HIGH PERFORMANCE POLYMERS
·
2017
·
IF 1.179
Shan Huang,Xiao Hou,Jiaojiao Li,Xiujuan Tian,Qing Yu,Zhongwei Wang
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.
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
·
2018
·
IF 3.193
Junjing Zhao,Xu Dong,Shan Huang,Xiujuan Tian,Liang Song,Qing Yu,Zhongwei Wang
Two phosphorus-containing flame retardants , (bis(4-hydroxyphenyl)methyl)diphenyl phosphine oxide (DPO–PHE) and 1-(bis(4-hydroxyphenyl)methyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO–PHE) were synthesized and characterized. The two target compounds both were used as a flame retardant and a co-curing agent of 4,4′-diaminodiphenylsulfone of bisphenol A diglycidyl ether to prepare flame-retardant epoxy resins (EP/DPO–PHE and EP/DOPO–PHE). The thermal and flame-retardant properties of the thermosets were investigated by thermogravimetric analysis (TGA), limited oxygen index (LOI) measurement, and UL-94 vertical burning testing (UL-94). The results indicated that both flame retardants can improve the flame retardancy of epoxy thermosets. TGA results indicated that the char yields of EP/DPO–PHE–P-0.9 and EP/DOPO–PHE–P-0.9 thermosets were increased from 19.1% of EP/P-0 to 25.3% and 27.8%, respectively. Compared with that of EP/P-0, the LOI of the EP/DPO–PHE–P-0.5 thermoset increased from 23.7% to 30.1%, and the sample reached UL-94 V-0. Meanwhile, the LOI of the EP/DOPO–PHE–P-0.7 thermoset increased from 23.7% to 28.9%, and the sample reached UL-94 V-0. Cone calorimetry test, scanning electron microscopy of burning residues, and pyrolysis–gas chromatography/mass spectrometry indicated that both flame retardants mainly act through the gas–phase mechanism. In addition, no condensed-phase activity of DPO–PHE was observed, whereas the condensed-phase activity of DOPO–PHE was negligible. Immersion experiments showed that the water absorption activity of flame retardant epoxy resins fluctuates. Compared with DOPO–PHE, DPO–PHE was more effective as a higher flame-retardant and exhibited better characteristics for improving the T g , thermal stability, and water absorption of modified resins.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2024
·
IF 12.7
Bin Zou,Ziyan Qian,Zixuan Zhang,Weiyi Xing,Shangshang Zhong,Jiajun Li,Fukai Chu,Yongchun Kan,Jie Chen,Yuan Hu
Fire hazards are a primary concern in aircraft accidents, and controlling combustible materials is pivotal in managing cabin fire risks. This work aims to elucidate the impact of widespread measures that introduce phosphorus-based flame retardants (PFRs) on the fire safety of carbon fiber epoxy composites (CF/EP). Firstly, the hazardous indicators for flame retardant CF/EP composites exhibit two categories of optimization and degradation, which are caused by the intrinsic feature, pyrolysis characteristics and chemical valence states of PFRs. Secondly, the fire hazards of composites are assessed by fusing the analytic network process and information weights guided by Nash Equilibrium theory. The method combines the merits of subjective and objective weights from dimensions of intrinsic hazards, interrelationships and data dispersion of indicators. Finally, the assessed fire hazard rankings under 35 and 65 kW/m 2 both are EP > CF/EP16%DOPO-HQ > CF/EP > CF/EP7%DPO. In conclusion, DOPO-HQ (+1) primarily increases the fire hazard of CF/EP due to gas-phase flame-retardant effects, while DPO (+3) predominantly reduces the fire hazard of CF/EP by contributing to condensed-phase effects. This work highlights the contradictory effects of PFRs on the fire safety of CF/EP composites due to structure and thermal stability. The proposed ANP and IW hybridization method provides a theoretical foundation for selecting flame retardants and assessing material fire hazards comprehensively.
