JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 40
·49224
·
IF 2.52
Yu Sun,Yazhen Wang,Yingbo Qing,Xueying Wu,Zhen Shi
A novel 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-based Schiff base derivative, 6,6′-(1,4-phenylenebis (((3-hydroxyphenyl)amino) methylene)) bis (dibenzo [c,e] [1,2] oxaphosphinine 6-oxide) (SD), was synthesized and applied to polystyrene. The structure of terephthalaldehyde dihydroxymethane benzene and SD are characterized by Fourier-transform infrared (FTIR) spectroscopy, 1 H-nuclear magnetic resonance spectroscopy, and elemental analysis. The results of thermogravimetric analysis tests show that the residue of the SD/PS composites increased from 0.21 to 7.09% with the increase of SD content, indicated that the thermal stability of the SD/PS composites was significantly improved. The introduction of SD also efficiently ameliorated the flame-retardant property of SD/PS composites with limiting oxygen index increased by 33.15%, rated UL-94 vertical burning test V-0 rating, lower peak heat release rate, and total heat release. The mechanism of SD/PS composite was explored by scanning electron microscopy images and FTIR spectra of residue of SD/PS composites after calcination by muffle furnace. These tests prove that SD can be used as an effective polystyrene (PS) flame retardant.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Bohan Liang,Ke Liu,Junming Dai,Wenxing Chen,Wangyang Lu
A polymer-type flame retardant (PFR) based on a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative was synthesised here to improve the flame retardancy of polyamide 6 (PA6). The chemical structure and thermal property of the PFR were characterised by Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The PFR and PA6 were melt-blended to obtain a flame-retardant polyamide 6 (FRPA6). Its thermal property, mechanical property and flame retardancy were characterised via TGA, DSC and tensile, impact, vertical burning and limiting oxygen index (LOI) tests. Its flame-retardant mode of action was analysed by scanning electron microscopy, FTIR spectroscopy, cone calorimetry and pyrolysis-gas chromatography-mass spectrometry. The FRPA6 with a phosphorus content of 3000 ppm passed the UL-94 V-0 rating, and the LOI of the FRPA6 with a phosphorous content of 5000 ppm reached 28.8 %. Compared with pure PA6 , the peak heat release rate, total heat release and effective heat of FRPA6–5000 were reduced by 35.4 %, 21.9 % and 26.5 %, respectively. These results indicate that the flame-retardant mode of action of PFR mainly involved the quenching effect of phosphorus-containing radicals in the gas phase.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Ying Zhou,Weidi He,Jiling Song,Dinghong Xu,Hongmin Wu,Jianbing Guo
The fabrication of ultralight high-performance flame-retardant composites significantly reduces fire risk for buildings. Flame retardation of porous polyvinyl alcohol (PVA) aerogels with directional arrangement is difficult. Herein, the polyvinyl alcohol/ 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivative/two-dimensional (2D) MXene (PVA/DiDOPO/MXene) composite aerogel was prepared by ice template one-way freezing process. PVA-DiDOPO4 composite aerogel with an oriented porous structure reaches the V-1 level at the UL-94 test. Moreover, the peak heat release rate (pHRR) value of PVA-DiDOPO4 reduces to 452.26 (W/g) from 482.88 (W/g) of pure PVA. In addition, PVA/DiDOPO/MXene composite aerogel has improved thermal decomposition properties such as the maximum decomposition temperature (T max1 ) of the PVA-DiDOPO4 sample attains 319.92 °C from pure PVA of 302.90 °C. The design strategy of PVA combined 2D MXene nanosheet and DOPO derivatives construct oriented porous composite aerogel paves the way for the fabrication and customization of ultralight flame-retardant polymer composites, which can be expected to be applied in construction and reduce fire risk.
