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The bisphenol‐containing 4,4′‐biphenylene moiety was prepared by the reaction of 4,4′‐bis(methoxymethyl) biphenyl with phenol in the presence of p‐toluenesulfonic acid. The bisphenol was end‐capped with the cyanate moiety by reacting with cyanogen chloride and triethylamine in dichloromethane. Their structures were confirmed by Fourier transform infrared spectroscopy, 1H‐NMR, and elemental analysis. Thermal behaviors of cured resin were studied by differential scanning calorimetry, dynamic mechanical analysis, and TGA. The flame retardancy of cured resin was evaluated by limiting oxygen index (LOI) and vertical burning test (UL‐94 test). Because of the incorporation of rigid 4,4′‐biphenylene moiety, the cyanate ester (CE) resin shows good thermal stability (Tg is 256°C, the 5% degradation temperature is 442°C, and char yield at 800°C is 64.4%). The LOI value of the CE resin is 42.5, and the UL‐94 rating reaches V‐0. Moreover, the CE resin shows excellent dielectric property (dielectric constant, 2.94 at 1 GHz and loss dissipation factor, 0.0037 at 1 GHz) and water resistance (1.08% immersed at boiling water for 100 h). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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Dongyue Liu Feng Jiang Tianlong Zhang Chunxiao Yu Zhiyu Hu Lei Zhang Shuangyou Shi 《应用聚合物科学杂志》2024,141(5):e54890
DOPO based flame retardants demonstrate exceptional flame retardancy efficiency when applied to epoxy resins. However, the crosslinking degree of epoxy resin may decrease due to the addition of DOPO, leading to a deterioration in flame retardancy and mechanical properties. Herein, a reactive DOPO derivative flame retardant 6-((1H-benzo[d]imidazol-2-yl) amino) dibenzo oxaphosphinine 6-oxide (BADO) was successfully synthesized, which contains multiple reactive sites, thus ensuring a higher degree of crosslinking in the system. As a result, the modified epoxy resin exhibits excellent flame retardancy. The limiting oxygen index value of the modified epoxy resins increased from 19.8% to 29.7% by adding 7.5 wt% BADO, and its UL-94 test passed V-0. Flame retardancy mechanism analysis reveals that BADO exhibits both gas-phase and condensed-phase flame retardant effects. In particular, the formation of a porous inside-char layer is a significant factor in reducing smoke release. The 7.5% BADO/EP composite exhibited a 43.2% reduction in total smoke production and a 43.6% reduction in total smoke rate compared to neat epoxy resins (EP). Furthermore, the addition of BADO slightly deteriorates the mechanical properties of the modified epoxy resin. 相似文献
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An aryl phosphinate dianhydride 1,4‐bis(phthalic anhydride‐4‐carbonyl)‐2‐(6‐oxido‐6H‐dibenz[c,e][1,2]‐oxaphosphorin‐6‐yl)‐phenylene ester (BPAODOPE) was synthesized and its structure was identified by FTIR and 1H‐NMR. BPAODOPE was used as hardener and flame retardant for preparing halogen‐free flame‐retarded epoxy resins when coupled with another curing agent. Thermal stability, morphologies of char layer, flame resistance and mechanical properties of flame‐retarded epoxy resins were investigated by thermogravimetric analysis, SEM, limiting oxygen index (LOI), UL‐94 test, tensile, and charpy impact test. The results showed that the novel BPAODOPE had a better flame resistance, the flame resistance and char yield of flame‐retarded epoxy resins increased with an increase of phosphorus content, tensile strength and impact strength of samples gradually decreased with the addition of BPAODOPE. The flame‐retarded sample with phosphorus contents of 1.75% showed best combination properties, LOI value was 29.3, and the vertical burning test reached UL‐94 V‐0 level, tensile strength and impact strength were 30.78 MPa and 3.53 kJ/m2, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
