中温固化EP体系研究进展

综述了近几年来中温固化环氧树脂(EP)体系的最新研究进展,详细介绍了双氰胺、酸酐和咪唑等常用固化剂及其促进剂的固化机制,最后对EP中温固化体系未来的研究方向进行了展望。     

含有联萘基团的环氧树脂的合成与固化

合成了一种具有联萘结构的环氧树脂(BEBN)。通过红外光谱、核磁共振氢谱以及元素分析对其结构进行了表征。以双酚A型环氧树脂(E-51)作为参照,采用二氨基二苯基甲烷为固化剂,通过差示扫描量热法(DSC)研究了BEBN,E-51的固化反应性;采用DSC,热重分析对固化物的热学性能进行测试,比较了固化物的力学性能、热性能以及吸水率;探讨了BEBN的结构与性能之间的关系。结果表明,同E-51相比,BEBN的固化反应平缓：BEBN固化物的玻璃化转变温度升高29℃,吸水率降低0．31％,热失重5％和50％的温度分别升高15℃和13℃。     

Synthesis of rosin‐based imidoamine‐type curing agents and curing behavior with epoxy resin

Rosin is an abundantly available natural product. The characteristic fused ring structure of rosin acids is analogous to that of some aromatic compounds in rigidity, and makes rosin and its derivatives potential substitutes for those aromatic compounds. In the study reported, the synthesis of biobased curing agents containing imide structure using rosin and the cure reaction were investigated. Rosin‐based imidoamine‐type curing agents were synthesized, and the chemical structure was confirmed using ¹H NMR, Fourier transform infrared and electrospray ionization spectroscopy. The curing behavior with diglycidyl ether of bisphenol A epoxy was studied using differential scanning calorimetry. The thermal mechanical properties and thermal stability of the cured epoxy resins were evaluated using dynamic mechanical analysis and thermogravimetry, respectively. The results indicate that the curing behavior of the rosin‐based curing agents is similar to that of curing agents with analogous structures. Cured products have good thermal stability due to the presence of the imide group and the bulky hydrogenated phenanthrene ring structure. Rosin acids have a great potential in the synthesis of epoxy curing agents as replacements for some of the current commercial aromatic or cycloaliphatic analogues. Copyright © 2010 Society of Chemical Industry     

脂环族环氧树脂/酸酐体系固化促进剂的研究

利用示差扫描量热仪研究了乙酰丙酮铝、三苯基膦、2-乙基-4-甲基咪唑(2E4MZ)等3种促进剂在脂环族环氧树脂(UVR-6103)/甲基六氢邻苯二甲酸酐(MHHPA)体系中的固化行为,通过Ellerstien方程计算得到了UVR-6103/MHHPA体系在3种促进剂作用下的固化动力学参数,其表观活化能分别为48.6,69.2,90.2kJ/mol,反应级数分别为0.96,2.09和1.60。     

Effect of prereaction on curing of elastomer-modified epoxy resins

Three multifunctional epoxy resins novolac epoxy (EPN), triglycidyl para-aminophenol (TGPAP), and tetraglycidyl diaminodiphenylmethane (TGDDM) were modified with a carboxy-terminated acrylate-based liquid elastomer (PnBA). The effect of prereaction of the epoxy groups in the resin and carboxyl group in the elastomer on curing parameters, such as the cure reaction conversions; processing parameters, such as gel times and vetrification times; initial cure temperatures, and activation energy values were evaluated. Fourier transform infrared spectrometry (FTIR), dynamic mechanical spectrometry (DMS), and differential scanning calorimetry (DSC) were used for the study. The results indicated that while the cure reactions were slightly retarded in the presence of elastomer, they were slightly accelerated when certain prereaction catalysts were used. The gel times and vitrification times decreased due to the prereaction. The physical properties such as fracture toughness and modulus of neat resin castings and flexural strength properties of carbon cloth-reinforced laminates were evaluated. Results indicated that the toughness property increased and the modulus decreased with elastomer addition. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:1751–1757, 1997     

不同化学结构环氧树脂电子束固化效果的分析

研究了化学结构对环氧树脂电子束辐射反应速率和辐射固化效果的影响。对于分子量相近的环氧树脂，反应速率大的环氧树脂体系最终达到的反应程度较高。酚醛型环氧树脂辐射反应活性高，固化后的高温模量及玻璃化转变温度高于双酚A型环氧树脂，但固化度沿辐射深度方向下降较快，脂环族环氧树脂的辐射反应活性小，在相同辐射条件下的固化效果差。缩水甘油胺结构的环氧树脂对于碘Wong盐引发的电子束辐射固化反应没有活性。     

