含磷阻燃环氧树脂体系研究进展

简要介绍了磷系阻燃剂作为一类新型无卤阻燃剂的特点和阻燃机理,重点综述了含磷阻燃环氧树脂体系的含磷固化剂、含磷环氧化合物及含磷环氧半固化物和添加磷型阻燃的进展,并通过热稳定性、成炭率和极限氧指数（LOI）等阻燃性能参数揭示了各类方法的阻燃效果,最后对含磷阻燃环氧树脂体系研究的未来进行了展望。     

含磷本质阻燃高聚物研究进展

本质阻燃高聚物阻燃效能持久,不存在挥发、溶出及迁移的问题,且可实现分子内协同阻燃效应,又为环境兼容,故近年日益崭露头角。文中综述了这方面的一些最新研究进展,包括本质阻燃环氧树脂、聚酰胺、聚酰亚胺及聚氨酯等,它们均为分子主链或侧链带含磷基团的无卤型高聚物。文中主要介绍了其合成方法及性能。     

无卤阻燃含磷环氧树脂体系的研究进展

综述了磷系阻燃环氧树脂体系的研究进展与现状。介绍了含磷阻燃体系的特征与阻燃机理,以及磷系阻燃环氧树脂磷元素引入的方式,包括添加型、反应型以及含磷固化剂。简述了现阶段磷系阻燃环氧树脂所存在的一些问题。     

DOPO型含磷本质阻燃环氧树脂的研究进展

9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物（DOPO）及其衍生物可以用于合成含磷环氧树脂及环氧固化剂,制备反应型的本质阻燃树脂;此类阻燃树脂阻燃效果持久、阻燃效率高,已成为当今阻燃剂研究开发领域的主攻方向。本文就结构型DOPO基含磷本质阻燃环氧树脂的合成及应用研究进行了综述。     

含磷环氧树脂体系研究进展

详细介绍了反应型含磷阻燃环氧树脂体系的研究状况及其在覆铜板中的应用,并指出了含磷环氧树脂的发展方向。     

含磷环氧树脂及其在无卤阻燃覆铜板中的应用研究进展

针对含磷环氧树脂在覆铜板无卤阻燃及其它方面的广阔应用前景,简述了含磷阻燃剂的阻燃机理,详细介绍了反应型含磷阻燃环氧树脂体系的研究状况,并指出含磷环氧树脂的发展方向。     

含硅及特殊结构本质阻燃环氧树脂

对含硅和特殊结构本质阻燃环氧树脂以及协同本质阻燃体系进行了评述。与添加型阻燃环氧树脂、含卤本质阻燃环氧树脂和和含磷本质阻燃环氧树脂相比,含硅和特殊结构本质阻燃环氧树脂具有阻燃效率高、阻燃持久、物理性能较少受影响、环境友好等优势。含硅和特殊结构环氧树脂符合绿色阻燃趋势。采用协同阻燃效应有助于进一步提高基材的阻燃性能。含硅和特殊结构本质阻燃环氧树脂存在制备工艺复杂、生产成本较高等问题亟待解决。     

无卤阻燃含磷环氧树脂的研究进展

无卤阻燃含磷环氧树脂中的磷成分具有气相和凝聚相的双重阻燃作用,且材料本身降解产物不产生可持续性环境污染物,因而作为环境友好型阻燃材料而被广泛研究。本文综述了近年来关于含9,10-二氢-9-氧杂-10-磷杂菲10-氧化物(DOPO)环氧树脂体系（包含DOPO环氧树脂、DOPO基固化剂和添加型DOPO改性聚合物）、磷酸酯型环氧树脂体系（包括磷酸酯环氧树脂、环状磷酸酯环氧树脂、磷酸酯型固化剂）、含磷固化剂以及磷腈环氧树脂和磷-硅环氧树脂的研究进展,介绍了每种体系的性能特点。总结了含磷环氧树脂的阻燃性能、热性能、阻燃机理,以及磷-氮协同效应、磷-硅复合二元体系的阻燃机理。     