研究领域:
航空工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS
·
2022
·
IF 1.052
Fengce Mei,Chong Tian,Hubo Li,Shan Huang,Qing Yu,Yuxi Han,Zhongwei Wang
A phosphorous-nitrogen flame retardant 1-N,4-N-bis(diphenylphosphorylmethyl)benzene-1,4-diamine (DPO-N) was synthesized by the reaction of p-phenylenediamine, formaldehyde and diphenylphosphine oxide (DPO). The modified epoxy resin (EP) was prepared using DPO-N as a flame retardant and co-curing agent in the presence of 4,4’-diaminodiphenylsulfone to cure bisphenol A diglycidyl ether (DGEBA). The flame retardancy of the DPO-N-modified EP was evaluated by the limiting oxygen index (LOI), vertical burning test (UL-94) and cone calorimeter test. The results showed that the EP/DPO-N-0.7 (DPO-N-modified EP at a phosphorus content of 0.7 wt.%) passed the UL-94 V-0 rating test, and the LOI value of the sample increased to 30.4%. The peak of the heat release rate (pk-HRR), average of the heat release rate (av-HRR) and average of the effective heat of combustion (av-EHC) of the modified EPs were reduced by 32.4, 27.4 and 28.4%, respectively. The flame retardant mechanism was investigated by scanning electron microscopy, pyrolysis/gas chromatography-mass spectrometry and Fourier transform infrared spectroscopy analyses. The results demonstrated that DPO-N exerted its flame-retardant effect through the barrier effect of the condensed phase and the quenching effect of the gas phase. Furthermore, the water resistance of the EP was enhanced with the incorporation of DPO-N.
✓ 已验证
DOI
高影响因子
JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY
·
2020
·Vol. 32
·期 6
·769-778
·
IF 0.909
Xiujuan Tian,Qingqing Yin,Zhongwei Wang
A type of reactive phosphorus based flame retardant, hydroxy(4-hydroxyphenyl)methyl)diphenylphosphine oxide (DPO-H), was synthesized and characterized by Fourier Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopies. 4,4′-Diaminodiphenylsulfone (DDS) was used as the curing agent and DPO-H was used as the reactive flame retardant and co-curing to prepare the flame-retardant epoxy resins with different P contents. It can be observed that the introduction of DPO-H could enhance the transparency of epoxy resin. Flame-retardant epoxy resin samples were investigated by limit oxygen index (LOI) test, vertical burning (UL-94) testing, cone calorimetry test and thermogravimetric analysis (TGA). The results indicated that DPO-H can increase the flame retardation and carbon formation of epoxy resin. The flame-retardant epoxy resin sample with P content of 0.5 wt% can reach UL-94 V-0 rate, and LOI value increased to 29.6%. The flame-retardant mechanism of the DPO-H modified flame-retardant epoxy resin was analyzed by thermogravimetry-infrared combination (TG-IR), pyrolysis gas chromatography mass spectrum (PY/GC-MS) and scanning electron microscope (SEM). The results showed that the introduction of DPO-H can inhibit the pyrolysis of epoxy resin effectively. Epoxy resin modified by DPO-H had evident flame-retardant effect both in gas phase and condensation phase.
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
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhenye Fu,Zirui Ma,Jiuhong Liu,Chunhui Li,Chuanmei Liu,Qidong Wang,Liang Song,Qing Yu,Guiqing Cheng,Yuxi Han,Hailong Liu,Zhongwei Wang
In the pursuit of epoxy thermosets with low dielectric properties and excellent flame retardancy, the 2- (diphenylphosphino)-1,4-benzenediol active ester (DPO-HQ-AE). and 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide active ester (DOPO-HQ-AE) were synthesized as bifunctional phosphorus-containing active ester flame retardants. The molecular structures of DPO-HQ-AE and DOPO-HQ-AE were characterized by MS, 1 H NMR, 13 C NMR, 31 P NMR and FTIR. The flame retardancy, thermal stability, crosslink density, water absorption and dielectric properties of active ester cured dicyclopentadiene (DCPD) epoxy resins were investigated. DCPD/DPO-HQ-AE with a phosphorus content of 0.9 wt% passed the UL-94 V-0 test. Meanwhile, DCPD/DOPO-HQ-AE containing 1.2 wt% phosphorus achieved a V-0 rating. DPO-HQ-AE and DOPO-HQ-AE showed noticeable gas-phase flame-retardant mechanism with active phosphorus species in the gas phase of pyrolysis. At the frequency of 1 GHz, the dielectric constant and dielectric loss of DCPD/DPO-HQ-AE-0.9 were 2.67 and 0.0042, respectively. Compared with the unmodified epoxy resin , the dielectric loss was reduced by approximately 5.5 times. The as-prepared epoxy thermosets with high thermal stability, excellent flame retardancy, low dielectric properties and low water absorption satisfied the requirements of high-speed and high-frequency encapsulation materials.
研究领域:
材料科学
·
高分子化学
·
电气工程
✓ 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）