A kind of preparation method of reinforced and toughened flame-retardant phenolic foam

Abstract

The invention relates to a preparation method for reinforced and toughened flame-retardant phenolic foam. The preparation method comprises: adding polyethylene glycol into a three-necked bottle, adding phosphorus pentoxide in batches under quick stirring at 30-60 DEG C, and after phosphorus pentoxide is almost dissolved, raising the temperature to 65-85 DEG C and maintaining the temperature for 1-3 hours, and then raising the temperature to 100-140 DEG C for reaction for 3-6 hours; and adding boric acid by one time and maintaining the temperature at 100-140 DEG C for 2-4 hours to obtain a faint yellow to deep yellow product, namely a polyethylene glycol borate phosphate flame-retardant flexibilizer, wherein the molar ratio of hydroxyl groups in polyethylene glycol to total acid hydroxyl groups in phosphorus pentoxide and boric acid is 1:1 to 1:3; the preparation method for the reinforced and toughened flame-retardant phenolic foam comprises: firstly weighing 100 parts of stage A phenolic resin; then separately adding a borate flame-retardant modifier, a surfactant, a curing agent and a foaming agent; quickly and uniformly stirring the mixture; adding the mixture into a die and closing the die; and carrying out foaming curing at 70-90 DEG C for 40-80 minutes to obtain the reinforced and toughened flame-retardant phenolic foam.

Description

technical field [0001] The invention belongs to the technical field of materials, and in particular relates to a method for preparing a reinforced and toughened flame-retardant phenolic foam compounded with a flame-retardant toughening agent and nano oxides. Background technique [0002] Currently commonly used polymer foam materials, such as polystyrene foam and polyurethane foam, are widely used due to their excellent thermal insulation performance, good mechanical properties and easy molding and processing. However, they are very flammable materials, which can easily catch fire and cause fire accidents, causing heavy casualties and property losses. Although phenolic foam has the advantages of excellent flame retardancy, good flame penetration resistance, low smoke and low toxicity when burning, but phenolic foam also has the defects of high brittleness, high hardness and easy pulverization, which seriously limits the application of phenolic foam. Therefore, it is very ne...

AI Technical Summary

Problems solved by technology

However, they are very flammable materials that can easily catch fire and cause fire accidents, causing significant casualties and property damage

Although phenolic foam has the advantages of excellent flame retardancy, good flame penetration resistance, low smoke and low toxicity when burning, but phenolic foam also has the defects of high brittleness, high hardness and easy pulverization, which seriously limits the application of phenolic foam. Therefore, it is necessary to toughen the phenolic foam

[0003] According to literature reports [Plastic Industry, 2011, 39(2): 25-27; FRP / composite materials, 2011, (2): 37-39; China Plastics, 2005, 19(12): 53-56; Henan Chemical Industry, 2006, 23(9): 22-23; Applied Chemical Industry, 2010, 39(11), 1693-1695.], polymer tougheners commonly used in phenolic foam, such as liquid nitrile rubber, polyurethane prepolymer, polyacrylic acid Although n-butyl ester, flexible epoxy resin, polyethylene glycol, etc. are flammable, they can improve the toughness of phenolic foam, but usually reduce the flame retardancy of phenolic foam

When fiber (such as short glass fiber) is used as a toughening agent, the viscosity of the resin will be greatly increased, and the mixing process will become difficult. At the same time, the fiber will be oriented along the flow direction of the resin and affect the formation of foam, reducing the quality of foam and foam. Uniformity, this method is difficult to meet the actual use requirements [J. Appl. Polym. Sci.2007, 104(3), 1399-1407]