不同固化体系对环氧粉末涂料性能的影响

通过非等温示差扫描量热分析(DSC),热重分析(TGA)及物理力学性能测试研究了分别以双氰胺、二氨基二苯基砜、线形酚醛树脂为固化剂,2-甲基咪唑为固化促进剂的环氧树脂体系的固化行为,热稳定性及其粉末涂料性能,并利用外推法求出不同固化体系的理论固化温度。结果表明:双氰胺/2-甲基咪唑体系的综合性能最好,其理论固化温度为142℃,热失重起始分解温度为410℃,冲击强度为50 cm,60°光泽为83,表面电阻为1.33×1012Ω。     

邻甲基苯胺改性双氰胺环氧固化剂的合成及性能研究

用邻甲基苯胺对双氰胺进行改性,制备了一种新型的改性双氰胺固化剂。对合成条件进行优化,并对其固化条件进行了研究。结果表明,邻甲基苯胺改性双氰胺的较佳工艺条件为:邻甲苯胺与盐酸的物质的量比为1∶1.1,邻甲苯胺与双氰胺的物质的量比为1∶1.4,于90℃反应3.5 h,收率为87.01%,原料利用率为74.74%。通过测试涂层硬度来考查固化工艺与性能。结果表明,作为环氧树脂固化剂单独使用时,质量比1∶10,固化温度为130℃,HV1=35.98比双氰胺体系固化温度降低了30℃。     

含杂萘联苯结构的环氧树脂固化动力学分析

采用差示扫描量热法（DSC）对含杂萘联苯结构环氧单体（3EPZ）与聚醚胺（ED-2003）的固化过程进行研究。采用Starink模型及自催化模型获得了不同转化率下体系的活化能及相关动力学参数,并建立了动力学方程。实验结果曲线与模型计算结果曲线的相关系数大于99%,表明所建立的自催化动力学模型能够较好地描述体系的固化过程。     

聚乙二醇接枝改性纳米炭黑对环氧树脂固化过程的影响

采用差示扫描量热法研究了以聚乙二醇(PEG)接枝改性的纳米炭黑(NC)(NC-PEG)为填料对环氧树脂/4,4-二氨基二苯砜非等温固化反应的影响,通过Flynn-Wall-Ozawa法和Malek法确定了固化反应的动力学参数.结果表明:两参数的自催化模型能够很好地描述环氧树脂及其复合材料的固化反应过程,各试样的模型拟合结果与实验数据相吻合.NC-PEG能够促进环氧树脂的固化,使固化活化能降低,其中,NC-PEG用量为3 phr时,活化能最低.     

改性双氰胺衍生物固化环氧树脂的研究

针对双氰胺固化环氧树脂时固化温度过高的缺点,从自行设计并合成的一系列改性双氰胺中筛选出一种,将其与环氧树脂复配制成单组分潜伏性环氧树脂胶粘剂,利用差示扫描量热法(DSC)和红外光谱法(FT-IR) 对单组分环氧树脂固化体系的固化反应进行了分析和研究。结果表明,改性双氰胺与双氰胺相比,具有较高的活性,显著降低了固化反应的反应温度;所配制的单组分环氧树脂胶粘剂具有较长的贮存期和良好的固化性能。     

The synergistic effect of dicyandiamide and resorcinol in the curing of epoxy resins

The synergistic effect of dicyandiamide (Dicy) and phenolic substances was studied, with resorcinol as a model compound. It was found that when Dicy and resorcinol are used jointly, the curing temperature of epoxy resin can be significantly lowered. FTIR and DSC data were used to illustrate the mechanism of the synergism. The addition of the phenolic hydroxyl group to epoxide was facilitated by Dicy, which favors the formation of phenoxy anions. The reaction of Dicy with epoxide was facilitated by resorcinol, which can exert “electrophilic assistance” for the addition of the amino group to epoxide. The presence of resorcinol also favors the addition of the hydroxyl group to the cyano group. The thermal and mechanical properties of the epoxy resins cured with Dicy/resorcinol or Dicy/phloroglucinol were studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1869–1874, 2003     

潜伏性环氧树脂固化促进剂M-Cd的合成及其应用

采用间苯二胺和溴化镉合成了一种具有潜伏性的环氧树脂固化促进剂M－Cd它是一种络合物，将它应用于二氰二胺／环氧树脂脂固化体系的高温结构粘剂中，能够显著地降低粘剂的固化温度，缩短固化时间，本文还讨论了合成该促进剂主要成分的投料比，应用于二氰二胺／环氧树脂固化体系的高温结构胶粘剂中该促进剂的使用量以及固化条件对粘剂力学性能的影响，同时还考核了应用该促进剂M的高温结构胶粘剂的综合性能。     

单组分环氧胶固化剂及促进剂的改性研究

采用间甲苯胺对固化剂双氰胺进行改性,红外表明双氰胺的—C≡N与间甲苯胺的—NH2发生反应,提高了固化剂的反应活性;XRD也证实了改性反应的进行。采用硫酸铜改性咪唑,XRD表明了有新的物质生成。经改性的双氰胺具有较好的活性和贮存稳定性。但单独使用改性双氰胺作固化剂,用量一般较大(为环氧树脂的25%),影响体系的流动性;而复合使用改性双氰胺和咪唑,在保证性能和固化时间的前提下,双氰胺的用量可减少至15%。改性双氰胺与环氧树脂具有较好的相容性,使环氧树脂固化体系的力学性能具有较大幅度的提高。     

