Method for synthesizing expandable phenolic resin

Abstract

The invention discloses a method for synthesizing an expandable phenolic resin, and belongs to the field of heat insulating materials. The method comprises the following steps of: adding phenol, a catalyst and paraformaldehyde into a reactor, wherein the mass ratio of the paraformaldehyde to the phenol is 1.1-1.9:1 and the mass ratio of the catalyst to the phenol is 0.01-0.04:1; stirring, heatingthe mixture to 70 to 85 DEG C and performing an isothermal reaction for 30 to 90 minutes; and continuously performing the isothermal reaction at the temperature of between 80 and 95 DEG C for 30 to 150 minutes and then stopping the reaction. The phenolic resin prepared by the method has the advantages of high compatibility with polyurethane, low viscosity and high solid content. The method has the advantages of simple operation process and low pollution.

Description

technical field

[0001] The invention relates to a synthesis method of expandable phenolic resin with good compatibility with polyurethane, low viscosity, high solid content, simple operation process, low pollution, relatively mild reaction with polyurethane prepolymer and high expansion ratio, belonging to The field of thermal insulation materials. Background technique

[0002] Phenolic resin is a synthetic resin obtained by polycondensation of phenol and formaldehyde. It is the first artificially synthesized polymer compound and the earliest synthetic resin in the world to achieve industrial production. It has a history of more than 100 years. Due to its easy availability of raw materials, low price, simple production process and equipment, and the cured product has excellent mechanical properties, heat resistance, cold resistance, electrical insulation, dimensional stability, molding processability, flame retardancy and low smoke , so it has become an indispensable materi...