Enhancing inflammability properties of organic based microencapsulated phase change materials used in building consruction materials

Buildings is one of the sectors with highest energy demand. Thermal energy storage systems for buildings have been developed to increase energy efficiency in buildings. Latent heat storage in Phase Change Materials (PCM) is the most common one. Paraffinic PCMs with suitable thermal properties are preferred. However, high flammability is a drawback. The purpose of this study is to improve inflammability properties of organic PCMs. In the experimental work carried out, paraffin as PCM is microencapsulated with polystyrene shell using emulsion polymerization. With a new approach flame retardants are added to micro-encapsulated PCM (mPCM) during polymerization. Ortho phosphoric acid (OFA) and pentaerythritol were applied as fire retardants. Characterization of the synthesis products were done by TGA, DSC, FT-IR, SEM analysis and flammability properties were determined by calorific value, non-combustibility test and single flame source test. Results show that flame retardants improve the inflammability properties of mPCMs in powdered form. With the second method of soaking mPCMs in OFA solution calorific value has been decreased by 30%. Fire safety analysis carried out with concrete samples including mPCMs with flame retardants, the best result was obtained for OFA90. It was determined that inflammability properties of organic mPCMs can be enhanced by adding flame retardants during microencapsulation and these materials can be used safely in buildings