Hybrid Silica-Phytic Acid Coatings: Effect on the Thermal Stability and Flame Retardancy of Cotton

New hybrid sol–gel coatings based on tetraethoxysilane (TEOS) and phytic acid (PA) were designed and applied to cotton; the flame-retardant properties of the treated fabrics were thoroughly investigated by means of flame-spread and forced-combustion tests. The first goal was to identify the TEOS:PA weight ratio that allowed the achievement of the best flame-retardant properties, with the lowest final dry add-on on the fabrics. Therefore, different TEOS:PA sols were prepared and applied to cotton, and the resulting coated fabrics were thoroughly investigated. In particular, solid-state NMR spectroscopy was exploited for assessing the condensation degree during the sol–gel process, even for evaluating the occurrence of possible reactions between phytic acid and the cellulosic substrate or the alkoxy precursor. It was found that a total dry add-on of 16 wt % together with 70:30 TEOS:PA weight ratio provided cotton with self-extinction, as clearly indicated by flame-spread tests. This formulation was further investigated in forced-combustion tests: a significant reduction of heat release rate (HRR), of the peak of HRR, and of total heat release (THR) was found, together with a remarkable increase of the residues after the test. Unfortunately, the treated fabrics were not resistant to washing cycles, as they significantly lost their flame-retardant properties, consequently to the partial removal of the deposited hybrid coatings.

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Flame Retardant Functionalization of Microcrystalline Cellulose by Phosphorylation Reaction with Phytic Acid

International Journal of Molecular Sciences ◽

10.3390/ijms22179631 ◽

2021 ◽

Vol 22 (17) ◽

pp. 9631

Author(s):

Hua-Bin Yuan ◽

Ren-Cheng Tang ◽

Cheng-Bing Yu

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Phytic Acid ◽

Microcrystalline Cellulose ◽

Weight Ratio ◽

Phosphorylation Reaction ◽

Combustion Flow ◽

Novel Strategy ◽

C 50 ◽

Application Fields

The functionalization of microcrystalline cellulose (MCC) is an important strategy for broadening its application fields. In the present work, MCC was functionalized by phosphorylation reaction with phytic acid (PA) for enhanced flame retardancy. The conditions of phosphorylation reaction including PA concentration, MCC/PA weight ratio and temperature were discussed, and the thermal degradation, heat release and char-forming properties of the resulting PA modified MCC were studied by thermogravimetric analysis and pyrolysis combustion flow calorimetry. The PA modified MCC, which was prepared at 90 °C, 50%PA and 1:3 weight ratio of MCC to PA, exhibited early thermal dehydration with rapid char formation as well as low heat release capability. This work suggests a novel strategy for the phosphorylation of cellulose using PA and reveals that the PA phosphorylated MCC can act as a promising flame retardant material.

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Phytic Acid and Biochar: An Effective All Bio-Sourced Flame Retardant Formulation for Cotton Fabrics

Polymers ◽

10.3390/polym12040811 ◽

2020 ◽

Vol 12 (4) ◽

pp. 811 ◽

Cited By ~ 3

Author(s):

Marco Barbalini ◽

Mattia Bartoli ◽

Alberto Tagliaferro ◽

Giulio Malucelli

Keyword(s):

Flame Retardant ◽

Phytic Acid ◽

Weight Ratio ◽

Chemical Conversion ◽

Cotton Fabrics ◽

Solid Product ◽

Untreated Cotton ◽

Naturally Occurring ◽

Flame Retarded ◽

Combustion Tests

Flame retardant systems based on bio-sourced products combine quite high fire performances with the low environmental impact related to their synthesis and exploitation. In this context, this work describes a new all bio-sourced flame retardant system designed and applied to cotton fabrics. In particular, it consists of phytic acid (PA), a phosphorus-based naturally occurring molecule extracted from different plant tissues, in combination with biochar (BC), a carbon-rich solid product obtained from the thermo-chemical conversion of biomasses in an oxygen-limited environment. PA and BC were mixed together at a 1:1 weight ratio in an aqueous medium, and applied to cotton at different loadings. As revealed by flammability and forced combustion tests, this bio-sourced system was able to provide significant improvements in flame retardance of cotton, even limiting the final dry add-on on the treated fabrics at 8 wt.% only. The so-treated fabrics were capable to achieve self-extinction in both horizontal and vertical flame spread tests; besides, they did not ignite under the exposure to 35 kW/m2 irradiative heat flux. Conversely, the proposed flame retardant treatment did not show a high washing fastness, though the washed flame retarded fabrics still exhibited a better flame retardant behavior than untreated cotton.

