Preparation Of Microencapsulated Phase Change Materials

How to package solid/liquid Phase Change Material is the key factor for its commercial application. The micro-encapsulation technology, including the core and the shell materials,different significant synthesize process, various characterization methods are studied in this thesis.The microencapsulated phase change materials were prepared using dodecanol as the core, urea-formaldehyde resin as the shell, and SMA (styrene-maleic anhydride) resin as the surfactant by in-situ po1ymerization. The influence of molecular-weight of SMA resin on microencapsulated technology were that molecular-weight of 40,000 was of best effect. Different properties of the microencapsulated phase change materials were characterized by FT-IR, DSC, Laser Particle Size Analyzer, OM and SEM. When the shell was urea-formaldehyde resin combine with melmac, the yield of MPCM increased from 50 percent to above 90 percent.With the shell of polyurea resin and the core of butyl stearate, microencapsulated phase change materials were prepared by interfacial polymerization for thermal energy storage application. Different kinds of surfactants, such as polyoxyethyleneoctylphenyl-10 (OP-10) and sodium alginate, and its dosage were investigated in order to clear the emulsify effect. When the surfactant is OP-10, 0.5 gram, it will be the best effect to microencapsulation. The grain size of MPCM is equality and its distribution is narrow. Optical microphotograph and SEM photograph of microcapsules appear homogeneous particles. The results of DSC showed that the melting point and heat of fusion of microencapsulated butyl stearate was 29.37℃and 85.92kJ/kg when the m (core) vs. m (shell) equaled 3:1. The heat capability was the best than other m (core) vs. m (shell). They can remain constant after suffering 400 cooling-heating cycles. The effect of different dosage of the surfactant was analyzed by the dry weight of microcapsule. The penetrability of the microcapsule was characterized well in water, toluene and ethanol by 721 spectrophometer.Polyurethane microcapsules containing phase change materials were prepared by interfacial polymerization in an emulsion system. Toluene-2, 4-diisocyanate (TDI)...