The preparation of phenolic resin/montmorillonite nanocomposites by suspension condensation polymerization and their morphology

Phenolic resin/clay nanocomposites were prepared using a suspension condensation polymerization method that was suitable to both novolac and resole. Natural montmorillonite and two kinds of organic modified montmorillonite were adopted to investigate the effect of modification on the final morphology of the nanocomposites. X-ray diffraction (XRD) measurements and Transmission Electron Microscope (TEM) observations showed that clay platelets were easier to be exfoliated or intercalated in novolac than in resole because novolac usually has a linear structure. The modifier with a phenyl ring was more compatible with novolac (or resole) than the aliphatic type modifier. The influence of curing on the morphology was studied as well. An exfoliation-adsorption and in situ condensation mechanism was proposed on the formation of the nanocomposites.

Dynamic constitutive equation of GFRP obtained by Lagrange experiment

The note presents a method of constructing dynamic constitutive equations of material by means of Lagrange experiment and analysis. Tests were carried out by a light gas gun and the stress history profiles were recorded on multiple Lagrange positions. The dynamic constitutive equations were deduced from the regression of a series of data which was obtained by Lagrange analysis based upon recorded multiple stress histories. Here constitutive equations of glass fibre reinforced phenolic resin composite(GFRP) in uniaxil strain state under dynamic loading are given. The proposed equations of the material agree well with experimental results.

酚醛树酯的热解动力学模型

建立了一种利用热重峰值分析进行酚醛树酯热解动力学研究的方法,这种方法利用热重谱峰上几个特征点的数据来确定动力学参数.根据酚醛树酯热解DTG曲线的特点,把酚醛树酯的热解过程分解成三个阶段,用峰值分析法对每个反应阶段分别建模,通过三个反应阶段的叠加得到了一个酚醛树酯分阶段热解动力学模型,该模型能够很好地描述酚醛树酯的热解过程. 

酚醛树酯的热解动力学模型

建立了一种利用热重峰值分析进行酚醛树酯热解动力学研究的方法,这种方法利用热重谱峰上几个特征点的数据来确定动力学参数.根据酚醛树酯热解DTG曲线的特点,把酚醛树酯的热解过程分解成三个阶段,用峰值分析法对每个反应阶段分别建模,通过三个反应阶段的叠加得到了一个酚醛树酯分阶段热解动力学模型,该模型能够很好地描述酚醛树酯的热解过程.

激波管在酚醛树脂高温热解动力学研究中的应用

使用激波管作为加热手段,利用其加热速率快的优点,突破了传统方法在加热速率上的限制,研究了酚醛树脂在1400～1700K温度范围内的热解动力学.主要碳氢产物是甲烷、乙烯、乙炔和苯.通过对反应扩散过程的分析,考察了扩散对热解过程的影响.结果表明,实验中酚醛树脂的反应扩散过程迅速达到稳态,扩散影响可以忽略,首次获得了酚醛树脂在芳环开环热解机制下的热解速率常数.

酚醛树脂高温热解的激波管实验研究

采用激波管方法研究了酚醉树脂在温度1100K～1800K范围之间的热解过程.在激波管高温和短实验时间条件下,分析了实验样品颗粒在高温气相中的传热过程,讨论了样品颗粒达到热平衡的条件.通过色谱和质谱方法检测热解产物,获得了酚醛树脂高温热解产物分布和热解速率常数.酚醛树脂高温热解最主要的产物为水、一氧化碳、氢、乙炔和苯.温度1400 K将酚醛树脂热解分为高温和低温区,分别表现出不同的热解速率常数与温度的关系.