环氧树脂和环氧/环硫树脂与胺的固化反应动力学

采用非等温DSC法对低黏度体系CY184/IPDA环氧树脂体系及对CY184/ES184/IPDA环氧/环硫树脂体系的固化反应动力学进行了研究。用高级等转化率Vyazovkin积分法求取活化能E_a,通过Málek法确定了固化反应机理函数和动力学参数,得到固化反应动力学方程。结果表明:CY184/IPDA环氧树脂体系的平均活化能为47.04 kJ·mol^-1;CY184/ES184/IPDA环氧/环硫树脂体系的活化能为48.97 kJ·mol^-1。两种体系的模型拟合曲线与实验得到的DSC曲线吻合得较好,均符合esták-Berggren(m,n)模型。     

动态DSC法研究BMI改性酚醛树脂固化反应动力学

采用非等温DSC(差示扫描量热)法研究BMI(双马来酰亚胺)改性PF(酚醛树脂)体系的固化动力学,借助升温速率-温度(β-T)外推法和红外光谱(FT-IR)跟踪固化反应过程,确定了BAN(BMI改性PF)体系的固化工艺和固化动力学参数。结果表明:BAN的固化工艺为"120℃/2 h→140℃/2 h→160℃/2 h→180℃/2 h",后处理工艺为220℃/3 h,BAN固化体系的动力学参数是表观活化能Ea=123.4 kJ/mol、频率因子A=1.96×1012s-1和反应级数n=1.05;根据n级动力学反应模型求解出该树脂的反应动力学方程,其计算值与试验值基本吻合,说明该模型能较好描述BAN的固化反应过程。     

高固含量聚醚醚酮改性酚醛树脂固化动力学研究

采用溶液聚合法合成了高固含量(>80%)聚醚醚酮(PEEK)改性酚醛树脂(PF),用非等温DSC(差示扫描量热)法和T-β(温度-升温速率)外推法对其固化反应动力学过程进行了研究,并根据Kissinger方程、Ozawa方程和Crane方程等计算出该固化反应的动力学参数。结果表明:改性树脂的凝胶化温度为136.68℃,固化温度为167.16℃,后处理温度为197.39℃;其固化体系的表观活化能为100.02 kJ/mol,频率因子为1.84×106 s-1,反应级数为0.94(近似于1级反应)。     

改性咪唑/环氧固化体系研究

本文利用DSC研究了改性咪唑/环氧树脂的固化反应动力学方程,借助DSC和DMA研究了不同改性咪唑含量对固化反应和树脂玻璃化转变温度的影响,同时利用红外分析对其反应机理进行了探究。结果表明,改性咪唑/环氧树脂固化体系的表观活化能Ea为60.21k J/mol,频率因子A为2.459×107s-1;改性咪唑/环氧固化物的Tg随改性咪唑用量先增加后降低,当用量为4%时达到最大值163.3℃;改性咪唑在固化过程中存在解封反应及异氰酸酯和羟基的氨酯化反应。     

GAP与炔丙基三嗪的固化反应动力学研究

采用动态差示扫描量热法(DSC)研究了炔丙基三嗪类新型多功能固化交联剂TPC与叠氮黏合剂GAP的固化反应动力学。根据所测量的不同升温速率的DSC曲线,采用Kissinger和Crane方程计算了GAP/TPC体系的动力学参数,建立了GAP/TPC体系的固化动力学方程。结果表明:TPC与GAP的固化反应为一级反应,反应级数n=0.935,表观活化能Ea=97.30 kJ/mol,表观频率因子A=2.38×1012min–1。     

聚醚胺/酚醛胺-环氧树脂体系的固化动力学研究

采用示差扫描量热法(DSC)研究了以聚醚胺/酚醛胺为固化剂的环氧树脂体系固化反应,在25~230℃范围内以不同的升温速率(5℃/min、10℃/min、15℃/min、20℃/min)对该体系的固化动力学参数分析。由Kisserger方程求得该体系固化反应的表观活化能为61.76 kJ/mol,频率因子A为7.1×107s-1;由Crane方程得出固化反应级数为1.116;并建立了固化动力学方程:-da/dty=k(1-a)1.116,其中。k=7.1×107exp(-7 429/t)。     

改性双马来酰亚胺树脂的固化特性

本文采用差示扫描量热（DSC）法研究了QYS91—Ⅱ改性双马树脂的固化反应动力学，利用Kissinger方程和Crane方程分别得到了该树脂固化反应表观活化能E、表观频率因子A和反应级数n，进而提出了该树脂固化成型过程的动力学模型，通过固化反应动力学模型对固化反应特性进行了预测，为改性双马树脂实际应用中固化工艺参数的进一步优化提供了一定的理论参考依据。     

