(18.204.2.190) 您好!臺灣時間:2021/04/22 06:56
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果

詳目顯示:::

我願授權國圖
: 
twitterline
研究生:溫正雄
論文名稱:聚醚型星狀聚胺酯之合成及其物性探討
論文名稱(外文):Synthesis and Studies on the Physical Properties of Polyether Type Star Polyurethanes
指導教授:邱文英邱文英引用關係
學位類別:碩士
校院名稱:國立臺灣大學
系所名稱:化學工程學研究所
學門:工程學門
學類:化學工程學類
論文種類:學術論文
論文出版年:1997
畢業學年度:85
語文別:中文
論文頁數:81
外文關鍵詞:two-step synthesis methodpolyether type star polyurethanesmulti-hydroxy coresrystallizationsoft segment concentrationintrinsic viscosityzero-shear viscosity
相關次數:
  • 被引用被引用:0
  • 點閱點閱:200
  • 評分評分:系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0

本實驗乃利用二階段縮聚合法來合成一系列之星狀聚胺酯。首先利用溶液聚合,以改變聚醚型二醇(PTMO)與芳香族二異氰酸鹽(MDI)反應當量比之方式,合成出不同分子童之預聚物成為星狀聚胺醋之側鏈;再加入二十分之一當量的多氫氧基小分子(含三個、四個氫氧基)當作鏈延長劑,與預聚物進行溶液聚合,成為星狀聚胺酯之核心。待反應完全後,再加入過量之正二丁胺(di-n-butyamine),將多餘之異氫酸鹽基反應掉,最後再加入非溶劑-CH3OH,將所欲之星狀聚胺酯分餾出來,並分析及研究其化學結構、分子量、分子量分佈、熱性質、動態機械性質及溶液之流變性質。
在化學結構上,由紅外線光譜和核磁共振氫譜可發現星狀聚胺酯之吸收峰表現與其線性側鏈相似。由GPC結果分析,本實驗所合成之星狀聚胺酯在分支及分支長度上皆有多分佈之表現,為一不完美之星狀聚合物。在熱性質(DSC)及動態機械性質(DMA)之測試,星狀聚胺酯在玻璃轉移溫度及結晶行為之表現主要是由其側鏈之軟鏈含量所決定,而星狀聚胺酯多分支之特性會破壞其分子排列結構,使得其結晶性變差。在稀釋溶液之流變性質表現,由毛細管測試之結果,對相同分子量之星狀、線性聚胺酯,星狀聚胺酯之本性黏度比線性聚胺酯來得小,且隨分支數之增加而遞減。在較高濃度溶液之黏度測試,由於形成之糾纏數目仍不夠,所得之零切變黏度對相同分子量之星狀、線性聚胺酯,線性聚胺酯比星狀聚胺酯大。


In this work, the two-step synthesis method was utilized to synthesize a series of polyether type star polyurethanes. First, the prepolymers with different molecular weights were prepared by change the reacting equivalent ratio of ether-type glycol(PTMO) of molecular weight 2000 with aromatic diisocyanate(MDI). Second, 1/20 equivalent of multi-hydroxy cores with different functionahties (including 3, 4 hydroxy groups) as chain extenders were put to react with the prepared polymers. Finally, the remaining free NCO groups were terminated by reacting with the di-n-butyl amine and the raw star polymers were fractionated by adding the nonsolvent, methanoi. The desired star polymer, its chemical structure, molecular weight and distribution, and physical properties were analyzed and studied.
In chemical structure, the IR and NMR spectra of star polyurethane were almost the same as their corresponding linear polyurethane. The analysis of GPC result indicated that the obtained star polyurethanes were imperfect, not only the attacted branches but also the length of branches had broad polydisperse values. The themial (DSC) and dynamic mechanical (DMA) properties of star polyurethanes were mainly dependent on the soft segment concentration of their corresponding linear polyurethane(side chain). However, the effect of branches would destroy the structure of polymer chain and decrease the crystalhzation. In dilute solution properties, the intrinsic viscosity of star polymer was lower than the linear one at the same molecular weight, whatever the solvent temperatures were changed. And in concentrated solution, because of the entanglements formed were not enough tested here, the zero-shear viscosity of star polymer was still lower than the linear one at the same molecular weight.

QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top
系統版面圖檔 系統版面圖檔