In response to the critical need for high-performance epoxy adhesives in underwater repair and engineering, this study prepared a novel Mannich base to serve as a curing agent for modified epoxy resin systems. The Mannich base was synthesized via the condensation reaction of nonylphenol, paraformaldehyde, and triethylenetetramine, incorporating both strongly hydrophilic groups and rigid benzene rings into its molecular structure to facilitate efficient penetration and rapid curing in aquatic environments. Mechanistic analysis indicated that the strong hydrophilicity of the Mannich base allowed it to effectively displace the water film on the surface of the substrate, while its active amine groups can react with epoxy groups in an aqueous environment, forming a dense, stable cross-linked network. The resulting Mannich base compound allowed for effective underwater curing of the epoxy resin. The cured adhesive exhibited curing rates exceeding 87

Effective underwater adhesion is crucial for repairing marine equipment and maintaining pipelines. A key obstacle to this process is interfacial water, which inhibits adhesion by disrupting contact with the substrate. Herein, we propose a novel strategy to enhance underwater adhesion by incorporating calcium oxide (CaO) filler into an epoxy matrix. The CaO reacts chemically with water to form Ca(OH)2 to reduce interfacial water in an exothermic reaction, releasing heat that promotes curing. Micro-infrared analysis revealed interfacial Ca(OH)2 accumulation, confirming targeted water removal. Remarkably, the CaO-enhanced adhesive attained an underwater shear strength of 9.9 MPa, representing a 152% increase from the starting material. It also showed sustained strength after hydrothermal aging as well as resisting dynamic water pressure up to 0.8 MPa, exceeding common pipeline pressures. This approach therefore establishes a practical route to high-performance adhesives for demanding underwater applications.

氰酸酯树脂是一种黏接强度高、介电性能优异的耐高温树脂,但因韧性较差严重限制了氰酸酯树脂的应用,采用双酚E型氰酸酯(BEDCy)树脂作为基体树脂,酚酞型聚芳醚砜(PES-C)作为增韧剂,通过加热共混得到了BEDCy/PES-C树脂.通过拉力机、动态力学热分析、热重(TG)分析、X射线光电子能谱、阻抗分析和扫描电子显微镜(SEM)测试了BEDCy/PES-C树脂对铝材的黏接强度、模量、耐热性、介电性能、微观结构和形貌的影响.结果表明,PES-C对BEDCy树脂的增韧效果显著,以剪切性能为例,BEDCy树脂在常温下剪切强度由最初的19.9 MPa提升至30.4 MPa,相比纯BEDCy树脂提高了52.8%,230℃下剪切强度提高了36.7%,此时,SEM下也能观察到明显的沟壑状增韧条纹.TG分析测试表明,少量PES-C(＜40%)的加入对耐热性能影响并不明显,失重率5%时温度基本保持在418℃.BEDCy/PES-C的介电性能也明显提高,当PES-C质量分数为20%时,10.1 GHz下的介电常数为2.41,介电损耗为0.010 6.

A series of high temperature resistant adhesives were synthesis from 2,2'-Bis-(4-cyanatophenyl) (BADCy), polyethersulfone (PES) and N, N'-4,4'-diphenylmethane bismaleimide (BMI) by solvent-free method. The effect of BMI content on the curing behavior, thermal, mechanical, fracture morphology, adhesive and thermal aging properties were studied. With the addition of BMI, the curing activation energy of resin increases from 67.44 kJ/mol of BMI-0 to 69.22 kJ/mol of BMI-30. The reason is mainly due to the higher activation energy of BMI self-polymerization. The BADCy/PES/BMI resin has a wider processing window (BMI-20 has the lowest viscosity in the range of 96 degrees-182 degrees C), and the processing window becomes wider as the BMI content increases. More interestingly, as BMI content increases, resins toughness decreases and lap shear strength at room temperature decreases (from 31.4 MPa of BMI-0 to 20.0 MPa of BMI-30), but the high temperature performance increases as BMI content increases (temperature for 5% weight loss under N-2 atmosphere of BADCy/PES/BMI increase from 404 degrees C of BMI-0 to 413 degrees C of BMI-30).

