Poly(4,4’-Oxydiphenylene Pyromellitimide)是最典型的聚亞醯胺,目前被廣泛用於航空、汽車以及電子等工業,在電子的層間塗膜及介電絕緣層的應用上,為滿足原件尺寸越來越小的趨勢,Poly(4,4’-Oxydiphenylene Pyromellitimide)被要求要具有更低的熱膨脹係數(Thermal expansion coefficient, CTE)、吸濕性以及介電係數,Poly(3,4’-Oxydiphenylene Pyromellitimide)是Poly(4,4’-Oxydiphenylene Pyromellitimide)的同分異構物,擁有更低的熱膨脹係數,及其他優異的性質,但是,仍需盡可能符合工業上,低吸濕性及低介電係數的趨勢。二氧化矽的加入已被證明可以降低材料的吸濕性及介電係數,但是無論如何,都要先克服二氧化矽在有機基材內的聚集問題。 本研究利用超臨界二氧化碳技術進行奈米級二氧化矽的表面接枝,將3- Glycidoxypropyltrimethoxysilane(Glymo)接枝在二氧化矽表面,以增加二氧化矽與聚亞醯胺Poly(3,4’-Oxydiphenylene Pyromellitimide)介面間的相容性以及分散性,以供給將來製備Poly(3,4’-Oxydiphenylene Pyromellitimide)複合材料的指標。 技術方面可以藉著超臨界二氧化碳技術避免掉化學溶劑的使用以及透過調整反應時間、溫度、壓力即可控制接枝量,並取得最佳參數條件,接枝結束後的樣品進行FTIR及TGA的鑑定,最後透過UV-vis及SEM偵測二氧化矽的分散性。結果顯示在溫度為1000C,壓力在30MPa,反應時間8小時的操作條件下,可以得到最大接枝量4.66 wt.%,並且透過UV-vis證明Glymo可以增加介面的相容性,使得二氧化矽在聚亞醯鞍的前趨物(Poly(amic acid), PAA)中的分散性被改善,最後利用SEM觀察改質後二氧化矽在聚亞醯鞍中分散情形,分散粒徑從改質前的50 μm降低到小於5μm。
In this study, SiO2 nanoparticles were successfully modified with 3- Glycidoxypropyltrimethoxysilane using supercritical carbon dioxide (SCCO2) as a solvent. By this way, we can change temperature、presure and reaction time to control degree of grafting without organic solvent. When temperature is 1000C, operating pressure is 30MPa and reaction time is 8 h, grafting percentage have maximax: 4.66 wt.%. Modified SiO2 were characterized by Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric (TGA). Further, SiO2/Poly(amic acid) mixture and SiO2/Poly(3,4’-Oxydiphenylene Pyromellitimide) composites were prepared. They were characterized by UV-vis and SEM. Modified SiO2 in organic substance observed good dispersibility compare to bare of that. Poly(3,4’-Oxydiphenylene Pyromellitimide) differs from the more common PMDA-4,4’-ODA only in the isomerization of the diamine unit. It was synthesized sunce 1991, there’s not nanocomposites about Poly(3,4’-Oxydiphenylene Pyromellitimide). Our study be a reference for PMDA-3,4’-ODA nanocomposites in the future.