蒙特納石與聚硅烷亞醯胺奈米複合材料之合成與物性

Abstract

本研究乃合成聚硅烷亞醯胺（BTDA-ODA-DSX）/蒙特納石奈米複合材料並分析其性質。以4-4'-oxydianiline（ODA）作為夾入劑來改質蒙特納石，製備得ODA-Mont，再以3, 3′, 4, 4′-benzophenone tetracarboxylic dianhydride、4-4'-oxydianiline（ODA）及1,3-Bis aminopropyl tetramethyl disiloxane合成copolyimidesiloxane，將ODA-Mont與聚硅烷亞醯胺在溶劑（DMAc）裡混合，經加熱脫水閉環反應形成聚硅烷亞醯胺/蒙特納石奈米複合材料，並以XRD分析其是否為奈米複合材料。 經由紅外線光譜的分析，可以得到當越多的有機黏土加入時同樣的時間與溫度內亞醯胺化的程度越高，利用一級及二級反應動力學來模擬亞醯胺化的反應，加入5phr有機黏土的聚硅烷亞醯胺/蒙特納石奈米複合材料其反應活化能比純的聚硅烷亞醯胺減少12 %。 聚硅烷亞醯胺/蒙特納石奈米複合材料的熱性質因加入層狀的矽酸矽酸岩而提升，加了5phr ODA-Mont的聚硅烷亞醯胺/蒙特納石奈米複合材料其熱裂解溫度提升了8 ℃（565 ℃ versus 573 ℃）。此外平行薄膜平面的熱膨脹係數，在低溫區間（50 ℃~100 ℃）5phr ODA-Mont的聚硅烷亞醯胺/蒙特納石奈米複合材料比純的聚硅烷亞醯胺降低了25 %。吸濕性的分析中將聚硅烷亞醯胺膜置於25 ℃、相對溼度80 %的環境下72 hr，當聚硅烷亞醯胺薄膜中添加的有機黏土少於3phr時，分布於薄膜表面之矽酸鹽層水氣阻隔性大於本身之吸水性，因而使得整體的聚硅烷亞醯胺/蒙特納石奈米複合材料的吸濕性降低，3phr的ODA-Mont使聚硅烷亞醯胺薄膜吸濕性降低56%，反之5phr時吸水率大於阻隔率而使得吸濕率上升。

Polyimidesiloxane/Montmorillonite nanocomposites have been synthesized, and the thermal properties of these nanocomposites were investigated. First Na+-Montmorillonite was intercalated with 4-4'-oxydianiline（ODA） to form ODA-Mont. Then, poly（amid acid） consisted of 3, 3′, 4, 4′-benzophenone tetracarboxylic dianhydride（BTDA）, 4-4'-oxydianiline（ODA） and 1,3-Bis aminopropyl tetramethyl disiloxane（DSX）was synthesized in N,N-dimethylacetamide（DMAc）. Subsequently, different amount of ODA-Mont in DMAc was mixed with poly（amic acid）. These poly（amic acid）/ODA-Mont films were subject to thermal treatment for converting to BTDA-ODA-DSX/ODA- Mont nanocomposites. It was found that the imidization treatment and time of the poly（amic acid） can be reduce through Fourier Transform analysis by dispersing a small amount of ODA-Mont in nanometer scale in polyimidesiloxane. First-order and Second-order kinetics model were used to simulate the imidization of poly（amic acid）/ODA-Mont, and a 12% drop in the activation energy of 5/100 ODA-Mont/BTDA-ODA-DSX was obtained as compared to that of neat BTDA-ODA-DSX. The thermal degradation temperature, at 5 % weight loss, of 5/100 ODA-Mont/ BTDA-ODA-DSX was 8 ℃ higher than that of pure BTDA-ODA-DSX（565 ℃ versus 573 ℃）. Moreover, the in-plane thermal expansion coefficient（CEC）of 5/100 ODA-Mont/BTDA-ODA- DSX was 25% lower than that of pure BTDA-ODA-DSX at 100 ℃.The moisture absorption of 3/100 ODA-Mont/BTDA-ODA-DSX was only one-half of that of pure BTDA-ODA-DSX（0.55% VS. 1.26%）.