基于DFT的液氧相容改性环氧树脂的化学特性研究

通过化学改性的方式在环氧树脂里面引入磷元素可以有效提高其液氧相容性,但这同时也会改变环氧树脂的化学特性,而关于化学特性的变化还有待研究。由于实验研究难以表征相关化学特性,采用密度泛函理论(DFT)对10-(2,5-二羟基苯基)-10-氢-9-氧杂-10-磷杂菲-10-氧化物(ODOPB)改性环氧树脂分子的化学特性做了深入研究。为了分析在环氧树脂分子上枝接ODOPB官能团对其化学特性的影响,同时还研究了未改性环氧树脂分子的相关特性并进行对比。研究结果发现,ODOPB改性后环氧树脂分子主链上的键解离能和拉普拉斯键级都有所增加,分子表面静电势和平均局部离子化能的最大值有所降低,表明枝接ODOPB可以提高环氧树脂的热稳定性,并有助于提高其液氧相容性。研究为从分子层面研究ODOPB改性环氧树脂的液氧相容机理提供了理论基础。     

含磷双酚A甲醛酚醛环氧树脂的合成与反应动力学研究

含磷环氧树脂是目前阻燃环氧树脂的主要发展方向,其在电子工业和复合材料方面有广泛的应用.本方法采用9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)与双酚A甲醛酚醛环氧树脂合成了新型含磷双酚A甲醛酚醛环氧树脂,通过红外谱图和核磁共振图谱确认了其结构,并简单的探讨了反应机理;采用DSC分析方法研究DOPO与双酚A甲醛酚醛环氧树脂的反应动力学,得到DOPO与双酚A酚醛环氧树脂反应的表观活化能Ea为54.379kJ/mol,反应级数n为1.08,表明该反应为一级反应.     

DOPO型无卤阻燃环氧树脂体系研究进展

综述了近5年来以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)及其衍生物为中间体制备新型无卤阻燃剂、阻燃型环氧树脂固化剂和无卤阻燃环氧树脂的研究新进展,并通过UL 94、极限氧指数(LOI)和成炭率等阻燃性能参数对它们的阻燃性能进行了评价.这些具有环境友好、低毒低烟和高效阻燃等优点的固化剂和环氧树脂,...     

敷铜层压板用阻燃遮光树脂配方

本发明配方组成：（A）四羟苯基乙烷环氧树脂,（B）不含卤的其它环氧树脂,（C）酚醛树脂和（D）不含卤的磷化物,例如,由甲酚酚醛环氧树脂（EpiclonN690）、四羟基苯乙烷环氧树脂（Epikote1031S）、双酚A环氧树脂（Epikote1016）、酚醛芳烷基树脂（Milex XLC—LL）、9,10-二氢-9-氧-10-磷杂菲-10-氧化物和氧化三苯膦配制的清漆浸渍玻璃布,与铜管层合热压得敷铜板,     

质谱法测量OLED封装材料的气体渗透率

本文介绍了质谱法渗透率测量系统和测量方法,利用该系统测量了水蒸汽、O2和CO2等气体对PET塑料薄膜和环氧树脂薄膜的渗透率,对所获得的实验结果进行了分析;结果表明PET塑料薄膜的水蒸汽渗透系数为1.76×10-6cm2/s,O2和CO2的渗透系数分别为4.5×10-9,2.25×10-8cm2/s,DG-4型环氧树脂的水蒸汽、O2和CO2的渗透系数分别为1.4×10-6,4.85×10-11和8.5×10-10cm2/s。实验结果表明PET塑料和环氧树脂的水和氧的渗透率很大,不适合作为长寿命OLED的封装材料;本文还讨论了所使用的质谱法渗透率测量系统存在的问题,以及该系统的改进方法。     

几种常用阻燃剂对环氧树脂的阻燃效果研究

针对环氧树脂阻燃剂开发的现状,研究了三聚氰胺多聚磷酸酯(MPOP)、包覆红磷、甲基磷酸二甲酯(DMMP)、和9,10-二氢-9-氧杂-10-磷菲-10-氧化物(DOPO)4种阻燃剂在环氧树脂中的阻燃应用,分别讨论了单阻燃剂体系和双阻燃剂体系的阻燃效果,应用极限氧指数测试和水平-垂直燃烧测试评价阻燃改性环氧树脂的阻燃性能。在单阻燃剂体系中,加入20gMPOP可以使LOI值达到25.3%,UL-94V-0级;而双阻燃剂体系中,加入DOPO的MPOP体系表现出了良好的协同效应,DOPO可以在提高相应的环氧树脂LOI值的同时减少MPOP的使用量。与只使用MPOP的体系相比,5gDOPO和20gMPOP共同使用可以将环氧树脂的LOI提高到30.5%同时垂直燃烧等级为V-0级。     

