Search

The use of biobased flame-retardant (FR) agents for reducing the flammability of polyester/cotton (T/C) blend fabrics is highly desirable. In this study, a novel and sustainable phosphorus/nitrogen-containing FR, namely, phytic acid–urea (PA-UR) salt, was synthesized. The PA-UR salt was further used to enhance the FR performance of T/C fabric through surface modification. We further explored the potential chemical structure of PA-UR and the surface morphology, thermal stability, heat release capacity, FR properties, and mode of action of the coated fabric. The coated fabric achieved self-extinguishing and exhibited an increased limiting oxygen index of 31.8%. Moreover, the coated T/C blend fabric demonstrated a significantly reduced heat release capacity, indicating a decreased fire hazard. Thermogravimetric analysis revealed the anticipated decomposition of the coated T/C blend fabric and a subsequent increase in thermal stability. The burned char residues also maintained their fiber shape structures, suggesting the presence of condensed FR actions in the PA-UR-coated T/C blend fabric. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Durable and formaldehyde-free flame-retardant (FR) modification of wool fabric using phosphorous compounds is of great interest. In this study, Schiff base imine groups were firstly introduced onto wool fiber through aldehyde-amine condensation between p -hydroxybenzaldehyde and wool fiber. Then, an efficient and durable FR wool fabric was fabricated by incorporating diethyl phosphite (DEP) into a Schiff base intermediate via the Pudovik reaction. The potential reaction mechanism among p -hydroxybenzaldehyde, DEP and wool fiber was explored. The thermal stability, smoke generation ability, FR ability and washing durability of the modified wool fabric were studied. The FR modification significantly increased the thermal resistance of wool fabric and suppressed smoke generation by half. The wool fabric modified by 20 g/L DEP was able to self-extinguish during the burning test, suggesting the higher FR efficiency of the DEP-incorporated Schiff base system. The modified wool fabric still self-extinguished after 20 commercial launderings, which is attributed to the covalent grafting of DEP onto wool fiber. Char residue analyses revealed the condensed charring FR mechanism of the DEP-incorporated Schiff base system on wool. This work provides a novel approach to prepare efficient and durable FR functional wool fabric via the Schiff base reaction and Pudovik reaction among p -hydroxybenzaldehyde, DEP and wool fiber. [ABSTRACT FROM AUTHOR]

• A water-soluble polyelectrolyte complex was prepared using phytic acid and polyethyleneimine. • Polyelectrolyte complex was applied to wool textile by a single dip coating technique. • Polyelectrolyte complex coating imparted good flame retardancy to wool textile. • Polyelectrolyte complex coating had appreciable washing resistance on fabric surface. The one-step polyelectrolyte complex (PEC) deposition approach shows great potential and feasibility to prepare flame retardant (FR) textile materials. This study developed a water-soluble PEC system by using phytic acid (PA) and polyethyleneimine (PEI) at pH 1.5 to improve the flame retardancy of wool fabric. After being dipped in the PEC solution, the wool fabric was treated with the pH 4 buffer solution to form a water-insoluble coating on the fabric surface. The coated wool substrates had superior inflating ability during the thermal radiation and flammability tests, giving rise to the greatly suppressed heat and smoke generation performance, and increased FR efficiency of wool fabrics through an intumescent charring mechanism. The coated wool fabric with the PEC consisting of 15% PA and 15% PEI was still able to self-extinguish after 10 washing cycles, demonstrating its good FR ability and durability to washing. The appreciable washing durability of the coated wool could be attributed to the abilities of PA and PEI to combine with each other to form insoluble coating on wool fiber surface and to ionically and covalently cross-link with wool fiber. [ABSTRACT FROM AUTHOR]

In this work, a novel phosphorus-rich hybrid organic-inorganic silica coating for improving the flame retardancy of silk fabric was prepared using naturally occurring phytic acid as phosphorus precursor and catalyst for the hydrolysis of tetraethoxysilane. In addition, three silane coupling agents, namely 3-aminopropyldimethoxymethylsilane, 3-chloropropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane, were added in the hybrid sol as cross-linkers with the aim of developing hydrophobic coatings and improving the washing durability of the treated silk fabric. The condensation degree of the hybrid sol was characterized by solid-state 29 Si nuclear magnetic resonance spectroscopy. The flammability and thermal degradation properties of the treated silk fabrics were determined in terms of limiting oxygen index, vertical burning, pyrolysis combustion flow calorimetry and thermogravimetric analyses. The surface morphology and hydrophobicity of the treated silk fabrics were evaluated by scanning electron microscopy, atomic force microscopy and water contact angle tests. The flammability tests revealed that the silicon sol could endow silk fabric with excellent flame retardancy when doped with phytic acid, and the treated silk fabrics self-extinguished immediately when the ignition source was removed. The silk fabrics treated with the modified hybrid sols exhibited hydrophobic surface and also better durability to washing. [ABSTRACT FROM AUTHOR]