研究领域:
材料科学
·
热分析
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2024
·Vol. 35
·期 4
·e6358
·
IF 3.1
Qinqin Luo,Yulin Sun
A novel organic salt containing DOPO and pyrimidine (AD) was successfully synthesized through a simple acid–base neutralization reaction. The salt was used as a reactive flame retardant for epoxy resin. Non-isothermal DSC tests disclosed that the epoxy resin displayed a lower temperature of onset curing and exothermic peak in the presence of AD. By using only 3 wt% AD, the epoxy resin achieved a UL-94 V-0 rating and a limited oxygen index value of 27.4%, revealing the high flame-retardant efficiency of AD. AD inhibited the release of heat and smoke. The analysis of the flame-retardant mode of action indicated that AD was able to impede combustion not only by the dilution and quenching effects in the gas phase but also by the charring effect in the condensed phase. During UL-94 testing, 3 wt% AD gave the epoxy resin good flame retardancy due to the charring and blowing-out effects formed by adding AD. The blowing-out effect was that the release of strong airflows suppressed or even blew out the flame based on the dilution and quenching effects of phosphorous-containing radicals and numerous non-combustible gases produced by the degradation of AD and epoxy resin matrix. Additionally, the incorporation of AD slightly increased the glass transition temperature and the tensile and flexural strengths of the epoxy resin. This study provided a meaningful attempt to improve the flame retardance of epoxy resin by introducing a reactive pyrimidine-organophosphonic acid salt.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Delai Jiao,Hengji Zhao,Haofei Sima,Chunzu Cheng,Bo Liu,Chunling Zhang
In this work, we synthesized a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative flame retardant dopamine modified DOPO (DOPO-DA) for flame retardant thermosetting epoxy resins (EP). The effects of different amounts of flame retardants on the flame retardancy, thermal properties, and mechanical properties of EP composites were studied. Compared with the control EP, the peak heat release rate (PHRR) of EP/5 wt% DOPO-DA decreased by 26.1%. In addition, EP/5 wt% DOPO-DA reached V-0 level. It can be attributed to the quenching effect of P element and catechol groups in DOPO-DA, reducing the active free radicals. N element can release non-combustible gases to dilute the concentration of oxygen. Meanwhile, P element can promote the formation of a dense carbon protective layer and slow down the heat and oxygen transfer on the surface. In addition, DOPO-DA can also participate in the crosslinking reaction of EP as a curing promoter, reducing crosslinking density and improving tensile properties.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2020
·Vol. 60
·期 11
·2804-2813
·
IF 1.917
Cong Xie,Fan Leng,Zhen Dong,Weilin Xu,Mengjiao Zhu,Kangjun Xie,Jifu Du,Long Zhao
Two novel flame retardant and anti-dripping PE films were successfully synthesized in three steps. PE-g-GMA film was first prepared by simultaneous electron beam irradiation to graft glycidyl methacrylate (GMA) onto PE film. 4,4′-[1,4-phenyl-bis(9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl)dimethyneimino)]diphenol (DOPO-t) and 4,4′-[1,3-phenyl-bis (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl)dimethyneimino)]diphenol (DOPO-m) were then fabricated via a one-pot method. Finally, two DOPO derivative functionalized PE films were obtained through the ring opening reactions of PE-g-GMA film with DOPO-t and DOPO-m, respectively. Combustion properties, flame retardancy, thermal performance, and thermal shrinkage of these films were evaluated. Compared with pure PE film, the burning rate of anti-dripping DOPO-t/DOPO-m functionalized PE films was reduced by 13.2% and 50.0%, and the limiting oxygen index value climbed to 18.5 and 19.5, respectively. The residual chars from DOPO-t/DOPO-m functionalized PE films at 700°C were increased, and the shrinkage ratio decreased remarkably, which could effectively prevent the spread of fire. We also discussed the effect of structural difference between DOPO-t and DOPO-m on the above properties and the flame retardant mechanism of two DOPO derivative functionalized PE films preliminarily. This work provides a method for introducing DOPO derivatives into PE molecules to improve their flame retardancy and anti-dripping properties.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Polymers
·
2020
·Vol. 12
·期 2
·317
·
IF 3.426
