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題 名 | 二異氰酸之化學結構對聚酼胺-醯亞胺之物性及加工性之影響 |
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作 者 | 李大剛; 杜佾璋; | 書刊名 | 宜蘭農工學報 |
卷 期 | 10 1995.06[民84.06] |
頁 次 | 頁69-82 |
分類號 | 467.42 |
關鍵詞 | 聚亞胺; 高溫穩定性; 加工性; 聚醯胺-醯亞胺; 二異氰酸鹽; 結構對稱性; Polyimide; High temperature stability; Processingability; Polyamideimide; Diisocyanate; Structure symmetry; |
語 文 | 中文(Chinese) |
中文摘要 | 聚醯亞胺(Polyimide),PI,具有極佳之抗化學藥品性、抗氧化力、高溫穩定性 (∼600℃)、機械性質及電氣性質。目前已廣泛地應用在電子工業、航太工業、接著劑及 漆包線等。聚醯亞胺為一價昂,加工困難之高分子材料,故本計劃將利用改質工作生產價廉 易加工,且仍具有耐高溫性,良好物性及電氣性質之材質:聚醯胺--醯亞胺(polyamide- imide),PAI。 本計劃將分別使用七種二異氰酸鹽:MDI、T100、T80、TODI、XDI、HDI及HMDI為原料與溶於 N-methy1-2-pyrrolidone (NMP) 中之 trimellitic-anhydride,TMA,以入料比1:1方式反 應生成聚醯胺--醯亞胺。聚醯胺--醯亞胺較聚醯亞胺有較低之極性及玻璃轉換溫度,Tg,故 可降低其加工溫度改善其加工性,並可選用極性較低且價廉之溶劑以降低其生產成本。合成 所得PAI成品之動態--機械性質、熱學性質及耐熱性質分別使用DMA、DSC及TGA測試。同時利 用其樹脂加工製成漆包線之後依照JIS C3003標準測試其電氣性質。 由四組PAI成品DMA測試結果可知均僅具一個Tg,其值自TODI-TMA之120℃至T80-TMA之167℃ 之間,其Tg值主要受醯亞胺基含量及結構之對稱性影響。當PAI成品有較高之醯亞胺基含量 及較佳之結構對稱性時其成品有較高之Tg及較佳之耐高溫性,而PAI成品具不對稱結構則不 易生成結晶使其成品之Tg值較低。此四組PAI成品之儲存模數在300℃仍維持3×10□至7× 10□N/m□,顯示PAI成品有良好之高溫穩定性。 DSC之測試結果顯示PAI成品之Tg值之趨勢與DMA測試結果相符。由熔點吸熱峰之面積積分而 得之熔解熱值,△H□具對稱結構者(MDI-TMA,HMDI-TMA等)有較高之△H□值(112.2及 54.OJ/g),可知其成品有較高之結晶度。具有立體障礙性之TODI-TMA之△H□=20.5J/g,其 結晶度次之,而同時具有不對稱結構及立體障礙性之T100-TMA其結晶性最低。此系統PAI成 品之Tm亦隨熔解熱值之降低而降低。由TGA測試結果知PAI成品之耐熱性質以具有苯環結構之 二異氰酸鹽為原料之成品(MDI-TMA,T100-TMA,TODI-TMA,XDI-TMA)有較佳之耐熱性,直 鏈結構者(HDI-TMA)次之,環狀結構者(HMDI-TMA)最差。MDI-TMA樹脂製成漆包線後進行 其電氣性質之測試,可知其成品無針孔產生,具低分散因子(tan δ=0.024),高耐破壞電 壓(4.8kV)及耐熱衝擊性為一電氣性質良好之漆包線材質。 |
英文摘要 | Polyimides have excellent antioxidation, mechanical, electric proprties and high temperature stability (∼600℃). It has been widely used in electronic products, aerospace and enamelled wires. The disadvantages of polyimides are expensive and processing difficulty. In this study, we use diisocyanates to replace diamines to form polyamide-inides, PAI, to improve the processingability with less adversely effects on the mechanical properties and high temperature performance. Seven different diisocyanates: MDI, T-100, T-80, TODI, XDI, HDI and HMDI were used as the raw material to react with trimellitic anhydride, TMA, (dissolved, in NMP) with the stocichiometric ratio of 1:1 to form polyamide - imides, PAI. These PAIs have lower Tg than corresponding polyimides can be processed easily. The dynamic-mechanical, thermal and thermal stability properties were characterised by using DMA, DSC and TGA, respectively. The electric properties will examined on enamelled wires by following the JIS C 3003 standards. From DMA results, all four PAIs show one single Tg, its value from 120℃ for TODI-TMA to 167℃ for T80-TMA. The value of Tg is affected mainly by imide group content and structure regularity. PAI specimens with higher imide group content (T80-TMA) and good structure symmetry (MDI-TMA) display higher Tg than those with lower imide group content (TODI-TMA) and poor structure symmetry (T100-TMA). All four PAI specimens have storage modulus of 3 x 10□ to 7 x 10□ N/m□ at 300℃, it exhibit good high temperature stability. From DSC data, Tg value show the similar trend as DMA result. PAI specimens with good structure symmetry (MDI-TMA, HMDI-TMA) show higher heats of fusion, △H□, values than those with poor structure symmetry (TODI-TMA, T100-TMA). It's probably due to the high degree of crystallinity. Melting point, Tm, decreases as the △H□ value decreased. PAI specimens based on aromatic diisocyanates (MDI-TMA, T100-TMA, TODI-TMA, and XDI-TMA) show better high temperature stability than those based on aliphatic diisocyanates (HDI-TMA and HMDI-TMA). The electric properties test on MDI-TMA based enamelled wires display good electric properties with no pin holes, low dissipation factor (tan δ=0.024), high dielectric strength (4.8kV). |
本系統中英文摘要資訊取自各篇刊載內容。