含芳醚芴二胺/环氧树脂固化反应动力学及性能研究

以9,9-双[4-4-氨基苯氧基苯基]芴(BAOFL)作为固化剂,采用非等温DSC技术,研究了BAOFL/环氧树脂(E-51、TDE-85和芴基环氧树脂)体系的固化反应动力学,利用动态热机械分析仪(DMA)和热重分析仪(TGA)测试了固化树脂的力学性能和热稳定性。结果表明,固化反应活化能与环氧树脂和固化剂的结构密切相关,芳醚的引入提高了氨基与环氧基的反应性,固化树脂呈现出优良的热性能和力学性能,其玻璃化转变温度(T)达到206~248℃,贮能模量为2.54~2.94 GPa,初始热分解温度312~375℃,700℃g时的残炭率达到15.2%~31.7%。()     

Curing kinetics and properties of epoxy resin-fluorenyl diamine systems

Diglycidyl ether of bisphenol fluorene (DGEBF), 9,9-bis-(4-aminophenyl)-fluorene (BPF) and 9,9-bis-(3-methyl-4-aminophenyl)-fluorene (BMAPF) were synthesized to introduce more aromatic structures into the epoxy systems, and their chemical structures were characterized with FTIR, NMR and MS analyses. The curing kinetics of fluorenyl diamines with different epoxy resins including DGEBF, cycloaliphatic epoxy resin (TDE-85) and diglycidyl ether of bisphenol A (DGEBA) was investigated using non-isothermal differential scanning calorimetry (DSC), and determined by Kissinger, Ozawa and Crane methods. The thermal properties of obtained polymers were evaluated with dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The results show that the values of activation energy (E_a) are strongly dependent on the structures of epoxy resin and curing agent. The curing reactivity of epoxy system is restrained by the introduction of rigid fluorene into chain backbone and flexible methyl into side groups. The cured DGEBF/fluorenyl diamine systems exhibit remarkably higher glass transition temperature, better thermal stability and lower moisture absorption compared to those of DGEBA/fluorenyl diamine systems, and display approximate heat resistance and much better moisture resistance relative to those of TDE-85/fluorenyl diamine systems.     

Curing kinetics and thermal properties of vinyl ester resins

The curing kinetics of dimethacrylate-based vinyl ester resins were studied by scanning and isothermal DSC, gel time studies, and by DMTA. The rate of polymerization was raised by increased methyl ethyl ketone peroxide (MEKP) concentration but the cocatalyst, cobalt octoate, retarded the reaction rate, except at very low concentrations. By contrast, the gel time was reduced for all increases in either peroxide or cobalt concentration. This contradictory behavior was explained by a kinetic scheme in which the cobalt species play a dual role of catalyzing the formation of radicals from MEKP and of destroying the primary and polymeric radicals. The scanning DSC curves exhibited multiple peaks as observed by other workers, but in the present work, these peaks were attributed to the individual influence of temperature on each of fundamental reaction steps in the free radical polymerization. Physical aging appeared to occur during the isothermal polymerization of samples cured below the “fully cured” glass transition temperature (T_g). For these undercured materials, the difference between the DSC T_g and the isothermal curing temperature was approximately 11°C. Dynamic mechanical analysis of a partially cured sample exhibited anomalous behavior caused by the reinitiation of cure of the sample during the DMTA experiment. For partially cured resins, the DSC T_g increased monotonically with the degree of cure, and this dependence was fitted to an equation related to the Couchman and DiBenedetto equations. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 769–781, 1997     

联苯酚醛环氧树脂固化动力学及热性能研究

以4,4'-二氨基二苯砜(DDS)为固化剂,采用非等温示差扫描量热法(DSC)研究了联苯酚醛环氧树脂(BPNE)的固化动力学。通过外推法确定了体系的固化工艺。采用Kissinger、Ozawa法计算出固化体系的表观活化能,根据Crane理论计算得到该体系的固化反应级数。采用DSC,热重分析(TGA)研究了固化物的耐热性。结果表明:BPNE的固化工艺为160℃/2h+200℃/2h+230℃/2h;固化反应的活化能约为61.86kJ/mol,指前因子为5.27×105min-1,反应级数为1.1;玻璃化转变温度(Tg)为167℃,其10%热失重温度为398.1℃,800℃残炭率为29.37%,与双酚A环氧树脂/DDS固化物相比,分别提高了22℃,11.71%。     

Reaction kinetics,thermal properties of tetramethyl biphenyl epoxy resin cured with aromatic diamine

