具光導電性之二階非線性光學特性聚酯酸及聚胺基甲酯之製備及特性研究

Abstract

本論文主要是嘗試將具二階非線性光學效應之有機雙官能基偶氮染料( Disperse Red - 19)和二異氰酸鹽(Dii- socyanate,MDI)及二酸肝( Dianhydride,PMDA)行聚合反應 ,並進而加入光導材料,分別製成具二階諧 波效應之高分子材料.藉著DSC及TGA的分析,了解高分子材料之玻璃轉移溫 度(Tg)及熱分解溫度(Td).由即時動態極化系統之觀察,可找出極化之最適 條件與Tg相近(DR19-MDI=102℃,DR19-PM- DA=90℃).在IR及DSC的分析中 亦發現 DR19-PMDA在極化過程中由於高溫高電壓的作用下, 酸基彼此反應 而形成網狀結構,並且產生藍位移之現象(blue shift).本實驗折射率之預 測乃是採用干涉法,有別於一般利用橢圓儀之測量.在經由 Maker-Fringe 圖譜之分析可得DR19-MDI之χ = 173 pm/v,DR19-PMDA之χ = 136pm/v,此 值已具實用性.利用UV -Vis光譜之檢測發現二種材料均具二階非線性光學 之穩定性. 最後在加入光導材料後則可觀察到二者均有明顯之光導電現 象, 因此可預測此二種非線性光學高分子材料可能具有光折變效應. New polymers containing azo dye ,disperse red-19,as a non- linear optically active chromophore in conjuction with di- isocyanate(MDI) and dianhydride(PMDA) have been synthesized .according to the DSC measuremwnts,these polymers exhibit that the glass transition temperature of DR19-MDI is 100 C and DR19-PMDA is 90 C.After poling process,the Tg of DR19-PMDA is shifted to higher temperature. This is due to the cross- linking reaction of carbonyl acid groups under the conditions of high temperature and high voltage. We use a method of interference to predict the refractive indices. The second harmonic generation coefficients (d33) are calculated from the Maker-Fringe experiments.The d33 of DR19-MDI is 173pm/ v and of DR19-PMDA is 136 pm/v.From the observation of UV-Vis spectrums,they show no significant decay in second harmonic generation for over 100 hours. At last,these polymers are doped with photoconductor and we can find high photocurrent by absorbtion of laser light. Thus,these nonlinear optical polymers might be of photorefractive.