Silicon dioxide hollow sphere/polymer composite heat insulating material and method for preparing same

Abstract

The invention relates to a silicon dioxide hollow sphere / polymer composite heat insulating material and a method for preparing the same. The composite material comprises a polymer substrate and submicron, agglomeration-free and monodisperse silicon dioxide hollow spheres evenly dispersed in the substrate, wherein the polymer substrate is a substrate of epoxy, polyurethane or polyethylene terephthalate; and for the submicron silicon dioxide hollow spheres, the hollow internal diameter is between 100 and 720nm, the thickness of the outer wall is between 50 and 100nm, and the weight of the submicron silicon dioxide hollow spheres is 1 to 35 percent of that of the polymer substrate. In the method, powder of the submicron, agglomeration-free and monodisperse silicon dioxide hollow sphere is prepared first; the powder is modified by the surface modifying technology; and finally, the modified powder is combined with the polymer taken as the substrate. The composite heat insulating material shows excellent heat insulating property, and the heat insulating property shows size-dependent characteristics in a rang of submicron. Moreover, because an organic foaming agent is not used in the preparation process, the composite heat insulating material is environment-friendly.

Description

technical field [0001] The invention relates to a silica hollow sphere / polymer composite heat insulating material and a preparation method thereof. technical background [0002] The dimension, morphology and structure of materials are important factors affecting the physical and chemical properties of materials. For heat insulation materials, in addition to selecting materials with low density and high reflectivity, the selection of structurally porous materials is the main factor for obtaining low thermal conductivity. Common insulation materials are mostly porous materials, such as foamed polymers (molded expanded polystyrene (EPS), extruded expanded polystyrene (XPS), polyurethane foam, epoxy foam, etc.) and Inorganic minerals (asbestos, calcium carbonate, clay, vermiculite, fly ash, perlite, etc.). The abundant porous channels in these materials contain gases with low thermal conductivity, which not only reduces the density of the bulk material, but also greatly reduce...

AI Technical Summary

Problems solved by technology

For example, among polymer or fibrous inorganic mineral reinforced silica airgel, silica airgel is an excellent thermal insulation material with a "fractal" network structure of nanoparticles and a large number of nanopore structures containing gas, but Its mechanical strength is poor, and it is reinforced by compounding with polymers or fibrous minerals, so that the mechanical properties are improved, but due to the addition of higher thermal conductivity materials, the overall heat insulation effect of the composite heat insulation material is deteriorated, that is, Although some properties can be improved through material compounding, for composite materials, the introduction of heterogeneous phases often improves material properties at the expense of other properties.