Epoxy resins, 4, 4′‐diglycidyl (3, 3′, 5, 5′‐tetramethylbiphenyl) epoxy resin (TMBP) containing rigid rod structure as a class of high performance polymers has been researched. The investigation of cure kinetics of TMBP and diglycidyl ether of bisphenol‐A epoxy resin (DGEBA) cured with p‐phenylenediamine (PDA) was performed by differential scanning calorimeter using an isoconversional method with dynamic conditions. The effect of the molar ratios of TMBP to PDA on the cure reaction kinetics was studied. The results showed that the curing of epoxy resins contains different stages. The activation energy was dependent of the degree of conversion. At the early of curing stages, the activation energy showed the activation energy took as maximum value. The effects of rigid rod groups and molar ratios of TMBP to PDA for the thermal properties were investigated by the DSC, DMA and TGA. The cured 2/1 TMBP/PDA system with rigid rod groups and high crosslink density had shown highest T_g and thermal degradation temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

香草醇基环氧树脂的合成、固化动力学及性能

以可再生香草醇为原料,合成了一种生物基环氧树脂（DGEVA）。通过使用甲基六氢苯酐（MeHHPA）作为固化剂,制备了一种新型的生物基环氧树脂交联网络（DGEVA/MeHHPA）。对其非等温固化动力学、热性能、热机械性能、机械性能和微观形貌结构进行了系统的研究,并用商用的石油基双酚A型环氧树脂组成的石油基环氧树脂体系（DGEBA/MeHHPA）进行对比。结果表明：DGEVA/MeHHPA和DGEBA/MeHHPA具有相似的固化反应活性。DGEVA/MeHHPA具有可以与DGEBA/MeHHPA相媲美的综合性能：玻璃化转变温度为82.2℃;拉伸强度和拉伸模量分别是 (66.7±6)MPa和 (2.8±0.1)GPa;T_d5%、T_d10%和T_dmax分别是242.4℃、284.9℃和392.4℃。此外,DGEVA/MeHHPA在形变过程中发生了塑性变形而吸收了更多的断裂能。DGEVA刚性骨架和低分子量带来的潜在高交联密度赋予了DGEVA优异性能,具有在实际应用中替代石油基环氧树脂的应用潜力。     

Cure kinetics of an epoxy/liquid aromatic diamine modified with poly(ether imide)

The cure kinetics and mechanisms of an epoxy oligomer based on diglycidyl ether of bisphenol A (DGEBA), polymerized with a liquid aromatic diamine based on diethyl toluene diamine (DETDA 80), and its blends with poly(ether imide) (PEI) at concentrations of 0–15 wt % were studied with differential scanning calorimetry under dynamic and isothermal conditions. The kinetic analyses were performed with a phenomenological approach. The reaction mechanism of the blends remained the same as that of the neat epoxy. However, the addition of PEI had a marked effect on the cure kinetics in the DGEBA/DETDA 80 system. The rate of reaction decreased with an increase in the thermoplastic content. Diffusion control was incorporated to describe the cure behavior of the blends in the latter stages. Greater diffusion control was observed as the PEI concentration increased and the cure temperature decreased. Polymer blends based on this epoxy/liquid aromatic diamine had not been previously studied from a kinetic viewpoint. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 660–672, 2005     

Cure kinetics of a diglycidyl ether of bisphenol a epoxy network (n = 0) with isophorone diamine

The study of the cure reaction of a diglycidyl ether of bisphenol A epoxy network with isophorone diamine is interesting for evaluating the industrial behavior of this material. The total enthalpy of reaction, the glass‐transition temperature, and the partial enthalpies at different curing temperatures have been determined with differential scanning calorimetry in dynamic and isothermal modes. With these experimental data, the degree of conversion and the reaction rate have been obtained. A kinetic model introduces the mechanisms occurring during an epoxy chemical cure reaction. A modification of the kinetic model accounting for the influence of the diffusion of the reactive groups at high conversions is used. A thermodynamic study has allowed the calculation of the enthalpy, entropy, and Gibbs free energy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

新型环氧树脂胶粘剂的固化动力学研究

在不同升温速率下采用非等温差示扫描量热（DSC）技术对一种新型改性环氧树脂胶粘剂的固化反应过程进行了跟踪,并利用Kissinger、crane方程以及Arrhenius方程对该固化反应进行了动力学分析。结果表明,该固化反应的活化能为59.18kJ／mol,反应级数为0．89;结合Dsc谱图确定其固化工艺为130℃／1h＋150℃／2h＋175℃／3h。     

Crystal structure,curing kinetics,and thermal properties of bisphenol fluorene epoxy resin

