Flame retardant cotton fabrics with anti-UV properties based on tea polyphenol-melamine-phenylphosphonic acid

Bio-based phytic acid/amino acid complex coating for antimicrobial and flame-retardant cotton fabrics

Here, a novel multifunctional coating containing bio-based phytic acid (PA), L-glutamic acid (L-Glu), and trimesoyl chloride (TMC) is constructed by a simple soaking strategy, giving cotton fabrics excellent flame retardancy, washability, and antibacterial properties. The coating layer on the cotton surface was prepared via the electrostatic and hydrogen bonding between PA and L-Glu, accompanied by the interface polymerization between PA, L-Glu, and TMC. Among them, the limiting oxygen index value of the treated cotton fabrics (C2 and C2-TMC) was as high as 40 %. During the vertical flammability test, both C2 and C2-TMC cotton showed self-extinguished behavior with a short damaged length (≤50 mm). Remarkably, the LOI of C2-TMC sustained a high value (30 %) even after 300 laundering cycles, maintaining its self-extinguishing behavior in the vertical combustion test. Additionally, in the cone calorimetry test, peak heat release rate and total heat release of treated cotton were lower than control cotton. Surprisingly, after 30 or 60 laundering cycles, the C2-TMC cotton exhibited excellent antibacterial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans due to the continuous exposure of PA and L-Glu. Moreover, the coating layer on the cotton surface had little impact on the mechanical properties and feel of the fabric.

Facile Fabrication of Highly Efficient Chitosan-Based Multifunctional Coating for Cotton Fabrics with Excellent Flame-Retardant and Antibacterial Properties

Interest in the development of eco-friendly, sustainable, and convenient bio-based coatings to enhance flame retardancy and antibacterial properties in cotton fabrics is growing. In this work, chitosan was protonated at its amino groups using a method with a high atom economy using an equimolar amount of amino trimethylene phosphonic acid (ATMP), resulting in the fabrication of a single-component chitosan-based multifunctional coating (ATMP-CS), thereby avoiding any additional neutralization or purification steps. Cotton fabrics coated with various loads of ATMP-CS were prepared through a padding-drying-curing process. The morphology, thermal stability, mechanical properties, antibacterial properties, flame-retardant behavior, and flame-retardant mechanism of these fabrics were investigated. The coating exhibited excellent film-forming properties, and it imparted a uniform protective layer onto the surfaces of the cotton fabrics. When the load capacity reached 11.5%, the coated fabrics achieved a limiting oxygen index of 29.7% and successfully passed the VFT test. Moreover, the ATMP-CS coating demonstrated antibacterial rates against Escherichia coli and Staphylococcus aureus reaching 95.1% and 99.9%, respectively. This work presents a straightforward and gentle approach to fabricating colorless, environmentally friendly, and highly efficient fabric coatings that have potential applications in promoting the use of bio-based materials.

Preparation and properties of flame retardant and hydrophobic cotton fabrics based on poly-(dimethylsiloxane-co-diphenylsiloxane, dihydroxy terminated)/ammonia phytate

Applications for cotton fabrics with multifunctional qualities, such as flame retardancy, hydrophobicity, and anti-ultraviolet properties, are increasingly common and growing daily. The primary objective of this study is to investigate the preparation of flame retardant, hydrophobic, and ultraviolet (UV) protection cotton fabrics through the utilization of Poly-dimethylsiloxane-co-diphenylsiloxane, dihydroxy terminated (HTDMS) and ammonia phytate (AP). The flame retardancy, thermal stability, mechanical properties, anti-UV properties, air permeability and the hydrophobicity properties of coated cotton fabrics were evaluated. The results indicated that the HTDMS/AP coating was successfully deposited on the surface of cotton fabrics. The damaged length of Cotton/HTDMS/AP was 4.7 cm, and the limiting oxygen index reached 31.5 %. The thermogravimetric analysis revealed that the char residues in the high-temperature range were increased. Furthermore, cone calorimetry results indicated that after the HTDMS/AP coating, the peak heat release rate, total heat release, and total smoke production values decreased by 88.7 %, 51.2 %, and 98.4 %, respectively. Moreover, the deposition of HTDMS/AP provided cotton fabrics with hydrophobicity with a water contact angle of over 130°, while Cotton/HTDMS/AP maintained their air permeability, and enhanced the breaking force compared with those of Cotton/AP. Such desirable qualities make HTDMS/AP a meaningful coating for producing multifunctional cotton fabrics.

A molecularly engineered fully bio-derived phosphorylated furan-based flame retardant for biomass-based fabrics

With the increasing awareness of environmental protection, the demand for eco-friendly bio-derived flame-retardant for textiles has received increasing attention. In this work, a fully bio-derived phosphorylated furan-based flame retardant (FAP) was synthesized by the Schiff reaction of furan-based compounds (furfural and furfurylamine). To evaluate the application scope and flame retardant efficiency of FAP, cotton fabrics and PLA nonwovens were selected as biomass-based representatives of natural fiber materials and synthetic fiber materials, respectively. Significantly, based on the composition of furan ring, phosphorus and nitrogen containing components of FAP, excellent charring and flame retardant properties of coated cotton fabrics and PLA nonwovens can be expected. TGA results showed that the residual char of C-FAP-3 and P-FAP-3 were 39.7% (increased by 267.6%) and 16.7% (increased by 215.1%), respectively, higher than those of control cotton (10.8%) and PLA nonwoven (5.3%). Cone test results exhibited that the peak heat release rate (PHRR) and total heat release (THR) values of C-FAP-3 were sharply decreased by 69.4% and 37.8%, respectively. P-FAP-3 also displayed a significant reduction in PHRR, implying high flame retardancy of C-FAP-3 and P-FAP-3. Notably, through the weight gains of FAP coating on cotton and PLA as well as the final LOI and VBT results of the flame retardant treated fabrics, it can be preliminarily inferred that control cotton fabrics are more likely to achieve better flame retardant effects than PLA. Additionally, the facile synthetic strategy of fully bio-derived flame retardants is expected to promote the development of green flame retardant strategies for high-performance textiles.

