Complexes of octadecyltrimethylammonium polyacrylate: properties in solution, gel and solid forms

Abstract

A polymer-surfactant complex (OTAPA) was prepared by titration of aqueous poly(sodium acrylate) with stoichiometric amounts of octadecyltrimethylammonium chloride. The resulting product is not water-soluble and does not dissolve in most polar and nonpolar, liquids. OTAPA has peculiar thermal behaviour and interesting structural properties. It has a high melting temperature and decomposes around 350 degreesC. According to preliminary X-ray findings, the complex is formed by an arrangement of alkyl chains around the polymer skeleton, packed into a layered structure. The complex forms an elastic gel in ethylene glycol, and, to a much lesser extent, in glycerol or tetrahydrofuran, but is hardly water-soluble. Indeed, the occurrence of micelle-assisted dissolution and the precipitation of OTAPA from such mixtures, upon dilution with water, have been observed. Applications of OTAPA as a hydrophobic modifier of surfaces can be considered

Polymer–surfactant and protein–surfactant interactions

“…At the same time, dispersing them in proper solvents favors the formation of amorphous plastic materials showing significant elastic properties [80].…”

“…In systems containing hexadecyltrimethylammonium polyacrylate complexes, PACTA, Fig. 6, surfactant in excess favors complex redissolution, to form supercolloids [80].…”

Rheological properties of protein–surfactant based gels

“…The accuracy on transition temperatures, T tr , is to ±0.1 • C; errors on the related enthalpies, H , are to ±1.0%. Details on the apparatus setup and on the measuring procedures are reported elsewhere [27].…”

Elasticity of Dispersions Based on Carbon Nanotubes Dissolved in a Lyotropic Nematic Solvent

“…Scanning electron microscopy was run by a SEM-LEO1450VP unit, equipped with an INCA300 EDS facility. , Dispersions were stratified onto 20 × 20 mm glass slides, heated at 50 ° C, properly dried, and transferred in the SEM chamber.…”