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综述了用于电缆料的无卤阻燃剂的种类及阻燃机理,介绍了用于电缆料的阻燃增效剂;另外,还对用于无卤阻燃剂的基础树脂的现状以及用于电缆料的聚烯烃树脂的改性方法进行了详细的阐述。 相似文献
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Polymethyl(3‐glycidyloxypropyl)siloxane (PMGS) was synthesized as a flame‐retardant additive, which were cocured with diglycidyl ether of bisphenol‐A (DGEBA) using 4,4′‐diaminodiphenylsulfone as a curing agent. The structure of PMGS was confirmed through Fourier transform infrared and 1H‐NMR spectra. The cured products were characterized with dynamic mechanical thermal analysis, thermogravimetric analysis, and oxygen index analyzer. With PMGS incorporated, the cured epoxy resin showed better thermal stability, higher limited oxygen index, and higher char yield. At moderate loading of PMGS, the storage modulus and glass transition temperature of the cured epoxy resin based on neat DGEBA were obviously improved. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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Layered double hydroxide (LDH) is a widely used flame retardant in polymer materials; however, the poor dispersion due to its high hydrophilic nature results in disappointing thermal stability and fire safety. In this work, LDH was in-situ grown on the disordered montmorillonite (MMT) nanosheets to obtain the hybrid of LDH and MMT nanosheets (LDH@MMT, simplified as LM). Various techniques, including X-ray diffraction, Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, and transmission electron microscope were used to characterize the microstructure of LM. In addition, the acrylonitrile-butadiene-styrene (ABS) composite containing LM and intumescent flame retardant (IFR) was prepared, and its mechanical and flame-retardant properties were also measured. The characterization results demonstrate that the LM exhibits a periodically alternating layered structure. The Limiting Oxygen Index (LOI) of the ABS composite reaches 27.2% with a V-0 rating in the UL-94 vertical burning test, while its flexural strength and tensile strength decrease by only 17.82% and 13.45%, respectively. Furthermore, the heat release rate, total heat release, smoke production rate, and carbon monoxide production rate of the ABS composite present a significant decline in cone calorimeter tests compared with those of pure ABS. The results further indicate that the hybridization could effectively improve the flame-retardant performance of ABS composites and perform lesser impacts on their mechanical properties. 相似文献
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无卤阻燃剂中磷酸酯类化合物的研究一直是当前的研究热点,文中着重对水性聚氨酯改性提高阻燃性能的研究进行讨论,设计分析了通过FRC-6合成水性聚氨酯实现阻燃剂的性能改进,采用FRC-6替代其他小分子二醇扩链剂,可以实现合成大量的稳定的有机磷阻燃改性的水性聚氨酯;P含量的增加会降低热释放量,提高阻燃性能。这一研究对于无卤阻燃剂的改进应用具有一定的借鉴价值。 相似文献
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环保型无卤阻燃热缩管以乙烯-乙酸乙烯共聚物(EVA)和低密度聚乙烯(LDPE)为基体树脂,以微胶囊红磷和氢氧化镁为阻燃剂,加入自制的增容剂、复合润滑剂以及复合抗氧剂,制备的环保型无卤阻燃热缩管的环境物质指标符合欧盟RoHS指令要求,产品性能符合UL224标准要求,达到了国外同类产品水平。自制的增容剂能够显著提高微胶囊红磷、氢氧化镁与基体树脂EVA/LDPE的相容性,产品表面光滑而且拉伸强度明显提高。 相似文献
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利用线形聚二氯磷腈(PDCP)与甲醚乙二醇钠反应,合成了聚乙二醇甲醚磷腈(PMEP);采用正交实验分析了溶剂用量、反应时间、反应物配比以及提纯方法对PMEP产率和相对分子质量的影响,优选出最佳的合成工艺条件;利用红外光谱、核磁共振磷谱、差示扫描量热法等手段对合成产物进行了表征;将PMEP与粘胶纺丝原液共混纺丝制备了PMEP共混改性粘胶纤维,初步探讨了PMEP对粘胶纤维的阻燃效果。结果表明:相转变法能减少提纯过程中产物的流失,且能减少提纯分离的周期;PMEP的最佳合成工艺为PDCP与甲醚乙二醇钠摩尔比1.0∶3.0,四氢呋喃溶剂25 m L,反应温度68℃,反应时间10 h;PMEP共混改性粘胶纤维具有良好的阻燃效果,PMEP质量分数为15%时,其阻燃改性粘胶纤维极限氧指数达33%。 相似文献
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Zhiguo Wang 《塑料、橡胶和复合材料》2018,47(7):306-314