CE2908聚酯粉末涂料固化反应特性

用示差扫描量热法(DSC)在动态条件下对CE2908聚酯/异氰尿酸三缩水甘油酯(TGIC)体系的固化反应动力学进行了研究。运用温度-升温速率图外推法确定了该体系的特征参数∶凝胶温度(T0)、固化温度(Tp)和后固化温度(Tf)分别为113℃、146℃和195℃。采用Kissinger方程和Crane方程计算CE2908聚酯/TGIC酯体系的动力学参数,平均表观活化能Ea为62.32 kJ/mol、频率因子A为8.50×106min-1、反应级数n为0.95。建立了该树脂体系的固化动力学模型。利用所建立的固化动力学方程分别讨论了等温和动态条件下CE2908聚酯/TGIC的固化反应特性,为优化聚酯/TGIC体系粉末涂料固化工艺提供了理论依据,并在生产工艺中验证了其正确性。     

环氧丁羟增韧双酚A环氧树脂固化反应动力学研究

采用动态差示扫描量热法(DSC)确定环氧丁羟(EHTPB)增韧双酚A环氧树脂固化体系的固化温度,利用Kissinger方程和Crane方程对固化反应动力学进行分析,确定了固化体系的动力学参数:表观活化能ΔE=102.40 k J/mol,指前因子A=1.90×1011,反应级数n=0.93。     

乙烯基酯树脂体系固化反应动力学研究

本文采用非等温DSC法对树脂体系的固化过程进行了研究。利用Kissinger和Crane法计算得到固化反应的表观活化能Ea、指前因子A、固化反应级数N等动力学参数,建立了固化反应动力学方程,并用T-β外推法确定了固化工艺温度,同时对体系的玻璃化转变温度进行了测定。     

A novel imidazole derivative curing agent for epoxy resin: Synthesis,characterization, and cure kinetic

A novel imidazole derivative (named as EMI‐g‐BGE) was synthesized through the reaction of 2‐ethyl‐4‐methyl imidazole (EMI) and butyl glycidyl ether (BGE) and characterized by elemental analysis, FTIR spectroscopy, and ¹H NMR spectroscopy. The curing kinetic of diglycidyl ether of bisphenol A (DGEBA) epoxy resin with EMI‐g‐BGE as curing agent was studied by nonisothermal DSC technique at different heating rates. Dynamic DSC scans indicated that EMI‐g‐BGE was an effective curing agent of epoxy resin. The apparent activation energy E_a was 71.8 kJ mol^?1 calculated through Kissinger method, and the kinetic parameters were determined by Málek method for the kinetic analysis of the thermal treatment obtained by DSC measurement. A two‐parameter (m, n) autocatalytic model (?esták‐Berggren equation) was found to be the most adequate selected kinetic model. In addition, the predicted curves from the kinetic model fit well with the nonisothermal DSC thermogram. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

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.     

Curing Kinetics of Liquid Crystalline Epoxy Resins Based on Bisphenol-S Mesogen with DDE by Nonisothermal DSC Data

The curing kinetics for a system of Sulfonyl bis(4,1-phenylene)bis[4-(2,3-epoxypro pyloxy)benzoate] (p-SBPEPB) with 4,4′-diaminodiphenyl ether (DDE) were investigated by nonisothermal differential scanning calorimetry (DSC). The dependencies of the apparent activation energy Ea and the conversion α during overall curing reaction were revealed by Ozawa's method. The results shown the Ea decreased drastially from 107 to 75 KJ/mol with α in the initial stages (α = 0–20%), the average apparent activation energy Ea of p-SBPEPB/DDE is 82.81 KJ/mol and was relatively constant in the 0.5 to 0.9 conversion interval. Some parameters were evaluated using the two kinetic models of ?esták–Berggren (S-B) equation and JMA model. The liquid crystalline (LC) phase had formed and was fixed in the system during the curing process.     

Nonisothermal cure of bisphenol epoxy resin with a nonlinear aliphatic polyamine hardener

The amino terminated polypropylenimine dendrimer (DAB‐dendri‐(NH₂)₄) was employed as a new nonlinear aliphatic curing agent for diglycidyl ether of bisphenol A (DGEBA). Nonisothermal curing reaction kinetics of DGEBA/DAB was investigated with a differential scanning calorimeter (DSC). The apparent reaction activation energy E_a is about 56.7 kJ/mol determined using the Kissinger equation, and a two‐parameter (m, n) autocatalytic model ([icirc]Sesták–Berggren equation) was confirmed to be able to well simulate the reaction kinetics in the light of the Málek method. In addition, the relation between reaction activation energy E_a and curing degree α was obtained by applying model‐free isoconversional analysis with the Kissinger‐Akahira‐Sunose (KAS) method. As α increases, E_a reduced quickly from >80 kJ/mol to ≈60 kJ/mol up to a ≈ 15%, then decreased slowly to 55 kJ/mol till a ～ 75%, and finally dropped to 44 kJ/mol at full conversion. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

