Effects of Fillers on Crystallinity

DSC of expanded graphite-reinforced, high-density polyethylene (HDPE) indicated that the fillers acted as nucleating agents to induce the crystallisation of HDPE in the 

Cebe and Rimt [56] used DSC to investigate the effect of inclusion size, shape and filler surface treatment with stearic acid on the crystallinity and gas permeability of HDPE composites filled with micron sized calcite or nanosized calcium carbonate or clay. It was foimd that spherical inclusions had no effect on gas permeability whereas the plate-like inclusions reduced gas permeability and that neither the calcium carbonate nor the clay nucleated the crystallisation of HDPE imder slow cooling conditions. 

Other filler studies include the effect of lignin particles in poly-3-hydroxy butyrate [57], PS-clay composites [58], nanosilicon particles in polyethylene-polypropylene blends [59], montmorillonitrite in polyethylene oxide [60] and starch filled polypropylene [61]. 

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