Preparation And Application Of The Flame Retardant And Paraffin Energy Storing Materials

With the rapid development of social economy and the rising of people’s living standards, people pursuit of the comfortable living enviroment is always accompanied by the increasing energy consumption, resulting in a series of problems of environment pollution etc. How to maintain the balance between human body comfort, energy saving, environmental protection has become a research hotspot in architectural design and energy-saving field. The use of phase change materials, which is the most effective way, has become the research focus of many scholars at home and abroad. At present, organic phase change materials were combustible, poor heat conductivity and oxidation. In addition, when the solid-liquid phase change materials happened the phase transition, the problem of liquid flowing would caused the pollution of the wall and reduced the heat storage properties of the materials. This paper took kaolin as raw materials, to prepare mesoporous materials by microwave synthesis method.Then with the mesoporous materials as carrier, paraffin as phase change materials, the paraffin/mesoporous composite phase change materials were synthesized successfully. Finally, adding it to the wall, the flame retardant paraffin phase change wallboard was prepared. First of all, precursor were prepared by kaolin through high-temperature calcination, acid leaching. Then the precursor was used to synthetize mesoporous material by microwave synthesis method. Through the orthogonal experiment, the specific surface area and pore volume were chosen as the evaluation index to study the impact on the pore structure by microwave heating temperature, heating time, CTAB concentration. The results showed that:the sequence of influence of mesoporous materials surface area was microwave time> microwave temperature> CTAB concentration. Microwave time had a significant effect on the surface area of the mesoporous materials. The order of the factors influencing mesoporous materials pore volume was microwave time> CTAB concentration> microwave temperature. Microwave time had a special effect and CTAB concentration had a certain effect on the pore volume of the mesoporous materials.The optimized technological conditions for the synthesis of mesoporous materials were that microwave time was3h, CTAB concentration was2%, microwave temperature was90℃.Secondly, the mesoporous materials were prepared under the optimized conditions, and were characterized by means of N2physical adsorption, SEM, TEM. The results showed that the materials obtained were mesoporous material with the average pore size of2.45nm. BET specific surface area was1122.5m2·g-1, and pore volume was1.059cm3·g-1. Mesoporous materials had the structure of thin layer, flake and polyporous.Then, paraffin/mesoporous composite phase change materials were synthesized successfully via vacuum adsorption with mesoporous materials as packaging materials, paraffin as phase change materials which had a melting point of59.5℃, phase change temperature was54.4℃, and phase change latent heat was238.1J·g-1. The composite material obtained was characterized and observed by FTIR, diffused-exudative circle method, N2physical adsorption, SEM and TEM, DSC. The results showed that:the optimal adsorption quantity of50%for paraffin. The composite materials’phase change temperature was56.9℃, phase change latent heat was75.20J·g-1. No liquid leakage after cycling heating. Phase change temperature and the phase change latent heat were unchanged basically. The composite material had good stability.Finally, with composite phase change materials obtained added to the metakaolin, phase change wallboard was prepared successfully. The thermal conductivity, flame retardance and heat insulation performance of the Wallboard were investigated. The results showed that:the heat conduction coefficient increased with the paraffin content increasing. When the paraffin content in the wall was50%, thermal conductivity coefficient was1.898W-(m.K)-1. At the same time, Phase change wallboard wasn’t combustible under90%oxygen concentration. Under the same environment and temperature, the higher paraffin content, the longer soaking time. The phase change wallboard had good insulation performance and flame retardant properties.