Papers by Author: Gabriel Rokicki

Abstract: This work presents results of research on compressive strength, microhardness, polymerization shrinkage and water sorption of some specially developed composite materials for dental fillings. The investigated powder fillers were divided into two groups: fluorine-based fillers, such as fluoridated glass, strontium fluoride, ytterbium fluoride and additives of improved mechanical characteristics such as nanosilica and polyethylene. The influence of fluoride ion source on the properties of the composite materials was evaluated. Tests were performed just after the material polymerization and, additionally, after seven, thirty and sixty days. Some small differences between composites were observed.

Abstract: The results of studies on the application of new water-dispersible binders such as poly(acrylic-styrene), poly(acrylic-allyl ether) for die and isostatic pressing and tape casting of Al2O3 ceramics are presented. The properties of these acrylic polymers were modified by insertion of selected amphiphilic macromonomers into the polymer chains. These amphiphilic macromonomers, due to the proper ratio of the hydrophilic to hydrophobic fragments, play the role of not only an internal plasticizer, but they also modify the adhesion of such binders to the ceramic powder particles. The influence of chemical structure of these copolymers on the properties of alumina ceramics is discussed. The investigations on properties of alumina ceramics obtained by gelcasting method using new water soluble acrylic monomers containing hydroxyl groups in their chemical structure as well as by direct coagulation casting method using polymeric flocculants are also presented and discussed.