PROGRESS IN ORGANIC COATINGS
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2024
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IF 6.5
Li-Ping Zhang,Zhen-Guo Zhao,Yuan-Yuan Huang,Xing Cao,Xin-Yu Tian,Yan-Peng Ni,Yu-Zhong Wang
The cationic waterborne polyurethanes (CWPU) exhibit excellent affinity towards various materials possessing negative surface charges owing to its positive charge. However, its limited heat resistance and flame retardancy greatly restrict its practical application. In this work, we synthesized a flame retardant , 2-(6-oxido-6H-dibenz〈c,e〉〈1,2〉oxaphosphorin-6-yl)-1,4-hydroxyethoxyphenylene (DOPO-HQ-HE), and incorporated it into the skeleton of cationic waterborne polyurethanes to prepare flame-retardant cationic waterborne polyurethanes (CWPU-DHHxs). The obtained CWPU-DHHxs showed excellent flame retardancy, in which the LOI value of CWPU-DHH 12 reached over 26.9 vol% and passed UL-94 V-0 rating. The findings showed that CWPU-DHHxs exhibited remarkable efficacy in both the vapor and condensed phase during combustion. Moreover, the incorporation of DOPO-HQ-HE led to a significant improvement in heat resistance performance by facilitating enhanced microphase separation . Meanwhile, the major comprehensive performance of CWPU-DHHxs, including emulsion storage stability, thermal stability, mechanical performance, and transparency were effectively preserved.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2023
·Vol. 140
·期 46
·e54674
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IF 3
Yingting Yin,Mao Feng,Wei Li,Jinbo Yao,Jiarong Niu
To improve the flame retardancy and solid content of waterborne polyurethane (WPU), AOT, and AOD series of WPU were synthesized and characterized. Carboxylic acid/nonionic composite units were used as hydrophilic groups, and OP550/THPO and OP550/DOPO-HQ combinations were used as flame retardant modifiers, respectively. The results revealed that the flame retardant-modified WPU emulsions still had excellent dispersion, stability, and fluidity. The UL-94 rating of modified WPU could reach V-0, and the AOD series samples had better flame retardancy than the AOT series, where AO 10 D 3 -WPU containing 3% DOPO-HQ had an limiting oxygen index value up to 30.5%. Besides, the peak heat release rate and total heat release of AO 10 D 3 -WPU were respectively decreased by 32% and 34%, compared with the control sample in the conical calorimetric test. The TGA, TG-IR, and SEM-EDS exhibited that the flame retardants functioned in the condensed phase by promoting carbon formation. The tensile strength of AOT series samples was excellent with a range of 15.84–27.47 MPa, while the elongation at break of AOD series samples was relatively high with a distribution of 850.8%–913.11%, which could be selected to suit the needs of different application scenarios.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
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2024
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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
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
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2026
·
IF 8.1
Puxi Zheng,Zhoufeng Wang,Wenchi Zhang,Hui Xu
To address the limited solution processability and insufficient thermo-oxidative char stability of conventional polyarylates, a molecular structure regulation strategy was proposed in this work. A series of DOPO-HQ-containing copolyarylates were synthesized by incorporating 10 - (2,5 - dihydroxyphenyl) - 10H - 9- oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ) into the polyarylate backbone through solution copolycondensation. The chemical structures and copolymer compositions were confirmed by 1 H NMR, HSQC NMR, quantitative 1 H NMR, and FT-IR analyses, while GPC and XRD were used to characterize the molar-mass parameters and amorphous structures, respectively. Thermal analysis showed that DOBA-20, prepared with 20 mol% DOPO-HQ in the total bisphenol feed, exhibited a glass transition temperature of 194.9 °C and a char yield of 38.3% at 800 °C under nitrogen. More importantly, DOBA-20 retained a char yield of 32.7% at 800 °C under air atmosphere, far exceeding that of the DOPO-HQ-free polyarylate, DOBA-0 (0.04%), indicating significantly enhanced char stability under oxidative conditions. TG-FTIR and Py-GC/MS analyses, together with XPS and SEM analyses of char residues, demonstrated that DOPO-HQ mainly promoted the retention of phosphorus species in the condensed phase, facilitating the formation of a continuous and compact phosphorus-rich char layer containing phosphate/pyrophosphate structures. This stable char layer could suppress heat transfer and oxygen diffusion, possibly accompanied by limited gas-phase inhibition. This work provides a molecular design strategy for regulating the thermal degradation pathway of polyarylates and improving their solution processability and thermo-oxidative stability.
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Peng Wei,Jiaojiao Li,Jinfei Yan,Junhui Li,Jichao Zhang,Yuchen Liu,Wanwan Li,Yumin Xia,Yanping Wang
In order to acquire polymeric fibers have both excellent flame retardance and mechanical properties, high molecular weight phosphorus-containing liquid crystal copolyesters derived from 6-hydroxy-2-naphthenic acid (HNA), terephthalic acid (TA) and 10-(2,5-dihydroxypheny)-10-hydro-9-oxa-10-phospha phenanthrene-10-oxide (DOPO-HQ) were synthesized via “one-pot” melt polymerization, and then the fibers were obtained by melt spinning method. The structure and property of the copolyesters were studied elaborately by experimental characterization technique and molecular simulation method. Shear shinning behavior was observed from rheology measurement, indicating that the copolyesters had excellent melt fluidity and spinnability. The rigidity of molecular chain was efficiently improved by the phosphorus-containing monomer DOPO-HQ and naphthalene HNA units which could be reflected by the molecular simulation results as well as high T g values. The flame retardant mechanism of the phosphorus-containing flame retardant copolyester was systematically studied via limiting oxygen index (LOI), vertical burning (UL-94) test, cone calorimetry, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that the copolyesters exhibit synergistic flame retardant mechanism of gas phase and condensed phase. Meanwhile, mechanical property of the as-spun fibers could be significantly improved by increasing the spinneret draw ratio (SDR) attributed to high molecular chain orientation. The maximum tensile strength of the as-spun fiber was 0.77 GPa observed for P-HNA60P20 at a relatively low SDR of 29. It was shown the unique combination of good thermal stability, spinnability as well as mechanical and flame retardant properties of the copolyesters would make them could be used as high-performance flame retardant materials.
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
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）