Compacted nanosilica-talc /calcium carbonate polyacrylate composites prepared using accelerated sedimentation

The effectiveness of centrifugation as the compacting method in preparing high filler composites has been investigated. Different size and shape of fillers were used to ensure efficient filler space filling. In situ polymerization of bisphenol-A ethoxy diacrylate after centrifugating produced biomimetic composites with 74-86 % filler content. The filler space was efficiently filled by using a combination of nano and microsize fillers, especially in the nanosilica-CaCO₃ composite. The morphology of the composites indicates that the fillers were well dispersed and embedded in the polymer matrix. The etched surface of the nanosilica-talc composite reveals that the combination of talc and nanosilica formed a biomimetic composite that displayed an ordered brick-and-mortar nacre-like structure. The wide-angle X-ray diffraction patterns indicate the crystal structure of CaCO₃ and talc were maintained in the composite.