Preparation And Characterization Of Paraffin/St-DVB Microencapsulation And Paraffin Aggregation

In recent years, thermal energy storage systems can provide the potential to attain energy savings, which reduce the environmental impact related to energy use. Phase changed materials(PCMs) which can absorb or release large amounts of heat during their phase transition are ―latent‖ energy storage materials. However, leakage of the melted PCMs during the phase change process and reactivity with the outside environment have limited their application. This paper adopts two methods to improve leakage of the melted PCMs. Firstly, encapsulation of PCMs can overcome the above problems effectively. Secondly, the principles of the preparation of the grease have been taken example. Using thickeners viscosify paraffin and make its formation semi-fluid.The microencapsules of paraffin melting point at 54℃as a novel phase change material(PCM) using styrene(St)-divinybenzene(DVB) co-polymer as shell is prepared by suspension-like polymerization. The surface morphologies, particle size distributions, phase change properties,and thermal stabilities of the microcapsules were investigated using FTIR, SEM, Laser Particle Size Analyzer, DSC, TGA, respectively. A series of different partical sizes and morphologies of paraffin / polystyrene-divinylbenzene microcapsules were prepared by using different kind and amount dispersing agent. The best dosage of polystyrene/divinylbenzene was 8:1.When the cross-linker DVB was added after 2h of polymerization, the obtained P(St-DVB) microencapsules exhibited good sphericity meanwhile display little influence on the phase change properties and thermal stabilities of the microcapsules. The amount of 54 # paraffin encapsulated was 69.2% when the ratio of paraffin / styrene was 5:2. The temperature of thermal resistant of microencapsules was approximately 230℃, which was higher 30℃ than that of pure 54 paraffin.Using lithium base, aluminum base and urea based three kinds of thickeners thickening on paraffin wax. The surface morphologies and dropping point were investigated using SEM and drop point meter, respectively. Results indicated that using urea based thickeners thickening on paraffin wax was best effect.