Diglycidyl ether of 9,9‐bis(4‐hydroxyphenyl) fluorene (DGEBF) monomer was successfully synthesized and characterized in detail. The crystal structure of DGEBF was measured by single‐crystal X‐ray diffraction analysis. Curing kinetics of DGEBF with 4,4‐diaminodiphenyl sulfone (DDS), thermal properties, and decomposition kinetics were investigated using nonisothermal differential scanning calorimetry (DSC) according to Kissinger, Ozawa and Crane methods. The glass transition temperature (T_g), thermal properties of cured polymer were estimated by DSC, dynamic mechanical analysis, and thermogravimetric analyses. Epoxy value of DGEBF monomer up to theoretical value leads to higher crosslink density of cured polymers. The cured DGEBF/DDS system exhibited obvious higher T_g and better thermal stability compared to those of DGEBF/diamine systems reported previously. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

碳纳米管改性酚醛树脂固化动力学研究

采用非等温示差法分析了碳纳米管改性酚醛固化反应过程,运用Kissinger和Ozawa法对其进行了动力学研究,得到了反应活化能。结果表明:碳纳米管改性PF树脂的固化反应为吸热反应;相应的峰始温度(Ti)为106.4℃,峰顶温度(Tp)为118.2℃,峰终温度(Tf)为157.6℃,固化体系的表观活化能Ea为111.094 kJ/mol,频率因子为9.56×10-5/s,反应级数为0.965,并得到了固化反应动力学方程。     

Studies of the curing kinetics and thermal stability of epoxy resins using a mixture of amines and anhydrides

This article describes the curing and thermal behavior of diglycidyl ether of bisphenol A with phthalic anhydride (PA)/pyromellitic anhydride/diaminodiphenyl sulfone (DDS) or a mixture of anhydrides and amines in varying ratios as curing agents. The kinetics of the curing behavior was investigated with a multiple‐rate method. The activation energy of the curing reaction as determined in accordance with Ozawa's method was found dependent on the structure of the anhydride and on the ratio of amines to anhydrides. The activation energy was highest with sample DP3 (0.25 : 0.75) and DM3 (0.25 : 0.75). We evaluated the thermal stability of epoxy resin, cured isothermally, by recording thermogravimetric traces in a nitrogen atmosphere. The char yield was highest for resins cured with a mixture of DDS and PA (0.5 : 0.5) and a mixture of DDS and pyromellitic dianhydride (0.25 : 0.75). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3919–3925, 2006     

Preparation and curing kinetics of bisphenol A type novolac epoxy resins

A bisphenol A type novolac resin (Bis‐ANR) was synthesized from bisphenol A and formaldehyde; the resulting novolac was epoxidized to generate a bisphenol A type novolac epoxy resin (Bis‐ANER). The chemical structures of Bis‐ANR and Bis‐ANER were confirmed by ¹H‐NMR spectroscopy and IR spectroscopy; the molecular weights and molecular weight distributions were determined by gel permeation chromatography. In addition, the curing process of Bis‐ANER with 4,4′‐diaminodiphenyl sulfone was studied in both dynamic and isothermal modes with differential scanning calorimetry. The dynamic curing kinetic analysis was evaluated with both the Kissinger and Flynn–Wall–Ozawa methods, and the curing activation energy values were obtained. The isothermal curing reaction exhibited autocatalytic behavior, and the curing kinetics were described with the Kamal kinetics model, which accounted for both the autocatalytic and diffusion‐control effects. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 858–868, 2006     

有机蒙脱土对环氧树脂固化反应动力学的影响

2wt％的有机蒙脱土（OMMT）显著影响环氧树脂／六氢苯酐固化体系的非等温固化反应动力学,可促进低温主固化过程,但对高温固化阶段有延迟作用。根据Mfilek最概然模型选择法采用Kissinger方程对两个DSCN化峰分别进行模拟,发现环氧树脂低温主固化峰与高温固化峰均属自催化反应,总反应级数均为15左右。所采用的分峰模拟法可描述整个固化反应过程,对较为复杂的高分子固化反应动力学研究具有指导意义。     

对苯二甲醛酚醛树脂的制备及其固化动力学研究

基于酚醛树脂原料中甲醛的危害性与不可再生性,使用安全、可再生的对苯二甲醛代替甲醛,合成了一种新型的酚醛树脂——对苯二甲醛酚醛树脂。采用核磁、红外、GPC和流变仪等分析手段对此类树脂的结构与性能进行了表征。为了进一步提高该树脂的热性能,使用二茂铁甲醛对其进行改性。采用Kissinger方程、等转换法及双参数自催化模型对改性前后树脂的固化动力学进行了研究,明确了二茂铁甲醛在树脂固化中的作用机理。最后通过MDSC和TG研究了改性前后树脂固化物的热性能,结果表明：在加入15%的二茂铁甲醛后,改性树脂呈现出优异的热性能,其玻璃化转变温度为319.3℃,起始分解温度为397.7℃,在800℃氮气气氛下质量保持率高达76.07%。     