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.

Bio-based alginate and Si-, P- and N-containing compounds cooperate toward flame-retardant modification of polyester fabrics

Imparting flame retardancy to polyester fabrics is still a pressing issue for the textile industry. To this end, a composite coating was developed by phosphite, pentamethyldisiloxane, urea and sodium alginate, and then applied together with calcium chloride to prepare flame-retardant polyester fabrics. The optimized polyester fabrics named PF-HUSC exhibited a rough surface with P, Si, N and Ca element distributions, as observed by scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDX). Flame retardancy evaluations showed that the damaged length of PF-HUSC with a limiting oxygen index (LOI) value of 35.3 ± 0.3 % was reduced from the contrastive 17.6 ± 0.4 cm to 4.6 ± 0.2 cm after vertical burning test. Thermogravimetric (TG) test confirmed that PF-HUSC retained a char residue as high as 35.1 % at 700 °C. Cone calorimetry test displayed that the total heat release (THR) and total smoke production (TSP) values of PF-HUSC were reduced to 3.1 MJ/m2 and 1.1 m2, respectively, as compared to those of pure polyester fabrics. More importantly, PF-HUSC still exhibited higher LOI value than that of pure polyester fabrics after 25 washing cycles. Hence, the coating scheme is considered as a new method to expand the preparation of flame-retardant polyester fabrics.

Flame retardant, heat insulating and hydrophobic chitosan-derived aerogels for the clean-up of hazardous chemicals

Leakage of hazardous chemicals often causes significant casualties, enormous economic losses, and negative social benefits. Presently, fire rescue personnel lack efficient and eco-friendly disposal materials for hazardous chemical leakage accidents. In this study, chitosan (CS) aerogels with excellent flame-retardant performance were prepared via cross-linking by two phosphorus-containing vanillin-based compounds (DV and TV). The as-prepared chitosan aerogels were lightweight and porous. The introduction of DV and TV greatly enhanced the residual char yields of CS at 700 °C and the flame-retardant performance of chitosan aerogels. TCS-5.0 possessed the best flame-retardant performance, indicating that TV was more effective than DV in enhancing the flame-retardant performance of chitosan aerogels. The greatly improved flame-retardant properties could be attributed to TV effectively promoting the residual char formation of chitosan aerogels and reducing the formation of combustible gas phase products. To improve the hydrophobicity of chitosan aerogels, TCS-5.0 was treated with solution immersion to load siloxane molecules on its surface. The water contact angle of HTCS-5.0 was 136.1°. HTCS-5.0 had a high oil absorption multiplicity, absorbing up to 31 times its own weight of chloroform. HTCS-5.0 could continuously absorb organic solvents on the water surface with the assistance of a vacuum pump, indicating that HTCS-5.0 could be used for the clean-up of hazardous chemical leakage accidents.

Durable multifunctional cotton fabric with superior biocidal efficacy and flame retardancy based on an ammonium phosphate N-halamine

Multifunctional textiles have become the mainstreams along with development of textile industry and the increased need of public. But a facile fabrication method with well-balance of multiple functions is still a challenge. In this work, an ammonium salt of tris(methylphosphonate)aminomethane (TAMPU), which can directly react with cellulose molecules and transform to N-halamine antibacterial structure, was easily synthesized and used to achieve multifunctional cotton fabric. As a result, the modified cotton fabric of 15.8 % weight gain exhibited excellent fire resistance with LOI value of 33.8 % and self-extinguishing behavior. Due to the good char-forming capacity of TAMPU, strong heat suppression was achieved and the peak of heat release rate (PHRR) and total heat release (THR) were decreased by 87.6 % and 60.8 %, respectively. Besides, the modified samples presented outstanding bactericidal effects, and all of S. aureus and E. coli could be inactivated within 5 min without dissolution phenomenon. Furthermore, the TAMPU-modified cotton fabric owned good washing durability and LOI value was remained at 29.8 % after 50 washing cycles. This TAMPU multifunctional modification had slight influence on the mechanical property and air permeability of cotton fabric. Thus, this work provides a convenient and friendly way to fabricate multifunctional flame-retardant and antibacterial cotton fabric.

An eco-friendly, highly efficient, and transparent coating derived from guar gum and citric acid for flame retardant treatment of cotton fabrics

A highly efficient, bio-ecofriendly, and transparent flame retardant (FR) for cotton fabric was developed and deposited onto the cellulose skeletal structure of cotton fabric through a one-pot sol-gel process. The flame retardant functional coating is composed of ammonium polyphosphate (APP), guar gum (GG), citric acid (CA), and a negligible amount of catalyst. Cotton fabrics were impregnated with different concentrations of ammonium polyphosphate and guar gum, with citric acid as a crosslinking agent. The overall crosslinking and grafting process was proven by FTIR and XPS. Based on the results, the designed coating exhibits over 90 % transmittance in the visible region. A 15 g/m2 flame-retardant coating induces excellent flame retardant efficiency at ultra-low flame-retardant concentrations of less than 6.25 wt%. Only a 5.25 wt% flame retardant concentration demonstrated condensed phase action, which resulted in 58.5 % and 73.6 % reductions in the pHRR and THR, respectively. Moreover, the limiting oxygen index (LOI) value showed a 74 % increase. The mechanical performance of FR coated cotton fibers was slightly reduced.