Abstract
One of promising fillers for polymers, sodium montmorillonite modified by dioctadecyldimethylammonium bromide (DODAB), has been studied by Raman spectroscopy, X-ray analysis, and differential scanning calorimetry (DSC). It has been shown that an increase in the DODAB content enlarges the height of a clay interlayer space through filling the clay interlayer galleries with DODAB molecules. According to both Raman and DSC data, DODAB molecules grafted to the clay can be in three different phase states depending on the modifier content. At a low DODAB content, its molecules are separated and contain a significant amount of gauche-conformers in methylene chains. At a medium content, the DODAB molecules form clusters, and the amount of trans-conformers in the DODAB methylene chains considerably increases. At a high DODAB content, its molecules are straightened and form a 2D ordered structure with either hexagonal or triclinic symmetry.