Liang Li,Zaisheng Cai
In this study, a flame-retardant additive with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) groups denoted DSD was successfully synthesized from DOPO, 4,4′-diaminodiphenyl sulfone (DDS), and salicylaldehyde. The chemical structure of DSD was characterized by FTIR–ATR, NMR, and elemental analysis. DSD was used as an amine curing agent, and the transparent, tensile strength-enhanced epoxy resins named EP–DSD were prepared via thermal curing reactions among the diglycidyl ether of bisphenol A (DGEBA), 4,4′-diaminodiphenylmethane (DDM), and DSD. The flame-retardancy of composites was studied by the limiting oxygen index (LOI) and UL-94 test. The LOI values of EP–DSD composites increased from 30.7% for a content of 3 wt % to 35.4% for a content of 9 wt %. When the content of DSD reached 6 wt %, a V-0 rating under the UL-94 vertical test was achieved. SEM photographs of char residues after the UL-94 test indicate that an intumescent and tight char layer with a porous structure inside was formed. The TGA results revealed that EP–DSD thermosets decomposed ahead of time. The graphitization degree of the residual chars was also investigated by laser Raman spectroscopy. The measurement of tensile strength at breaking point shows that the loading of DSD increases the tensile strength of epoxy thermosets. Py-GC/MS analysis shows the presence of phosphorus fragments released during EP–DSD thermal decomposition, which could act as free radical inhibitors in the gas phase. Owing to the promotion of the formation of intumescent and compact char residues in the condensed phase and nonflammable phosphorus fragments formed from the decomposition of DOPO groups, EP–DSD composites displayed obvious flame-retardancy.Keywords:thermosets;amine curing agent;DOPO derivatives;mechanical properties;epoxy resins
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2018
·
IF 3.193
Siqi Huo,Jun Wang,Shuang Yang,Chuan Li,Xiaolei Wang,Haopeng Cai
A novel DOPO-containing imidazole curing agent (DIB) was successfully synthesized, and served as a co-curing agent of 4,4‘-diaminediphenyl sulfone (DDS) to prepare a reactive flame-retarded epoxy thermoset (EP/DDS/DIB). The DSC results showed that the curing temperature of EP/DDS/DIB mixture was much lower than that of EP/DDS mixture due to the catalytic curing effect of imidazole group. Although the T g values of EP/DDS/DIB thermosets decreased in some degree, they were still obviously higher than that of EP/DDS/DOPO thermoset. The combustion tests indicated that DIB was a high-efficiency flame retardant for epoxy resin . The LOI value and UL94 rating of EP/DDS/DIB-0.75 sample reached 36.8% and V-0, respectively. In addition, the pk-HRR, av-HRR and THR of EP/DDS/DIB-1.0 thermoset were decreased by 57.2%, 37.9% and 36.0%, respectively, compared with those of EP/DDS thermoset. The studies concerning decomposition products in both condensed and gaseous phases revealed that the introduction of DIB brought about the formation of a protective intumescent char layer and the release of phosphorus-containing radicals and noncombustible nitrogen-containing fragments during combustion. DIB exerted bi-phase flame retardant effect on epoxy resin.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2014
·
IF 2.633
Liqiang Gu,Guoan Chen,Youwei Yao
Two novel halogen-free flame retardants , DP-DDE and DP-DDS, were synthesized via a one-pot procedure based on the Pudovik reactions between 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) and imines directly resulting from the condensation reactions of 3-methoxy-4-hydroxybenzaldehyde with two typical curing agents , 4,4′-oxydianiline (DDE) and 4,4′-diaminodiphenylsulfone (DDS), respectively. The fire-resistant properties of DP-DDE or DP-DDS modified epoxy resins (2,2-bis(4-glycidyloxyphenyl)propane) with 4,4′-methylenedianiline as hardener were been investigated by UL-94 vertical test. Their high flame-retarding performance has been found: the epoxy thermosets with a relatively low addition amount of DP-DDE or DP-DDS (on the account of phosphorus content of 0.75 wt.% or 0.73 wt.%) can reach UL-94 V-0 flammability rating. These thermosets demonstrated excellent thermal stability, high glass transition temperature ( T g > 135 °C) and high char yields (>22% at 800 °C). Moreover, the thermal degradation kinetics of the flame retardants and their corresponding epoxy thermosets were studied based on Kissinger, Ozawa and FWO methods by thermogravimetric analysis .