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Functionalized CNTs with DOPO and Silicon Containing Agents: Effective Reinforcer for Thermal and Flame Retardant Properties of Polystyrene Nanocomposites

Frontiers in Chemistry ◽

10.3389/fchem.2020.627642 ◽

2021 ◽

Vol 8 ◽

Author(s):

Congling Shi ◽

Xiaodong Qian ◽

Jingyun Jing ◽

Honglei Che

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Sol Gel ◽

Polymer Chains ◽

Multiwalled Carbon ◽

Combustible Gas ◽

Peak Heat Release Rate ◽

Sol Gel Process ◽

Flame Retardant Properties

DOPO and silicon containing agents modified multiwalled carbon nanotubes (MCNTs) were synthesized through sol-gel process and MCNTs are introduced into polystyrene (PS) through in situ polymerization. TEM observations and FTIR results of MCNTs demonstrated that the MCNT nanofillers were coated with the organic/inorganic flame retardant compound. Moreover, the TEM results of the composites indicate that MCNTs dispersed in polystyrene PS matrix uniformly due to the modification. The PS/MCNTs composites showed improved thermal stability as well as flame retardant properties in comparison with PS/CNTs composites, which are due to the good dispersion of MCNT in the PS matrix. MCNTs in the PS matrix can also reduce the peak heat release rate, total heat release and improve the smoke suppression performance. The improved flame retardant properties are attributed to the char reinforcing effect of CNTs, which can provide enough time for MCNTs and organic/inorganic compound to trap the degradation of polymer chains and catalyze the formation of char. The char layers can not only serve as an efficient insulating barrier to reduce the exposure of PS matrix to heat source but also retard the releasing of combustible gas.

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Phosphorus-Silica Sol-Gel Hybrid Coatings for Flame Retardant Cotton Fabrics

Tekstilec ◽

10.14502/tekstilec2017.60.29-35 ◽

2017 ◽

Vol 60 (1) ◽

pp. 29-35 ◽

Cited By ~ 2

Author(s):

Giuseppe Rosace ◽

◽

Claudio Colleoni ◽

Emanuela Guido ◽

Giulio Malucelli ◽

...

Keyword(s):

Flame Retardant ◽

Sol Gel ◽

Cotton Fabrics ◽

Silica Sol ◽

Hybrid Coatings

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In Situ Synthesis of SiO2 Nanoparticles by Sol-Gel Method on Cotton Fabrics and Investigation of their Physical and Chemical Properties

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.891.37 ◽

2021 ◽

Vol 891 ◽

pp. 37-42

Author(s):

Sheila Shahidi ◽

Hakimeh Mohammadbagherloo ◽

Seyedmohammad Elahi ◽

Sanaz Dalalsharifi ◽

Rattanaphol Mongkholrattanasit

Keyword(s):

Flame Retardant ◽

Water Drop ◽

Sol Gel ◽

Cotton Fabrics ◽

In Situ Synthesis ◽

Order Structure ◽

Gel Method ◽

Sol Gel Method ◽

Flame Retardant Properties

In this paper, the sol-gel method was used for in-situ synthesis of SiO2 nanoparticles (NPs) on cotton fabrics with tetraethyl orthosilicate (TEOS) in the presence of acid and alkaline indicators. The samples were characterized using by (X-ray diffraction) XRD, (scanning electron Microscopy) SEM, (Inductively coupled plasma) ICP, water drop test and also the flame retardant properties were studied by char yield. The SEM images showed that the nanoparticles are spherical in shape and the acidity or alkalinity of the medium has an effect on the formation of particles. The XRD patterns showed the typical diffraction of amorphous SiO2 (Si-O short-order structure), also ICP analysis showed that by washing the fabrics, the nanoparticles are still present on the fabric, and this indicated the stability of the washing of the fabrics impregnated with the nanoparticles. By in-situ synthesis of SiO2 nanoparticles, the flame retardant properties have been improved significantly and the amount of residual char was increased and samples were observed to be hydrophilic.

