Influence of the polymeric additives on the process of calcium sulfatedihydrate crystallization

Abstract

The research is aimed to the clarification of the calcium sulfatedihydrate crystals growth and formation of in the presence of the different polymers based functional additives. The calcium sulfatedihydrate crystals have been synthesized both in the pure form and with the additives. The additives have included a super plasticizer based on a sulfonated melamine-formaldehyde resin (SMF), a methylcellulose (MC) and a redispersible polymer powder based on vinyl acetate, ethylene and vinyl chloride copolymers (VAEVC). The X-ray analysis and the electron microscopy have been applied to identify an influence of the polymer additives over the configuration and size of the calcium sulphate dihydrate crystals. The structural and strength characteristics of the gypsum materials have been also investigated.