磷氮阻燃剂PDAB-DOPO的制备及阻燃环氧树脂复合材料性能研究

以对苯二胺、9,10-2H-9-氧杂-10-磷杂菲-10-氧化物(DOPO)、四氯化碳为原料制备磷氮阻燃剂6,6′-(1,4-亚苯基双(氮烷二基)双(6H-二苯并[c,e][1,2]氧杂磷苯-6-氧化物)(PDAB-DOPO)。利用傅里叶变换红外光谱仪、核磁共振氢谱仪对PDAB-DOPO结构进行了表征并将其用于阻燃环氧树脂;通过热失重分析对PDAB-DOPO及环氧树脂复合材料的热性能进行了表征,通过极限氧指数(LOI)和UL94测试对环氧树脂复合材料阻燃性能进行了表征,通过扫描电子显微镜对环氧树脂复合材料残炭形貌进行了分析。结果表明:当体系中磷质量分数为1.65%时,800℃时环氧树脂复合材料残炭量提高到18.9%,环氧树脂复合材料体系的LOI为27.3%,通过UL 94V-0级测试。扫描电子显微镜分析表明,PDAB-DOPO的加入使得环氧树脂体系残炭表面形貌发生明显变化,PDAB-DOPO对环氧树脂具有良好的阻燃效果。     

液氧相容改性环氧树脂体系低温力学性能分子动力学模拟

使用含磷阻燃剂分子对环氧树脂进行化学改性可以提高材料的液氧相容性,但将显著改变环氧树脂固化物的力学性能。利用分子动力学(MD)模拟方法,研究了10-(2,5-二羟基苯基)-10-氢-9-氧杂-10-磷杂菲-10-氧化物(ODOPB)改性环氧树脂的低温力学性能。首先采用两步反应方案来制备改性的环氧热固性交联网络,然后分别给予ReaxFF与Dreiding力场,基于截断键长实现精确有效的键断裂模拟。着重探索了不同磷含量对分子网络结构和材料性能的影响。研究发现,链长分布特征是决定材料力学性能的关键因素。而通过链长调节(CLR),材料在低温下的力学性能可以明显增强。为高性能液氧相容热固性树脂和复合材料的设计和制造提供了有价值的参考,有助于提高复合材料在恶劣工程环境下的耐受性。     

POSS嵌段共聚物改性环氧树脂

采用可逆加成-断裂转移聚合(RAFT)方法合成甲基丙烯酰氧丙基七异丁基笼形倍半硅氧烷(MAiBuPOSS)和9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物甲基丙烯酸乙酯(HEPO)的嵌段共聚物PMAiBuPOSS-b-PHEPO(BCP),用于改性双酚A型环氧树脂。利用扫描电镜表征环氧树脂复合材料的断面形貌,发现PMAiBuPOSS-b-PHEPO嵌段共聚物可在环氧树脂中发生自组装,形成了以POSS嵌段为核、含磷嵌段为壳的核壳结构自组装体。动态力学分析、热重分析、差示扫描量热分析、垂直燃烧测试(UL-94)及极限氧指数(LOI)研究表明,PMAiBuPOSS-b-PHEPO嵌段共聚物中PHEPO链段增强了聚合物与环氧树脂的相容性,PMAiBuPOSS链段显著提高了环氧树脂的热稳定性和阻燃性能。当PMAiBuPOSS-b-PHEPO质量分数为5%时,环氧树脂复合材料LOI值为33.0%,UL-94燃烧等级为V-0级,且其力学性能也得到显著提升。     

三相环氧树脂纳米复合材料的制备及其性能分析

环氧树脂因韧性差而限制了其在高端领域的应用,为了改善环氧树脂的韧性同时改善环氧树脂的热稳定性,将长径比不同的多壁碳纳米管(MWNTs)进行酸化,对蒙脱土(MMT)进行有机化处理,将MWNTs和MMT共掺杂环氧树脂通过溶液共混法制备三相环氧树脂纳米复合材料。结果表明,当碳纳米管质量分数为1%时,CMWNTs40-60/O-MMT/EP和C-MWNTs10-20/O-MMT/EP环氧树脂纳米复合材料的冲击强度比未改性的环氧树脂分别提高了107.1%、127.9%,热分解温度比未改性的环氧树脂高20℃、21℃,马丁耐热温度比未改性的环氧树脂高12.4℃、13.8℃。     

Effect of DOPO units and of polydimethylsiloxane segments on the properties of epoxy resins