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Synthesis of a Novel Phosphorous-Nitrogen Based Charring Agent and Its Application in Flame-retardant HDPE/IFR Composites

Polymers ◽

10.3390/polym11061062 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1062 ◽

Cited By ~ 13

Author(s):

Junlei Chen ◽

Jihui Wang ◽

Aiqing Ni ◽

Hongda Chen ◽

Penglong Shen

Keyword(s):

Thermal Stability ◽

Heat Release ◽

Flame Retardant ◽

Flame Retardancy ◽

Fire Hazard ◽

Weight Ratio ◽

Charring Agent ◽

Migration Percentage ◽

Ul 94 ◽

Thermal Stability Of

In this work, a novel phosphorous–nitrogen based charring agent named poly(1,3-diaminopropane-1,3,5-triazine-o-bicyclic pentaerythritol phosphate) (PDTBP) was synthesized and used to improve the flame retardancy of high-density polyethylene (HDPE) together with ammonium polyphosphate (APP). The results of Fourier transform infrared spectroscopy (FTIR) and 13C solid-state nuclear magnetic resonance (NMR) showed that PDTBP was successfully synthesized. Compared with the traditional intumescent flame retardant (IFR) system contained APP and pentaerythritol (PER), the novel IFR system (APP/PDTBP, weight ratio of 2:1) could significantly promote the flame retardancy, water resistance, and thermal stability of HDPE. The HDPE/APP/PDTBP composites (PE3) could achieve a UL-94 V-0 rating with LOI value of 30.8%, and had a lower migration percentage (2.2%). However, the HDPE/APP/PER composites (PE5) had the highest migration percentage (4.7%), lower LOI value of 23.9%, and could only achieve a UL-94 V-1 rating. Besides, the peak of heat release rate (PHRR), total heat release (THR), and fire hazard value of PE3 were markedly decreased compared to PE5. PE3 had higher tensile strength and flexural strength of 16.27 ± 0.42 MPa and 32.03 ± 0.59 MPa, respectively. Furthermore, the possible flame-retardant mechanism of the APP/PDTBP IFR system indicated that compact and continuous intumescent char layer would be formed during burning, thus inhibiting the degradation of substrate material and improving the thermal stability of HDPE.

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Sol–Gel Treatments to Flame Retard PA11/Flax Composites

Fibers ◽

10.3390/fib7100086 ◽

2019 ◽

Vol 7 (10) ◽

pp. 86 ◽

Cited By ~ 1

Author(s):

Samyn ◽

Vandewalle ◽

Bellayer ◽

Duquesne

Keyword(s):

Solid State ◽

Flame Retardant ◽

Solid State Nmr ◽

Flame Retardants ◽

Sol Gel ◽

Deposition Method ◽

One Pot ◽

Successive Layer ◽

Coating Methods ◽

Flame Retardant Properties

This work investigates the efficiency of sol–gel treatments to flame retard flax fabric/PA11 composites. Different sol–gel treatments applied to the flax fabrics were prepared using TEOS in combination with phosphorus and/or nitrogen containing co-precursors (DEPTES, APTES) or additives (OP1230, OP1311). When the nitrogen and the phosphorus co-precursors were used, two coating methods were studied: a ‘one-pot’ route and a successive layer deposition method. For the “one-pot” method, the three precursors (TEOS, DEPTES, and APTES) were mixed together in the same solutions whereas for the different layers deposition method, the three different treatments were deposited on the fibers successively, first the TEOS, then a mix of TEOS/DEPTES, and finally a mix of TEOS/APTES. After deposition, the sol–gel coatings were characterized using scanning electron microscope, electron probe microanalyzer, and 29Si and 31P solid-state NMR. When only TEOS or a mix of TEOS and DEPTES is used, homogeneous coatings are obtained presenting well-condensed Si units (mainly Q units). When APTES is added, the coatings are less homogenous and agglomerates are present. A lower condensation rate of the Si network is also noticed by solid-state NMR. When additives are used in combination with TEOS, the TEOS forms a homogenous and continuous film at the surface of the fibers, but the flame retardants are not well distributed and form aggregates. The flame retardant (FR) efficiency of the different treatments on flax fabrics was evaluated using horizontal flame spread test. The following ranking of the different systems is obtained: TEOS + Additives > TEOS > TEOS + DEPTES ~ TEOS + DEPTES + APTES > multilayers. All the sol–gel coatings improve the flame retardant properties of the flax fabric, except the multilayer treatment. Based on these results, the three most efficient sol–gels were selected to prepare sol–gel-modified flax/PA11 composites. The composite modified with only TEOS showed the best FR properties. Surprisingly, the composite modified with the phosphorus-based flame retardant (AlPi) did not exhibit improved FR properties. This effect was attributed to the fact that the amount of the FR additive deposited on the fabrics was too low.

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Synthesis, characterization and flame retardant of UV-curable hybrid coatings containing SiO2–P2O5–B2O3 via sol–gel method

Journal of Sol-Gel Science and Technology ◽

10.1007/s10971-012-2797-4 ◽

2012 ◽

Vol 63 (3) ◽

pp. 382-388 ◽

Cited By ~ 4

Author(s):

Fan Xu ◽

Xiaoying Sun ◽

Jianzhong Hang ◽

Dan Shang ◽

Liyi Shi ◽

...