自制高效无卤含磷阻燃剂阻燃环氧树脂研究

采用自制的阻燃剂双｛4-［4-（4-氨基苄基）苯氨基］ ［（6-氧二苯并［c,e］［1,2］氧磷菲?6?基）甲基］苯基｝苯基膦酸酯（DOP-DDM）,以及DOP?DDM与金属氧化物复合,分别用于制备高效阻燃环氧树脂（EPM）。通过极限氧指数（LOI）、垂直燃烧（UL 94）和锥形量热燃烧试验评价了阻燃性能,利用热失重分析和动态热机械分析研究了热性能,热失重与红外光谱仪联用、扫描电子显微和拉曼光谱分析了阻燃机理。结果表明,DOP-DDM的引入会降低阻燃EPM的起始降解温度,但不会影响其玻璃化转变温度,提高了残炭率、储能模量、损耗模量和阻燃性能;DOP?DDM添加量为4.7 %（质量分数,下同）,磷含量仅0.37 %,阻燃EPM的LOI 值为33.5 %,UL 94达V-0 级,热释放速率峰值、总热释放量和总烟释放量分别降低了23.2 %、17.8 %和12.4 %;3.7 %的DOP-DDM与1.0 %的Al₂O₃复合,阻燃EPM达UL 94 V-0级,不仅热释放速率峰值和总烟释放量进一步降低,而且CO和CO₂毒气分别降低了7.7 %和17.2 %。     

Carbon nanotubes coated with phosphorus-nitrogen flame retardant and its application in epoxy thermosets

ABSTRACT

Carbon nanotubes coated with phosphorus-nitrogen flame retardant (PDAP-CNTs) were produced. The compositions and structures of PDAP-CNTs were systematically characterized, and the flame retardancy of PDAP-CNTs/EP composites were also tested. The results indicated that PDAP-CNTs demonstrated excellent flame retardancy performance on the flame-retardant EP composites (FR-EP), incorporation of 5.0wt% PDAP-CNTs improved the LOI values of EP from 26.0% to 31.8% and reached UL-94 V-0 classification. The analysis of flame-retardant mechanism indicating the flame-retardant ability of PDAP-CNTs was ascribed to the synergism of the phosphorus-nitrogen containing coating layer (PDAP) and CNTs.     

A novel intumescent flame‐retardant epoxy resins system

Pentaerythritol diphosphonate melamine–dicyandiamide–formaldehyde resin salt, a novel macromolecular intumescent flame retardants (IFR), was synthesized, and its structure was a caged bicyclic macromolecule containing phosphorus characterized by IR, NMR and element analysis. The flame retardancy and thermal behavior of a new IFR system for epoxy resin were investigated by LOI, UL‐94 test, TG, and IR. Activation energy for the decomposition of samples was obtained using Kissinger equation. 25% of weight of IFR were doped into epoxy resin to get 27.5 of LOI and UL 94 V‐0. The TG curves and IR spectra show that IFR decreases the initial decomposition temperature and the maximum weight loss rate of epoxy resin, and enhances the thermal stability of epoxy resin at high temperatures and char yield. The activation energy for epoxy resin containing IFR was decreased by 44.8 kJ/mol, which shows that IFR can catalyze decomposition of epoxy resin. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

用于环氧树脂不饱和聚酯的聚合物型磷系阻燃剂

研究了1种新型富芳香结构的含磷聚合物阻燃剂聚苯基磷酸(9,10-二氢-9-氧杂-10-膦酰杂菲)苯撑酯(PDPPP)的合成及其对环氧树脂(ER)、不饱和聚酯树脂(USPE)的阻燃性能的影响。这种阻燃剂是由2-(6-氧-6氢-膦酰杂菲)1,4-对苯二酚(ODOPB)与苯膦酰二氯通过熔融缩聚获得。将磷含量为13.8%的PDPPP添加到环氧树脂、不饱和树脂中,结果表明该聚合物对环氧树脂、不饱和树脂具有良好的阻燃性能,PDPPP含量只需达到2%即磷含量只需达到0.28%时氧指数LOI可达28,阻燃性UL-94可达到V0级。     

含磷阻燃剂阻燃环氧树脂热降解动力学

以2-二苯基膦酰基-1,4-苯二酚(DPO-HQ)为阻燃剂制备了阻燃环氧树脂,利用动态热重分析法(TGA)研究了纯环氧树脂(EP)和阻燃环氧树脂(FR-EP)在不同升温速率下的热稳定性,建立了EP和FR-EP体系的动力学模型和非模型动力学(MFK),并对比分析了模型动力学和非模型动力学对于描述EP体系和FR-EP体系的适用性.结果表明:阻燃剂的引入降低了环氧树脂初始降解温度,但增加了残炭率.由Flynn-Wall-Ozawa方法和Coats-Redfern方法建立的模型动力学表征EP和FR-EP体系高温降解过程中误差较大,而非模型动力学能更准确地预测和描述EP和FR-EP体系的高温降解行为.     

Flame retardant aircraft epoxy resins containing phosphorus

As part of a program to develop fire resistant exterior composite structures for future subsonic commercial and general aviation aircraft, flame retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured neat epoxy formulations were characterized by thermogravimetric analysis, propane torch test, elemental analysis, microscale combustion calorimetry, and fire calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness and compressive strength of several cured formulations showed no detrimental effect due to phosphorus content. The chemistry and properties of these new epoxy formulations are discussed.     

