Core-shell synergistic flame retardant polyurethane microencapsulation expandable graphite and application thereof in rigid polyurethane foaming plastic

Abstract

The invention discloses a core-shell synergistic flame retardant polyurethane microencapsulation expandable graphite and the application of the expandable graphite in rigid polyurethane foaming plastic. The core-shell synergistic flame retardant polyurethane microencapsulation expandable graphite comprises polyether and / or polyester polyol, a foaming agent, a foam stabilizer, a catalyst, an organic phosphorus-based flame retardant, a halogen-free intumescent flame retardant, an organic modified nano inorganic filler, core-shell synergistic flame retardant polyurethane microencapsulation expandable graphite, polyisocyanate compound and isocyanate index, wherein the polyisocyanate compound has two or more isocyanate groups; the core-shell synergistic flame retardant polyurethane microencapsulation expandable graphite takes expandable graphite particles as a capsule core and takes cyclodextrin or polyurethane as a capsule shell, wherein the cyclodextrin or polyurethane is formed by crosslinking cyclodextrin / modified resin and toluene diisocynate. The expandable graphite microcapsule can effectively improve the initial decomposition temperature, the heat stability and the flame retardant effect of a material and remarkably reduces the heat release rate and the total heat release quality during combustion.

Description

technical field [0001] The invention belongs to the technical field of flame-retardant polyurethane foam, in particular to a core-shell synergistic flame-retardant polyurethane microencapsulated expandable graphite and its application in rigid polyurethane foam. Background technique [0002] Rigid polyurethane foam has the advantages of low density, high strength, low thermal conductivity, strong adhesion, and convenient construction. It can be used as thermal insulation materials and structural load-bearing materials, and is widely used in construction, transportation, refrigerators, freezers, petroleum Chemical pipelines, aviation military and other fields. However, due to the large specific surface area, low density and low thermal conductivity of the foam itself, the oxygen index of rigid polyurethane without flame retardant treatment is lower than 19%, which is a flammable material and emits toxic gases such as HCN and CO during combustion. , often bring serious harm t...

AI Technical Summary

Problems solved by technology

Through research, it is found that the flame retardant effect of expandable graphite in rigid polyurethane foam is closely related to its particle size. The larger the particle size, the better the flame retardant effect, but it leads to a decrease in the mechanical properties of the foam and an increase in thermal conductivity; When the particle size of expandable graphite is small, although the influence on the mechanical properties and thermal conductivity of the foam is reduced, its flame retardant effect is also significantly reduced

In addition, the addition of expandable graphite inevitably leads to the destruction of the polyurethane rigid foam cell structure, which makes the products generally have the problem of increased thermal conductivity.

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