scholarly journals Flame-Retardant Mechanism and Mechanical Properties of Wet-Spun Poly(acrylonitrile-co-vinylidene chloride) Fibers with Antimony Trioxide and Zinc Hydroxystannate

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2442
Author(s):  
Ji Su Kim ◽  
Ji Eun Song ◽  
Daeyoung Lim ◽  
Heejoon Ahn ◽  
Wonyoung Jeong

To produce flame retardant poly(acrylonitrile-co-vinylidene chloride) (PANVDC) fibers with limiting oxygen index (LOI) values above 28%, flame retardants are added to fibers. Because antimony trioxide (ATO) used widely for PANVDC is suspected as a carcinogen, non-toxic zinc hydroxystannate (ZHS) could be the alternative for reduction of ATO usage. Moreover, a flame retardant efficiency of the combination of ATO with ZHS could be expected because it was reported that ATO resists flame in the gas phase, whereas ZHS reacts in the condensed phase. Therefore, this study discussed the flame retardant mechanisms of ATO and ZHS in PANVDC, and evaluated the efficiency of the combination. PANVDC fibers with ATO and ZHS in 15 phr were produced by wet spinning. When ZHS was added, a more cyclized structure was detected (e.g., 1-methylnaphthalene) through pyrolysis−gas chromatography-mass spectrometry (Py-GC/MS). As a result of SEM-EDX analysis, Sb and Cl hardly remained in char layers of PANVDC-ATO; meanwhile, Zn, Sn, and Cl remained in that of PANVDC-ZHS. This implied that SbCl3 from reaction of ATO and HCl reacts in the gas phase, whereas ZnCl2 and SnCl2 from ZHS and HCl promotes the cyclization reaction of PANVDC in the condensed phase. The LOI values of PANVDC, PANVDC-ATO, and PANVDC-ZHS were 26.4%, 29.0%, and 33.5%, respectively. This suggests that ZHS is a highly effective for PANVDC. Meanwhile, the LOI of PANVDC containing ATO-ZHS mixture is 31.0%. The combination of ATO and ZHS exhibited no efficiency. The addition of ATO and ZHS slightly reduced the tenacities of the fibers, respectively, 3.11 and 3.75 from 4.42 g/den.

2021 ◽  
Author(s):  
Na Li ◽  
Panpan Chen ◽  
Dongni Liu ◽  
Gaowei Kang ◽  
Liu Liu ◽  
...  

Abstract Cotton fibers as original materials of cotton fabrics have a widely application due to its perfect hygroscopicity, air permeability and largest annual output. However, cotton materials have potential safety hazard during its application because of flammability (limiting oxygen index is about 18%). In order to improve the flame retardancy of cotton fibers and reduce the damage of its mechanical properties, novel P/Si based flame retardant (PFR) nanoparticles were synthesized by one-step radical polymerization. Vinyl phosphoric acid and tetramethyl divinyl disiloxane were introduced into the nanoparticles. The structure, morphology and thermal stability of PFR was characterized by fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis test (TGA). Durable flame retardant cotton fibers were prepared by dip-coating and plasma induced crosslinking methods. Micro-calorimeter (MCC) characterization showed that the peak of heat release rate (pHRR) and the total heat release were reduced by 47.3% and 29.8% for modified cotton fibers compared with pure cotton fibers. Limiting oxygen index (LOI) of modified cotton fibers was increased to 27%. The residue carbon of modified cotton fibers was 19.0% at 700 o C, while the value of pure cotton fibers was 3.0%. Besides, durability of the modified cotton fibers was approved by cyclic washing test. In addition, flame retardant mechanism was revealed by collecting and analyzing condensed and gaseous pyrolysis products. The data of FE-SEM for residue carbon, FT-IR spectra of products at different pyrolysis temperatures and pyrolysis gas chromatography mass spectrometry (Py-GC-MS) showed that PFR was a synergistic flame retardant contained barrier and quenching effecting applied on cotton materials.


Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1575 ◽  
Author(s):  
Peng Xu ◽  
Peiyuan Shao ◽  
Qing Zhang ◽  
Wen Cheng ◽  
Zichao Li ◽  
...  