非等温DSC法研究环氧树脂固化反应动力学过程

采用非等温DSC(差示扫描量热)法研究了环氧树脂(EP)体系的固化过程,并采用Kissinger方程、Crane方程和T-β(温度-升温速率)外推法计算出该EP体系固化反应的动力学参数和固化温度。研究结果表明:当m(EP)∶m(填料)∶m(固化剂)∶m(促进剂)=100∶30∶90∶0.4时,EP体系固化反应的表观活化能为78.90 kJ/mol、指前因子为2.58×109min-1和反应级数为0.914,其最佳固化条件为"从室温升温至92℃(开始凝胶)→继续升温至140℃(恒温固化)→最后升温至169℃(进行后固化处理)"。     

Curing Behavior,Kinetics and Thermal Properties of o-Cresol Formaldehyde Epoxy Resin Modified by Liquid Crystalline Epoxy Resin

The curing kinetics of a bi-component system of o-cresol-formaldehyde epoxy resin (o-CFER) modified by liquid crystalline p-phenylene di[4-(2,3-epoxypropyl) benzoate] (p-PEPB), with 4,4-diamino-diphenyl ether (DDE) as a curing agent, was investigated by nonisothermal differential scanning calorimetry (DSC) method. The relationship between apparent activation energy, Ea, and the conversion α was obtained by the isoconversional method of Ozawa. A molecular reaction mechanism is proposed. The results show that the values of Ea in the initial stage are higher and tend to decrease slightly with the reaction progress. The primary amines have a higher Ea than secondary amines. The average curing Ea of o-CFER/p-PEPB/DDE system is 61.64 KJ/mol. These curing reactions can be described by a model proposed by ?esták and Berggren, which includes two parameters of m and n. Parameters such as reaction orders were evaluated using the ?esták-Berggren (S-B) equation and the following kinetic equation: dα/dt = Aexp(?Ea/RT)α ^m (1 ? a) ⁿ . The curing behavior of the system was studied by polarized optical microscopy (POM) and torsional braid analysis (TBA). The compatibility of the p-PEPB and o-CFER system is very good. Temperature of mechanical loss peak is higher by 63°C than the common o-CFER epoxy resin, when the weight ratio of p-PEPB with o-CFER is 4:100.     

聚酯/TGIC粉末涂料固化动力学分析

通过傅里叶变换红外光谱（ FT-IR）分析 EWA1113与 PWA1221两种聚酯 /TGIC粉末涂料固化前后结构的变化,判断粉末涂料是否发生固化反应;运用差示扫描量热分析（ DSC）分析粉末涂料的固化过程,探究不同颜料对粉末涂料的固化行为的影响。结果表明： EWA1113与 PWA1221两种粉末涂料的理论固化温度范围分别为 133. 2~232. 2 ℃和 151. 6~232. 2 ℃;采用 T-β外推法确定 EWA1113粉末的固化工艺参数,线性拟合可得到凝胶化温度 T₀为 97 ℃,固化温度 T_p为 159. 6 ℃,后处理温度 T_f为 195. 98 ℃;通过 Kissinger微分法和 Doyle-Ozawa方程研究反应的活化能,通过计算分析得出活化能 E_a为 92. 14 kJ/mol;采用 Crane经验方程进行计算得出固化反应级数 n为 0. 93;并通过 DSC分析涂层的固化特性、固化度与温度的关系、理论最小固化时间等,得出在同一温度下,升温速率越慢,粉末涂料的固化程度越大的结论。     

环氧树脂潜伏性体系固化反应动力学研究

本文用差式扫描量热仪（ＤＳＣ）对ＢＰＥＡ－２／环氧树脂潜伏性固化体系的固化反应进行分析,并 分别利用Ｋｉｓｓｉｎｇｅｒ和Ａｒｒｈｅｎｉｕｓ方法求得了体系固化反应的表观活化能,利用Ｃｒａｎｅ等理论求出 了体系固化反应的反应级数及不同反应温度下的反应速率常数,’写出了固化反应的动力学方程。 结果表明：ＢＰＥＡ－２／ＣＹＤ－１２８环氧树脂潜伏性固化体系的表观活化能约为８４．１１ｋＪ／ｍｏｌ,其反应 方程式为：－ｄａ／ｄｔ＝ｋ（１－ａ）０．９６。