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%。     

硅烷单体改性环氧树脂的固化及性能

分别用苯基三甲氧基硅烷(PTMS)和3-缩水甘油醚氧丙基三甲氧基硅烷(KH560)单体对环氧树脂进行了化学改性,通过红外(FT-IR)、核磁(1H NMR)对其化学结构进行了表征。以聚酰胺650为固化剂,用差示扫描量热仪(DSC)研究了固化物的固化动力学。此外还研究了涂膜的热失质量(TGA)、吸水率、附着力等性能。结果表明:苯基三甲氧基硅烷和3-缩水甘油醚氧丙基三甲氧基硅烷接枝上环氧树脂,与纯环氧树脂相比,改性后的树脂具有更好的热稳定性和更低的吸水率。改性环氧树脂固化后形成两面性质不同的涂层,与底材接触的涂层底面保留了环氧树脂原有的附着力,而涂层表面则具有高憎水性,起到防腐等作用。     

改性环氧树脂体系固化动力学及实际固化工艺的研究

主要采用差示扫描量热分析法研究了一种改性环氧树脂基体的固化反应动力学.利用Kissinger-Ozawa方程进行数据处理,获得其固化反应动力学参数,建立了该改性树脂的固化动力学模型.研究结果表明:该固化体系的表观活化能AE=150.56 kJ/mol,反应能级n ≈ 0.95,固化参考温度在177℃左右,并根据此参数研...     

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。     

多氨基倍半硅氧烷改性环氧树脂E-51固化动力学及热性能

以氯甲基笼型倍半硅氧烷(CM-POSS)为原料,与乙二胺通过取代反应合成多氨基倍半硅氧烷(POSS-NH2),并通过红外光谱(FT-IR)对产物进行表征.采用动态差示扫描量热法(DSC)和热失重分析(TGA)研究多氨基倍半硅氧烷( POSS-NH2)/环氧树脂(E-51)/二氧基二苯基砜(DDS)和E-51体系的固化动力学和热性能.结果表明:杂化树脂的固化反应活化能较大,POSS-NH2的加入提高了固化杂化树脂的热性能.     

聚酰亚胺改性环氧树脂/酸酐体系固化动力学研究

采用非等温差示扫描量热(DSC)法研究了聚酰亚胺(PI)改性环氧树脂(EP)/酸酐体系的固化反应动力学及其固化工艺。通过Kissinger法、Ozawa法和Crane法计算出该体系的动力学参数。结果表明:该固化体系具有较高的活性,其固化工艺条件为"80℃/2 h→120℃/2 h",后处理工艺为150℃/2 h;采用Kissinger法和Ozawa法计算出该体系的平均表观活化能为8.24 kJ/mol;结合Crane方程计算出该体系的反应级数为0.95,近似一级反应。     

环氧树脂固化动力学的研究及运用

环氧树脂作为防腐蚀的主要材料,具有密实、抗水、防渗漏等特点,所以在很多行业中都得到了广泛应用。本文对环氧树脂固化动力学的相关内容,进行了简要的分析和阐述,并且对其运用进行了相应的展望。     

酚醛胺固化环氧树脂热降解动力学研究

利用市售酚醛胺PPA固化剂固化环氧树脂E-44,对固化产物热稳定性进行研究,用Flynn-Wall-Ozawa法建立了固化产物热降解动力学模型,得出热解活化能E=227.51 kJ/mol,lgA=14.34（A=2.19×1014 s^-1）。     

笼型环氧GM-POSS改性双酚-A环氧树脂的固化动力学与热性能

为降低笼型倍半硅氧烷环氧树脂的官能度,合成了一种含有部分甲基的笼型倍半硅氧烷环氧树脂(GM-POSS),其结构以六面体的T8结构为主.用DSC、TG、TBA和x-射线能谱仪研究了GM-POSS/双酚-A环氧共混物与甲基四氢苯酐(MeTHPA)的固化性能及热性能.结果表明2种环氧可共同固化,固化反应的平均活化能Ea为71.10 kJ/mol,反应级数为一级;固化树脂的玻璃化转变温度、热分解温度及热残余量均随GM-POSS加入量的增加而升高.     

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。     

聚磷酸铵对环氧树脂固化反应动力学的影响

采用动态DSC分析法,利用Kissinger和Crane方程研究了阻燃剂聚磷酸铵对环氧树脂固化反应动力学的影响。结果表明:随着阻燃剂用量的增大,固化反应向高温方向移动,表观活化能从45.7 kJ/mol增大到48.4 kJ/mol,而反应级数基本不变,均为0.88,说明聚磷酸铵的加入增大了环氧树脂的固化反应难度,但不影响其固化反应机理;在同等阻燃剂用量下,环氧树脂固化反应热值随着升温速率的增大而减小;而在一定的升温速率下,固化反应热值随着阻燃剂用量的增大而减小。     

