English  |  正體中文  |  简体中文  |  Items with full text/Total items : 43312/67235
Visitors : 2079489      Online Users : 11
RC Version 5.0 © Powered By DSPACE, MIT. Enhanced by NTU/NCHU Library IR team.

Please use this identifier to cite or link to this item: http://nchuir.lib.nchu.edu.tw/handle/309270000/154010

標題: 高效能木材乙醯化改質技術之開發
Development of high efficiency method for wood acetylation
作者: 楊振寧
Yang, Chen-Ning
Contributors: 吳志鴻
森林學系所
關鍵字: 液相改質法;微波改質法;氣相改質法;醋酸酐;醋酸乙烯酯
Liquid phase reaction method;Microwave reaction method;Vapor phase reaction method;Acetic anhydride;Vinyl acetate
日期: 2012
Issue Date: 2013-11-19 12:37:38 (UTC+8)
Publisher: 森林學系所
摘要: 本研究主要探討液相改質、微波改質及氣相改質法等三種乙醯化(Acetylation)改質方式及不同改質藥劑,對木材各項化學、物理及機械性質之影響。試驗結果顯示,柳杉(Cryptomeria japonica)試材經醋酸酐以三種不同改質方式改質後,其紅外線光譜於波數1731 cm-1(-OCOCH3, C=O)、1370 cm-1(-OCOCH3, C–H)及1251 cm-1(-OCOCH3, C–O)之吸收峰均有明顯增強之趨勢,顯示試材經改質後確實具有乙醯基之特性吸收。而比較三種乙醯化改質法則可以得知,試材之重量增加率均隨反應時間增加而上升,且以氣相改質法進行改質時,能以較少之藥劑量達到與液相改質及微波改質相同之改質效果。另外,在相同的改質程度下,以微波改質法所需之全程改質時間最短。在尺寸安定性方面,三種乙醯化改質試材之抗膨潤效能(Anti-swelling efficiency, ASE),於反應初期(0–60 min)均隨著改質時間的增加而上升,而當改質時間超過120 min時,液相及微波改質者則呈現下降之趨勢。然而,試材之彈性模數(Modulus of elasticity, MOE)於改質前後並無顯著差異,但乙醯化改質後,試材之損失模數(Log E")均呈現α及γ轉移峰往低溫偏移,β轉移峰之強度明顯下降之現象。另一方面,利用醋酸乙烯酯對木材進行氣相乙醯化改質時,以碳酸鉀及醋酸鉀作為催化劑可有效提升柳杉試材羥基與醋酸乙烯酯之反應性。此外,由傅立葉紅外線光譜儀及固態核磁共振光譜儀之分析結果得知,柳杉試材經醋酸乙烯酯改質後,確實具有乙醯化之現象。而利用醋酸乙烯酯進行柳杉乙醯化改質時試材,其改質效能隨催化劑含量及反應時間增加而提高,其中,又以催化劑含量為5%及反應時間6 h時,具有較佳之重量增加率。
This study was to investigate the effect of liquid, microwave, vapor phase reaction methods and different treat agent on physical and chemical properties of acetylated wood. Results revealed that all infrared spectra of sugi (Cryptomeria japonica) displayed strong absorption bands of acetyl group at 1731 cm-1 (-OCOCH3, C=O), 1370 cm-1 (-OCOCH3, C–H), and 1251 cm-1 (-OCOCH3, C–O) after acetic anhydride treated. On the other hand, the weight percent gain increased with increasing the reaction time for all three reaction methods. Among them, the microwave reaction method required the least reaction time to achieve the same level of weight percent gain. The anti-swelling efficiency (ASE) of acetylated wood increased with increasing the reaction time at the first 60 min. However, the ASE decreased with increasing the reaction time over 120 min for both liquid and microwave reaction methods. Moreover, there were no significant difference between acetylated and untreated sugi on the modulus of elasticity for all three reaction methods, but the α and γ transitions of acetylated wood (Log E") shifted to lower temperature and the intensity of β transition decreased as compared to untreated one. Moreover, the transesterification reaction between vinyl acetate and hydroxyl groups of sugi could be improved in the presence of potassium carbonate and potassium acetate as a catalyst. The acetylation was confirmed by Fourier transform infrared spectroscopy and solid state nuclear magnetic resonance spectroscopy. In addition, the efficiency of the acetylation increased with increasing reaction time and catalyst content, and a significant weight percent gain was obtained after 6 h duration with 5% of catalyst content.
Appears in Collections:[依資料類型分類] 碩博士論文

Files in This Item:

File SizeFormat
index.html0KbHTML144View/Open


 


學術資源

著作權聲明

本網站為收錄中興大學學術著作及學術產出,已積極向著作權人取得全文授權,並盡力防止侵害著作權人之權益。如仍發現本網站之數位內容有侵害著作權人權益情事者,請權利人通知本網站維護人員,將盡速為您處理。

本網站之數位內容為國立中興大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用。

聯絡網站維護人員:wyhuang@nchu.edu.tw,04-22840290 # 412。

DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU/NCHU Library IR team Copyright ©   - Feedback