Composites based on poly(vinyl chloride) and organically modified clay

Abstract

Composites based on native and chemically modified clay have been prepared via stir-solution intercalation method in poly(vinyl chloride) (PVC) matrix using dimethyl sulphoxide as a solvent and ethylene glycol as a plasticizer. The composite structures based on PVC-native clay (control) and PVC-organoclay were characterized using scanning electron microscopy and FT-IR spectroscopy. The results indicated that the modified clay particles were well intercalated and homogenously dispersed in the PVC matrix. As a result, exfoliated PVC-organoclay composite were formed. The success of modification was revealed by FT-IR results, as it confirmed the formation of CO, -COO-, CH3 and -C-CH3. The formation of hydrogen bonds between the solvent molecules (dimethyl sulfoxide) and the inner surface hydroxyl groups of clay was evidenced by the appearance of hydrogen bonds. The elemental analysis of clay samples made by EDX indicated the presence of radon, a radioactive element in clay samples up to 52 % of the total concentration of elements present in the clay sample. Biodegradation studies showed that microbes were able to biodegrade composites, with high activity recorded at dump site. Absorption kinetics of composites showed that organoclay-PVC composites were resistant to water, acid and base solutions compared to control samples based on immersion time for the test. This study demonstrated that vinegar is useful for the chemical modification of clay for enhanced surface interaction with PVC and the improvement of barrier properties.