scholarly journals Mechanically Sustainable Starch-Based Flame-Retardant Coatings on Polyurethane Foams

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1286
Author(s):  
Kyung-Who Choi ◽  
Jun-Woo Kim ◽  
Tae-Soon Kwon ◽  
Seok-Won Kang ◽  
Jung-Il Song ◽  
...  

The use of halogen-based materials has been regulated since toxic substances are released during combustion. In this study, polyurethane foam was coated with cationic starch (CS) and montmorillonite (MMT) nano-clay using a spray-assisted layer-by-layer (LbL) assembly to develop an eco-friendly, high-performance flame-retardant coating agent. The thickness of the CS/MMT coating layer was confirmed to have increased uniformly as the layers were stacked. Likewise, a cone calorimetry test confirmed that the heat release rate and total heat release of the coated foam decreased by about 1/2, and a flame test showed improved fire retardancy based on the analysis of combustion speed, flame size, and residues of the LbL-coated foam. More importantly, an additional cone calorimeter test was performed after conducting more than 1000 compressions to assess the durability of the flame-retardant coating layer when applied in real life, confirming the durability of the LbL coating by the lasting flame retardancy.

2020 ◽  
Vol 56 (2) ◽  
pp. 1172-1188
Author(s):  
Anna M. Szczotok ◽  
Dan Madsen ◽  
Angel Serrano ◽  
Manuel Carmona ◽  
Patrick Van Hees ◽  
...  

Abstract Thermoregulating microcapsules (MC) with flame-retardant properties were used to produce polyurethane (PU) foams. Thermogravimetric analyses of the microcapsules performed under atmospheric air and nitrogen confirmed that the hexa(methacryloylethylenedioxy) cyclotriphosphazene (PNC-HEMA) monomer raised the amount of residue after exposure to high temperature, proving the formation of a thermally stable char layer. Additionally, the flame-retardant properties of the microcapsules were analyzed by micro-combustion calorimetry (MCC), and the PU foams were tested by both MCC and cone calorimetry. The total heat release and maximum heat release rate were lower for microcapsules containing the flame-retardant PNC-HEMA. The composition of the microcapsules has been proved by MCC and TGA, where the release of the encapsulated phase change material (PCM) occurred at the expected temperature. However, in PU foams, the release of PCM is shifted to higher temperatures. Accordingly, these materials can be considered as an important alternative to commonly used microcapsules containing phase PCMs, where a lower flammability is required for their future application. Graphic abstract


2021 ◽  
Vol 8 ◽  
Author(s):  
Chunzhuang Yang ◽  
Shuiyu Shao

Ammonium polyphosphate (APP) with different polymerization degrees were modified by a novel phosphorus-containing organosilicon compound (PCOC), and the products obtained were coded as MAPP-30 and MAPP-1000. Then they were applied to prepare flame-retardant rigid polyurethane foam (RPUF) separately. The impact of modified APP (MAPP) on the flame-retardant properties of RPUF was investigated by the limited oxygen index (LOI) test, horizontal burning test, and cone calorimeter test. The morphologies of the char residues were observed by SEM. Furthermore, the mechanical properties of RPUF composites were measured by the compressive strength test. The results showed that whether the degree of polymerization of MAPP is 30 or 1000, they both had greater charring ability and better flame-retardant properties than unmodified APP. The residual char yield of RPUF/MAPP-30 (37.3%) and RPUF/MAPP-1000 (36.5%) were both significantly higher than RPUF/APP-30 (22.8%) and RPUF/APP-1000 (24.9%). The peak heat release rate value of RPUF/MAPP-30 was 29.9% lower than that of RPUF/APP-30, and the drop of RPUF/MAPP-1000 was 50.9% compared to RPUF/APP-1000. Moreover, the total heat release of RPUF/MAPP-1000 (9.7 MJ/m2) was much lower than that of RPUF/MAPP-30 (11.3 MJ/m2). In summary, MAPP-1000 has the best flame-retardant properties among all RPUF composites. In addition, the results also showed that flame-retardant performance and the mechanical properties dramatically decreased with the increase in the addition of MAPP-1000, and the RPUF composite had the best comprehensive performance with 20% content of MAPP-1000.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3588
Author(s):  
Jiayi Chen ◽  
Yansong Liu ◽  
Jiayue Zhang ◽  
Yuanlin Ren ◽  
Xiaohui Liu

