PP/clay nanocomposites: Effect of clay treatment on morphology and dynamic mechanical properties

Abstract

ABSTRACT:The morphology and properties of polypropylene (PP)/clay nanocomposites are described. The melt intercalation of organophilic clay was carried out with a single-screw extruder. The effects of two kinds of treatments of clay are discussed. Maleic anhydride (MAH)-grafted PP was used as a compatibilizer. The expansion of the intergallery distance of the clay was governed by the interaction between the clay treatment and the compatibilizer. In one case, the composites exhibited significantly reduced intensities of diffraction peaks, suggesting partial exfoliation of the clay layers, whereas for the second clay sample, expansion of the gallery height was noted. The mechanical properties of the PP/clay composites showed significant enhancement in their mechanical and thermal properties. About a 35% increase in the tensile modulus and about a 10% increase in the tensile strength were observed. The thermal degradation temperature increased from 270 to about 400°C as a result of the incorporation of clay, and the extent depended on the dispersion of clay in the composite. The most interesting outcome of this study was the changes in morphology for PP/clay composites, which are reported here for the first time. An optical microscopic study revealed that the PP/clay composites could be crystallized at higher temperatures than pure PP and that the morphology was remarkably altered because of the presence of layers of clay.

Effect of clay types on the processing and properties of polypropylene nanocomposites

“…Many studies have shown a nucleating effect of nanoclay for different polymers [16][17][18]. This effect can be used to enhance the mechanical and thermal properties of the polymer.…”

Polymer Nanocomposites: Synthesis, Microstructure, and Properties

“…The presence of tactoids, owing to a poor dispersion of the fi ller, was also reported to cause a decrease in spherulite size [34] . Kodgire et al . reported that, in the presence of clay, PP showed an advanced crystallization and a fi brous morphology rather than the usual spherulite behavior [35] . Similarly, a decrease in crystallinity and an increase in nucleus density was observed, owing to a nucleation effect of the clay platelets [36,37] .…”

Particulate Fillers in Thermoplastics

“…The very strong nucleating effect of talc in PP was proved many times [64,65]. Similarly to talc, layered silicates, and especially montmorillonite (MMT), were shown to nucleate polypropylene quite strongly [66][67][68][69][70]. The influence of other fillers and reinforcements is not so clear.…”