A Novel DOPO‐Based Diamine as Hardener and Flame Retardant for Epoxy Resin Systems

10‐Ethyl‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide ( 1 ) can be nitrated using acetic anhydride and fuming nitric acid. The nitro group is reduced using palladium on charcoal and hydrogen. These reaction conditions are used for the synthesis of an analogous DOPO‐based diaminic hardener ( 7 ). An evaluation of the curing behavior, mechanical properties and flammability of a neat resin made of DGEBA and 7 (DGEBA + 7 ) and of a carbon fiber‐reinforced resin made of DGEBA, 4,4′‐diaminodiphenylsulfon (DDS) and 7 (DGEBA + DDS + 7 ) shows the potential of this hardener to lead to flame‐retardant systems while keeping relevant properties on a high level; especially when compared to a similar system (DGEBA + DDS + 1 ).

     

溴/氮本质阻燃环氧树脂的热性能和阻燃性能研究

采用热分析仪、傅里叶变换红外光谱仪(FTIR)、极限氧指数仪和综合垂直燃烧测定仪研究了反应型磷/氮阻燃剂聚N-(2,3,5,6-四溴对二亚甲基苯基)-N-乙基胺(BNFR)阻燃环氧树脂的热性能、阻燃性能、成烟性能等。结果表明,BNFR分子通过参与固化反应而以化学键键合于固化树脂的立体网络结构之中,无迁移,通过改变固化树脂的热降解过程提高树脂的热稳定性能以及阻燃性能;BNFR分子结构中含有Br和N两种阻燃元素,气相和固相阻燃机理同时起作用,因此阻燃效率较高,环氧树脂中添加12%的BNFR可以使极限氧指数达到30%,600℃成炭量高于10%。     

An Excellent Intrinsic Transparent Epoxy Resin with High Flame Retardancy: Synthesis,Characterization, and Properties

In this paper, a novel multifunctional, liquid, and colorless curing agent, namely DPTA, is prepared through diphenylphosphinic chloride (DPPC) and tetraethylenepentamine (TEPA). Different measurements confirm that the DPTA is prepared successfully and the cured DPTA‐EPs simultaneously display excellent flame retardancy and transparency. The resulting DPTA‐EP system reaches high optical transmittance up to 90% within the visible region. Meanwhile, the introduction of the flame‐retardant groups in DPTA‐EP does not deteriorate the mechanical behaviors compared with that of reference sample TEPA‐EP. More importantly, with only 15 wt% DPTA addition, the resulting DPTA‐EP with 1.6 mm passes UL‐94 V‐0 rating, and limiting oxygen index reaches 29.0%. Moreover, the peaks of heat release rate and total smoke production of DPTA‐EP are largely reduced by 43.1% and 58.8%, respectively, further verifying the excellent smoke‐suppression efficiency and flame retardancy. The analyses from both cone calorimeter (CC) and thermogravimetric (TG) results suggest that the satisfactory flame retardancy of cured DPTA‐EP dominates in the gaseous phase. The earlier release of large amount of non‐combustion gas and phosphorus containing groups improve the flame‐retardant efficiency.     

An Itaconic Acid-Based Phosphorus-Containing Oligomer Endowing Epoxy Resins with Good Flame Retardancy and Toughness

With the aim to reduce the influence of flammability and brittleness of epoxy resin (EP) on its applications, a phosphorus-containing oligomer (BID) containing phosphophenanthrene group and flexible chain segment is designed and applied to methyltetrahydrophthalic anhydride (MeTHPA) curing EP systems. Compared with EP/MeTHPA, the glass transition temperature (T_g) declines after introducing BID. But the addition of BID endows EP/MeTHPA with good flame retardancy. When the dosage is only 19.2 wt.%, the limiting oxygen index (LOI) of EP/BID/MeTHPA increases by 77% to 36% (P content: 1.5 wt.%) compared with EP and reaches the vertical combustion (UL-94) V-0 rating. Cone calorimetry (CC) results reveal that PHRR and THR drop by 40% and 31%. The pyrolytic process and char residue data analysis show that BID plays flame-retardant role in gas phase and condensed phase. In addition, impact and flexural and tensile strength improve by 84%, 19% and 54% individually, proving that BID holds a potential on enhancing mechanical performance of EP/MeTHPA.     

