Study On The Preparation Method And Performance Of Flexible Thermal Insulation Composite Material

With the rapid development of the national defense industry and the national economy,thermal insulation materials have attracted more and more attention from scholars,and their applications in electronics,chemical,medical,food and other industries have gradually been widely used.At the same time,energy saving and environmental protection is a hot issue that people cannot avoid.This problem is ultimately due to the waste of energy in industry and life.Therefore,this leads to more demand and expectations for existing insulation materials.At present,the common domestic thermal insulation materials mainly include porous fibrous materials,organic polymer foamed materials and porous particle materials according to their internal structure.Among them,porous fibrous materials have low strength and thermal insulation performance is not particularly ideal,so that the application in the field of low thermal conductivity is limited;organic polymer foams have poor high temperature resistance,poor flame retardancy and long-term use will Disadvantages such as the emission of toxic substances also limit their application;porous particles with low thermal conductivity and high porosity are widely used in the field of high temperature insulation,but most of them are in a brittle state or difficult to be made into flexible materials.Combining the advantages and disadvantages of current thermal insulation materials,it is imperative to develop composite materials that combine the excellent performance of the above thermal insulation materials.In this paper,based on the existing insulation materials,different methods are used to prepare thermal insulation composite materials and study their thermal insulation and flexibility properties,and compare the advantages of various methods to prepare flexible and thermal insulation properties.Thermal insulation composite material.The main research contents and results of this topic are as follows:(1)Using polydimethylsiloxane(PDMS)as the matrix and expandable microspheres as the foaming agent,make expandable microspheres/PDMS flexible thermal insulation materials.The foaming process of expandable microspheres and the effects of the amount of expandable microspheres on the thermal insulation performance,flexibility and mechanical properties of expandable microspheres/PDMS flexible thermal insulation materials were studied.The research results show that obtaining the best foaming time of 10min and temperature of 120? is the best process condition for preparing composite insulation materials;when the proportion of expandable microspheres is 10%,expandable microspheres/PDMS The thermal insulation performance of the flexible thermal insulation material is better.At this time,the thermal conductivity at normal temperature is 0.1588 W/(m K),the hardness is 12.75 HA,and the tensile strength is 0.21 MPa.(2)Use microporous calcium silicate and aluminum silicate fiber to prepare microporous calcium silicate/aluminum silicate fiber composite flexible heat insulation material by vacuum suction filtration method.The ultrasonic dispersion technology for preparing composite materials and the insulation performance,hardness and flexibility of calcium silicate/aluminum silicate fiber composite insulation materials were studied.The research results show that the best dispersion slurry concentration of aluminum silicate fiber is 0.4%,the dispersion time is 6 min,and the concentration of dispersant is 0.6%;when the content of aluminum silicate fiber is 60%,microporous calcium silicate/silicic acid The overall performance of the aluminum fiber composite insulation material is better,the thermal conductivity is 0.0747W/(m·K),the hardness is 48HA,and the bending radius is 4mm.(3)The structural design model of flexible thermal insulation materials is proposed,and microporous calcium silicate microspheres/PDMS flexible thermal insulation materials are prepared,and the effects of calcium silicate morphology,adhesive configuration,and encapsulation layer structure on the properties of composite materials are studied.,Proved the feasibility of the model.The research results show that the thermal conductivity of the sample prepared according to the structural model is 0.0944W/(m·K),the tensile strength is 0.191MPa,the bending radius is 3.5mm,and the hardness is 30.93HA.The structural design improves the flexibility and thermal insulation performance of the composite material The experimental results are consistent with the model.Compared with the best sample of expandable microspheres/PDMS flexible thermal insulation material,the thermal insulation performance is improved by 83.2%and the flexibility is reduced by 58.7%,but this flexibility is sufficient for applications in many fields,while greatly improving its thermal insulation performance.Compared with the best sample of calcium silicate/aluminum silicate fiber composite insulation material,the thermal insulation performance is not very different,and the bending radius is reduced by 14.2%,the hardness is reduced by 55.24%,and the flexibility is significantly improved.This sample has better thermal insulation performance and flexibility,which expands the application range of thermal insulation materials.