Preparation And Properties Of Sandwich Foam Composite Materials Reinforced By SiC Nanoparticles

In order to make the performance of foam materials biomass based can rival with pure petroleum-based products, and improve its mechanics, acoustics, thermal properties, it is widely used in construction, packaging and other fields as a lightweight, sound-absorbing, insulation material. The project studies the preparation processes, performance and the relevant basic theory of sandwich foam materials, using salix powder as raw materials, the combination of polymer foaming technology and man-made panels technology.The results are as follows:(1) The liquefaction process to obtain the best conditions, catalyst:5%, liquid ratio:5:1,temperature:160℃, liquefaction time:60min, material diameter>40mesh. Under the optimum process conditions, residue rate is0.764%, physical and chemical properties of liquefied products meet the requirements of preparation of polyurethane foam, Moreover, Salix powder and liquefaction product were analyzed with FTIR, the results showed that Salix powder via liquefaction, the molecular structure of Salix powder take significant change, liquefaction product have more group than before reaction.(2) we got the better foaming technology condition:liquid ratio:5:1, the dosage of isocyanate is120%, the optimum mass fraction of distilled water is1%, the optimum mass fraction of catalyst is6%, the optimum mass fraction of CaCO3is4%; Under this condition, the density of foam materials is0.054g/cm3, the bending strength is4.575MPa, the elastic modulus is144.7GPa, the internal bond strength is0.228MPa.(3) the mass fraction of SiC nanoparticles is1.5%and ultrasonic time is20minutes, the mechanical performance of the sandwich foam composite materials are significantly improved, Under this condition the density of foam materials is0.072g/cm3; it conform to the requirements of polyurethane foam, the average sound absorption coefficient of the foaming materials and sandwich foam composite materials is above0.5, belongs to the strong absorption material, and after joining SiC nanoparticles, absorption coefficient increased significantly; the SiC nanoparticles has few effects on its thermal insulation performance, the average coefficient of thermal conductivity of sandwich materials are under0.13(W/(m· K)), it will provide a sound-absorbing, insulation and good mechanical properties of green environmental protection of lightweight materials in the future.(4) Salix foaming materials appeared on the FTIR of N-H、-CH2、C-O-C and other functional groups which are the characteristic absorption peak of carbamate that it is polyurethane skeleton structure, other characteristic absorption peak appear within600-1100-cm-1band after joining SiC nanoparticles in the FTIR; Foaming material of SEM analysis:after joining SiC nanoparticles, the bubble hole of foaming material is smaller and more uniform, SiC nanoparticles are uniformly dispersed in the bubble hole wall, enhance its mechanical properties;...