Simultaneously Improving the Thermal,Flame‐Retardant and Mechanical Properties of Epoxy Resins Modified by a Novel Multi‐Element Synergistic Flame Retardant

To obtain epoxy resins with satisfactory thermal, flame retardant, and mechanical properties, a novel multi‐element synergistic flame retardant (PPVSZ) is synthesized through the reaction between P? H of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) and C?C of polysilazane (PVSZ) and utilized as a multi‐element synergistic flame retardant for epoxy resins. The flame retardant mechanism is explored by XPS and SEM, confirming that the excellent flame‐retardance efficiency owes itself to an optimal flame retardant way which jointly exerts the flame‐retardant effects in the gaseous and condensed phase. The thermal properties deduced from DSC, TGA, and DMA, indicate the glass transition temperature, maximum weight loss rate, and char yields at 700 °C for EP‐2 increase by about 5.0 °C, 8.4 °C and 8.8%, respectively. Furthermore, mechanical properties such as impact strength, tensile strength, and flexural strength are also increased by 45.38%, 14.16%, and 17.43%, respectively, which show that the incorporation of PPVSZ does not deteriorate the mechanical properties of modified resin. All the results demonstrate that epoxy resins modified by PPVSZ not only have good effect on the flame retardance, but also have good improvement on thermal and mechanical properties, indicating the potential for applications in many fields requiring fire safety.     

环氧树脂/三羟甲基三聚氰胺硅化物固化体系阻燃性能与耐热性研究

利用三聚氰胺和甲醛合成了三羟甲基三聚氰胺（TMM）,将其与正硅酸乙酯(TEOS)反应得到三羟甲基化三聚氰胺硅化物（TMMSi）。将TMMSi与环氧树脂复合,采用4,4'-二氨基二苯基甲烷(DDM)作固化剂来制备环氧树脂/TMMSi固化物,并对固化物的热性能和阻燃性能进行了分析。结果表明,与环氧树脂/TMM固化物相比,环氧树脂/TMMSi固化物的玻璃化转变温度变化较小,高温耐热性提高不明显,但是阻燃性能得到了大幅度提高。当TMMSi含量为15份时,环氧树脂/TMMSi固化物的极限氧指数达到29.6 %,比纯环氧树脂固化物提高了40 %。     

新型P-Br阻燃剂对环氧树脂阻燃和力学性能的影响

研究了一种新型P-Br阻燃剂-1,3,5－三（5,5－二溴甲基－1,3－二氧杂己内磷酰氧基）苯(FR)的含量对环氧树脂(EP)的阻燃性能和力学性能的影响。结果表明,当阻燃剂FR的含量为15 %（质量分数,下同）时,与纯EP相比,阻燃EP的极限氧指数从25.0 %提高到29.3 %,垂直燃烧通过UL 94 V-0级,火势增长指数从3.63 kW/(m2·s1)下降到0.77 kW/(m2·s1),放热指数从1.89 MJ/m2下降到1.34 MJ/m2,600 ℃残炭率从18.54 %升至29.02 %,呈现良好的阻燃效果,但力学性能有所下降,拉伸强度从62.04 MPa下降到39.81 MPa,冲击强度从13.46 kJ/m2 降到10.13 kJ/m2。     