固化体系对环氧树脂耐高温性能的影响

针对覆铜板的耐高温要求,分别使用胺类固化剂4,4′-二氨基二苯砜(DDS)、4,4′-二氨基二苯醚(DDE)和乙二胺(EDA)固化改性双酚A型环氧树脂,研制适用于耐高温覆铜板的环氧树脂固化物。用示差扫描量热法(DSC)研究其固化过程,讨论了固化剂用量、固化剂种类及固化温度等因素对固化物玻璃化转变温度(Tg)的影响。实验结果表明,固化物耐热性最好的配比不是化学计量,而是偏离化学计量,在理论用量的基础上适当增加固化剂用量,可有效地提高固化产物的玻璃化温度Tg值;使用芳香胺类固化剂固化双酚A型环氧树脂,其固化产物有较高的玻璃化温度,可以满足覆铜板耐高温的要求。     

改性双氰胺衍生物环氧固化剂的制备及性能研究

分别采用环氧丙烷、环氧丙烷丁基醚(501)和环氧树脂(EP)对双氰胺(DICY)进行改性,制备了一系列新型的改性DICY衍生物作为EP固化剂,并对改性DICY/EP固化体系的性能进行了初步研究。结果表明:当反应温度为95～105℃、n(DICY)∶n(环氧丙烷)=1∶1.1和n(DICY)∶n(501)=1∶1.3时,环氧丙烷改性DICY(反应3.0 h左右)和501改性DICY(反应3.0～4.0 h)的收率较高;EP改性DICY的最佳反应条件为反应温度105℃左右、反应时间4.0 h左右和n(DICY)∶n(EP)=1∶1.3。环氧丙烷(或501)改性DICY在室温时具有一定的潜伏性,与EP的相容性得到明显改善,并且其固化体系的起始放热温度比DICY体系降低了近40℃(或30℃);EP改性DICY具有较好的潜伏性(与DICY相当),并且极易溶于EP中,但其固化体系的起始放热温度稍低于DICY体系。     

双氰胺固化双酚F/间苯二酚共聚型环氧树脂的研究

为提高双酚F环氧树脂的综合性能,以双酚F、间苯二酚与环氧氯丙烷反应制得双酚F/间苯二酚共聚型环氧树脂。通过差示扫描量热法(DSC)研究了2-乙基-4-甲基咪唑对双氰胺-双酚F/间苯二酚共聚型环氧树脂体系固化反应的促进作用,并系统地探讨了固化体系及固化条件对固化物性能的影响。结果显示,其最佳固化工艺条件是:间苯二酚与双酚F质量比为20∶80,双氰胺质量分数为6%,2-乙基-4-甲基咪唑质量分数为4%,固化温度为110℃,固化时间为3 h。     

Synthesis and characterization of a new phosphorus‐containing furan‐based epoxy curing agent as a flame retardant

In this study, 5‐hydroxymethyl‐2‐furfural (HMF) was used as a renewable resource for preparing an epoxy curing agent (furan‐based flame retardant, FBF), and a phosphorus‐containing functional group was also incorporated to enhance the flame retardancy of FBF. FBF was easily synthesized, and the total yield was 83%. 2‐Methyl imidazole was chosen as an accelerant to reduce the activation energy for the reaction of FBF with diglycidyl ether of bisphenol A (DGEBA). The DGEBA cured with FBF showed a low glass transition temperature and cross‐linking density compared with those of DGEBA cured with isophorondiamine (IPDA) and 4,4′‐diaminodiphenylmethane (DDM). However, the FBF‐cured DGEBA exhibited a comparable tensile strength with that of the DGEBA‐IPDA and DGEBA‐DDM systems (81.96 MPa) and a significantly higher tensile modulus (1721 MPa) owing to the H‐bonding via oxygens of the phosphorus group of FBF in the network structure. The DGEBA cured with FBF showed a high char yield and a high limitation of oxygen index value (29.7%) compared with those of the IPDA‐ and DDM‐cured ones. The cone calorimeter measurement also showed that the DGEBA‐FBF system had a low heat release rate, total heat release, and smoke production rate, indicating the improved flame retardancy mediated by FBF.     

环氧树脂中温固化促进剂的研制

双氰胺固化环氧树脂时的固化温度高,利用不同含量的乳酸改性咪唑生成的盐作为环氧树脂／双氰胺体系固化促进剂对该体系进行了改进。结果表明,改性咪唑促进剂可以使环氧树脂／双氰胺体系的固化温度降低,并且贮存期显著增加,耐水性和耐热老化性能增加。