Exfoliation of smectite clays by branched polyamines consisting of multiple ionic sites |
| |
Authors: | Chih-Wei Chiu Wen-Tung Cheng |
| |
Institution: | a Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan b Department of Chemical Engineering, National Chung Hsing University, Taichung 40227, Taiwan |
| |
Abstract: | Exfoliation through an ionic exchange reaction of layered silicate clays, including synthetic fluorinated mica (Mica) and natural montmorillonite (MMT), were achieved by using polyvalent amine salts as the intercalating agents. The requisite polyamine was synthesized from the epoxy/amine coupling reaction, involving a trifunctional poly(oxypropylene)-triamine (ca. 440 g/mol Mw) and diglycidyl ether of bisphenol-A. The polyamine was a mixture of oligomeric adducts consisting of multiple amine functionalities and a branched backbone. Partial acidification by HCl addition generated a series of amine salts that affected the intercalation and the expansion of the silicate interlayer in the range of 15.2-60.0 Å XRD d spacing. At the specific acidified ratio (H+/amine = 1/3 equiv ratio), the polyamine salts rendered the clay’s layered structure into randomization. The result was confirmed by using XRD and transmission electronic microscopy (TEM). The hybrids of polyamines and Mica or MMT were blended into epoxy resins and cured into nanocomposites, which exhibited the improvements of thermal stability and hardness. |
| |
Keywords: | Intercalation Exfoliation Smectite clay Poly(oxypropylene)-amine |
本文献已被 ScienceDirect 等数据库收录! |
|