不同固化体系低毒脲醛树脂固化特性研究

采用不同固化体系对6种低毒脲醛(UF)树脂胶的固化速度、适用期及pH值变化情况进行了研究。研究表明：单组分固化体系中,过硫酸铵固化速度最快;磷酸与氯化铵组成的多元固化体系。固化速度虽然很快-但适用期较短;多元固化体系中加入2％～3％尿素对固化速度影响不大;乌洛托品对延长UF树脂胶的适用期效果较好。对加入固化剂后胶液pH值变化情况的研究表明。pH值在15min内下降较快。30min之后逐渐趋于稳定。     

双环戊二烯酚型环氧树脂的固化反应研究

研究了ＤＣＰＤ酚环氧树脂与酸酐及胺类固化剂的固化反应活性。通过ＤＳＣ热分析方法表征了ＤＣＰＤ酚环氧树脂与甲基六氢苯酐（ＭeHHPA)及４,４′－二氨基二苯甲烷（ＤＤＭ）的固化反应过程,测定了反应热焓,并分析了固化温度、时间及固化剂结构等对ＤＣＰＤ酚环氧树脂凝胶时间及固化度的影响,探讨了温度、时间对ＤＣＰＤ酚环氧树脂固化反应活性的影响。     

聚酰亚胺树脂固化动力学参数研究

采用DSC方法研究PMR型的BMP350聚酰亚胺树脂的固化反应过程。用动态方法分析其固化反应特征温度,为确定固化工艺参数提供了依据。采用Kissinger-Ozawa方法进行数据处理,获得了其固化反应动力学参数,建立了该树脂体系的固化动力学模型,结果表明模型与实验数据在固化度低于0.7时拟合效果较好。此模型对合理地研究PMR型聚酰亚胺树脂体系的工艺参数,保证产品质量以及工艺优化提供了必要的前提条件。     

环氧改性氰酸酯树脂固化动力学的研究

采用示差扫描量热法(DSC)对缩水甘油醚类环氧树脂(E-51)与脂环族环氧树脂(R-122)共同改性的双酚A型氰酸酯(BADCy)树脂的固化反应历程进行了研究。由Kisserger方程求得共聚体系固化反应的表观活化能为60.5 kJ/mol,根据Crane理论求得固化反应级数为0.89,接近于1级反应。该体系起始固化温度为132.1℃,峰顶固化温度为168.7℃,终止固化温度为246.0℃。研究表明,环氧树脂可促进BADCy的固化,改性体系可在177℃以下实现较完全固化。     

Synthesis of a liquid zirconium hybrid resin and the ability of the resin to accelerate the curing of a transparent silicone‐modified cycloaliphatic epoxy nanocomposite

A liquid zirconium hybrid resin (Zr–QR) was synthesized through sol‐gel reactions of zirconium butoxide with silanol‐terminated polydimethylsiloxane (DMS‐S12) and γ‐glycidoxypropyltrimethoxysilane (Z‐6040). The sol‐gel reactions were monitored using Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance spectroscopy. The Zr–QR morphology was investigated using field emission transmission electron microscopy. The Zr–QR had a well‐ordered morphology and the dimensions were less than 5 nm. These properties were achieved because DMS‐S12 was used to separate the zirconium clusters and Z‐6040 was used to stabilize the Zr–QR. The acceleration of the curing reaction between silicone‐modified cycloaliphatic epoxy (SEP) and methylhexahydrophthalic anhydride (MHHPA) caused by the Zr–QR was investigated. Differential scanning calorimetry and FTIR spectroscopy investigations showed that the Zr–QR first reacted with MHHPA, producing chelating ligands and carboxylic acid. Unlike in the conventional method (adding acetic acid to cause non‐reactive chelating ligands to form), the carboxylic acid produced effectively accelerated the curing reaction between the SEP and MHHPA. The chelating ligand produced from the Zr–QR and MHHPA suppressed the gelation of the Zr–QR itself during the nanocomposite (SEP–Zr–QR) curing process. The cured SEP–Zr–QR nanocomposite exhibited excellent optical transmittance at visible wavelengths.© 2015 Society of Chemical Industry     

