Preparation And Properties Of Energy Storage Poplar Inorganic Composites

With the rapid development of Chinese national economy and the increasing demand for buildings,the ratio of building energy consumption and total social energy consumption has reached about 40%,which has a huge burden on the development of the national economy.Building energy conservation work is comprehensively and deeply promoted,and the demand for different forms of thermal insulation system is increasingly urgent.The development,promotion and application of building thermal insulation materials will promote the healthy development of building energy conservation work in China,which has significant social,technical and economic benefits.Inorganic thermal insulation material expanded perlite has the advantages of excellent thermal insulation performance,low cost,environment-friendly and so on.Phase change material paraffin can control the temperature,which can be used in building materials to create a comfortable living environment.Using these two materials to prepare composite thermal insulation materials is expected to achieve the purpose of building energy saving with high quality and high efficiency.In this paper,from the perspective of building energy conservation,expanded perlite(EP)was used as thermal insulation filler,paraffin as phase change material,polyvinyl alcohol(PVA)as film-forming agent,combined with renewable resources poplar,and environmental friendly and non-toxic inorganic adhesive was used to prepare inorganic thermal insulation composite.The mechanical properties,thermal properties and flame retardancy of the composite were studied in detail,and its application in building energy conservation was investigated The feasibility of thermal insulation materials.The main conclusions are as follows:(1)The influence of expanded perlite mesh on the main properties(mechanical properties,thermal properties,flame retardancy)of inorganic composites was studied by single factor experiment.The results show that the flexural strength,elastic modulus and softening coefficient of the composites increase with the increase of EP mesh number,and the 24 h water absorption thickness expansion rate decreases.The frost resistance is proportional to the mesh number.When the EP mesh is 60-70 mesh,the thermal conductivity of the composite is 0.0958 W/(m·K).The ignition time of EP/poplar inorganic composite was 465 s.(2)In order to further improve the thermal insulation performance of inorganic composite and enhance its building energy saving effect,based on EP/poplar inorganic composite,paraffin was used as phase change material to fill the rich pores of EP.Through single factor experiment,the influence of EP/paraffin setting phase change material on the performance of inorganic composite was explored.The results show that the paraffin and EP are only physically blended,and the chemical properties of the shape stabilized phase change materials are stable.In the process of inorganic composite preparation,EP damage leads to paraffin leakage,which has an impact on the properties of the composite.With the increase of EP/paraffin phase change material content,the MOR,MOE,24hts of the composites first decrease and then increase,while the softening coefficient first increases and then decreases.When the content of EP/paraffin phase change material is 3wt%,the mechanical properties of the composites are the best.The thermal conductivity of the composites can reach 0.113 w/(m·K)when the content is 7 wt%.The phase transition temperature Te of the composite is 32.4℃,which can buffer the heat transfer inside and outside the room when it is used as wall material.The composites show good thermal stability within 100℃,and their flame retardancy can meet the national standard of building materials.Magnesium cement gives the materials excellent flame retardancy and smoke suppression performance.(3)In order to solve the problem of paraffin leakage in Experiment 2,phase change microcapsules were prepared by coating EP/paraffin shape stabilized phase change material with PVA as film-forming material.The influence of the amount of microcapsules on the properties of inorganic composites was investigated by single factor test.The results show that the components of phase change microcapsules are simple physical blending without chemical reaction,PVA can effectively protect EP from crushing and prevent paraffin leakage,and the chemical properties of phase change microcapsules are stable.The MOR,MOE and softening coefficient of the composites increase with the increase of the content of phase change microcapsules,while the 24hts decreases.When the content of phase change microcapsules is 3 wt%,the best mechanical properties of the composites are 14.6 MPa,2573 MPa,70.2%and 4.8%respectively.The addition of phase change microcapsules increases the porosity of inorganic composites,and the greater the content,the worse the frost resistance.The thermal conductivity of the composite decreases with the increase of phase change microcapsule content,and the minimum is 0.143 W/(m·K)when the content is 7 wt%.The latent heat of the composites increases with the addition of microcapsules,and the maximum is 192.3 J/g,which confirms the variation of thermal conductivity of the composites.The phase transition temperature of the composite is 27.3℃,which indicates that the adjustable temperature of the composite is about 27.3℃,which is close to the suitable temperature for human body and indoor living.The results show that the flame retardancy of the composites with different contents can meet the requirements of the national standard,and have good flame retardancy and smoke suppression performance.