New flame retardant epoxy resins containing phosphorus and/or silicon atoms were prepared by the introduction into the epoxy chemical structure of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and/or of polydimethylsiloxane segments. The structure and morphology of cured epoxy resins were evaluated by Fourier transform infrared spectroscopy and scanning electron microscopy analyses, respectively. The polymers exhibited good thermal stability, having initial decomposition temperature above 310 °C. Thermogravimetric analyses and limiting oxygen index values indicated that the incorporation of DOPO units/polydimethylsiloxane segments in the polymer structure significantly enhanced flame retardancy and thermal stability of char layer at high temperature. Broadband dielectric spectroscopy measurements over a wide range of frequency and temperature revealed two subglass transitions, γ and β. The experimental data were fitted to the Havriliak–Negami and Arrhenius models, and the obtained parameters were analyzed. An α relaxation process attributed to the glass transition was observed in the high temperature and high frequency ranges. The influence of DOPO units and polydimethylsiloxane segments on the properties of the polymers was examined.     

含磷双环戊二烯酚醛固化剂的合成及固化环氧树脂的性能

合成了一种含磷酚醛型环氧树脂固化剂DCPD-DOPO,通过红外光谱和核磁共振谱对其化学结构进行了表征,采用凝胶渗透色谱测量了其相对分子质量。以DCPD-DOPO、苯酚型酚醛树脂(PF8020)或其复合物为固化剂,双酚A环氧树脂(DGEBA)为基料,制备了不同磷含量的阻燃环氧树脂。通过热重分析、差示扫描量热分析研究了环氧树脂固化物的热性能和阻燃性能;通过极限氧指数(LOI),垂直燃烧实验和锥形量热法研究了固化后环氧树脂固化物的燃烧特性。结果表明,DCPD-DOPO固化的环氧树脂的LOI可达31.6%,垂直燃烧性能达到UL94 V-0级,玻璃化转变温度(T_g)为133℃。采用DCPD-DOPO与PF8020复合物固化的环氧树脂的T_g提高到138℃以上,LOI值略有降低,但仍能通过UL 94V-0测试。DCPD-DOPO与PF8020添加DCPD-DOPO后,复合固化的环氧树脂的热释放速率峰值及总释热量较PF8020固化的环氧树脂大幅度降低。此外,还用Kissinger法对环氧树脂固化反应动力学进行了研究。     

无卤本质阻燃环氧树脂

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。文中论述无卤本质阻燃环氧树脂的一些制备方法及性能,且涉及的主要是分子中含DOPO侧基及含磷酸酯基的两类本质阻燃环氧树脂。     

The effect of graphene presence in flame retarded epoxy resin matrix on the mechanical and flammability properties of glass fiber-reinforced composites

The effect of adding graphene in epoxy containing either an additive (MP) or reactive-type (DOPO) flame retardant on the thermal, mechanical and flammability properties of glass fiber-reinforced epoxy composites was investigated using thermal analysis; flexural, impact, tensile tests; cone calorimetry and UL-94 techniques. The addition of MP or DOPO to epoxy had a thermal destabilization effect below 400 °C, but led to higher char yield at higher temperatures. The inclusion of 10 wt% flame retardants slightly decreased the mechanical behavior, which was attributed to the poor interfacial interactions in case of MP or the decreased cross-linking density in case of DOPO flame retarded resin. The additional graphene presence increased flexural and impact properties, but slightly decreased tensile performance. Adding graphene further decreased the PHRR, THR and burning rate due to its good barrier effect. The improved fire retardancy was mainly attributed to the reduced release of the combustible gas products.     

Organic/inorganic flame retardants containing phosphorus,nitrogen and silicon: Preparation and their performance on the flame retardancy of epoxy resins as a novel intumescent flame retardant system

This paper presents the preparation of novel organic/inorganic flame retardants containing phosphorus, nitrogen and silicon (organic/inorganic FRs). The organic/inorganic FRs were highly water resistant, as suggested by the water contact angle and water solubility tests. The organic/inorganic FRs were then incorporated into epoxy resins (EP) at different phosphorus/nitrogen ratios and the flame retardancy of EP/FRs composites was characterized. The results showed that synergistic effects on the flame retardancy of EP composites existed between the DOPO-VTS and TGIC-KH. The char residues for EP/FRs composites were increased, and the highest char residues were obtained in air atmosphere (3.8 wt.%) when the DOPO-VTS/TGIC-KH is 4/1. The MCC results also showed that the THR of epoxy resins were also decreased when the DOPO-VTS/TGIC-KH is 4/1, which was in accordance with the highest LOI and UL-94 results. The SEM, FTIR, XPS and TG-FTIR results of pyrolysis products in both condensed and gases phases indicated that the strategy of organic/inorganic FRs combined condensed phase and gases phase flame retardant strategies such as the phosphorus–nitrogen synergism systems, the silicon reinforced effects in the condensed phase and DOPO flame retardant systems in the gases phase, resulting in significant improvements in the flame retardancy of epoxy resins.     