阻燃环氧树脂/有机蒙脱土纳米复合材料制备及阻燃性能

研究制备了环氧树脂(EP)/有机蒙脱土(OMMT)、N,N-二(2-羟乙基)氨甲基膦酸二乙酯(BHAPE)阻燃剂阻燃的EP和EP/OMMT等复合材料。XRD证明分散在复合材料中的OMMT为剥离型的,且BHAPE的加入不影响材料中OMMT剥离后的层间距。研究证明,单独使用BHAPE很难使EP通过UL 94 V-0阻燃级,仅添加OMMT的EP固化物,其氧指数和UL94阻燃性能几乎与纯EP固化物的一样。但是同时添加BHAPE和OMMT的EP固化物,当BHAPE和OMMT的添加量分别为25%和5%时,不仅BHAPE/EP/OMMT复合物的CONE阻燃参数都明显降低,而且能通过UL94V-0级。可能是BHAPE和OMMT在凝聚相同时发挥作用,即BHAPE和OMMT协同阻燃作用提高了复合材料的综合阻燃性能。     

环氧灌封材料的阻燃研究动态

介绍了国内外环氧灌封材料的生产现状及其在电子封装业中的发展前景,并概述了对现代电子封装材料的环保新要求及电子封装无卤化阻燃对环氧树脂提出的挑战。     

聚氨酯／聚磷酸胺体系的阻燃及力学性能

应用热重量分析,水平燃烧,应力－应变和扫描电镜等实验手段,研究了聚氨酯／聚磷酸胺（ＰＵ／ＰＰＡ）体系的热分解特性以及阻燃和力学性能,实验结果表明,随阻燃剂ＰＰＡ添加量的增加,ＰＵ的热分解峰明显地移向 温,并与阻燃机理有关,在ＰＵ中加入ＰＰＡ可显著改善ＰＵ的阻燃性能,但同时也使的力不性强度明显下降。     

反应型和添加型含磷阻燃剂阻燃环氧树脂的性能研究

研究了不同填充量的反应型和添加型含磷阻燃剂对阻燃环氧树脂力学性能和阻燃性能的影响,并对比研究了2种类型阻燃环氧树脂的热稳定性。结果表明,反应型阻燃剂中9,10-二氢-9-氧-10-磷杂菲-10-氧化物（DOPO）阻燃环氧树脂的力学性能和阻燃性能好于6-氢-二苯并[c,e][1,2]氧磷酰杂-6-甲醇,6-氧化物（DOPO-CH2OH）,添加型阻燃剂中三聚氰胺磷酸盐（MP）阻燃环氧树脂的性能好于聚磷酸铵（APP）;2种类型阻燃剂相比,2种反应型阻燃剂阻燃环氧树脂的力学性能、阻燃性能和热稳定性均好于添加型的MP和APP阻燃剂。     

低聚物型溴／氮阻燃剂在环氧树脂中的应用

以α，α’，2，3，5，6-六溴对二甲苯与乙二胺的线形低聚物（BNFR）为阻燃剂，采用热分析、红外光谱、有限氧指数和UL94V燃烧实验分析了BNFR对环氧树脂热性能和阻燃性能的影响。结果表明：BNFR能够参与树脂的固化反应，通过化学键成为树脂立体固化网络的组成部分。加入BNFR后，体系热降解5％和10％时的热降解温度均升高了15℃。在常规环氧树脂中添加6％BNFR（间苯二胺为固化剂）或者11％BNFR（邻苯二甲酸酐或JAq改性胺为固化剂）即能赋予基材UL94V-0的阻燃级别，有限氧指数大于26。使阻燃体系交联密度增加的固化剂及固化条件能进一步提升该体系的阻燃性能和热性能。阻燃体系中，n（Br）：n（Sb）最佳配比为3：1。     

