聚醚醯胺酸插層之層狀水滑石與特性研究

Abstract

本論文以聚醚胺(poly(oxypropylene)-amine)與馬來酸酐(maleic anhydride)合成插層劑poly(oxypropylene)-bis-amidoacids (POAs)，對人工合成的陰離子型黏土水滑石(LDH)進行改質，探討其反應機制，並與實驗室早期已發表的陽離子型黏土(蒙脫土、雲母)比較。 (1)一系列POAs插層水滑石，經由不同極性鏈段的POAs改質會有不同的性質的結果。隨著POP-amidoacids分子量的增加而層間距提升，最高可將水滑石層間撐開至XRD 94 Å之高層間距。 (2)隨著POP2000-2MA-2Na量的增加，水滑石層間變化會有個臨界點，超出此臨界點層間距會瞬間增大，利用此機制可輕易控制分子在層間的型態改變。 (3)經由POP2000-2MA-Na改質後的有機黏土具有雙性性質，為一新穎的有機無機界面活性劑，在臨界微胞濃度下(CMC=0.01wt%)可使甲苯/水的界面張力降低至4.5 mN/m。 (4)以同一類型插層劑對此三種不同類型黏土做比較，有別於傳統離子交換改質的黏土，新的改質機制包含氫鍵力及螯合分別作用在不同類型的黏土上(水滑石，蒙脫土和雲母)。 (5)有機改質的水滑石複材具有酸鹼應答特性，其層狀結構可在較低pH的環境下分解並釋放出層間有機物，此黏土複材同時具有溫度敏感特性，可在低溫下分散(5~10 oC)，高溫下聚集(＞20 oC)。結合上述特性，此有機水滑石可應用在藥物釋放等生醫工程上。

This thesis concerns the organic modification for the Mg–Al layered double hydroxides (LDHs), more specifically, the intercalation profile of the clay with a series of poly(oxypropylene)-bis-amidoacids (POAs). A number of important issues are included in the thesis. (1)The intercalation of LDH by the POP-amidoacids and the spatial enlargement of the gallery up to 94 Å d spacing. (2)The critical intercalation of using the POP2000-2MA-2Na for expanding the LDH gallery. It provides a new way for manipulating nanomaterials and control of polymer conformations in the LDH confinement. (3)The amphiphilic property of POP2000-2MA-Na/LDH hybrid and their ability of lowering the toluene/water interfacial intension to 4.5 mN/m at the critical micelle concentration (CMC) of 0.01 wt%. (4)Newly discovered mechanisms that involving hydrogen-bonding and chelation. The different clays such as LDH, MMT and Mica are compared for the generality of the new mechanisms. (5)A pH dependence of the organo-LDH hybrids that particularly occurrence of layered structure collapse at low pH environment. The implication is an application of organic encapsulation and control release that could be developed for such a clay hybrid. In addition, the hybrids also possess thermal-sensitivity, that allows a fine dispersion at low temperature (5~10 oC) and aggregation at higher temperature (＞20 oC).