A novel flame-retardant composite material based on zinc alginate (ZnAlg) and nano-cuprous oxide (Cu2O) was prepared through a simple, eco-friendly freeze-drying process and a sol-gel method. The composites were characterized and their combustion and flammability behavior were tested. The composites had high thermal stability and achieved nearly non-flammability with a limiting oxygen index (LOI) of 58. The results show remarkable improvement of flame-retardant properties in the ZnAlg/Cu2O composites, compared to ZnAlg. Furthermore, the pyrolysis behavior was determined by pyrolysis–gas chromatography–mass spectrometry (Py-GC-MS) and the flame-retardant mechanism was proposed based on the combined experimental results. The prepared composites show promising application prospects in building materials and the textile industry.


2017 ◽  
Vol 30 (6) ◽  
pp. 667-676 ◽  
Author(s):  
Wei Yan ◽  
Jie Yu ◽  
Mingqiu Zhang ◽  
Lijuan Long ◽  
Tao Wang ◽  
...  

A series of flame-retardant epoxy resins (EPs) containing either phenethyl-bridged 9 or 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivative (bisDOPO) were prepared. The flame-retardant properties of bisDOPO on EP composites were characterized by the limiting oxygen index (LOI), the UL-94 vertical burning, and the cone calorimeter test (CCT).The LOI of the EP/bisDOPO composites increased from 21.8% to 38.0%, and the hybrids with the 10 wt% bisDOPO obtained a V-0 rating in the UL94 vertical burning test. The char residue following the CCT showed intumescent structures with continuous and compact surfaces that can effectively suppress the spread of the flame and extinguish the fire. This was confirmed through both visual observation and scanning electron microscopy (SEM) measurements. The flame-retardant mechanism was studied by Fourier transform infrared spectroscope (FTIR), thermogravimetric analysis/infrared spectrometry, SEM/energy-dispersive X-ray, and pyrolysis-gas chromatography/mass spectrometry. Overall, bisDOPO was an effective flame retardant with potential applications within EP.


Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1365 ◽  
Author(s):  
Ji Eun Song ◽  
Ji Su Kim ◽  
Daeyoung Lim ◽  
Wonyoung Jeong

In this study, zinc hydroxystannate ([ZnSn(OH)6], ZHS) was coated with aluminum phosphate (AlPO4, ALP) to prepare the ZHS-ALP composite. During the coating process, the reaction conditions, such as the ALP to ZHS molar ratio, were controlled, and the morphology of the products was characterized by scanning electron microscopy (SEM). The prepared composites were introduced into poly(acrylonitrile-co-vinylidene chloride) (PANVDC), and the change in compatibility between ZHS and the polymer matrix was characterized. The results showed that ALP-ZHS (1:1), which was prepared by ALP-ZHS composite molar ratio of 1:1, could improve the dispersion and compatibility of ZHS in the polymer matrix and decrease the hydrophilicity and viscosity. Moreover, the ALP-ZHS composite had a better flame-retardant effect on PANVDC than ZHS alone. PANVDC could pass the V-0 rating in UL94, particularly the highest limiting oxygen index (LOI) value of 33.2% obtained when the ALP-ZHS (1:1) composite was added to PANVDC.


Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 42
Author(s):  
Hyelim Kim ◽  
Ji-Su Kim ◽  
Wonyoung Jeong

Antimony oxide (ATO) is used mainly as a flame retardant, but it is classified as a hazardous substance. Therefore, regulations on the use of antimony trioxide (ATO(3)) and antimony pentoxide (ATO(5)) in textile products are being developed. Accordingly, there is a need for alternative flame retardants. In this study, antimony tetroxide (ATO(4)), which has higher thermal stability and resistance to acids and alkalis than ATO(3) or ATO(5), was selected to assess its use as an alternative flame retardant. First, ATO(3) or ATO(4) were added to poly(acrylonitrile-co-vinylidene chloride) (PANVDC), and the film and wet-spun fiber were prepared. The PANVDC film with flame retardants was prepared to evaluate the flame retardancy and the mechanism of action of the flame retardants. Flame retardancy analysis showed that a limiting oxygen index of 31.2% was obtained when ATO(4) was added, which was higher than when ATO(3) was used. Subsequently, PANVDC fibers with antimony oxide were manufactured and showed improved mechanical and thermal properties when ATO(4) was used, compared to when ATO(3) was tested. In addition, migration analysis due to antimony in the fiber confirmed that the elution amount was below the acceptable standard when PANVDC fibers with ATO(4) were added. Therefore, based on these results, the flame-retardant and thermal properties of antimony tetroxide were superior to antimony trioxide, and it was confirmed that ATO(4) could be used as an alternative flame retardant to ATO(3).