CA型环氧树脂固化剂性能研究

用ＩＲ光谱表征了自制ＣＡ型环氧树脂固化剂的结构特点,测定了ＣＡ型固化剂的固化特性,固化树脂的性能和增塑效果。实验结果表明,ＣＡ型固化剂能使环氧树脂涂料在潮湿表面和带油表面上固化成膜,其固化的树脂具有良好的耐蚀性,冲击强度较二乙撑三胺固化的树脂有较大提高,同时也是一种较好的环氧树脂用增塑剂。     

快固型钛酸酯杂化酚醛树脂的合成

通过钛酸四丁酯与热塑性酚醛树脂(Novolac树脂)的酯交换反应合成了一类快速固化型杂化酚醛树脂,可加入六亚甲基四胺进行固化。通过红外、核磁、凝胶时间和粘度等测试研究了树脂的分子结构和理化性能。结果表明:随着钛酸四丁酯用量增大,杂化酚醛树脂的分子质量明显增大,凝胶时间缩短,杂化酚醛树脂溶液的粘度增大,并基本呈线性关系。钛酸酯键有效改进了酚醛树脂的粘接性。固化速率的加快来源于改性树脂分子质量的增大和钛酸酯结构对于固化反应的催化作用;而杂化酚醛树脂粘接性的提高是由于酚醛树脂中的钛酸酯结构起到了偶联剂作用。     

硅倍半氧烷-环氧杂化材料的研究

将环己基硅倍半氧烷硅三醇与环氧树脂E-51在环烷酸钴催化下进行反应,制成硅倍半氧烷-环氧杂化材料.通过傅立叶红外光谱、差热分析证实,反应具有较低的活化能,只是笼型结构外围的Si-OH与环氧基团进行反应,反应对笼型结构无影响;动态力学性能与热稳定性的分析表明,与4,4′-二氨基二苯砜固化的环氧固化物相比,硅倍半氧烷-环氧杂化材料具有较高的玻璃化转变温度、储能模量及热分解温度和热残余量.     

丁香酚环氧有机硅树脂的制备及其固化动力学研究

利用丁香酚环氧和环四硅氧烷硅氢加成得到新型生物基环氧树脂D4EUEP,通过核磁共振氢谱和飞行时间质谱表征其准确结构。使用非等温DSC对D4EUEP/33DDS固化体系进行分析,采用双参数自催化模型和Málek判据建立了该体系固化动力学模型。模型计算结果与实验结果相关系数大于99%,证明该模型可以较好地描述D4EUEP/33DDS体系的固化过程。通过AICM方法研究了体系的有效活化能与转化率之间的关系,揭示了微观反应机理的变化,并通过Vyazovkin法对D4EUEP/33DDS体系进行了等温固化预测。     

Thermal scanning rheometric analysis of curing kinetic of an epoxy resin. I. An anhydride as curing agent

The curing reaction of the system diglycidyl ether of bisphenol A (DGEBA), an organic anhydride (HMTPA), as curing agent and a tertiary amine (DMP 30) as initiator has been studied by Thermal Scanning Rheometry (TSR) under isothermal conditions. The gel time, which is defined by several different criteria, has been found to be a good parameter to determine the activation energy of this curing process; on the other hand, the gel time depends on the concentration of the initiator. An empirical model has been used to predict the change in viscosity (η*) of the system with time until the gelation is reached; the first‐order kinetics, the apparent kinetic constant (k′), and the activation energy before gelation have been determined. Furthermore, these results are reported together with the reaction mechanism proposed by another authors. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1239–1245, 1999     

Thermochemical and isoconversional kinetic analysis of a polyester–epoxy hybrid powder coating resin for wood based panel finishing

