含二氮杂萘酮环氧树脂体系的固化反应动力学研究

以 4- (4-羟基苯基 ) - 2 ,3 -二氮杂萘 - 1-酮 (DHPZ)为固化剂 ,用示差扫描量热法 (DSC)对环氧E44 /DHPZ体系的固化反应过程作了系统的研究 ,计算出固化反应的表观活化能为 10 4 0 4kJ/mol,固化反应近似为一级反应。通过固化剂份数对化学反应程度影响的研究 ,得知当DHPZ份数为 4 5～ 5 5时固化反应完全     

Optimalization of processing conditions for thermosetting polymers by determination of the degree of curing with a differential scanning calorimeter

The curing reaction of thermosetting polymers is accompanied by exothermal heat which has been measured with a differential scanning calorimeter. The Perkin-Elmer DSC-1 B was used for recording the curing behavior of a diallyl phthalate molding compound and two unsaturated polyester molding compounds. The residual heat of reaction has also been determined by a dynamic DSC scan of partly cured products made at various mold temperatures and curing times. It was thus possible to calculate the degree of curing and to dictate the optimum processing conditions for the indicated molding compounds. The interpretation of results leads to the conclusions that the DSC can be used to set specifications and to perform quality control for the molding compounds and that the most significant processing parameter is mold temperature.     

Effects of low-profile additives on the curing reaction of unsaturated polyester resins

The effect of low-profile additives (LPA), i.e., poly(vinyl acetate) (PVAC) and poly(methyl methacrylate) (PMMA), on the curing reaction of unsaturated polyester (UPE) resins was studied by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The curing reaction profiles were determined by DSC, while GPC was used to investigate the variation of the sizes of microgel particles during the early stage of curing reaction in UPE–styrene resins. The DSC experimental results indicated that the curing reaction rate decreased as the concentration of LPA increased. At a fixed LPA concentration, the curing reaction rate was slower for resins mixed with LPA possessing worse compatibility with UPE resins. During the early stage of curing reaction, the size and structure of the UPE microgels formation strongly depended on the concentration of LPA and also on the compatibility of the components in the curing system. The experimental results of this study revealed that the concentration of LPA and the compatibility of LPA with UPE resins had a strong influence on the polyester microgel formation and the curing behavior. © 1995 John Wiley & Sons, Inc.     

On the curing of a vinylester-urethane hybrid resin

Curing kinetics of a vinylester-urethane hybrid (VEUH) resin consisting of vinylester resin (VE) diluted in styrene and novolac type polyisocyanate (NPI) have been studied by differential scanning calorimetry (DSC). As VEUH is crosslinked via free radical polymerisation between the vinyl functions of styrene and VE, and polyaddition reaction between the secondary -OH groups of VE and -NCO of NPI, it was necessary to study these reactions separately. This was achieved by studying the curing with and without incorporating the NPI. The curing reaction was monitored by measuring the heat of reaction under isothermal and dynamic temperature conditions. Models describing the curing were developed, which are in good agreement with the experiments. A comparison between the curing of the VEUH and the VE resin without NPI leads to the conclusion that the curing of the VEUH as accessed by DSC is dominated by the radical polymerisation of styrene with VE although the two reactions are not time separated.     

不饱和聚酯/复合引发体系非等温固化动力学研究

采用非等温DSC法研究了不饱和聚酯/复合引发体系在不同升温速率下的固化行为,通过T-Φ外推法确定了该体系的凝胶温度、固化温度和后固化温度分别为102.7℃,124.0℃和196.5℃。通过Kissinger和Crane方程对DSC数据进行处理,获得了固化反应的表观活化能E=116.88 kJ/mol,碰撞因子A=7.35×1014,反应级数n=0.945,并由此得到了该体系的固化动力学方程。     

硫磺固化烯丙基环氧树脂的动力学研究

通过非等温和等温差式扫描量热法(DSC)对硫磺(S)固化2,2’-二烯丙基双酚A型环氧树脂(DADGEBA)的动力学进行了研究。从DSC曲线两个放热峰得知,DADGEBA/S体系是两步反应,通过等温DSC分析确定该体系在温度高于170℃低于210℃时满足Kamal自催化模型,通过非等温DSC确定该体系在温度高于210℃时,满足n级反应模型,得到了动力学模型的相关参数。DADGEAB/S体系在整个固化反应过程中满足两种动力学机理函数,这与DADGEBA/S体系双固化机理相符。     