Lyocell fabrics are widely applied in textiles, however, its high flammability increases the risk of fire. Therefore, to resolve the issue, a novel biomass-based flame retardant with phosphorus and nitrogen elements was designed and synthesized by the reaction of arginine with phosphoric acid and urea. It was then grafted onto the lyocell fabric by a dip-dry-cure technique to prepare durable flame-retardant lyocell fabric (FR-lyocell). X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated that the flame retardant was successfully introduced into the lyocell sample. Thermogravimetric (TG) and Raman analyses confirmed that the modified lyocell fabric featured excellent thermal stability and significantly increased char residue. Vertical combustion results indicated that FR-lyocell before and after washing formed a complete and dense char layer. Thermogravimetric Fourier-transform infrared (TG-FTIR) analysis suggested that incombustible substances (such as H2O and CO2) were produced and played a significant fire retarding role in the gas phase. The cone calorimeter test corroborated that the peak of heat release rate (PHRR) and total heat release (THR) declined by 89.4% and 56.4%, respectively. These results indicated that the flame retardancy of the lyocell fabric was observably ameliorated.


Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 13 ◽  
Author(s):  
Rosica Mincheva ◽  
Hazar Guemiza ◽  
Chaimaa Hidan ◽  
Sébastien Moins ◽  
Olivier Coulembier ◽  
...  

In this study, a highly efficient flame-retardant bioplastic poly(lactide) was developed by covalently incorporating flame-retardant DOPO, that is, 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide. To that end, a three-step strategy that combines the catalyzed ring-opening polymerization (ROP) of L,L-lactide (L,L-LA) in bulk from a pre-synthesized DOPO-diamine initiator, followed by bulk chain-coupling reaction by reactive extrusion of the so-obtained phosphorylated polylactide (PLA) oligomers (DOPO-PLA) with hexamethylene diisocyanate (HDI), is described. The flame retardancy of the phosphorylated PLA (DOPO-PLA-PU) was investigated by mass loss cone calorimetry and UL-94 tests. As compared with a commercially available PLA matrix, phosphorylated PLA shows superior flame-retardant properties, that is, (i) significant reduction of both the peak of heat release rate (pHRR) and total heat release (THR) by 35% and 36%, respectively, and (ii) V0 classification at UL-94 test. Comparisons between simple physical DOPO-diamine/PLA blends and a DOPO-PLA-PU material were also performed. The results evidenced the superior flame-retardant behavior of phosphorylated PLA obtained by a reactive pathway.


2018 ◽  
Vol 31 (2) ◽  
pp. 186-196 ◽  
Author(s):  
Shuang Yang ◽  
Yefa Hu ◽  
Qiaoxin Zhang

In this article, a phosphorus–nitrogen-containing flame retardant (DOPO-T) was successfully synthesized by nucleophilic substitution reaction between 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and cyanuric chloride. The chemical structure of DOPO-T was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance (NMR) and phosphorous-31 NMR, and elemental analysis. DOPO-T was then blended with diglycidyl ether of bisphenol-A to prepare flame-retardant epoxy resins. Thermal properties, flame retardancy, and combustion behavior of the cured epoxy resins were evaluated by differential scanning calorimetry, thermogravimetric analysis, limited oxygen index (LOI) measurement, UL94 vertical burning test, and cone calorimeter test. The results indicated that the glass transition temperature ( Tg) and temperature at 5% weight loss of epoxy resin (EP)/DOPO-T thermosets were gradually decreased with the increasing content of DOPO-T. DOPO-T catalyzed the decomposition of EP matrix in advance. The flame-retardant performance of EP thermosets was significantly enhanced with the addition of DOPO-T. EP/DOPO-T-0.9 sample had an LOI value of 36.2% and achieved UL94 V-1 rating. In addition, the average of heat release rate, peak of heat release rate, average of effective heat of combustion, and total heat release (THR) of EP/DOPO-T-0.9 sample were decreased by 32%, 48%, 23%, and 31%, respectively, compared with the neat EP sample. Impressively, EP/DOPO-T thermosets acquired excellent flame retardancy under low loading of flame retardant.


2017 ◽  
Vol 30 (10) ◽  
pp. 1229-1239 ◽  
Author(s):  
Shan Huang ◽  
Xiao Hou ◽  
Jiaojiao Li ◽  
Xiujuan Tian ◽  
Qing Yu ◽  
...  