Keyword(s):

Flame Retardant ◽

Sol Gel ◽

Hybrid Coatings ◽

Uv Curable ◽

Gel Method ◽

Sol Gel Method

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Environmentally Benign Phytic Acid-Based Nanocoating for Multifunctional Flame-Retardant/Antibacterial Cotton

Fibers ◽

10.3390/fib9110069 ◽

2021 ◽

Vol 9 (11) ◽

pp. 69

Author(s):

Eva Magovac ◽

Bojana Vončina ◽

Ana Budimir ◽

Igor Jordanov ◽

Jaime C. Grunlan ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Phytic Acid ◽

Environmentally Benign ◽

Lower Amount ◽

Layer By Layer ◽

Limiting Oxygen Index ◽

Untreated Cotton ◽

Microscale Combustion Calorimeter ◽

Combustion Calorimeter

Environmentally benign layer-by-layer (LbL) deposition was used to obtain flame-retardant and antimicrobial cotton. Cotton was coated with 8, 10, and 12 phytic acid (PA) and chitosan (CH)-urea bilayers (BL) and then immersed into copper (II) sulfate (CuSO4) solution. Our findings were that 12 BL of PA/CH-urea + Cu2+ were able to stop flame on cotton during vertical flammability testing (VFT) with a limiting oxygen index (LOI) value of 26%. Microscale combustion calorimeter (MCC) data showed a reduction of peak heat release rates (pHRR) of more than 61%, while the reduction of total heat release (THR) was more than 54%, relative to untreated cotton. TG-IR analysis of 12 BL-treated cotton showed the release of water, methane, carbon dioxide, carbon monoxide, and aldehydes, while by adding Cu2+ ions, the treated cotton produces a lower amount of methane. Treated cotton also showed no levoglucosan. The intumescent behavior of the treatment was indicated by the bubbled structure of the post-burn char. Antibacterial testing showed a 100% reduction of Klebsiella pneumoniae and Staphylococcus aureus. In this study, cotton was successfully functionalized with a multifunctional ecologically benign flame-retardant and antibacterial nanocoating, by means of LbL deposition.

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Effects of a Macromolecule Spirocyclic Inflatable Flame Retardant on the Thermal and Flame Retardant Properties of Epoxy Resin

Polymers ◽

10.3390/polym12010132 ◽

2020 ◽

Vol 12 (1) ◽

pp. 132 ◽

Cited By ~ 3

Author(s):

Kunpeng Song ◽

Yinjie Wang ◽

Fang Ruan ◽

Jiping Liu ◽

Nianhua Li ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Epoxy Resin ◽

Phosphorus Oxychloride ◽

Raw Materials ◽

Smoke Suppression ◽

Step Method ◽

Scanning Calorimetry ◽

New Strategy ◽

Flame Retardant Properties

A new strategy for the preparation of an integrated three-source intumescent flame retardant (IFR) has been developed to improve the flame-retardant and smoke suppression performance of epoxy resin (EP) with a synergistic flame retardant effect. Herein, the synthesis of a macromolecular spirocyclic phosphorus/nitrogen-containing IFR poly sulfonamide spirocyclic pentaerythritol bisphosphonate (SAPC) is reported via a two-step method that uses pentaerythritol, phosphorus oxychloride and sulfonamide (SAA) as raw materials. Subsequently, the SAPC was incorporated into EP to prepare the composite to investigate its thermal stability, flame retardancy, and smoke suppression performance. Herein, a differential scanning calorimetry (DSC) analysis showed that the addition of SAPC increased the glass transition temperature (Tg) of the composite. Cone test results indicated that the incorporation of 8 wt % SAPC significantly improved the flame-retardant performance for the composite, with a 43.45% decrease in peak of heat release rate, a 28.55% reduction in total heat release, and a 30.04% decrease in total smoke release. Additionally, the composite received the V-0 rating in a UL-94 vertical burning test, accompanied by the “blowout” phenomenon. After the addition of SAPC, the amount of flammable gas products from the EP composite decomposition was obviously suppressed, and the amount of non-flammable as was increased. All of this suggests a good dilution role of SAPC. There are enough reasons to believe that the enhanced flame-retardant and toxicity suppression performance for the EP composite can be attributed to the good coordination of carbonization agent, acid source, and blowing agent in the SAPC structure.

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