有機-無機奈米複材的物性及化性研究

Abstract

本論文致力於高分子-二氧化矽奈米粒子製作奈米複材、物性與化性的研究，包含三個部份。第一部份為奈米相轉移的量測，第二部份為奈米粒子大小及高分子化學種類對奈米複材物性的影響，第三部份研發新穎的具超疏水及低水氣穿透性之奈米複材。我們發現當奈米複合材料中的奈米粒子濃度達到透路限度(percolation threshold)時，我們無法以傳統宏觀的熱示差掃瞄卡量計(DSC)或是熱機械分析儀(TMA)量測到複合材料的玻璃轉移溫度。因此，我們建立一種新的奈米複合材料的量測方法 – 藉由臨場可變溫式原子力顯微鏡儀器(in situ thermal AFM)來即時觀察奈米複合材料的高分子鏈段因受熱而產生的奈米相轉移(nanophase transition)現象，進而找出奈米複合材料的表面玻璃轉移溫度(Tg, surface)。而當奈米複合材料中的二氧化矽奈米粒子含量達到透路限度(percolation threshold)時，不論是改變有機成份的化學結構，抑或是改變無機成份的奈米粒子顆粒大小時，最終複合材料整體的熱性質及機械性質均會有明顯非線性的變化量產生。最後，我們合成出氟化醯酯壓克力作為有機成份的主體，添加二氧化矽奈米粒子來補強高分子材料的耐熱及機械性質，開發出無溶劑紫外光固化的有機無機混成材料，控制其奈米區域的大小可以得到超疏水的性質，氟化醯酯的組成使材料具有極佳的透光性及極低的透水性，可以應用在光波導元件、發光二極體、太陽能電池元件封裝及牙科填補材料等多方面的用途上。

This thesis is devoted to polymer-silica nanocomposites to study its physical and chemical properties. It contains three parts, the first part is to monitor the nanophase transition of the nanocomposites, the second part is to discuss effects of nanoparticle sizes and type of polymer chemical structures on the properties of nanocomposites, and the final part is to develop an innovative nanocomposite which has superhydrophobic and low moisture permeation properties. We have found that when the concentration of nanoparticles reaches its percolation threshold, the glass transition temperature of nanocomposite which can not be measured by to conventional macroscale thermal analytic instruments such as DSC and TMA. Therefore, we have established a methodology basis on in-situ thermal atomic force microscope to monitor the nanophase transition of the nanocomposite upon heating. When the concentration of nanoparticles reaches its percolation threshold, a dramatic increasing in thermal and mechanical properties that is universal regardless the chemical structure of polymers and the particles of the nanoparticles in the nanocomposite. Finally, we synthesize a fluoroimide acrylate as an organic component of nanocomposite, then add silica nanoparticles to reinforce the thermal stability and mechanical properties of polymer to develope a solventless photocurable nanocomposite resin system. To control the size of nanodomain can make materials have the superhydrophobic, and fluoroimide acrlate make materials have very low water vapor permeation. It has potential application in optical waveguides, light emitting diodes, device encapsulation, dental restorative materials and so on.