A phosphorous/nitrogen-containing diphenylphosphine oxide (DPO) derivative (DPO-SS) was designed and synthesized via a two-step reaction of 4,4′-diaminodiphenylsulfone, 2-hydroxy-benzaldehyde, and DPO. The structure of DPO-SS was confirmed by Fourier transform infrared spectroscopy (FTIR), 1H and 31P nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS). DPO-SS was used as a flame retardant and curing agent for copolymerizing with diglycidyl ether of bisphenol-A. Thermal and flame-retardant properties of the obtained flame-retardant epoxy resin (F-EP) were investigated by thermogravimetric analysis, dynamic thermomechanical analysis, limited oxygen index (LOI) measurement, vertical burning test (UL-94), and cone calorimeter test. Results indicated that all F-EP samples exhibited excellent thermal stability and flame-retardant property. Especially for F-EP with P content of 0.7 wt% (denoted as EP/P-0.7), it achieved high LOI values (32.4%) and UL-94 V-0 rating. Compared with pure EP, all F-EP samples showed lower heat release rate, total heat release, total smoke produce, and little Tg fluctuation. In order to study the flame-retardant mechanism, the char residues were investigated by FTIR, scanning electron microscopy, and energy-dispersive spectrometer analysis. The results manifested that DPO-SS acted as flame retardant in both gas phase and condensed phase. Water absorption properties of pure EP and F-EP were also compared through immersion experiments. Results showed that EP/P-0.7 sample had apparently lower water absorptivity than pure EP.


2016 ◽  
Vol 30 (2) ◽  
pp. 255-272 ◽  
Author(s):  
Xilei Chen ◽  
Lili Huo ◽  
Jianbo Liu ◽  
Chuanmei Jiao ◽  
Shaoxiang Li ◽  
...  

Flame-retardant polyurethane elastomers (PUEs) have been prepared using trichloroethyl phosphate (TCEP) as flame retardant. The combustion performances and thermal decomposition properties of PUEs were studied using cone calorimetry test and thermogravimetric analysis, respectively. Kissinger method and Flynn–Wall–Ozawa (FWO) method were adopted to discuss the pyrolysis kinetics of PUEs. The experimental results showed that TCEP has good flame-retardant effect for PUE. With the increase of TCEP, the peak heat release rate and total heat release values decrease. A good diagram of linear regression can be obtained from both Kissinger and FWO methods. The activation energy values of flam- retardant PUE can be calculated from FWO method at different conversion rates.


2014 ◽  
Vol 881-883 ◽  
pp. 863-866
Author(s):  
Chao Peng ◽  
Shi Bin Nie ◽  
Lei Liu ◽  
Qi Lin He ◽  
Yuan Hu ◽  
...  

Nanoporous nickel phosphates (VSB-1) was synthesized by hydrothermal method. Then VSB-1 was added to the ammonium polyphosphate and pentaerythritol system in polypropylene (PP) matrix.The synergistic effect of VSB-1 with intumescent flame retardants (IFR) was studied by cone calorimetry test. The results of cone calorimetry show that heat release rate peak (pHRR) and total heat release (THR) of intumescent flame retardant PP with 2wt% VSB-1 decrease remarkably compared with that of without VSB-1. The pHRR and THR decrease respectively from 1140 to 286.0 kW/m2, and from 96.0 to 63.2 MJ/m2.


2016 ◽  
Vol 87 (11) ◽  
pp. 1367-1376 ◽  
Author(s):  
Chaohong Dong ◽  
Zhou Lu ◽  
Peng Wang ◽  
Ping Zhu ◽  
Xuechao Li ◽  
...  

A novel formaldehyde-free flame retardant containing phosphorus and dichlorotriazine components (CTAP) for cotton fabrics was synthesized. As an active group, the dichlorotriazine could react with cotton fabric via covalent reaction. The addition of 20.7 wt% CTAP into the cotton fabric obtained a high limiting oxygen index value of 31.5%, which was 13.5% higher than the pure cotton fabric. The results of heat release rate, total heat release and effective heat combustion indicated that CTAP effectively imparted flame retardancy to cotton fabric by the cone calorimetry test. With respect to the untreated cotton fabrics, the treated cotton fabrics degraded at lower decomposition temperature and form a consistent and compact char layer, which could be observed by thermogravimetric analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. Compared to the untreated cotton fabrics, CTAP performed an effective role in flame retardancy for treated cotton fabrics. Meanwhile, it stimulated the formation of char and promoted the thermal stability of treated cotton fabrics during combustion.


Fibers ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 69
Author(s):  
Eva Magovac ◽  
Bojana Vončina ◽  
Ana Budimir ◽  
Igor Jordanov ◽  
Jaime C. Grunlan ◽  
...  

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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