Preparation of High Security N-Octadecane MicroPCMs by In Situ Polymerization

N-octadecane microcapsules phase change materials(MicroPCMs) were prepared by thein-situ polymerization method using n-octadecane as core materials, urea-formaldehyde resin as shellmaterials respectively. Melamine–formaldehyde (MF) microcapsules have been widely applied inmany functional materials. Free formaldehyde content are important safetyfactor determining the survival of the microcapsules during fabrication andapplication. In this study, the formaldehyde content of n-octadecane MicroPCMs decrease to 0.35g/Kg which even lower than the standard EuropeanE3 level (0.6g/Kg) through regulation the synthesis conditions such as urea/formaldehyderatio of weight from 1:2 to 1:1.6, urea batch feeding three times ,curing endpH value to 1.0-1.5,reactive time extend to 4h,addition melamine and PVA.