聚醯亞胺-黏土奈米複合材料之合成及其特性探討

Synthesis and Properties of Polyimide-Clay Nanocomposite Materials

董睿軒(Rui-Xuan Dong)

指導教授 ： 王宏文

中原大學/理學院/化學研究所/碩士(2006年)

https://doi.org/10.6840/cycu200600370

摘要

本論文分成三部分(1)雙改質劑有機化黏土並合成聚醯亞胺-黏土奈米複材(2)不同類型的黏土合成聚醯亞胺-黏土奈米複材。(3)含氟單體合成聚醯亞胺-黏土奈米複材。利用WAXRD觀察黏土層間距變化；TEM觀察黏土載聚醯亞胺中之分散狀況；TGA和DSC觀察聚醯亞胺-黏土奈米複材之熱性質；DMA觀察其機械性變化及LCR測其在變溫、變頻下的介電行為。
在第一部分研究中，我們藉著加入兩種改質劑使其增加與聚醯亞胺中的Dianhydride末端基之鍵結機率。利用此方法，增加了黏土在聚醯亞胺中之分散效果，進而提升PI-Clay奈米複材熱性質、機械性質和介電性。
在第二部分研究中，利用兩種黏土中其矽酸鹽層之負電荷分布於不同位置，使改質劑和高分子與黏土間鍵結方式不同，造成分散狀況及特性提升上的不同。由實驗結果得知，負電荷位於八面體時，其改質劑與其較易以凡得瓦爾力鍵結，黏土在PI中分散效果佳；位於四面體時，改質劑與其則以離子鍵或是共價鍵鍵結。
在第三部分研究中，我們利用兩種含氟與兩種不含氟單體合成聚醯亞胺-黏土奈米複材，測量其特性的差異。由實驗結果發現，介電特性上會有很明顯的變化，由於介電常數會因(1)黏土的分散程度(2)對稱性(3)氟含量(4)薄膜厚度的變化有關，單體含氟且對稱之複材，比不含氟之聚醯亞胺-黏土奈米複材介電常數更低。

關鍵字

聚醯亞胺-黏土 ； 奈米複合材料 ； 介電特性

並列摘要

Clay-dispersed polyimide nanocomposites were synthesized by a in-situ polymerization processes. By using the wide angle X-ray diffraction(WAXRD) and transmission electron microscopy (TEM) technique, polyimide inserted between the interlayer of montmorillonite (MMT) clay was indentified. The thermal and mechanical properties of polyimide-clay nanocomposites were studied by the TGA、DSC and DMA. The reduced moisture absorption of polyimide-clay nanocomposites was found to be related with content of clay. The dielectric properties of polyimide-clay nanocomposites were measured under frequency of 1kHz ~1MHz and temperature of 25℃~ 150℃.
Three major topics were investigated in the present study：First, PI-clay nanocomposites exhibit better intercalation/exfoliation, enhance thermal, mechanical properties and lower dielectric constants when double-swelling agents are used.
Second, PK 802, a clay with negative charge resident in its octahedral polyhedra, results in lower moisture absorption, dielectric constant and loss in PI-clay nanocomposies due to its weak ionic strength to polymer matrix.
Third, it was found that dielectric constant of PI-clay nanocomposites is related to the：(1) dispersion of clay, (2) symmetry of fluorine atom, (3) fluorine content in the PI, and (4) thickness of film specimen. Higher fluorine content in PI matrix results in lower dielectric constant.

並列關鍵字

PI-clay ； dielectric property ； nanocomposites