In addition, the introduction of PEI also produced more nonflammable gases to enhance the flame retardancy of the PTCO fabrics. Importantly, the GP/PEI coating barely deteriorate the physical and mechanical properties of the PTCO fabrics. The antibacterial rate of the GP/PEI-coated PTCO fabrics against Escherichia coli and Staphylococcus aureus was 99.99 %, similar to that of GP-coated fabrics, indicating the efficacy antibacterial properties of GP, and the addition of PEI did not compromise the antibacterial properties of GP. This work offers an efficient and simple approach to producing multifunctional PTCO fabrics with excellent flame retardancy and antibacterial properties, which are hopeful to expand the promising application of PTCO fabrics.

A P/N flame retardant for polyester-cotton fabrics: Flame retardancy, mechanical properties and antibacterial property

A phosphorus‑nitrogen synergistic flame retardant (named POI) was obtained by the chemical reaction between phenylphosphonic acid (PPOA) and polyethyleneimine (PEI), and used to give the flame retardancy of PTCO. The effects of PPOA and POI on various properties of PTCO were investigated. PPOA obviously improved the flame retardancy of PTCO/PPOA, while the breaking force of PTCO/PPOA was greatly reduced. However, the introduction of PEI made the surface of fabrics smoother. PTCO/POI had better flame retardancy than PTCO/PPOA did, and the limiting oxygen index value of PTCO/POI reached to 29.8 %. POI had a good effect on reducing the Rmax of both cotton and polyester components. The phosphoric acid groups in POI can promote the dehydration and carbonization reactions of PTCO, which protects the inner fabrics, and POI can release incombustible gases such as NH3 and N2 during burning, which can dilute the oxygen concentration. The flame-retardant mechanism of PTCO/POI was mainly the condensed phase. At the same time, there were no changes in whiteness and mechanical properties compared with those of PTCO, and it also had antibacterial property. This work provides a simple and effective method to prepare flame-retardant and antibacterial PTCO.

Halogen-Free Waterborne Polymeric Hybrid Coatings for Improved Fire Retardancy of Textiles

Wildfires are becoming more intense and more frequent, ravaging the habitations and ecosystems in their path. One solution to reducing the risk of damage to buildings and other structures during a fire event is the use of fire-retardant coatings that can stop or slow down the spread of flames, especially for textile materials. The present study focuses on the preparation and application of halogen-free boron/bentonite-based polymeric fire-retardant (FR) hybrid coating formulations for fabrics such as cotton (CO) and polyester (PE) fibers. For the preparation of FR composites, two types of boron derivatives, disodium octaborate and zinc borate, were used in combination with sodium bentonite. A styrene-acrylic copolymer was specifically synthesized and used as a coating binder for FR components to apply on fabrics. The properties of the synthesized copolymer and FR composites were characterized with a particle size analysis, FTIR spectroscopy, a dynamic mechanical thermal analysis (DMTA), and rheological measurements. The obtained hybrid composites based on styrene-acrylic copolymers and two different inorganic fillers were applied on cotton (CO) and polyester (PE) fabrics with a screen-printing technique, and the flame retardancy performance of the finished textile samples was investigated by means of flame spread and limit oxygen index (LOI) tests. The findings showed that the FR-composite-coated fabrics had higher LOI values and much decreased flame spread rates in comparison with uncoated ones. Among the boron derivatives, the composites prepared with disodium octaborate (FR-A) had much more pronounced LOI values and decreased flame spread behavior in comparison with the composite with zinc borate (FR-B). When compared to a commercial product, the FR-A composite, in conjunction with the specially synthesized polymer, demonstrated commendable fire retardancy performance and emerged as a promising candidate for a halogen-free waterborne fire-retardant coating for fabrics.

Environmental benign foam finishing with a hyperbranched polyphosphonate flame retardant for polyethylene terephthalate fabric

It is still a big challenge for textile industry in improving fire resistance and reducing melt dripping with minimal loss on the physical properties of polyethylene terephthalate (PET) fabrics. In this work, a highly-effective hyperbranched flame retardant (DT) was first synthesized by ester exchange without using any organic solvent. Then, the DT foam was prepared and blade coated on PET fabric to improve the fire performance. The prepared PET fabric with only 2.7% weight gain of DT was self-extinguished and did not produce any molten dripping during the vertical flammable test. The peak heat release rate and total heat release of the PET fabric sample with 19.4% DT were decreased by 42.0% and 57.1%, respectively compared with that of the control PET. Besides, the as-prepared PET fabric sample showed better physical properties such as breaking strength, vapor permeability, air permeability, antistatic property, and softness than the control PET fabric sample. The DT foam finishing process did not involve any organic solvent and consumed less water and energy compared with conventional fabric treatments. It is expected that this work provides a facile and eco-friendly strategy for fabricating flame retardant PET fabric with excellent comprehensive performances.

Fabrication of P/N/B-Based Intumescent Flame-Retardant Coating for Polyester/Cotton Blend Fabric

Polyester/cotton (T/C) blend fabrics are highly flammable due to the particular "scaffolding effect". In this work, an intumescent flame retardant (IFR) agent containing P, N, and B was designed and synthesized using bio-based phytic acid, pentaerythritol, boric acid, and urea. The IFR compounds were deposited onto a T/C blend fabric by the surface-coating route. The chemical structure of IFR agent and its potential cross-linking reactions with T/C fibers were characterized. The morphology, thermal stability, heat-release ability, flame retardancy, and mechanism of coated T/C blend fabrics were explored. The self-extinguishing action was observed for the coated T/C blend fabric with a weight gain of 13.7%; the limiting oxygen index (LOI) value increased to 27.1% versus 16.9% for a pristine one. Furthermore, the intumescent flame retardant (IFR) coating imparted T/C blend fabrics with high thermal stability and significantly suppressed heat release by nearly 50%. The char residue analyses on morphology and element content confirmed the intumescent FR action for coated T/C blend fabrics. The prepared IFR coating has great potential to serve as an eco-friendly approach for improving the flame retardancy of T/C blend textiles.