Study of the orientation and the degree of exfoliation of nanoparticles in poly(ethylene-vinyl acetate) nanocomposites

Nanocomposites formed from organically modified montmorillonite and poly(ethylene-co-vinyl acetate) were studied by X-ray diffraction techniques. Wide- and small-angle X-ray scattering intensities (SAXS and WAXS) were recorded by transmission mode on test bars cut from compression-molded plaques tilted by different angles with respect to the plane of the plaque. The height of the Bragg peaks characteristic of intercalated particles reduced to the baseline at tilt angles greater than 30°. Guinier analysis of the SAXS characteristic of particle scattering showed a radius of gyration of 0.69 nm and the scattering intensity was slightly dependent on the tilt angle. Recording of WAXS in the usual (i.e., in reflective) mode enhanced the effect of the structural features of the surface area and showed much higher degree of intercalation and particle size of the scattering particles than that in transmission mode.