Thermal degradation behaviors and flame retardancy of epoxy resins with novel silicon‐containing flame retardant

A novel macromolecular silicon‐containing intumescent flame retardants (Si‐IFR) was synthesized, and its structure was a caged bicyclic macromolecule containing phosphorus‐silicon characterized by IR. Epoxy resins (EP) were modified with Si‐IFR to get the flame retardant EP, whose flammability and burning behavior were characterized by UL 94 and limiting oxygen index (LOI). Twenty percentage of weight of Si‐IFR was doped into EP to get 27.5% of LOI and UL 94 V‐0. The degradation behavior of the flame retardant EP was studied by thermogravimetry, differential thermogravimetry, scanning electron microscopy, and X‐ray photoelectron spectroscopy analysis. The experimental results exhibited that when EP/Si‐IFR was heated, the phosphorus‐containing groups firstly decompose to hydrate the char source‐containing groups to form a continuous and protective carbonaceous char, which changed into heat‐resistant swollen char by gaseous products from the nitrogen‐containing groups. Meanwhile, SiO₂ reacts with phosphate to yield silicophosphate, which stabilizes the swollen char. The barrier properties and thermal stability of the swollen char are most effective in resisting the transport of heat and mass to improve the flame retardancy and thermal stability of EP. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Phosphorus-containing epoxy for flame retardant. III: Using phosphorylated diamines as curing agents

Two phosphorus-containing diamine compounds, bis(4-aminophenoxy)-phenyl phosphine oxide and bis(3-aminophenyl)phenyl phosphine oxide, were synthesized for use as curing agents of epoxy resins. Phosphorylated epoxy resins were obtained by curing Epon 828 and Eponex 1510 with these two diamine agents. For raising the phosphorus contents of the resulting epoxy resins, the phosphorus-containing epoxy, bis(glycidyloxy)phenyl phosphine oxide (BGPPO), was also used. These two diamine agents showed similar reactivity toward epoxies. Their reactivities were higher than DDS and lower than DDM. High char yields in TGA evaluation were found for all the phosphorylated epoxy resins, implying their high flame retardancy. The excellent flame-retardant properties of these phosphorylated epoxy resins were also demonstrated by the high limiting oxygen index (LOI) values of 33 to 51. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 895–901, 1997     

Reactive cyclic phosphonamide flame retardant for epoxy resins

To take the advantage of reactivity of five-membered cyclic phosphorus compounds, 1,2,3-tri-phenyl-1,3,2-diazaphospholidine-2-oxide (TPDPO) was explored as a reactive flame retardant for epoxy resins (EPs). Through model compounds, it has been established that TPDPO selectively reacts with the secondary hydroxyl group and is inert toward both aryl amino groups and epoxide groups. The result of Soxhlet extraction supports that TPDPO is permanently bonded to the cured EPs. At a loading of only 8 wt % (0.74 wt % phosphorus), TPDPO enables the cured epoxy to achieve a UL-94 V0 rating. The thermogravimetric analysis–Fourier transform infrared analyses of the gaseous products suggest that the excellent flame retardancy of EP–TPDPO is partly due to the enhanced dehydration process of the epoxy. Also an increased char yield and the formation of a coherent char layer contribute to the good fire performance of EP–TPDPO. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 47411.     

Synthesis of novel phosphorus-containing epoxy hardeners and thermal stability and flame-retardant properties of cured products

Two novel flame-retardant curing agents for epoxy resins, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-containing 4-[(phenylamino)methyl]phenol (P-Ph) and DOPO-containing Mannich-type bases (P-DDS-Ph), were synthesized by the condensation of 4-hydroxybenzaldehyde with 4-aminophenol and DDS, respectively, followed by the addition of DOPO to the resulting imine linkage. Chemical structures of these materials were characterized with FTIR, ¹H-NMR spectra, ³¹P-NMR spectra, and elemental analysis. The thermal properties and flame retardancy of o-cresol novolac epoxy resin (CNE) cured with different contents of the phosphorus-containing compounds were investigated by nonisothermal differential scanning calorimetry, thermogravimetric analysis, and limiting oxygen index (LOI). The obtained results showed that more char was formed while containing lower contents of the phosphorus-containing compounds in the P-Ph/CNE and P-DDS-Ph/CNE indicating their excellent flame retardancy. Moreover, the P-DDS-Ph/CNE exhibited higher T_g (224°C) and better thermal stability (T_10%, 330°C) than that of P-Ph/CNE. Therefore, the developed P-DDS-Ph/CNE may be potentially used as environmentally preferable products in electronic fields. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012