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2017
·Vol. 29
·期 1
·603-611
·
IF 1.907
Ting Chen,Xianming Chen,Meijie Wang,Peixin Hou,Cao Jie,Jilu Li,Yiting Xu,Birong Zeng,Lizong Dai
A novel halogen-free 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-containing co-curing agent, 6,6′-(1,4-phenylenebis(((4-(phenylamino)phenyl)amino)methylene))bis(dibenzo[c,e][1,2]oxaphosphinine 6-oxide) (DPN) was synthesized via a simple 1-pot or 2-step procedure with yield of 86.2% and 70.8%, respectively. The molecular structures of 4,4′-((1,4-phenylenebis(methanylylidene))bis(azanylylidene))bis(N-phenylaniline) (DPN intermediate) and DPN are characterized by FTIR, NMR, and MS. TGA tests show that the char yield of DPN/EP composites raises to 30.9% when the molar ratio of DPN to 4,4-diaminodiphenyl methane(DDM) is 20:80. T g values of DPN/EP composites tested by DSC and DMA are similar to neat epoxy resin (EP), which is due to the secondary amine in DPN that participates in the cross-linking reaction of epoxy resin. The storage modulus in the rubber stage (E′-190 °C) of flame-retardant epoxy resin is close to that of neat EP, while their tanδ's are lower, which indicates the similarity of samples' cross-linking density due to the participation of DPN in the cross-linking reaction. The results show that when the molar ratio of DPN and DDM is 5:95, the epoxy has a higher T g value and better mechanical properties than other samples. The introduction of DPN efficiently improves the flame-retardant properties of epoxy resin with V-0 rating of UL-94 vertical burning test, non-dripping, 41% of limit oxygen index (LOI) value, low peak heat release rate (PHRR), and total heat release (THR).
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2020
·
IF 4.032
Chanchal Kumar Kundu,Xin Wang,Mohammad Ziaur Rahman,Lei Song,Yuan Hu
A DOPO-based phosphorus compound (DOPA) was synthesized and applied onto the pure and chitosan (CS) modified polyamide 66 (PA66) fabric surfaces via a simple pad-dry-cure method to improve the flame retardant properties of the same. The pure and chitosan modified fabric samples treated with DOPA at different content % degraded in a different way as the char residue formation and releasing of volatile and non-volatile gas species were dissimilar which were evident from the thermogravimatric and thermogravimetric-gas chromatography-mass spectroscopy (TG-GC-MS) test analysis. Obtained results also showed that no dripping occurred in the vertical burning test and a sharp increase in limiting oxygen index (LOI) values was noticed for all the treated fabric samples. CS modified PA66 fabric sample treated with a 10 wt % of DOPA exhibited a greater reduction in pHRR by 40% and showed superior flame retardant performance compared to the only DOPA treated pure fabric sample. The superb flame retardant properties of CS modified fabrics were due to the co-presence of DOPA and CS; where a synchronized gas phase and a condensed phase flame retardant mechanism was realized as DOPA showed a quenching effect in a gas phase mechanism and simultaneously, catalyzed the charring of CS in a condensed phase activity which was also justified from the TG-GC-MS analysis, TGA and FTIR analysis of char residues. However, this kind of facile application showed poor wash durability and deteriorated the physical properties of the fabric materials specifically treated with a higher DOPA content.
研究领域:
材料科学
·
纺织工程
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
E-POLYMERS
·
2019
·Vol. 19
·期 1
·235-243
·
IF 1.491
Lin Liu,Rui Lv
A DOPO (9,10-dihydro-9-oxa-10-phosphaphen-anthrene-10-oxide)-based halogen-free flame retardant (ODOPM-CYC) was synthesized and incorporated in rigid polyurethane foam (RPUF). The structure of ODOPM-CYC was characterized by Fourier transform infrared spectra (FTIR), 1 H NMR and 31 P NMR. The effects of ODOPM-CYC on the flame resistance, mechanical performances, thermal properties and cell structure of RPUF were also investigated. The results showed that the incorporation of ODOPM-CYC strikingly enhanced flame retardant properties of RPUF. The flame retarded RPUF acquired a limiting oxygen index (LOI) value of 26% and achieved UL-94 V-0 rating with the phosphorus content of 3 wt%. The smoke production rate (SPR) also showed an obvious decrease and total smoke release (TSR) was 39.8% lower than that of neat RPUF. Besides, the results demonstrated that the incorporation of ODOPM-CYC provided RPUF better thermal stability but did not show any obvious influence on its thermal conductivity. Graphical
研究领域:
材料科学
·
阻燃材料
·
聚合物化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）