• Sustainable and reactive pentaerythritol phytate ethylenediaminetetraacetic acid ester (PPEDTE) intumescent flame-retardant is synthesized. • PPEDTE coating is grafted on silk surface through covalent reaction. • PPEDTE coating has high flame retardancy and durability on silk textile. • PPEDTE coating offers an eco-friendly and durable flame-retardant approach for silk in practical applications. The exploitation of plant-derived phytic acid as effective and durable flame retardant (FR) for textiles is of great significance for developing novel and ecological functional textile products. In the present study, a reactive and phytate-based FR namely pentaerythritol phytate ethylenediaminetetraacetic ester (PPEDTE) prepared by the esterification of phytic acid, pentaerythritol and ethylenediaminetetraacetic acid was investigated as intumescent FR agent for silk fabric. The chemical structure of PPEDTE and its potential grafting mechanism on silk were studied. The thermal stability, heat and smoke suppression property, flame retardancy and washing resistance on silk fabric were studied. The deposition and covalently cross-linked PPEDTE on silk fabric enabled it to self-extinguish in vertical burning test. The coated silk fabric with an add-on of higher than 10.7% could withstand 15 washing cycles, displaying good washing durability. The intumescent FR coating remarkably decreased the release of heat and smoke of silk during burning. The coated silk had high thermal stability and left significant combustion residues after the burning tests. These results demonstrate that the synthesized PPEDTE warrant potential as efficient and reactive intumescent FR approach for silk. [Display omitted] [ABSTRACT FROM AUTHOR]

A cyclic phosphonate ester flame retardant was applied to improve the flame retardancy of poly(lactic acid) (PLA) nonwoven fabric by a pad-dry-cure technique. The effects of curing temperature and flame retardant dosage on the flammability of PLA fabric were analyzed. The burning behavior, thermal stability and flame-retardant mechanism of the flame-retardant PLA fabric were investigated by limiting oxygen index (LOI), vertical burning test, microscale combustion calorimetry (MCC), thermogravimetric (TG) analysis and scanning electron microscopy (SEM) with energy dispersive spectrum (EDS). The treated PLA fabric exhibited good flame retardancy, and its LOI was about 35%, whereas this value was 26.3% for the untreated fabric. No obvious difference of the MCC test results between the untreated and treated fabrics was found. The results from TG analyses indicated the formation of a very small amount of char during the thermal degradation process of the treated PLA fabric. The SEM-EDS analysis showed an obvious decrease in the phosphorus content of the flame retardant fabric after burning. These indicate that the gas-phase flame-retardant mechanism during combustion is dominant, and results in the good flame retardancy of the treated fabric in the presence of a very small amount of char residue. [ABSTRACT FROM AUTHOR]

The exploitation of resourceful plant derivatives for fabricating durable flame retardant (FR) textiles is of great interest. Herein, this study offers a novel and facile approach for developing FR wool fabric by covalently grafting bio-based ammonium phytate (APH) onto wool fibers. The potential grafting action of APH with wool fibers, the flame retardancy and washing durability, smoke and heat emission performance and FR mechanism of modified wool fabrics were explored. The modified wool fabrics could pass the vertical burning B 1 classification with a reduced char length of approximately 10.0 cm from 30.0 cm, and they also had an increased LOI of approximately 32.0% from 23.6%. The modified wool fabrics possessed increased tensile strength; they also self-extinguished during the vertical burning test after 15 washing cycles, which was attributed to the cross-linking action of APH with wool fibers. Besides, a significant reduction in smoke and heat release of wool fabric was achieved after FR grafting. The investigations on char residue confirmed the intumescent FR mechanism for APH modified wool fabrics. In general, the present study provides an industrial feasible strategy to prepare sustainable and durable FR wool fabrics using phytate derivatives. [Display omitted] • Phytate derivative APH is obtained from resourceful crops. • APH covalent grafting approach is a green, sustainable and promising technique. • APH covalent grafting approach shows high flame-retardant efficiency and durability on wool fabric. • APH covalent grafting approach offers a cleaner and industrial feasible way to minimize fire hazards of wool textile. [ABSTRACT FROM AUTHOR]