Powder coating is an established technology especially for the surface finishing of metallic substrates for example in the automotive industry. Moreover, powder technology holds also great promises for the coating of non-conventional substrates like plastics or wood due to the lack of solvents and good recoverability. Here, low-temperature curing resins are required and especially mild processing conditions are demanded by the substrates. Advanced characterization methods need to be established that allow the precise balancing of the processing conditions required for adequate melting, flowing and curing of the powder with the process conditions that can be tolerated by the temperature-sensitive substrates. In the present contribution it is shown that differential scanning calorimetry (DSC) in combination with isoconversional kinetic analysis (ICKA) provides great potential for this purpose. DSC is a standard thermo-chemical method that can be successfully used to study both the melting and curing processes of powder coatings and to determine, for example the glass transition temperature of the cured coating directly from the measured thermograms. However, still more information can be extracted from the enthalpy signals when more sophisticated methods of data post-treatment and analysis are employed. Isoconversional kinetic analysis techniques such as the Kissinger–Akahira–Sunose (KAS) or the advanced Vyazovkin (VA) approaches allow calculating the time-dependencies of physical and chemical processes at various temperatures based on the estimates of activation energies which are obtained from DSC raw data. These analyses allow for example to calculate the time required for a certain degree of cross-linking in the coating after processing the coating under specified curing conditions. In the present contribution the application of ICKA of DSC measurements for the analysis of the flowing and curing behaviour of a powder coating based on a polyester–epoxy hybrid resin is illustrated and the potential of this approach to predict optimal curing times for arbitrary curing temperatures is demonstrated. This is especially useful when temperature-sensitive substrates like wood-based panels are coated. Additionally, the potential to relate the thermo-chemical properties of the powder coating to the surface properties of the coated substrates is discussed.     

Hybridization of aqueous PU/epoxy resin via a dual self‐curing process

Amino‐terminated and carboxyl‐containing polyurethane (PU) is prepared by an isocyanate‐terminated PU prepolymer process. Carboxyl‐containing epoxy resin is obtained from a half‐esterification of epoxy resin with maleic anhydride. These two aqueous resins are obtained after neutralization with triethylamine and dispersion into water phase, respectively. A latent curing agent (TMPTA‐AZ) is prepared by a Michael addition of aziridine with trimethylolpropane triacrylate (TMPTA). A self‐curing system of PU/epoxy hybrid is obtained from a blending of these two aqueous resins with latent curing agent. PU/epoxy hybrid is derived from two self‐curing reactions on drying. The first curing for hybridization between PU amino groups with oxirane groups of epoxy resin is via a ring‐opening reaction and the secondary curing takes place on carboxyl groups of PU/epoxy hybrid with aziridine of TMPTA‐AZ. The final properties of these dual self‐cured PU/epoxy hybrids are reported. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

超支化环氧／双酚A环氧树脂杂化材料的性能研究

以超支化环氧树脂HTDE-2改性HTDE-2／双酚A型环氧树脂杂化材料的粘接性能和胶膜性能,探讨了HTDE-2的含量对杂化材料的剪切强度、剥离强度、铅笔硬度和耐磨性的影响。研究表明,随着超支化环氧树脂含量的增加,杂化材料的剪切强度、剥离强度、铅笔硬度和耐磨性先增加后下降,在HTDE-2用量为4％左右时具有最大值,综合性能最好。     

环氧树脂涂料用脂肪族二胺加成物固化剂

介绍了一类性能独特的脂肪族和脂环族二胺加成物环氧固化剂,其毒性低、气味小。用其制备的涂料具有良好的耐化学腐蚀性、高硬度和良好的光泽性。     

环氧树脂插层纳米复合材料固化动力学研究

运用自制的有机蒙脱土，采用浇模固化成型法制备环氧树脂／二乙烯三胺／有机蒙脱土纳米复合材料，对固化产物利用XRD（X射线衍射）分析有机蒙脱土的层间距变化，确定产物为插层型的纳米复合材料，并用DSC（差示扫描量热法）跟踪环氧树脂固化行为。运用Kissinger,Flynn-Wall-Ozawa,Crane方法对环氧树脂的固化反应过程进行分析，求出活化能和反应级数等动力学以在数。结果发现，加入有机化蒙脱土后使固化反应活化能和频率下降，从而有利于固化工艺的实现，便于纳米复合材料实际应用。     