Polyimide (PI) foams possess excellent mechanical properties, high-temperature resistance, and other unique properties, which facilitate impact in aerospace, automotive, and microelectronics industries. However, when they are used as lightweight insulation structural layers for high-temperature carbon fiber reinforced composites, improvement in thermal-insulating properties and temperature resistance of PI foams without compromising the flexibility in extreme environments is a challenging task. In this study, the flexible blocks were linked into rigid polymeric structures to fabricate a thermoplastic structure through a simple aqueous strategy to construct hydrogen-bonding networks. Thus, with a low shrinkage of 8.42%, an ultrahigh compressive modulus of 11.17 MPa, and a specific modulus of 81.03 MPa cm3 g-1 was successfully achieved. Benefitting from the formation of ultra-strong network backbones, foams showed excellent thermal-insulating properties and temperature resistance. The robust porous material with thermal-insulating properties (0.0481 W m-1 K-1) exhibited a compression modulus of 4.21 MPa after heat treatment at 300 degrees C and maintained 91% strength retention, thus it can be used as lightweight heat-insulation composite sandwich structures up to 300 degrees C. The copolymer foam obtained by using 30 mol% flexible blocks reserves its high flexibility undergoing only 10% dimensional changes after 40,000 compression-release cycles. The lightweight thermoplastic PI foams with flexibility, thermalinsulating properties, and temperature resistance can be used for high-temperature lightweight composite sandwich structures in aeronautics and space exploration.

以4,4'-双马来酰亚胺二苯甲烷(BMI-1)、双酚A型氰酸酯(BADCy)和酚酞型聚芳醚砜(PES-C)为原料通过加入发泡剂合成了双马来酰亚胺/氰酸酯耐高温发泡胶.通过差示扫描量热分析和红外表征分析了树脂的固化行为.扫描电子显微镜分析表明,该发泡胶发泡均匀细腻(平均泡孔直径0.275 mm).热重分析结果表明,该发泡胶具有很高的耐温性:空气和氮气氛围下10％分解温度分别为393℃和412℃.发泡胶在9.375 GHz频率下的介电常数为1.65、介电损耗为0.0057,展现了优异的介电性能.管剪测试表明,该发泡胶具有优异的黏结性能和耐温性能,-55℃、25℃和150℃管剪强度均大于7 MPa,205℃管剪强度不小于4 MPa.与多种材料的拉伸测试结果表明,该发泡胶与多种材料具有优异的黏结性能,铝-铝拉伸强度为9.2 MPa、钛-钛拉伸强度为5.9 MPa、双马基复材-双马基复材拉伸强度为5.9 MPa.

以双马树脂为原料,加入氰酸酯、聚芳醚砜、发泡剂等填料,并通过混料、延压成膜等工艺制备出耐高温发泡胶膜J-381.通过万能拉力机测试了发泡胶膜在不同温度下的管剪、压缩和抗拉等性能;管剪测试表明该发泡胶具有优异的粘结性能和耐温性能:-55℃、25℃和150℃管剪强度均不小于8MPa,205℃管剪强度大于4MPa.与多种材料的抗拉测试结果表明J-381与各种材料具有优异的粘结性能:铝-铝抗拉强度9.2MPa;钛-钛抗拉强度5.9MPa;双马基复材-双马基复材抗拉强度5.9MPa.J-381与典型环氧树脂发泡胶膜、氰酸酯树脂发泡胶膜和国外双马树脂发泡胶膜的基本性能也进行了比较.

通过FT-IR和DSC等对N,N--4,4’-二苯甲烷型双马来酰亚胺树脂(BMI)、双酚A型氰酸酯(BADCy)和聚芳醚砜(PES-C)的共固化反应进行研究.结果 表明,固化过程前期的主反应是氰酸酯和双马来酰亚胺的自聚反应,固化反应进行2h以后,氰酸酯和双马来酰亚胺共聚反应成为主反应.动力学研究确定了树脂固化反应的活化能(Ea=70.765kJ· mol-1),频率因子(lnA=16.6)和反应级数(n=0.923).并根据动力学数据确定了树脂的固化条件.