2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Mingyang Du ◽  
Chunze He ◽  
Canhui Zhou

The effect of Isocyanate trimer on the flame retardancy mechanism of polyisocyanurate (PIR) foam was studied through 3 aspects including the mechanism of thermal decomposition stage in condensed phase, the barrier mechanism of carbon layer formation on the surface in condensed phase and the mechanism in gaseous phase by using infrared spectroscopy, scanning electron microscopy, thermal analysis, cone calorimeter, high temperature pyrolysis gas chromatography mass spectrometry. The results show that the trimer can improve the thermal stability of the PIR foam and is not easily decomposed in the combustion. The trimer can increase the carbon content of the PIR foam to 29.9% than that of the polyurethane (PU) foam. The carbon layer formed is denser, and it can retards heat and oxygen and thus improve the flame retardant properties; trimer can reduce the release of flammable polyol gas, decompose into more carbon dioxide which is inert gas and it has certain flame retardant effect in the gaseous phase.


2021 ◽  
pp. 095400832199241
Author(s):  
Zijin Luo ◽  
Zhe Chen ◽  
Jun Wei ◽  
Dongchao Wang ◽  
Han Chen ◽  
...  

A novel intumescent flame retardant, PPMD, was designed from phosphaphenanthrene and nitrogen heterocycles through the two-step gut reactions of 1,4-phthalaldehyde and 3-methyl-1-phe-nylpyrazol-5-ylamine. After determination of its structure by nuclear magnetic resonance and Fourier-transform infrared analyses, PPMD was added to an epoxy resin (EP) to facilitate a curing process. Thus, EP/PPMD samples with excellent transparency and flame retardancy were acquired. For example, the EP sample satisfied the UL-94 V-0 standard and achieved a limiting oxygen index value of 30.5% because of the incorporation of 5 wt% PPMD. The cone calorimeter test of the EP/5% PPMD sample revealed that its total smoke production (TSP) and total heat release (THR) values of EP/5% PPMD was only 22.5% and 56.4% of the control group, respectively. Moreover, the average effective heat of combustion (av-EHC) value of EP/5% PPMD was reduced by 34.1%, indicating that PPMD possessed high flame-inhibition activity and smoke suppression efficiency. The flame-retardant mechanisms of PPMD were also investigated in gas phase by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and in condensed phase by XPS and IR.


Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1304 ◽  
Author(s):  
Shengjie Zhu ◽  
Weiguang Gong ◽  
Ji Luo ◽  
Xin Meng ◽  
Zhong Xin ◽  
...  

A novel phosphorus-silicon flame retardant (P5PSQ) was prepared by bonding phosphate to silicon-based polysilsesquioxane (PSQ) and used as flame retardant of poly (lactic acid) (PLA). The results show that PLA with 10 wt % P5PSQ has a limiting oxygen index (LOI) 24.1%, the peak heat release rate (PHRR) and total heat release (THR) of PLA decrease 21.8% and 25.2% compared to neat PLA in cone calorimetric test, indicating that P5PSQ shows better flame retardancy in comparison to PSQ. Furthermore, the study for the morphology and composition of carbon residue after the combustion of PLA and the gas release of PLA during combustion illustrate that P5PSQ has flame retardancy in condensed phase and gas phase simultaneously. In condensed phase, phosphorus from phosphate promotes the formation of more stable and better carbon layer containing Si and P, which inhibits the transfer of heat and oxygen in the combustion. In gas phase, the phosphate in P5PSQ emits phosphorus-containing compound that can restrain the release of C–O containing products, which may have effective flame retardancy for PLA in gas phase to a certain extent. In one word, P5PSQ is denoted as a good phosphorus-silicon synergistic flame-retardant.


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