端异氰酸酯聚醚增韧环氧树脂固化动力学研究

采用差示扫描量热（DSC）技术测定了在芳胺类为固化剂的条件下,增韧环氧体系固化反应过程中的热行为,得出固化反应过程的动力学参数,实验数据表明,以芳胺为固化剂的体系中,固化反应表观活化能及动力学频率因子,反应级数均有明显降低。     

水性环氧树脂涂料固化机理的研究

以自制水性环氧树脂固化剂与自制的E型非离子型水性环氧树脂乳胶混合,于室温下固化交联,观察固化效果与涂膜性能,探究其固化机理,并提出固化模型,以期指导固化剂的结构设计。利用粒径分析、激光共聚焦显微镜(LSCM)、透射电镜(TEM)、扫描电镜(SEM)、原子力显微镜(AFM)等测试方法,对其固化过程和固化效果进行了表征。结果表明:固化剂胶粒吸附于水性环氧树脂胶粒表面,随水分挥发,二者相互扩散、融合、交联,但扩散快于交联,最终固化均匀完全,涂膜致密均一。     

异氰酸酯改性环氧树脂固化过程的二维红外相关光谱研究

采用二维红外相关光谱研究了异氰酸酯改性环氧树脂高温固化反应过程中分子结构动态变化的规律和相互作用。结果表明,在固化过程中,环氧基开环与酚羟基反应,最终生成脂肪醚。二维相关红外光谱分析技术可提高吸收峰的分辨率,是分析复杂分子结构动态变化的1种有力手段。     

环氧树脂与氰酸酯共固化反应的研究—Ⅰ.固化反应行为、机理及其固化物结构特征

应用DSC、FT-IR对乙酰丙酮过渡金属络合物催化促进的环氧树脂与氰酸酯共固化反应行为、历程以及固化物的结构特征进行了研究探讨。结果表明,促进剂能够明显降低固化反应温度,缩短固化反应时间。反应历程首先是氰酸酯发生自聚反应形成二聚体或三聚体（三嗪环）,然后二聚体可进一步其聚形成三嗪环,此过程伴随着环氧基的聚醚反应,最后是三嗪环与剩余的环氧基反应形成恶唑烷酮,在氰酸酯适量的条件下,固化树脂中主要是恶唑烷酮和聚醚结构,三嗪环结构很少;在氰酸酯适量或过量条件下,固化树脂主要是三嗪环和恶唑烷酮结构,聚醚结构很少。     

DSC法研究聚异氰酸酯/环氧树脂胶粘剂的固化反应动力学及固化工艺

采用差示扫描量热法(DSC)研究了聚异氰酸酯/环氧树脂的固化过程,研究了不同配比对固化反应的影响、固化度与固化温度的关系,计算了固化反应表观活化能和反应级数,确定了聚异氰酸酯/环氧树脂胶粘剂的固化工艺。结果表明:胶粘剂中固化剂的含量对环氧树脂的固化反应过程有显著的影响,随着聚异氰酸酯含量的增加,固化放热量增加。当聚异氰酸酯的含量达到1.2份时,固化反应放热量达到最大值;在不同升温速率下,体系固化温度有很大差异,随着升温速率的提高,固化温度升高。通过动力学计算得到体系最佳固化温度为108℃,固化时间为6—8h,固化体系的活化能为43.31kJ/mol,反应级数为1.17。     

DSC法研究聚异氰酸酯／环氧树脂胶粘剂的固化反应动力学及固化工艺

采用差示扫描量热法(DSC)研究了聚异氰酸酯／环氧树脂的固化过程,研究了不同配比对固化反应的影晌,固化度与固化温度的关系,计算了固化反应表观活化能和反应级数,确定了聚异瓤酸酯／环氧树脂胶粘剂的固化工艺。结果表明:胶粘剂中固化剂的含量对环氧树脂的固化反应过程有显著的影响,随着聚异氰酸酯的增加,固化放热量增加。当聚异氰酸酯的含量达到1．2份时,固化反应放热量达到最大值;不同升温速率下,体系固化温度有很大差异,随着升温速率的提高,固化温度增加。通过动力学计算得到体系最佳固化温度为108℃,固化时间为6-8h,固化体系的活化能为43．31kJ／mol,反应级数为1．17。     

胺化酰亚胺固化的环氧树脂体系的特性及其固化机理

能热分解成异氰酸酯和叔胺的胺化酰亚胺是很好的潜伏性环氧树脂固化剂和环氧-酸酐体系的固化促进剂,它固化的环氧树脂有许多优异的性能,特别是高的韧性和粘接强度。由胺化酰亚胺热分解速度控制的、高温下相对慢的、独待的固化机理是韧性的起因。     

