Structure-Property of Pigmented Polypropylene Nanocomposites Incorporating Organo-Layered Silicates

摘要

Nanocomposites were produced from isotactic polypropylene (iPP) incorporating synthetic organo-layered silicate clay through melt compounding process. Compatibiliser was admixed to promote exfoliation and dispersion of the multilayered clay crystallites. The effect of pigmentation on the structure-property of the nanocomposites (and vice versa) was studied using an organic phthalocyanine blue pigment. No difference in colour appearance was noted between the virgin and clay-incorporated, pigmented samples through visual inspection and CIELAB measurement. Wide-angle X-ray diffraction (WAXD) analysis of the nanocomposite samples suggested a mixture of intercalated and exfoliated clay structure, and the polymorphism of the PP was not affected by either the clay or the pigment. The mechanical properties of the materials were highly dependent on the clay to pigment ratio. Overall, a two to one ratio yielded optimum improvement in the tensile, flexural and impact performance, while increasing pigment loading had an adverse effect the on impact strength. The addition of pigment had no significant effect on the polymer crystallinity. The crystallinity decreased for the unpigmented nanocomposites and increased for the pigmented nanocomposites. Both the pigment and clay considerably reduced the crystallisation temperature of the polymer.