用耐热的环氧树脂、改性环氧树脂(自制)、稀释剂、紫外荧光粉、脂肪多胺、聚醚胺和促进剂按一定比例混合,制备了一种可用于干式空心电抗器包封绝缘微裂纹检测及修复的渗透剂.并通过万能拉力机、介电测试仪,电镜等对渗透剂的基本性能、介电性能、微观结构等性能进行了考察.结果 表明,本渗透剂对干式空心电抗器包封绝缘结构的复合材料有良好的浸润性、渗透性以及粘接性能,并有着较好的耐热性能,可保证干式空心电抗器整个工作温区内正常运行,固化后的渗透剂具备优秀的机械和电气性能:拉伸剪切强度为8.64MPa,冲击强度为34.5kJ/m2,体积电阻率为8.1×101SQ ·cm,电气强度为26.4kV/mm,适合干式空心电抗器包封绝缘微细裂纹户外的判定及修复.

Poly(imide siloxane), block and blend copolymer, were synthesized using different methods to explore the influence of siloxane chains. The flexible siloxane chains enrichment on surface of copolymer, enhance hydrophobic and adhesive with copper foil. It also improves light transmittance of polyimide film in the visible light region. The effect of different preparation methods on the aggregation in polymers and on polymer properties, especially adhesion and water absorptivity, are also discussed. The imidization temperature and synthesis method (blend and block) during the reaction has a significant effect on the properties of the product, especially thermal properties (T-g values are 207 degrees C for block and 180 degrees C for blend) and mechanical properties (elongation of 130% for block and 50% for blend). The bonding strength of polymer films used as hot melt adhesive was also tested. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48148.

制备了一种室温下为半固态的聚砜改性双酚A型氰酸酯预聚体.采用红外(FTIR)测试确定了其氰酸酯单体转化率为47.06％;采用差式扫描量热法(DSC),分析了其在不同催化剂含量下的固化过程,计算出催化剂含量为1％和7％时,各固化动力学参数分别是:表观活化能79.42kJ/mol和70.43kJ/mol、指前因子1.09×107和5.17×107、反应级数0.976和0.978;以外推法为基础确定体系的固化工艺为123℃/3h(催化剂含量1％)和1(催化剂含量7％).

Three kinds of polysulfones (PSF,PES and PPSF) are adopted as toughening resins,after mixing and pre-polymerizing with cyanate (BADCy) monomer,three kinds of cyanate prepolymer/polysulfone blended resins are prepared.The effect of types of polysulfones on shear strength of blended resin are studied,the results show that the three kinds of blended resins possess excellent mechanical performance and the highest serving temperature which are 180℃,230℃ and 280℃ respectively.The TG analysis indicates that the three kinds of blended resins are all outstanding heatresistant materials,and the weight-loss process follows the rule of heat oxygenolysis of BADCy.

The heat-resistant epoxy-benzophenonetetracarboxylic dianhydride (BTDA)adhesive is prepared. The relation between the ratio of BTDA/E51 and shear strength of the adhesive demonstrates that when the ratio of BTDA/E51 is in the range of 60％～80％, the mechanical property at both room and high temperature(230℃)is excellent. The mechanical properties of the adhesive cured base on different curing mechanisms are stud-ied. The shear strength at each temperature shows that the mechanical property is stable from room temperature to 230℃. The TGA and evaluation of heat-aging indicates that the heat-resistance of the adhesive is excellent. Compared with the commercially available ECCOBAND-104, the prepared epoxy-BTDA adhesive possesses a better thermal stability.

在航空航天领域,发泡结构胶黏剂应用广泛,其作用是提高制件的整体力学性能.另外,由于其密度低,有利于制件的减重.介绍了发泡结构胶的特点、作用、应用部位.主要阐述了发泡结构胶在国内外的发展历程和发泡结构胶的品种,列举了部分中温、高温发泡结构胶的主要性能指标.详述了波音公司对发泡结构胶的分类和标准要求,并对发泡结构胶黏剂的研发方向做出了展望.

