Low-thermal-conductivity polyimide foam material and preparation method thereof

Abstract

The invention discloses a low-thermal-conductivity polyimide foam material and a preparation method thereof. The method comprises the following steps: mixing aromatic dianhydride with a polar solvent,dissolving under a heating condition, adding low-molecular-weight alcohol, and continuously heating to carry out esterification on each component to obtain an esterification precursor solution; adding a catalyst, a foaming agent, a surfactant, polymer polyol and a foaming agent, uniformly dispersing to obtain a foaming white material, finally adding isocyanate into the white material, quickly stirring for uniform dispersion, then putting the mixture into a mold, foaming and molding, and heating and curing after foaming is finished to obtain the polyimide foam material. The polyimide foam material prepared by the method has the advantages of low heat conductivity coefficient, high limit oxygen index, good flame retardance, uniform cell size, controllable density and high mechanical strength, and can be widely applied to the fields of aerospace, military ships and warships, building insulation, vehicle construction and the like.

Description

technical field [0001] The invention belongs to the technical field of polymer foaming materials, and in particular relates to a low thermal conductivity polyimide foaming material and a preparation method thereof. Background technique [0002] Polyimide foam material is a kind of lightweight porous foam plastic with specific chemical structure. Quality and other performance characteristics, excellent performance. It is widely used in aerospace, ships, construction, automobiles, electronic appliances, machinery industry and other fields or has great application potential. [0003] At present, the thermal insulation materials widely used are mainly inorganic materials such as rock wool, glass wool, and expanded perlite, and organic materials such as polyurethane foam and polystyrene board. Among them, rock wool and glass wool have poor thermal insulation performance, high moisture absorption rate, poor environmental protection performance, and are harmful to human health. ...

AI Technical Summary

Problems solved by technology

[0008] At present, the preparation process of polyimide foam is divided into one-step method and two-step method. The one-step method refers to making a foam precursor solution in a certain solvent with dianhydride or diacid ester, low molecular weight alcohol, catalyst and other additives. Condensation reaction with isocyanate then produces small molecular gas as foaming agent to prepare PI foam. This method has relatively simple process and short production cycle, but the degree of imidization is not high; the two-step method refers to the dianhydride first mixed with Diamine is reacted to prepare precursor powder, which is then foamed under certain conditions to prepare PI foam. This method can prepare foam with higher density, but the process is more complicated and there are many defects in the foam; therefore, the production cost is reduced. And production process conditions are still the focus of research on polyimide foam materials, and optimizing its unique properties is also crucial

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