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无机纳米粘土—热固性树脂复合体系的研究
The Study of Inorganic Clay-thermoset Nanocomposites
【作者】 胡盛;
【导师】 唐晓林;
【作者基本信息】 复旦大学 , 高分子化学与物理, 2009, 硕士
【摘要】 本文介绍了一种新的凹凸棒改性方法,将环氧端基聚环氧乙烷(PEGDE)吸附于凹凸棒表面对其改性,傅立叶红外(FTIR)结果显示,改性后在3615cm-1和989cm-1处新出现的吸收峰分别对应于PEGDE与凹凸棒表面硅羟基的氢键作用以及凹凸棒表面的金属离子与PEGDE中的醚键氧之间的螯合作用。热失重分析(TGA)结果显示PEGDE在凹凸棒表面的吸附量与PEGDE的丙酮溶液浓度密切相关。X射线衍射(XRD)结果显示PEGDE的插入扩大了凹凸棒之间的层间距离,有利于凹凸棒在聚合物基质中的分散。本文探讨了不同PEGDE浓度改性凹凸棒以及不同凹凸棒含量对氰酸酯/环氧大豆油共混体系结构和性能的影响。扫描电镜(SEM)结果显示,改性凹凸棒在共混体系中能够呈现纳米尺度的分散结构;TGA结果显示,改性凹凸棒的加入对共混体系的热稳定性没有明显影响;动态力学分析(DMA)表明,PEGDE浓度较低时,改性凹凸棒的加入能够提高共混体系的模量和玻璃化转变温度(Tg),但当PEGDE浓度过高时,由于引进了过多的PEGDE低聚物,共混体系的模量和Tg反而下降。凹凸棒含量的提高同样能提高共混体系的模量和玻璃化转变温度,其中凹凸棒的最佳含量为3wt%左右。当改性凹凸棒在共混体系中分散均匀时,凹凸棒的加入在保持了共混体系的断裂伸长率的同时,能使共混体系的拉伸强度有所提高。在凹凸棒/PPO/环氧共混改性体系中,SEM结果显示,凹凸棒的加入能够改变共混体系的相结构,比如PPO含量为80phr的共混体系,凹凸棒加入后共混体系的相结构由反转相结构变为双连续相结构;采用OM与TRLS跟踪不同组成体系的相分离过程表明:凹凸棒的“钉锚”效应对相界面的流动有明显的阻碍作用,减小了最终相结构的相区尺寸,并延缓了相分离发生的时间。
【Abstract】 A convenient method was employed to modify the attapulgite(ATT) clay by bonding the poly(ethylene glycol) diglycidyl ether(PEGDE) onto it’s surface.The result of FT-IR spectroscopy showed that the new absorption of 3615cm-1 and 989cm-1 are attributed to the hydrongen bonding and chelation respectively. Thermogravimetic analysis showed that the amount of PEGDE grafted on ATT was influenced by the PEGDE concentration in acetone solution.The XRD result showed that the PEGDE had inserted between the layered ATT.A novel biobased nanocomposite was prepared by blending surface modified natural clay with epoxidized soybean oil(ESO) and cyanate ester resin(CE).The influence of PEGDE concentration and ATT content was discussed.Scanning electron microscope(SEM) results showed that nanoscaled ATT dispersed in the blend of epoxidized soybean oil(ESO) and cyanate ester resin(CE) aider curing.The TGA results showed that the thermostability of the nanocomposites was influenced little with addition of ATT.The moduli and Tg of the composites were enhanced with addition of ATT.The nanocomposites with 3wt%ATT showed the best performance. The tensile strength of the nanocomposites had been enforced,at the same time,the high elongation had been maintained compared with the ESO/CE blends we had reported previously.In the ATT/PPO/Epoxy blends,the SEM results showed that the incorporation of a small amount of ATT into the blends could change the final morphology,especially for the blend with 80phr PPO.The results of OM and TRLS showed that the pinned ATT particles slowed the interfacial motion and decreased the size of the phase domains and delayed the occurrence of phase separation.
【Key words】 Attapulgite; poly(ethylene glycol) diglycidyl ether; nanocomposite; thermoset resin; phase separation;