Study On Preparation Of Redispersible Emulsion Powder

Chemical building materials prepared by organic polymers materials and its compositematerials are usually used in building engineering construction. The materials havecharacteristics of low consumption, low density, good corrosion resistance, heat insulationand High Decorative. With the development of city building construction and constructionindustry, more and more new building materials appear continuously, and chemical buildingmaterials has become the foundational industry of our society.AVE is a common cement mortar additive, but it's inconvenient and costly to store andtransport, and the ratio of AVE and cement mortar is uncertain. This problem can be easilysolved by means of preparing emulsion.This paper studied the method of preparation of redispersable emulsion powder by spraydrying, the purpose is in search of a practical and useful processing technology.First, AVE and MMA were applied as seed emulsion and shell monomer in thecore-shell emulsion polymerization. The effect of monomer ratio, emulsifier and initiatorchoice and the feed method were investigated. Then taking inlet air temperature and feedspeed as reference factor during the spray-drying process. Through experiment, the goodcoated milk white emulsion powder with good fluidity, evenly-distributed average diameter of100μm, and good membrane performance was achieved. The suitable conditions to preparethe emulsion powder were experimentally found as follows: the ratio of the core to shell was2:1, the feed method was semi-continuous process, the content of emulsifier is 2%, thecontent of initiator is 3%, the inlet air temperature was 150℃, and feed speed was 10.5ml/min.Secondly, AVE and BA, VA were applied as seed emulsion and shell monomer in thecore-shell emulsion polymerization. The same technology is used in this experiment. Throughexperiment, the optimal technological parameters are given: the ratio of the core to shell was1.25:1, the feed method was semi-continuous process, the content of emulsifier is 6%, thecontent of initiator is 4%, the inlet air temperature was 150℃, and the content of talcumpowder is 15%. And the MFT of the powder prepared through this experiment is 10℃.In conclusion, emulsion powder prepared by spray drying can be used in building mortar,especially prepared by BA, VA which are used as shell monomers.