Synthesis of stable W/O microemulsions of a hybrid grafted copolymer using a new inorganic cationic backbone within a unique “polyhedral cell”

Abstract

A novel graft copolymerization on an inorganic cationic backbone processing within polyhedral cell(s) (PHC) is discussed. This procedure can produce stabilized W/O (water in oil) PHC microemulsions of hybrid grafted acrylic type copolymers. Three water-soluble monomers acrylamide, sodium acrylate and dimethyldiallylammonium chloride were examined and all were proved to be successful. MgAl-LDH3 (MgAl-layered double hydroxide with Mg/Al = 3), an electropositive colloid, was first applied as an inorganic backbone for hybrid graft polymerization in this study. MgAl-LDH3 not only acted as a cationic functional backbone, but also stabilized the PHC system due to the electropositive repulsion force. The polymerization occurring within the PHC system could reduce the oil phase percentage of the emulsion, which potentially increases the stability of the final product. The polymerization was initiated by the backbone/ceric sulfate redox system and a variety of hybrid graft copolymers with MgAl-LDH3 as the backbone chain was synthesized. The influence of [monomer] and [MgAl-LDH3][Ce⁴⁺] were examined based on the obtained reaction kinetic data. The percentages of PHC under different F_d were determined by microscopy and the backbone structure was characterized by X-ray diffraction (XRD).