纳米TiO2/UPR复合体系的固化动力学及固化工艺研究

采用动态差示扫描量热法（DSC）对纳米TiO2／UPR复合体系的固化过程进行研究,得出不同升温速率下纳米TiO2／UPR复合体系固化过程中的DSC曲线;并根据动态DSC曲线求出固化反应的表观活化能、固化反应级数及动力学方程中的指前因子等参数;建立了复合体系固化反应动力学的数学模型并且确定了分阶段变温固化新工艺。     

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.     

对甲苯磺酰氯催化酚醛树脂固化工艺及反应动力学研究

采用对甲苯磺酰氯作为酚醛树脂的固化促进剂,利用差热扫描量热技术（DSC）研究了对甲苯磺酰氯对酚醛树脂体系固化反应及其动力学的影响,分析了不同百分比含量的对甲苯磺酰氯/酚醛树脂反应体系的固化性能。实验结果表明：随着对甲苯磺酰氯含量的增加,固化反应温度降低,固化时间缩短。并采用Kissinger法和Ozawa法分别计算了固化反应的表观活化能和反应级数,发现采用对甲苯磺酰氯催化时,PF体系的固化反应活化能降低。     

环氧树脂／液晶固化剂固化反应动力学研究

通过差热分析（DSC）研究了非等温过程环氧树脂／液晶固化剂体系的固化反应动力学,研究了不同配比对固化反应的影响,固化反应转化率与固化温度的关系,计算了固化反应的活化能,确定了环氧树脂／液晶固化剂的固化工艺条件,用偏光显微镜观察了环氧树脂／液晶固化剂／4,4－二氨基二苯砜（DDS）体系在不同温度下固化时的形态。结果表明：液晶固化剂的加入量越大,固化反应速度越快;环氧树脂／液晶固化剂体系固化反应的活化能力为71.5kJ/mol,偏光显微镜观察表明：随着固化起始温度的增加,固化体系的形态由原来的具有各向异性的丝状结构变化为各向同性,液晶丝状条纹消失。     

咪唑催化苯并噁嗪树脂固化的研究

研究了以咪唑为催化剂的苯并口恶嗪树脂的固化反应。通过平板小刀法测凝胶化时间、等温DSC和程序升温DSC等方法,表征了含有咪唑的苯并口恶嗪树脂的固化反应过程,计算了该体系的固化动力学参数。结果表明,咪唑的引入使苯并口恶嗪树脂的固化初始温度从242℃降到了130℃左右,DSC曲线出现催化固化和热固化2个放热峰;咪唑对苯并口恶嗪树脂的催化作用在一定用量范围内随着用量的增加而增加;通过等温DSC分析,含有咪唑的苯并口恶嗪树脂在150℃下的固化反应是不完全的,经过高温后处理才能固化完全;经过等温动力学计算,咪唑催化苯并口恶嗪的固化反应级数为1.72,活化能为86.3kJ/mol。     

含氟环氧丙烯酸酯树脂固化动力学研究

采用甲基丙烯酸甲酯(MMA)、甲基丙烯酸缩水甘油酯(GMA)、丙烯酸六氟丁酯(F6BA),通过溶液聚合法制备了含氟环氧丙烯酸酯树脂P(MMA/GMA/F6BA)。采用DSC研究了以己二酸为固化剂的固化反应,确定固化反应动力学方程和固化反应级数;采用FTIR跟踪固化反应过程,确定固化反应时间。     

Studies on Cure Kinetics of Diglycidyl Ether of 4,4′-Bisphenol/4,4′-Diaminobiphenyl Using the Advanced Isoconversional Method

The cure kinetics of a rigid-rod epoxy monomer, diglycidyl ether of 4,4′-bisphenol (DGEBP), and the curing agent with the similar rigid-rod group, 4,4′-diaminebiphenyl (DABP), was studied using an advanced isoconversional method (AICM). DGEBP/DABP curing system was carried out by means of differential scanning calorimetry (DSC). Three exothermic peaks were depicted by nonisothermal DSC studies: the first two peaks were attributed to the curing reaction, and the last peak was attributed to the decomposition of the cured epoxy resin. The LC phase transformation of the curing process was observed by PLM. Using AICM, the largest activation energy of the curing reaction of DGEBP/DABP system was obtained as 108 kJ/mol. It can also be learned that LC phase transformation of the curing process affects the reaction significantly.     