采用模型化合物研究环氧树脂电子束固化机理

通过红外光谱、凝胶渗透色谱及核磁共振分析研究了单官能模型化合物苯酚缩水甘油醚在不同辐射剂量、引发剂浓度和羟基化合物掺杂情况下的电子束固化反应特性及机理。结果表明,环氧基团反应完全后,大幅度增加辐射剂量不会导致已经聚合的环氧树脂出现明显的辐射降解,但是引发剂浓度的增加和羟基化合物乙醇使聚合环氧树脂的分子质量下降。     

特种异氰酸酯改性环氧树脂涂料

采用自制4－丁氧甲酰氨基甲苯2－异氰酸酯（BCATI）或4－丙烯酰氧乙氧甲酰氨基甲苯2－异氰酸酯（AECATI）改性（丙烯酸）环氧（酯）树脂制备涂料。结果表明，所用两种原料BCATI或AECATI中的－NCO与（丙烯酸）环氧（酯）树脂中－OH比为－0．25／1时，所制成的清漆综合性能优良。     

改性芳香胺固化环氧树脂的研究

本文研究了改性芳香胺固化剂固化环氧树脂动力学。分析确定了该体系的最佳固化工艺,使用两种模型法对固化过程进行了拟合。研究表明,该固化体系适用于中低温固化条件,n级模型法不适用该体系,而自催化模型中使用简化双参数SB模型能够较好的拟合固化过程。     

Polydimethylsiloxane containing isocyanate group-modified epoxy resin: Curing,characterization, and properties

A synthesized polydimethylsiloxane containing an isocyanate group was used to improve the flexibility and to reduce the internal stress of epoxy resin cured with MDA (4,4′-methylene dianiline). The effect of polysiloxane content on the curing kinetics of a novolac-type epoxy modified with an isocyanate group was investigated. It was found that the modified epoxy resin showed significant improvement in impact strength. The polysiloxane containing isocyanate groups effectively depressed the internal stress of cured epoxy resins by reducing the flexural modulus and the coefficient of thermal expansion, while the glass transition temperature was increased. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2739–2747, 1999     

Curing and characterization of oxazolidone-isocyanurate-ether networks

Oxazolidone-isocyanurate-ether networks were prepared by copolymerization of mixtures of DGEBA and toluene-2,4-diisocyanate (TDI) in presence of benzyldimethylamine (BDMA) as catalyst. Changes during curing and final properties of the cured materials were investigated by using DSC, FTIR/ATR, TMA, DMTA, TGA, and densitometry. The influence of the molar ratio of isocyanate to epoxide groups on the properties and curing were studied. The kinetics of curing was analyzed by means of an integral isoconversional nonisothermal procedure. The fractions of oxazolidone, isocyanurate, and ether groups present in the final network were evaluated and were found to be dependent on the initial isocyanate/epoxy ratio and curing conditions. By increasing the initial proportion of isocyanate the glass transition temperature, the thermal stability, the shrinkage, and the amount of isocyanurate rings increase, whereas the fraction of ether linkages and oxazolidones decreases. It was observed that the gelation is controlled by the formation of isocyanurate rings at the beginning of the curing. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

苯并(口恶)嗪改性环氧酸酐体系的固化机理及动力学

利用一种二胺型苯并(口恶)嗪改性环氧酸酐体系。通过FT-IR和DSC分析了改性体系的固化机理。结果表明：共混树脂体系在固化时存在两个反应,首先是环氧树脂与足量的酸酐在咪唑作用下在100℃先开始固化,并在150℃固化2 h后固化完全,之后苯并(口恶)嗪在180℃发生开环聚合。用非等温DSC法研究了该共混体系的固化动力学。采用Flynn-Wall-Ozawa方法求出了共混体系在固化时两个固化反应的活化能,分别为65.27 kJ·mol^-1和92.8 kJ·mol^-1,并利用Friedman方法判断了两个反应都是自催化反应,计算得到自催化模型曲线与实验曲线能较好地吻合。     

Curing characteristics of epoxy resin systems that include a biphenyl moiety

The curing characteristics of epoxy resin systems that include a biphenyl moiety were investigated according to the change of curing agents. Their curing kinetics mainly depend on the type of hardener. An autocatalytic kinetic reaction occurs in epoxy resin systems with phenol novolac hardener, regardless of the kinds of epoxy resin and the epoxy resin systems using Xylok and DCPDP (dicyclopentadiene‐type phenol resin) curing agents following an nth‐order kinetic mechanism. The kinetic parameters of all epoxy resin systems were reported in terms of a generalized kinetic equation that considered the diffusion term. The fastest reaction conversion rate among the epoxy resin systems with a phenol novolac curing agent was obtained in the EOCN‐C epoxy resin system, and for systems with Xylok and DCPDP hardeners, the highest reaction rate values were obtained in NC‐3000P and EOCN‐C epoxy resin systems, respectively. The system constants in DiBenedetto's equation of each epoxy resin system with different curing agents were obtained, and their curing characteristics can be interpreted by the curing model using a curing agent as a spacer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1942–1952, 2002     

