Preparation And Properties Of Silica Aerogel Modified Polymer Composite

Silica aerogel(SA)is one of the most used inorganic nanomaterials.Due to its three-dimensional network structure,high specific surface area,porosity and low thermal conductivity,it has been widely used in vehicles,construction and military fields.However,as a nano-powder material,silica aerogel has shortcomings such as high brittleness,easy crushing and easy destruction of the three-dimensional framework,which limits its application.By silica aerogel with polymer material,the three-dimensional nano-skeleton structure is introduced into the polymer matrix,which can solve the problem that the structure of silica aerogel is easily destroyed;At the same time,silica gas as a filler,silica aerogel can improve the mechanical properties of the polymer matrix,enhance its thermal insulation and solvent resistance,etc..The specific research content of this paper is as follows:1.Silica aerogel(SA)and fumed silica(FS)were added to liquid silicone rubber(SR)by physical blending to prepare SA/SR and FS/SR composites.The composite materials were characterized by thermal rubber processing analyzer(RPA),weight loss analysis(TGA)and tensile testing.The results show that compared to FS,SA improves the mechanical properties of SR more significantly;As the content of SA increases,the mechanical properties of the composite show a trend of first improving and then decreasing.When the addition amount is8%SA,the lifting effect is the best.The tensile strength of the 8%SA/SR composite is1.74 MPa,which is 569% higher than pure SR,and the storage modulus is 496% higher than pure silicone rubber.2.Using a physical blending method,hydrophobic silica aerogel is added as a filler to polysulfide rubber(PSR)to prepare SA/PSR composites.Through testing and analysis,it is found that SA can improve the mechanical properties of the composite,and the best filler ratio is 3%SA.The elongation at break of the 3% SA/PSR composite is 539.4%,which is 207%higher than pure PSR.The thesis also conducted research on the thermal conductivity,solvent resistance and thermal stability of composite materials.3.Polylactic acid porous microspheres(PLAm)and silica aerogel composite porous microspheres(SA/PLAm)were prepared by thermally induced phase separation.SA,PLAm and SA/PLAm were then filled into the heat-not-burn cigarette filter rods.After testing the suction resistance of the rods,the gas phase temperature analysis and the total particulate matter(TPM)removal rate of the smoke,it is found that the addition of SA,PLAm and SA/PLAm will increase the smoking resistance of cigarettes,but can reduce the smoke temperature,and the cooling effect of SA/PLAm is the most significant.The average smoke temperature per puff of the composite cigarette filled with 0.033 g SA/PLAm is reduced above20?.The removal efficiency of SA/PLAm for TPM can reach up to 0.965g/g,which is 201%higher than the traditional cellulose diacetate tow filter rod.