Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/3327
標題: Preparation and Applications of Layered Silicates and Poly(oxyalkylene)amine Hybrids
聚醚胺鏈段之有機/無機聚合物之製備與應用
作者: 陳宜見
Cheng, I-Jein
關鍵字: montmorillonite;蒙脫土;poly(oxyalkylene)diamine;poly(propylene);interfacial tension;epoxy;聚醚胺;聚丙烯;界面張力;環氧樹脂
出版社: 化學工程學系
摘要: 
Abstract
In this research, the organic/inorganic hybrids were prepared, in which inorganic part is layered-silicate clay (Na+-montmorillonite or Na+-MMT). Due to highly hydrophilic properties of layer silicates and gallery cations, Na+-MMT is incompatible with polymer or organic solvents. To modify hydrophilic MMT by enlarging the basal-spacing of layered silicates in order to improve the miscibility is the main purpose of this research.
In part one, the comb-like copolymers were prepared from the reaction of maleated polypropylene and poly(oxyalkylene)diamine. By the acidification of the end group amine of the copolymers, the quarternary amine salt can exchange with the Na+ in the layer silicate galleries. By using X-ray diffraction analysis, the enlarged basal-spacing was observed. This organic/inorganic hybrids have enhanced surfactancy and can be easily mix with polypropylene (PP) to form PP/clay nanocomposites.
In part two, we proved that the basal-spacing of silicate layers were widened by using an increasing molecular weight of intercalating agent which had a backbone of polyoxypropylene (POP). With 2000 Mw POP, the basal spacing reached 58.0 (much larger than those reported and commercial organic clay: 30 ) and able to be dispersible in organic solvents such as toluene and ethanol. The modified organic clay possessed critical micelle concentration (cmc) in toluene/water and effectively lowered the interfacial tension to 1.5 dyne/cm. (The origin interfacial tension between toluene/water is 36.0 dyne/cm) Besides, a thin film was obtained in toluene/water inter-phase. The film has mechanical properties and uniform crystal array clearly observed by SEM.
In part three, the epoxy/clay nanocomposites were prepared. With loading the organophilc clay in epoxy polymer matrix, the layer silicates were completely exfoliated in the epoxy polymer matrix. With 10 wt% organoclay loading, the improved tensile strength (2.8 versus 0.3 MPa), flexural modulus (9.5 versus 3.0 Mpa), and elongation (81.2 versus 25.3 %) relative to pristine epoxy were obtained. Due to the silicate dispersion in epoxy matrix, the amount of solvent soaked in polymer was decreased in comparing with pure epoxy.
In summary, the highly organophilic and large basal-spacing clay are surfactants. The organophilic clay can be blended with a wide spectrum of polymers to prepare polymer/clay nanocomposites which have better mechanical properties and thermal stability.

摘要
本研究主要在於製備有機/無機混成材料,無機材料為具有天然層狀結構之蒙脫土。由於蒙脫土具有高的親水性,而與一般的高分子材料或有機溶劑均不相容,因此如何改質蒙脫土之表面極性與提高蒙脫土之層間距以增加有機材料與無機材料之相容性為本論文之重點。以下將分為三部份論述:
(1)以聚醚胺類接枝馬來酸酐共聚聚丙烯高分子(maleic polypropylene),利用此梳狀高分子之側鏈帶有末端胺基,經酸化後成為四級胺鹽,與蒙脫土之層間陽離子進行陽離子交換反應,而將聚醚鏈段導入無機層材中,製備得聚丙烯/黏土複合材料。經由X-ray繞射證實聚醚鏈段插層進入黏土層中並導致黏土之層間距提高(12.4Å至19.6Å)。此一有機/無機複合材料除了可與聚丙烯摻混製備聚丙烯/黏土奈米複合材料外,更具備特殊之界面性質。
(2)以不同分子量之聚丙烯醚(polyoxypropylene)鏈段插層黏土層間,經實驗證實黏土之層間距高度與插層劑分子量成正比關係。以分子量2000以上之聚丙烯醚改質黏土,可使黏土之層間距達58.0 Å以上 (一般文獻報導與商業化之有機黏土最高僅達30 Å),此一系列有機黏土更可分散於有機溶劑中,如甲苯、乙醇;將有效提高黏土在高分子融熔混摻或單體聚合中達完全脫層(exfoliate)。此外,所製備之有機黏土除黏土本身之極性結構外亦同時具備非極性結構,因此具有界面活性劑之特質。實驗結果發現此有機黏土除具有臨界微胞濃度外,更能有效降低甲苯與水的界面張力(由原始之36.0 dyne/cm降至1.5 dyne/cm);其在界面處更可形成薄膜,此薄膜不僅具有強度且在SEM觀察下,可見規則之結晶排列,並具偏光性質。
(3)在環氧樹脂硬化反應中加入所製備之有機黏土,經實驗推論黏土於環氧樹脂基材中已達脫層型之奈米級分散。經機械性質測試之結果證實黏土之分散確實能有效提昇環氧樹脂之機械性質;在有機黏土10 wt%添加下,材料之抗張強度提高9倍、抗繞曲模數提昇3倍、最大伸長量提高3.2倍。此外,此複合材料之玻璃轉移溫度(Tg)隨黏土之添加而提高;在TGA測試中,更可證實黏土層狀結構之分散確實可提高材料之熱穩定性。
綜合以上論述,所製備得之高有機性與高層間距之有機黏土除了具有特殊界面性質外,更可與高分子基材摻混製備奈米級分散之複合材料,以提昇材料之機械性質與耐熱性,使其具備更多元與廣泛的使用性。
URI: http://hdl.handle.net/11455/3327
Appears in Collections:化學工程學系所

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