提供了一种制备氰酸酯预聚物/聚砜共混树脂的工艺,该工艺过程平稳、温和、易控制.通过红外光谱IR研究,随着反应时间的延长,-OCN的红外特征吸收峰变弱,triazine特征吸收峰明显增强.随着PSF/BADCy比值提高,共混树脂的常温剪切强度相应增加;低含量的PSF对树脂高温(230℃)强度影响不大,高含量时,高温剪切强度降低明显.通过DMA分析,共混物只体现出BADCy相关的Tg值,BADCy预聚物和PSF树脂事实上形成一种互穿网络结构(IPN).共混树脂的真实Tg值为230℃左右.E'-T关系表明,只有高含量的PSF才对BADCy有明显的增韧作用.Tan δ～T关系表明,Tanδ=0.02,总体上共混树脂的韧性不高.通过TG分析,共混树脂的初始分解温度达到400℃,是一种优异的耐高温材料,共混树脂的失重过程完全遵从BADCy自身的热氧化分解规律.

The toughening modification methods of cyanate ester resins, including the modification methods with the thermoset resins, the thermoplastic resins, the rubber elastomers or the nanoparticles, and other methods, were briefly introduced in this paper.

以氰酸酯树脂和中空玻璃微球为原料制备了复合泡沫.通过检测复合泡沫的剪切强度、平面拉伸强度以及压缩强度评价复合泡沫的机械性能.结果表明,复合泡沫的机械性能由玻璃微球的性质以及在复合泡沫中的含量决定.微球的密度越大,泡沫的机械性能越高,反之亦然.泡沫的力学性能与微球的含量几乎呈线性降低的关系.通过TG分析表明,复合泡沫的热性能主要由氰酸酯本身性质决定,起始分解温度为400℃,但在高温阶段,微球的存在加速了复合泡沫的分解速率.在180℃下经过30d热老化试验,复合泡沫的热失重不明显,但固化物的外观颜色加深.

对J-273高温固化发泡胶进行了力学性能、耐水煮、耐盐雾等性能的测试.研究结果表明,J-273高温固化发泡胶的综合性能满足波音BMS5-90V标准的要求,而且具有良好的质量批次稳定性,可广泛用于金属或各种复合材料构成的夹芯蜂窝结构件中,适于蜂窝零件的周边、侧面和与之相接的梁、肋、腹板之间的结构胶接.

研制了一种双组分室温固化型糊状环氧树脂胶粘剂.该胶具有双增韧机制,即环氧组分采用端羧基液体丁腈橡胶(CTBN)增韧,固化剂采用了分子结构内具有多个醚键的胺类作内增韧.该胶粘剂可在室温下固化,且具有厚胶层高强度的特性,即胶层厚度在0.1～1.6 mm内可保持剪切强度基本不变,已用于无人机复材机翼结构件的胶接、各种复材结构件的粘接与修理,取得了良好的效果.

对J-262高温氰酸酯发泡胶黏剂进行了力学性能、介电性能、耐水煮、耐盐雾、湿热老化等性能的测试.研究结果表明:J-262高温氰酸酯发泡胶黏剂既有传统环氧树脂型高温发泡胶黏剂的力学性能,又具备优良的介电性能,其综合性能满足波音BMS5-90V标准的要求.J-262高温氰酸酯发泡胶黏剂对铝材、PMI泡沫以及纸蜂窝都有良好的粘接力,发泡胶固化后的本体强度大于PMI泡沫以及纸蜂窝的本体强度,可以用于PMI泡沫、纸蜂窝与铝材之间粘接和填充,而且具有良好的质量和批次稳定性,可广泛用于金属或各种复合材料构成的夹芯蜂窝结构件中,以及蜂窝零件的周边、侧面和与之相接的梁、肋、腹板之间的结构胶接.