环氧灌封料固化反应动力学及其性能研究

采用非等温示差扫描量热法(DSC)研究了环氧树脂(E-51)/甲基四氢苯酐/DMP-30/球形SiO2体系的固化反应动力学,采用Kissinger法和Crane公式对体系的DSC数据进行了处理,获得了固化反应动力学参数,确定了固化工艺。同时通过力学性能和热性能测试研究了球形SiO2添加量对复合材料性能的影响。结果表明,SiO2质量分数为10%的体系其起始固化温度为109.7℃,峰顶固化温度为134.8℃,终止固化温度为154.3℃;较好的固化工艺为100℃/2 h+140℃/2 h+160℃/2 h。该体系反应级数n=0.917,表观活化能Ea=78.52 kJ/mol。当SiO2添加量为30%时,其弯曲强度达到最大值97 MPa,同时热分解温度达到最大值332℃,试样热膨胀系数也明显降低。     

Effect of structure of aromatic diamines on curing characteristics,thermal stability,and mechanical properties of epoxy resins. I

The curing behavior of diglycidyl ether of bisphenol-A (DGEBA) with aromatic diamines having aryl–ether, aryl–ether–carbonyl, and aryl–ether–sulfone linkages was studied using differential scanning calorimetry (DSC). Aromatic diaminessuch as 1,3-bis(aminophenoxy)benzene (R), 1,4-bis(aminophenoxy)benzene (H),2,2′-bis[4-(4-aminophenoxy)phenyl]propane (B), 4,4′-bis(4-aminophenoxy)benzo-phenone (P), and bis[4-(4-aminophenoxy)phenyl]sulfone (S) were synthesized and characterized in the laboratory. Curing of DGEBA was done using both stoichiometric and nonstoichiometric amounts of diamines and the reaction was monitored using DSC. The reactivity of the diamines depended on the structure. The presence of electron withdrawing groups, even though significantly apart from the reaction site, reduced the nucleophilicity. No significant change was observed in the activation energy for curing, which was around 56 ± 2 kJ/mol. The glass transition temperature of the epoxy network depended on the structure and was higher when diamines P and S were used in comparison to diamines R, H, and B. The cured resins were stable up to 300°C, and maximum char yield (i.e., 32% at 600°C) was obtained in DGEBA cured with diamine P. The room temperature mechanical properties only changed marginally with the structure of the diamines. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1759–1766, 1998     

Curing behavior of epoxy resins in two‐stage curing process by non‐isothermal differential scanning calorimetry kinetics method

In this research, a new thermal curing system, with two‐stage curing characteristics, has been designed. And the reaction behaviors of two different curing processes have been systematically studied. The non‐isothermal differential scanning calorimetry (DSC) test is used to discuss the curing reaction of two stages curing, and the data obtained from the curves are used to calculate the kinetic parameters. Kissinger‐Akahira‐Sunose (KAS) method is applied to determine activation energy (E_a) and investigate it as the change of conversion (α). Málek method is used to unravel the curing reaction mechanism. The results indicate that the curing behaviors of two different curing stages can be implemented successfully, and curing behavior is accorded with ?esták‐Berggren mode. The non‐isothermal DSC and Fourier transform infrared spectroscopy test results reveal that two different curing stages can be implemented successfully. Furthermore, the double x fitting method is used to determine the pre‐exponential factor (A), reaction order (m, n), and establish the kinetic equation. The fitting results between experiment curves and simulative curves prove that the kinetic equation can commendably describe the two different curing reaction processes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40711.     

笼型倍半硅氧烷(POSS)/环氧杂化树脂体系固化反应动力学及性能研究

为了提高环氧树脂的耐热性,采用笼型倍半硅氧烷(POSS)改性双酚A型环氧树脂E51,得到有机无机杂化树脂。采用Ozawa和Kissinger两种方法研究了杂化树脂/4,4′-二氨基苯砜(DDS)体系的固化反应动力学。TGA分析表明,POSS的加入提高了E51/DDS固化树脂体系的热性能。     

The curing reaction and physical properties of DGEBA/DETA epoxy resin blended with propyl ester phosphazene

The influences of different amounts of propyl ester phosphazene (FR) on the curing kinetics and physical properties of diglycidyl ether of bisphenol A (DGEBA) epoxy prepolymer cured with diethylenetriamine (DETA) were investigated with DSC, SEM, DMA, and tensile testing. The results revealed that FR could be a catalyst or a diluent depending on the FR content. In addition, the blending systems were partially miscible. The tensile strength and modulus of blends decreased with increasing amounts of FR, but the elongation increased with increasing FR. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 229–237, 1999