本研究係選用幾種改質劑改質囊脫石(Nontronite),再將此改質好之有機黏土(Organoclay)以混摻或反應方式製備PU/Organoclay 奈米複合材料。所製備之材料以XRD及TEM測量有機黏土在PU奈米複合材料中分佈之形態;以TGA及DSC測量其熱性質;以萬能拉力機測量其拉伸性質,並以CV測試其防腐蝕特性。其結果顯示,在製備PU奈米複合材料上,以反應型有機黏土比混摻型之分散效果更好,較容易達到片狀剝離(Exfoliation) 的效果,且性質也比混摻型佳。此類材料熱穩定性最大可以提高到49℃,而第二段最大裂解溫度更上昇了55℃,且由於PU之高分子鏈可與反應型有機黏土生成強而有力的鍵結,只要很少的添加量即可使拉伸性質提昇一、二倍,另外其腐蝕電位也較塗布PU之試片高出334 mV,且隨著添加比例遞增而呈上昇趨勢。
The organoclays were then used to prepare two aliphatic and two reactive aliphatic ammoniom salts were used as swelling agent to treat Na+-Nontronite to form the corresponding organoclays through ion-exchage reaction. Two series of elastomeric polyurethane/organoclay nanocomposites based on polypropylene glycol (PPG), 1,4-butanediol (1,4-BD), and methylene diphenyl diisocyanante (MDI) by the solution blending and reactive polymerization techniques. The results of wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM) studies showed that the inorganic monolayers of the organoclays were dispersal and intercalated or exfoliated structure. The glass transition temperature (Tg), thermal stabilities, and degradation temperature of the PU film were significantly increased in the presence of a small amount of organoclay. In particular compared to that for the pristine polyurethane, a 49℃ increase in the thermal degradation temperature (T5%), 55℃ increase in the maximum degradation temperature (Tmax) , a three-fold increase in the tensile strength and a two-fold increase in the elongatioin were obtained for the nanocomposite containing 7 wt% reactive organoclay. In addition, the polyurethane /reactive organoclay nanocomposites were found to exhibit much better corrosion protection over those of the polyurethane/blending organoclay nanocomposites.