聚酯树脂粉末涂料的固化行为

用差示扫描量热法(DSC)对固态条件下聚酯/TGIC(triglycidyl isocyanurate)体系的非等温固化反应动力学进行了研究。根据DSC和热重（TG）的分析结果,对聚酯粉末的固化过程及热稳定性进行了探讨,通过温度-升温速率图外推法确定了该体系的凝胶温度、固化温度和后固化温度分别为113、146和195℃。采用Kissinger方程、Doyle-Ozawa方程和Crane方程对DSC数据进行分析,得到了固化反应的平均表观活化能65.71 kJ·mol^-1,频率因子8.50×106 min^-1、反应级数0.95,建立了该树脂体系的固化动力学模型。讨论了固化反应速率、固化度、固化温度与时间等关系的变化规律及影响因素,为优化铝型材用粉末涂料聚酯体系的固化工艺提供了理论基础。     

TDE-85/DICY/取代脲中温固化体系的固化动力学

采用DSC研究了以双氰胺/取代脲为潜伏型中温固化体系的三官能团环氧树脂TDE-85的固化反应动力学,探讨了反应机理并确定了最佳的固化工艺参数。结果表明,固化温度<140℃时,受扩散效应和双氰胺在环氧树脂中溶解速率的影响,体系的等温固化行为与自催化模型存在偏差;固化温度>150℃后,体系的等温固化行为可用自催化反应模型很好地描述,其表观活化能为86.33 kJ/mol,指前因子为2.68×1010,总反应级数(m+n)为2～3。综合变温DSC和等温DSC的实验结果,可确定体系的最佳固化工艺条件为:120℃下预固化1 h后再升温至150℃保温1 h。     

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。     

纳米二氧化钛对环氧树脂固化反应的影响

采用非等温DSC研究了纳米二氧化钛改性环氧树脂体系(EP)的固化动力学,采用Flynn-Wall-Ozawa和Vyazovkin非线性等转化率方法(NLV)法分析了固化活化能与转化率的关系,利用Kissinger和Crane方程研究了固化动力学参数,根据不同升温速率下DSC固化反应曲线确定了固化工艺参数。结果表明,纳米二氧化钛促进了环氧树脂的固化,降低了固化反应的活化能,但没有改变环氧树脂的固化机理。     

钢质管道防腐用熔结环氧粉末固化反应特性

采用示差扫描量热法(DSC)在动态条件下研究了钢质管道防腐用熔结环氧粉末的反应特性,根据不同升温速率下测得的动态DSC曲线图谱,运用温度-升温速率(T-β)图外推法获得了基础的固化工艺参数,即凝胶温度(Tg)92.76℃、固化温度(Tc)133.94℃和后处理温度(Tt)160.58℃。并采用Kissinger方程和Crane公式计算确定了体系的固化反应动力学模型方程式,在此基础上,预测了等温条件下该种管道用熔结环氧粉末涂料的固化反应特性,对今后的管道防腐涂层施工提供了理论参考。     

用DSC法研究环氧树脂/环氧封端酚酞聚芳醚腈的固化特性

利用差示扫描量热法研究了AG - 80环氧树脂和环氧封端酚酞聚芳醚腈 (简称E -PCE)共混物中固化剂含量对树脂基体固化反应温度、反应热的影响。此共混环氧树脂基体的最低固化反应温度为1 61 .3℃ ,固化反应表观活化能为 60 .66kJ/mol,固化反应级数为 0 .875。     

橡胶硫化反应热对硫化温度场的影响

探讨长方体胶块和轮胎硫化反应热对硫化温度场的影响。用热电偶硫化测温仪测试胶块和轮胎硫化过程中的温度,用差示扫描量热法测试硫化反应热,用有限元分析法进行硫化热模拟。通过硫化模拟温度与实测温度比较得出,胶块和轮胎硫化反应热对硫化温度场有明显影响。