Method for preparing isocyanate terminated polyether/phenolic resin foamed plastic

Abstract

The invention discloses a method for preparing isocyanate terminated polyether / phenolic resin foamed plastic and belongs to the field of foam heat insulating materials. The method comprises the following steps of: adding a surfactant and a foaming agent into special expandable phenolic resin to form a component A; and uniformly mixing and stirring the component A and an isocyanate terminated polyether pre-polymer serving as a component B; pouring the mixture into a mold; and foaming and curing the mixture at normal temperature, wherein the mass ratio of -NCO contained in the isocyanate terminated polyether pre-polymer to the expandable phenolic resin is 0.1-0.6:1; the foaming agent is a physical foaming agent of which the boiling point is low; the -NCO group content of the isocyanate terminated polyether pre-polymer is between 18.5 and 19.5 mass percent; and the viscosity of the isocyanate terminated polyether pre-polymer is between 0.15 and 0.65 Pa.S at the temperature of 25 DEG C. The speed of the reaction of the phenolic resin and an isocyanate group is stable and foam density is appropriate (between 56 and 109 kg / m<3>) and can be adjusted through the using amount of the foaming agent.

Description

technical field [0001] The invention specifically relates to a method for preparing an isocyanate-terminated polyether / phenolic resin two-component system foam thermal insulation material by using a physical foaming agent with simple process, strong operability, no corrosion, heat resistance, non-pulverization and good toughness, It belongs to the field of foam insulation materials. Background technique [0002] Phenolic foam has received much attention in the past two decades due to its excellent characteristics in terms of thermal insulation, flame retardancy, low smoke during combustion, low toxicity and dimensional stability, and has been widely used as thermal insulation materials and sound insulation materials. , packaging materials, building decoration materials and super absorbent materials, etc. [Wang Junxiao, Liu Xinmin, Pan Jiongxi, Wang Hongwu. Research on the properties of rigid phenolic foam for sandwich panels [J]. Modern Plastics Processing and Application, 2...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the invention is to provide a method for preparing isocyanate-terminated polyether / phenolic resin foam by a physical blowing agent, adopting isocyanate-terminated polyether (polyurethane prepolymer) to replace traditional curing agent (acid), and expandable phenolic resin Form a two-component system to prepare a brand-new foam. In the system, a physical blowing agent is used, and organic / inorganic acids are no longer used as a blowing agent. There are few side reactions and the reaction is easy to control; special expandable phenolic resin is used to solve the problem. The problem of poor compatibility between the polyurethane prepolymer and the bulk phenolic resin is solved, and the reaction speed between the phenolic resin and the isocyanate group is stable, and the prepared foam density is moderate, at 56kg / m 3 -109kg / m 3 Among them, the foam has good temperature resistance, toughness and non-chalking characteristics