DOPO基低聚物与介孔二氧化硅协同阻燃环氧树脂

采用介孔二氧化硅(MS)与9,10–二氢–9–氧杂–10–磷杂菲–10–氧化物基低聚物(PDAP)对环氧树脂(EP)进行阻燃,制备阻燃环氧固化物。通过热重分析、极限氧指数(LOI)和UL–94测试对固化物的热稳定性和阻燃性能进行研究,并利用红外光谱、裂解–气相色谱/质谱联用仪和扫描电子显微镜对MS与PDAP的协同阻燃机理进行研究。结果表明,PDAP与MS存在较好的协同阻燃作用,当4%的PDAP和0.5%的MS添加至EP中,得到的固化物在燃烧时出现剧烈的吹熄现象,其LOI值高达34.3%,并通过UL–94的V–0级测试。在凝聚相,PDAP降解产生的磷酸类物质与MS反应生成磷硅酸盐,促进生成富磷、硅的致密炭层。在气相的阻燃机理主要是含磷自由基的猝灭作用和难燃气体的稀释作用。     

膨胀型阻燃剂阻燃环氧树脂的阻燃性能及影响因素

研究了季戊四醇磷酸酯三聚氰胺盐微胶囊化的多聚磷酸铵（KDIFR）、三聚氰胺-甲醛树脂微胶囊化的多聚磷酸铵（MAPP）和多聚磷酸铵（APP） 3种膨胀型阻燃剂,及引入硼、铝元素对膨胀型阻燃环氧树脂(EP)阻燃性能的影响,采用极限氧指数法和水平燃烧法测试材料的燃烧性能。结果表明,3种阻燃剂中APP的阻燃效果最好,当APP/EP为0.3（质量比,下同）时,其极限氧指数为32.2 %,达到难燃级水平;在EP/APP中引入铝元素或硼元素可使阻燃效果提高,硼、铝共存时阻燃效果更加突出,加入APP总量0.8 %的硼酸铝可使EP/APP的自熄时间由48 s降为24 s;热分析结果表明,APP热分解吸热恰与EP的热降解产物燃烧放热相匹配,这是使EP/APP的阻燃性能提高的主要原因;在EP/APP中引入硼和铝元素可明显促进EP/APP成炭,起到协同阻燃作用。     

反应性P–N膨胀阻燃剂化学阻燃尼龙66的研究

以自制的1–氨基苯甲酸–3–酰胺基苯甲酸–苯基氧化膦(BNPPO)、己二胺、尼龙(PA)66盐为原料,通过高压(1.7 MPa,210℃),高温(280℃,0.1 MPa)两步聚合制备了阻燃PA66。傅立叶变换红外光谱分析表明,BNPPO盐含有N–P膨胀结构;热重分析表明,阻燃PA66较纯PA66有更优异的热稳定性;极限氧指数及垂直燃烧法结果显示,阻燃PA66具有良好的阻燃性能;锥形量热法及扫描电子显微镜分析发现,BNPPO以气相阻燃及凝聚相协效阻燃作用于PA66基体材料;力学性能结果显示,BNPPO化学阻燃PA66依然保持有良好的力学性能。     

Effect of Bio-Based Cobalt Alginate on the Fire Safety and Mechanical Properties for Epoxy Resin

There is a growing demand to develop epoxy resins (EP) with smoke suppression as well as satisfactory flame retardancy. Herein, bio-based cobalt alginate is successfully fabricated and incorporated into EP to prepare EP/Cobalt Alginate composites with better fire safety performance. The addition of cobalt alginate reduces the thermal-decomposition rate, temperature at maximum weight-loss rate of EP, whereas obviously improves the thermal stabilities at a higher temperature range. Furthermore, the addition of cobalt alginate substantially reduces the fire hazard of EP, resulting in 56.2% reduction in peak heat release rate, as well as 17.8% and 56.3% reduction in total smoke production and peak smoke production rate, respectively, compared with EP matrix. Moreover, the presence of cobalt alginate increases smoke-suppressant properties, according to the smoke density test. Additionally, the incorporation of cobalt alginate has no obviously destructive effect on the mechanical properties of EP, while EP/Cobalt Alginate-3 exhibits a 27.0% improvement in impact strength. In prospective, this study may provide a significant method for producing eco-friendly flame retardant EP.     

