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|Title: ||三步驟法製備具可加工性之聚醯胺酸共聚亞胺;Preparation of Soluble Poly(amic acid-co-imide) by Three-Step Method|
|Keywords: ||聚醯胺酸共聚亞胺;聚醯亞胺;化學環化;熱環化;化學程度;熱性質;poly(amic acid -co- imide);polyimides;chemical imidization;thermal imidization;imidization degree;thermal properties|
|Issue Date: ||2014-08-11 18:13:57 (UTC+8)|
|Abstract: ||本論文以三步驟的方式製備聚醯胺酸共聚亞胺(poly(amic acid-co-imide), PA-I)，可分別合成出聚醯胺酸(polyamic acid, PAA)、低環化程度聚醯胺酸共聚亞胺(PA-IL)與高環化程度聚醯胺酸共聚亞胺(PA-IH)。而且第二步驟所合成之PA-IL在極性溶劑中具有可溶性，再以120 oC熱處理提高環化程度後，PA-IH則具有耐溶劑性及其他優異性質，以解決一般聚醯亞胺(polyimide, PI)使用高反應性的單體時，所遇到的加工性困境。|
第一步驟是以4,4′-二胺基二苯醚(4,4’-Oxydianiline, ODA)和均苯四甲酸二酐(Pyromellitic dianhydride, PMDA)合成出PAA，結果顯示增加PMDA的劑量可提高PAA的分子量。
第二步驟以亞硫醯氯(SOCl2)進行化學環化，得到PA-IL。探討PAA分子量、反應溫度、SOCl2對環化程度(imidization degree, ID)的影響。ID是以紅外線光譜進行檢測。結果顯示PAA分子量並不會對ID有所影響，反應溫度70oC下所得到可溶性PA-IL，較易維持其可溶性，且在SOCl2添加量為80 %時，ID可達到49 %，並在N-甲基吡咯酮(1-methyl-2-pyrrolidinone, NMP)下仍為可溶狀態，具備加工性。
第三步驟進行120 oC熱環化，得到PA-IH。探討PA-IL分子量、反應溫度與SOCl2下所得PA-IL對ID的影響。結果顯示不同分子量、不同反應溫度與SOCl2下所得PA-IL經熱處理後皆可提高ID，提升其耐溶劑性。當PA-IL在反應溫度70 oC下以及SOCl2添加量大於60 %時，可得到ID達到69 %且耐NMP溶劑之PA-IH。
熱重分析結果(TGA)，發現PA-IL和PA-IH皆有兩階段重量損失，第一階段(200~220 oC)為熱環化所造成；第二階段(640~650 oC)為熱裂解的溫度，此溫度與PI相同。而進行微差掃描熱分析(DSC)可知PA-I的玻璃轉移溫度(Tg)為270~300 oC。
機械性質測試顯示PA-IH的最大抗張強度隨ID上升而增加，最高可至41.7 MPa，並從伸長量(7~12 %)與楊氏模數(0.3~0.7 GPa)顯示出PA-IH的薄膜具有堅硬不易變形的特性。
;Preparation of poly(amic acid-co-imide) has been developed by three-step method. Poly(amic acid) (PAA), poly(amic acid-co-imide) with low imidization degree (PA-IL) and poly(amic acid-co-imide) with high imidization degree (PA-IH) were obtained in each step. In addition, soluble PA-IL was easily prepared at the second step. Then insoluble PA-IH with high imidization degree (ID) was prepared by heat treatment at 120 oC.
4,4’-Oxydianiline (ODA) and pyromellitic dianhydride (PMDA) were polymerized to become PAA in first step and the molecular weight of PAA was able to controlled by the amount of PMDA.
PA-IL was prepared by chemical imidization of PAA with SOCl2 in second step. Effects of molecular weight of PAA, temperature and SOCl2 on ID were discussed. IDs of polymers were measured from FT-IR. It was found that molecular weight of PAA didn’t effect ID. PA-IL prepared at 70 oC was easily controlled to keep soluble. On the other hand, ID of PA-IL was reached to 49% by adding 80% SOCl2 at 70 oC and the PA-IL was still soluble in 1-methyl-2-pyrrolidinone (NMP) at the same time.
PA-IH was prepared by heat treatment of PA-IL at 120oC in third step. Effects of molecular weight of PA-IL, temperature and SOCl2 on ID were discussed. The ID of PA-IL with differential molecular weight, temperature and SOCl2 was increased by heat treatment and PA-IH had solvent resistance. ID of PA-IH prepared from soluble PA-IL (70 oC, SOCl2≧60%) was reached to 69% and PA-IH kept shape in NMP.
Thermal gravimetric analyzer (TGA) of PA-IL and PA-IH both showed two stages of mass loss. The first stage (200~220 oC) was result from thermal imidization of the polymers. The second stage (640~650 oC) was decomposition temperature of the polymers and the decomposition temperature was the same as PI. Differential scanning calorimeter (DSC) showed glass transition temperature (Tg) of PA-IH was at 270~300 oC.
Ultimate tensile strength (UTS) of PA-IH increased with ID and reached to 41.7 MPa. Elongation at break(7~12 %) and Young’s modulus(0.3~0.7 GPa) showed that PA-IH film was tough and robust.
|Appears in Collections:||[化學工程與材料工程研究所] 博碩士論文|
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