Zinc Stearate Production by Precipitation and Fusion Processes

In this study, the production of ZnSt2 using sodium stearate and zinc sulfate in a precipitation process, and stearic acid and zinc oxide in a fusion process, was investigated with regard to product purity. In the fusion process, an increase in mixing rate decreased the induction time occurring at the beginning of the reaction. While the melting point of the zinc stearate prepared by the precipitation process was found to be about 122 °C by optical microscopy, it was slightly lower than 122 °C for zinc stearate produced by the fusion process. Differential scanning calorimetry (DSC) indicated onset of melting at 120 °C and 118 °C for samples prepared by precipitation and fusion processes, respectively. Characteristic peaks of ZnSt2 were present in XRD patterns of the products obtained by both processes. From SEM micrographs, it was seen that zinc stearate obtained by both processes had lamellar structure.