Surface Modification of Bentonites. Ⅱ. Modification of Montmorillonite with Cationic Poly(ethylene oxides)

摘要

Surface modification of clay minerals has become increasingly im- portant for optimizing the practical application of bentonites, kaolins, and clays. We describe the reaction of montmorillonite, an impor- tant mineral in bentonites, with cationic poly(ethylene oxides). Poly(ethylene oxides), PEOs, with molecular masses between 1550 and 35000, were modified by substituting the OH end groups by bromine, then replacing Br by trimethylammonium (TMA) groups. Mono-endcapped PEOs displaced external and internal exchangeable nomethyl ethers. These cationic PEOs were strongly adsorbed by montmorillonite and bound by cation exchange.