A kind of intumescent ?ame-retardant curing agent (PCDSPB) was synthesised by using pentaerythritol, phosphorus oxycholoride, cyclohexane-1,3-diyldimethanamine (1,3- BAC) as raw materials and the structure was characterised by FTIR and MS. The composite materials were investigated by using TG, TG-FTIR, LOI, UL-94, SEM, and CCT. The results show that the ?lling of PCDSPB can improve the ?ame resistance of EP composites. When the phosphorus content of the composite system was 1.74 wt-%, the initial weight loss temperature was 299°C and the char yield was 26.3% at 600°C. Tensile strength was 35.4 MPa, impact strength was4.3 kJ m?2, LOI was 27.9, and the UL94 passed V-0 level. In the CCT, the peak heat release rate reduced to 276.0 kW m?2(EP-2) from 622.8 kW m?2 (EP-0), the total heat release decreased from 121.8 MJ m?2 (EP-0) to 89.5 MJ m?2 (EP-2). Therefore, the PCDSPB is a good intumescent ?ame-retardant curing agent for EP. 相似文献
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Lucie Zarybnicka Radka Bacovska Miroslav Vecera Jaromir Snuparek Milan Alberti Jozef Rychly Petr Kalenda 《应用聚合物科学杂志》2016,133(4)
Epoxy resins are, due to their excellent properties (such as chemical resistance, dimensional stability, and heat resistence), widely used in practice. The basic principle of curing epoxy resins with a hardener containing multiple amino groups is the crosslinking reaction between active hydrogen atoms in the hardener and the oxirane groups in the epoxy resin. This study deals with the synthesis and characterization of hexachloro‐cyclo‐triphosphazene derivative and its subsequent use for curing epoxy resins. The new hardener was prepared from hexachloro‐cyclo‐triphosphazene by nucleophilic substitution with isophorone diamine and its curing capability was compared with original isophorone diamine. The prepared derivative hexaisophorone diamino‐cyclo‐triphosphazene (HICTP) provided advantages over conventional curing system, as it improved mechanical properties as well as the flame resistance. Testing of the cured epoxy resin during burning was carried out using dual cone calorimeter, which enables more extensive monitoring of parameters in comparison with testing using oxygen index that has been used in many publications. The epoxy resin cured with the prepared phosphorus containing HICTP exhibits lower values for total heat release, amount of smoke released and oxygen consumed, which may cause a slower flame spread. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42917. 相似文献
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综述了最近印制电路板用无卤无磷阻燃型环氧树脂的研究开发现状。重点介绍了新型的含氮、含硅和本质阻燃环氧树脂,并对其发展前景进行了展望。 相似文献
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To study flame retardant mechanism of epoxy resin (EP) by octaphenyl silsesquioxane and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide, an experimental method is set up to investigate the residue of the EPs, which is extinguished during the cone calorimeter testing at different times. The chemical structures of the residues are investigated by the FTIR and XPS. The breakdown of EPs network and formation of new crosslinking structure are supported by the FTIR analysis. The changes of C and O concentrations in the condensed phase during the combustion are investigated by XPS in detail. Moreover, formation of organic carbon is uncovered by the plasmon loss curves based on XPS that could track the carbon crosslinking. These results exhibited a whole degradation and charring process of EP during the combustion: degradation of EP chain, more crosslinking charring, and thermal oxidation of the char. Furthermore, a program of combustion and degradation process of EPs is described in this research. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4119–4128, 2013 相似文献