液体乙烯基硅树脂的制备及固化反应动力学

合成了一种液体乙烯基硅树脂,并用FT-IR、GPC、¹H NMR和²⁹Si NMR等手段对其结构进行表征。采用非等温差示扫描量热法（DSC）研究了乙烯基硅树脂/苯基含氢硅油体系的固化反应动力学,用Kissinger方程和高级等转化率法（Vyazovkin方法）分别计算了该体系的表观活化能E_a,用Málek法进行模型拟合动力学分析,通过T-β外推法确定该体系的固化工艺参数。结果表明：Kissinger法和Vyazovkin法得到的活化能分别为85.3 kJ·mol^-1和84.0 kJ·mol^-1,二者所得结果的差别较小;乙烯基硅树脂体系固化动力学符合Šesták-Berggren（m,n）模型,m和n分别为0.092、1.440,拟合曲线与实验的DSC曲线吻合;该树脂体系的近似凝胶化温度为89.1℃,固化温度为127.8℃,后处理温度157.6℃。     

环氧树脂固化剂的改性研究

以异佛尔酮二胺和1,6-己二胺为原料,加入适量自制的催化剂,在190℃反应2.5 h,即制成新型环氧树脂固化剂(简称YFJA)。将其按不同比例添加到传统固化剂二氨基二苯甲烷(简称DDM)和甲基四氢苯酐(简称Me-THPA)中,通过对固化物的冲击强度、拉伸强度和力学损耗等性能的检测分析,发现当自制固化剂添加量为固化剂总量的50%时,体系的力学性能达到最佳效果,冲击强度最高可提高346.5%,拉伸强度可提高73.0%。     

Modelling of phenolic resin polymerisation

The kinetics of the polymerisation of resol-type phenolic resins has been modelled taking into account the phenol and formaldehyde equilibria. The kinetic parameters were obtained by adjusting the experimental evolution of phenol, formaldehyde and initial addition products during synthesis. The influence of the type and amount of catalyst, the initial pH, the initial formaldehyde-to-phenol molar ratio and the condensation temperature, on the kinetics rate constants was quantified.     

氮化硼杂化环保型酚醛树脂的研究

采用硅烷偶联剂对氮化硼(BN)微米粒子进行表面处理,并在酚醛树脂(PF)的聚合反应过程中将其加入,制备出一种新型的有机/无机BN杂化环保型PF。采用红外光谱(FT-IR)、扫描电镜(SEM)和热重分析(TGA)等手段对杂化树脂的结构与性能进行了研究,并运用Kissinger、Ozawa和Crane方法计算其热分解反应的动力学参数。结果表明:杂化树脂的活化能和频率因子分别为126.1kJ/mol和1.64×108s-1(Kissinger法),反应级数为0.929(Crane法),其热分解反应机理比较复杂;经偶联剂处理过的BN粒子在PF中的分散性较好,BN杂化PF的耐热性略有提高;采用玻璃纤维增强杂化树脂制备BN杂化PF复合材料,其力学强度和电性能明显提高,拉伸强度由476.6MPa提高到610.5MPa,表面电阻率由2.88×1012Ω增加到1.92×1015Ω。     

耐热有机硅树脂研究进展

阐述了国内外耐热涂料有机硅树脂的研究概况,从有机硅树脂的分子结构设计,有机硅树脂与其他有机聚合物共聚改性,以及有机硅树脂新型固化剂等方面论述了近年来的研究进展,并对今后的研究方向进行了展望。