A kind of heat preservation rigid melamine foam with low water absorption rate and preparation method thereof

Abstract

The invention relates to a heat-preserving rigid melamine foam with a low water absorption rate and a preparation method thereof, belonging to the technical field of polymer materials. The density of the low water absorption thermal insulation rigid melamine foam is less than 53kg / m 3 , The water absorption rate is as low as 6.7%, the thermal conductivity is as low as 0.034W / m·K, the closed cell rate is 80%, the compressive strength is 300kPa, and the limiting oxygen index is as high as 35%. In the preparation process of the present invention, small molecules of short-chain hydrophobic alcohols and solid fillers are added; side groups of the molecular chains of the melamine resin prepolymer modified by small molecules of short-chain hydrophobic alcohols are introduced into "hanging" short-chain hydrophobic alkyl groups, Effectively improve the hydrophobicity of the resin, and at the same time, the increase of the "hanging" short chain content with better flexibility can improve the toughness of the resin and reduce the foam pulverization rate; in the preparation stage of the modified hydrophobic melamine prepolymer foaming liquid, solid fillers are added as The nucleating agent can adjust the cell structure, and can effectively reduce the free energy barrier of the growth of the cell nuclei to promote the heterogeneous nucleation, and prepare the low water absorption thermal insulation rigid melamine foam with small cell size and uniform distribution.

Description

technical field

[0001] The invention belongs to the technical field of polymer materials, and relates to a preparation method of a low water absorption rate thermal insulation rigid melamine foam. Background technique

[0002] Rigid melamine foam, also known as rigid melamine formaldehyde foam, is a foam material prepared from melamine resin through a certain foaming process. Due to its special triazine ring structure, a dense carbon layer can be rapidly formed on the surface of the foam to isolate oxygen and generate a large amount of N during the combustion process. 2 , so that the foam has intrinsic flame retardancy and is widely used in building fire protection materials. Since there are still unreacted hydrophilic groups (-NH-, -OH) in the melamine foam matrix, it is easy to form hydrogen bonds with water molecules in the air, increasing the hydrophilicity of the foam matrix. In addition, the closed cell ratio of melamine foam is low, and the open-cell foam structure ...

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