Preparation of Redispersible Emulsion Powder by Spray Drying

Abstract

There is a large demand for redispersible emulsion powder in various industrial applications because of its unique features. However, the use of this novel material is hindered by the complex synthesis processing technology and consequently high cost. In this paper, a simple preparation method for building material used redispersable emulsion powder is proposed. This method mainly includes two steps, a core-shell emulsion polymerization reaction and a following spray drying. In the emulsion polymerization step, AVE and MMA were used as seed emulsion and shell monomer for the core-shell polymeric structure. The influences of various factors such as monomer ratio, emulsifier and initiator as well as the feed method on particle configuration of core-shell structure polymeric emulsion were investigated. The suitable conditions to prepare the emulsion powder are: SDS as the emulsifier, KPS as the initiator, 40°C of the reaction temperature, and 2:1 of the ratio of the core to shell with a semi-continuous process. The successful fabrication of core-shell bedded structure was verified with scanning electron microscope. In the following spray drying step, the optimized operation parameters are: 150°C of the inlet air temperature, 75°C of the outlet temperature, and 10.5 ml/min of the feed flow rate. Under optimized operating conditions, coated milk white emulsion powders with uniform size, good fluidity, and good membrane performance were obtained.