PP/clay composites with different dispersions

namely

exfoliated dispersion

intercalated dispersion and agglomerates and particle-like dispersion

were prepared by direct melt intercalation or compounding. The effect of clay dispersion on the crystallization and morphology of PP was investigated via PLM

SAXS and DSC. Experimental results show that exfoliated clay layers are much more efficient than intercalated clay and agglomerates of clay in serving as nucleation agent due to the nano-scale dispersion of clay

resulting in a dramatic decrease in crystal size (lamellar thickness and spherulites) and an increase of crystallization temperature and crystallization rate. On the other hand

a decrease of melting temperature and crystallinity was also observed in PP/clay composites with exfoliated dispersion

due to the strong interaction between PP and clay. Compared with exfoliated clay layers

the intercalated clay layers have a less important effect on the crystallization and crystal morphology. No effect is seen for samples with agglomerates and particle-like dispersion

in regard to melting temperature

crystallization temperature

crystal thickness and crystallinity.