Toughening epoxy resin with blocked isocyanate containing soft chain

A series of imidazole (MI) blocked 2,4‐toluene diisocyanate (TDI) with polyethylene glycol (PEG‐400) as soft segment (PEG‐MI‐b‐TDI) were synthesized for toughening and curing the bisphenol A type epoxy resin (E‐44). Fourier transform infrared (FTIR) spectrum indicates that the NCO groups of the isocyanate molecule are blocked with MI. For curing epoxy systems, elimination of epoxy group and the formation of urethane bonds were studied by FTIR spectroscopy. The results of mechanical property were shown that the tensile shear and impact strengths of neat MI and MI‐b‐TDI cured E‐44 are lower than those of PEG‐MI‐b‐TDI cured E‐44. Based on the scanning electron microscope studies, microstructure evolutions of the E‐44 cured by different curing agents were imaged. The mechanical, thermal, and dynamic mechanical properties were measured by universal testing machine, differential scanning calorimeter and dynamic mechanical analyzer (DMA). The toughness of E‐44 cured by PEG‐MI‐b‐TDI was effectively improved without sacrificing the tensile shear strength. Based on the DMA studies, the long soft chain of PEG brought in a noticeable lowering in the glass transition temperature (T_g). The glass transition temperature is near 165°C for the neat MI cured E‐44, which is higher than the T_gs of the other curing agents cured epoxy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41345.     

纳米粒子改性环氧树脂固化反应动力学研究

采用示差扫描量热仪(DSC)研究了不同用量纳米Al2O3粒子改性的环氧树脂基体的固化反应动力学,根据DSC实验的结果采用Kissinger和Crane方法计算得到不同树脂体系的固化动力学参数并研究了固化度与温度之间的关系。结果表明,纳米粒子的加入使固化的起始温度与终止温度降低,并缩短了固化时间。随着纳米粒子含量的增加,改性树脂体系固化反应放热峰的峰值温度逐渐降低,固化反应的表观活化能降低,但反应频率因子及反应级数基本不变。     

Curing of epoxy resin contaminated with water

Epoxy resins used for reinforcement of bridges and buildings are explored in the light of both curing rates and mechanical properties when resins are contaminated with water in outdoor construction. The developed resin is composed of a conventional resin of bisphenol A diglycidyl ether and a hardener with a polyoxipropyldiamine base. Curing rates were obtained by time variation of the near infrared absorbance of amine groups in the hardener at various water contents. They obeyed the second‐order reaction law with respect to the hardener, of which the activation energy was 70 kJ mol⁻¹. Water increased the reaction rate. Mechanical properties such as ultimate tensile strength, adhesive shear stress, and flexural strength were measured at various water contents for the developed epoxy resin and the commercially available low‐temperature epoxy resin. The developed cured resin shows not only higher mechanical strengths but also much less deterioration by water than the conventional cured resin. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 214–220, 2001     

含异氰脲酸酯基环氧树脂的合成

为了改善环氧树脂的耐热性与韧性 ,以三羟乙基异氰脲酸酯 (THEIC)为原料 ,与环氧氯丙烷 (ECH)合成了氯化聚醚多元醇 (CPP) ,CPP与氢氧化钠反应制备了一种新型的含异氰脲酸酯基和醚键的液体环氧树脂 (EP) ,并通过IR确定了结构。CPP与氢氧化钠的摩尔比为 1∶3.2 5,在 2 50ml乙醇 ( 0 .1molCPP)中 ,室温反应 3h ,产率 87.7% ,环氧值 0 .36 87。     

纳米粒子／环氧树脂复合材料的固化动力学研究

为了改善纳米SiO2粒子在环氧树脂基体中的分散性,提高无机粒子与基体的界面结合力,文章选择马来酸酐和苯乙烯单体在粒予表面进行接枝改性。改性粒予与环氧树脂在固化条件下基本不发生反应,而固化剂2-乙基-4-甲基咪唑使得改性粒子上的酸酐开环生成羧酸;固化动力学分析表明：纳米粒子表面的羟基对环氧树脂的固化起促进作用;与未改性的粒子相比,填充SiO2-SMA粒子的固化体系的粘度较低,所以固化起始温度降低,但反应活化能较高。     

环氧树脂固化促进剂的研究

以甲苯二异氰酸酯(TDI)和3-二甲氨基丙胺为单体、甲苯为溶剂,合成了环氧树脂(EP)的固化促进剂——甲苯-2,4-二(N,N′-二甲氨基丙脲)。为了验证自制促进剂的性能,以EP/双氰胺/促进剂为基体,并辅以填料、增韧剂、沉淀硫酸钡和流平剂等助剂,制备了粉末涂料。结果表明:制备促进剂的最佳工艺条件为n(TDI)∶n(3-二甲氨基丙胺)=1∶1.8、3-二甲氨基丙胺/甲苯溶液的滴加时间为1.5 h;当w(促进剂)=2.0%、固化温度为160℃时,粉末涂料的固化时间为6.5 min、胶化时间约100 s,并且其硬度、附着力和柔韧性俱佳,完全满足生产要求和使用要求。