Synergistic flame retardancy effect of graphene nanosheets and traditional retardants on epoxy resin

Novel non-toxic halogen-free flame retardants are replacing traditional flame retardants in polymer and polymer matrix composite structures. In this study, graphene nanosheet (GNS) is investigated in combination with traditional layered double hydroxide (LDH), layered rare-earth hydroxide (LRH), and phosphorus-based flame retardant (DOPO) to enhance the flame retardancy of epoxy resin. A synergistic flame retardancy effect is achieved in GNS/LDH and GNS/DOPO systems where combined GNS and LDH increased the viscosity of the epoxy melt, and limited the flame propagation through inhibition of dripping. The limiting oxygen index of epoxy increased from 15.9 to 23.6 with addition of 0.5 wt.% each of GNS and LDH. With the addition of 2.5 wt.% of both GNS and LDH, the total heat release of epoxy resin also reduced from 33.4 MJ/m² to 24.6 MJ/m². The synergistic effect of GNS and DOPO adopted a different mechanism. The addition of 2.5 wt.% of GNS and DOPO reduced the peak heat release rate from 1194 kW/m² to 396 kW/m², and the total heat release rate from 72.5 MJ/m² to 48.1 MJ/m². The synergistic mechanisms of the flame retardants were closely analyzed and correlated with the flame retardant properties.     

环氧树脂的阻燃性研究进展

按发挥阻燃功效的物质或元素与环氧树脂分子结构的关系,将各种阻燃环氧树脂分为复合型和结构型两类,并分别介绍了它们的研究现状、主要问题及发展趋势。     

Effect of structure on thermal behaviour of phosphorus containing addition polyimides and epoxy resins

Addition polyimides, [e.g. endo-5-norbornene-2.3-dicarboximide(nadimides), maleimides etc.] and epoxy resins have been used extensively in the past as matrix resins for advanced fiber-reinforced composites. However, inadequate flame resistance and thermal stability of these resins is one of their serious limitations. Our earlier studies have shown excellent flame resistance properties of addition polyimides based on bis(3-aminophenyl) methyl phosphine oxide (B) or tris(3-aminophenyl) phosphine oxide (T). Carbon fiber reinforced composites based on such matrix resin did not burn even in pure oxygen. In order to investigate the effect of weight percent of phosphorus on thermal behaviour and flame resistance, a series of addition polyimides and epoxy resins were prepared using B, T and amide-amines. The effect of structure on curing behaviour of resins and thermal and flame resistance of cured resins was evaluated. The results demonstrate an improvement in char yield of resins containing higher weight percent of phosphorus. Received: 6 November 2000 / Reviewed and accepted: 7 November 2000     

聚磷酸铵-三聚氰胺-三嗪成炭剂协同阻燃改性环氧树脂及玻璃纤维增强树脂复合材料

采用聚磷酸铵(APP)与不同比例三聚氰胺(MA)和三嗪成炭剂(CFA)复配对环氧树脂进行阻燃改性。系统研究了不同配比阻燃剂(总量保持40wt%)的加入对环氧树脂流变特性、固化行为、热机械性能、力学性能及阻燃性能的影响。将优化后的阻燃改性环氧树脂用于制备玻璃纤维增强环氧树脂复合材料(GFRC),对并其力学和阻燃性能进行了研究。结果表明,APP单独与MA或CFA复配改性环氧树脂并未表现出明显的协同阻燃效应,但它们组成的三元复配阻燃体系(30wt%APP-5wt%MA-5wt%CFA)具有良好的协同阻燃效应。相比未改性环氧树脂,APP-MA-CFA改性环氧树脂的极限氧指数(LOI)由18.0%提高到了50.2%,热释放峰值速率(PHRR)下降了84%,总热释放量(THR)下降了78%。树脂基体中加入阻燃剂后,GFRC的力学性能有所下降,尤其是层间剪切强度。同样地,基于APP-MA-CFA复配改性环氧树脂的GFRC表现出最佳阻燃性能,相比未改性的GFRC,其LOI值由22.8%提高到了66.0%,PHRR由354 kW/m2下降到93 kW/m2,THR由49.3 MJ/m2下降到22.8 MJ/m2。