含联萘结构环氧树脂的合成、固化动力学及其性能

合成了两种含联萘结构的环氧树脂2,2'-二(9-环氧基壬酰氧基)-1,1'-联萘(R1)和2,2'-二(3-环氧基丙酰氧基)-1,1'-联萘(R2)。通过1HNMR和EA对目标产物结构进行了表征。以4,4'-二氨基二苯基甲烷(DDM)为固化剂,通过Ozawa法计算出R1/DDM和R2/DDM固化体系的反应活化能(E_a)分别为56.29和56.88 k J/mol,随着固化反应转化率(α)的增加,R1/DDM的E_a不断增大,而R2/DDM的E_a略微减小。考察了不同长度碳链对固化物的热稳定性、玻璃化转变温度(T_g)、力学性能和吸水率的影响。结果表明:短碳链的R2/DDM较长碳链的R1/DDM,固化物的初始分解温度由220.3℃下降到210.5℃,800℃下残炭率由3.45%上升至6.77%,T_g由135℃上升到141℃,断裂伸长率由6.7%下降至4.3%,吸水率由0.35%降至0.28%。     

The Effect of Hyperbranched Polyester Epoxy Resin on the Curing Kinetics and Thermal Degradation Kinetics of the Diglycidyl Ether of Bisphenol-A Epoxy Resin

Hyperbranched poly(trimellitic anhydride butylene glycol)ester epoxy (HTBE) has relatively low viscosity and high molecular mass and holds great promise as a functional additive for enhancing the strength and toughness of thermosetting resins. The effect of molecular mass or generation and content of HTBE on the activation energy, reaction order, and curing time was discussed using DSC and TG techniques. The results indicated that HTBE could accelerate the curing speed and reduce the activation energy and reaction order of the curing reaction, and the thermal degradation activation energy (Ea ₂) of HTBE/DGEBA hybrid resin also decreased remarkably in high temperature section.     

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.     

环氧树脂固化物的阻燃化研究

就环氧树脂固化物的阻燃方法及环氧树脂固化物的阻燃基础进行了研究。     

耐高温树脂的固化动力学分析及其力学性能

本文对一种耐高温环氧树脂体系进行了固化动力学研究,计算出该树脂体系的活化能为70.62kJ/mol、反应级数为0.93,并得到该体系的反应速率常数方程和动力学方程式,确定了树脂体系的固化工艺。还制备了T700碳纤维单向板,并对其力学性能进行测试。结果表明,该树脂体系具有优良的耐热性（树脂固化物的Tg达到218℃）、反应活性高,适用于快速成型固化工艺,其复合材料具有良好的力学性能。     

氨基硅烷活化绢云母改性环氧树脂的固化反应动力学研究

采用氨基硅烷偶联剂(KH550)活化绢云母,在甲基四氢邻苯二甲酸酐(MeTHPA)作用下制备活化绢云母改性环氧树脂.设定不同的升温速率,分别对活化绢云母/环氧树脂/MeTHPA体系进行DSC测定,并采用Kissinger法和Ozawa法处理数据,研究了其固化反应动力学.结果表明,添加活化绢云母前后环氧树脂/MeTHPA...     

Study on Curing Kinetics and Thermal Degradation Kinetics of Hyperbranched Poly(Trimellitic Anhydride Ethylene Glycol) Epoxy (HTME)/Diglycidyl Ether of Bisphenol-A Epoxy Hybrid Resin

Hyperbranched poly(trimellitic anhydride ethylene glycol) epoxy (HTME) not only has relatively low viscosity and high molecular weight but also is a functional additive of enhancement and toughness and is used in the thermosetting resin field widely. The curing kinetics and thermal degradation kinetics of HTME/diglycidyl ether of bisphenol-A epoxy hybrid resin were studied in detail using differential scanning calorimetry and thermogravimetric analysis technique, respectively, by the Coats-Redfern model. The effect of molecular weight or generation and content of HTME on activation energy, reaction order, curing time, and curing reaction were discussed and analyzed, and the results indicated that HTME could accelerate curing reaction and reduce activation energy and reaction order of the curing reaction.     

Curing and Morphology of BPA Epoxy Resin/LC Epoxy Resin PEPEB Composites

Liquid crystalline epoxy resin (LC epoxy resin) – p-phenylene di{4-[2-(2,3-epoxypropyl)ethoxy]benzoate} (PEPEB) was synthesized. The mixture of PEPEB with bisphenol-A epoxy resin (BPAER) was cured with a curing agent 4,4-diamino-diphenylmethane (DDM). The curing process and thermal behavior of this system were investigated by differential scanning calorimeter (DSC) and torsional braid analysis (TBA). The morphological structure was measured by polarizing optical microscope (POM) and scanning electron microscope (SEM). The results show that the initial curing temperature Ticu (gel point) of this system is 68.1°C, curing peak temperature T _pcu is 102.5°C, and the disposal temperature T _fcu is 177.6°C. LC structure was fixed in the cured epoxy resin system. The curing kinetics was investigated by dynamic DSC. Results showed that the curing reaction activation energy of BEPEB/BPAER/DDM system is 22.413 kJ/mol. The impact strength is increased 2.3 times, and temperature of mechanical loss peak is increased to 23°C than the common bisphenol-A epoxy resin, when the weight ratio of BEPEB with BPAER is 6 100.     

电抗器用环氧树脂体系配方及固化工艺的研究

环氧树脂具有良好的电气绝缘性能,在干式空心电抗器生产中被大量使用。由于配方和固化工艺决定树脂固化物的性能,因此研究环氧树脂体系的配方和固化工艺具有重要的工程意义和实用价值。以理论为依据计算了环氧体系的理论配比,并结合实际确定出生产用的实际配比;同时从升温、保温、降温3个过程出发,制定出环氧树脂体系的固化制度。