氢氧化铝对PE-HD／木粉复合材料阻燃性能和力学性能的影响

对Al(OH)3阻燃的高密度聚乙烯／木粉复合材料研究结果表明：随木粉和Al(OH)3添加量的增加，Al(OH)3对复合材料的阻燃效率增加，高木粉添加量的复合材料氧指数达27．1％，Al(OH)3的阻燃效率达0．203。增加木粉含量，复合材料的拉伸强度和弯曲强度明显提高；但Al(OH)3对拉伸强度的影响不大，而明显提高弯曲强度。增加木粉和Al(OH)3的含量，均能明显降低复合材料的冲击强度，破坏复合材料的韧性。     

Phytic Acid-Iron/Laponite Coatings for Enhanced Flame Retardancy,Antidripping and Mechanical Properties of Flexible Polyurethane Foam

The use of flexible polyurethane foam (FPUF) is severely limited due to its flammability and dripping, which can easily cause major fire hazards. Therefore, choosing an appropriate flame retardant to solve this problem is an urgent need. A coating was prepared on the FPUF surface by dipping with phytic acid (PA), Fe₂(SO₄)₃·xH₂O, and laponite (LAP). The influence of PA-Fe/LAP coating on FPUF flame-retardant performance was explored by thermal stability, flame retardancy, combustion behavior, and smoke density analysis. FPUF/PA-Fe/LAP has a good performance in the small fire test, which can pass the UL-94 V-0 rating and the limiting oxygen index reaches 24.5%. Meanwhile, the peak heat release rate values and maximum smoke density of FPUF/PA-Fe/LAP are reduced by 38.7% and 38.5% compared with those of neat FPUF. After applying PA-Fe/LAP coating, the value of fire growth rate index decreases from 10.5 kW/(m²·s) to 5.1 kW/(m²·s), dramatically reducing the fire risk. Encouragingly, the effect of PA-Fe/LAP coating on cyclic compression and permanent deformation is small, which is close to that of neat FPUF. This work provides an effective strategy for making a flame-retardant FPUF with antidripping and keeping mechanical properties.     

Mechanical Properties and Morphology Studies of Thermosets from a Liquid‐Crystalline Epoxy Resin with Biphenol and Aromatic Ester Groups

Liquid‐crystalline epoxy thermosets were prepared by adding M1 into DGEBA/DDM blends. M2 was added to DGEBA/DDM to produce thermosets for comparison. The influences of the concentration and chemical structure on the mechanical and thermal properties were investigated systematically. The M1 /DGEBA blends possessed increased rubbery plateau modulus, higher glass transition temperatures, and lower tan δ. The use of small amounts of M1 may improve the mechanical properties greatly. Izod notched impact strength could be enhanced by 55% by addition of 2% M1 compared to unmodified DGEBA blends. Extremely rough and highly deformed fracture surface could be obtained in the M1 /DGEBA blends. M1 /DGEBA blends also exhibited excellent thermal properties.

     

环氧树脂/含磷有机硅杂化物固化体系的耐热性与阻燃性研究

利用γ(2,3-环氧丙氧基)丙基三甲氧基硅烷与磷酸反应制备了一种含磷有机硅杂化物,并利用红外光谱对这种含磷有机硅杂化物进行了结构表征。将这种含磷有机硅杂化物加入到双酚A环氧树脂/4,4'-二氨基二苯基甲烷体系制备了环氧树脂/含磷有机硅杂化物固化体系,对这种固化物进行了热失重分析,并测试了其玻璃化转变温度(Tg)和极限氧指数。结果表明,该固化物的Tg比纯环氧树脂固化物有所提高,初始分解温度比纯环氧树脂低,而高温残炭率有大幅提高;当含磷有机硅杂化物含量为30份时,固化物的Tg提高9 ℃,极限氧指数到达27.3 %,700 ℃残炭率达到34.1 %,比纯环氧树脂分别提高28 %和77.8 %。