Synthesis and application of reaction type halogen-free phosphorus-containing flame retardant for polyurethane

Abstract

The invention discloses synthesis and application of a reaction type halogen-free phosphorus-containing flame retardant for polyurethane. A phosphorus-containing monomer derivative is formed by a phosphorus-containing monomer 9, 10-dihydro-9-oxa-10-phospha- phenanthrene-10-oxide (DOPO) and unsaturated polycarboxylic acid or anhydride, further the phosphorus-containing monomer derivative and polyhydric alcohols are subjected to esterification reaction so as to form the reaction type halogen-free phosphorus-containing flame retardant which is liquid at a room temperature, the molecular weight of the flame retardant is 300-1000g / mol, a terminal group of the flame retardant is a hydroxide radical, and the degree of functionality of the flame retardant is 2-6. The application shows that the flame retardant has a very good compatibility with a polyurethane raw material system and can be mixed with a polyurethane raw material in any proportion. The flame retardant is used for preparing rigid polyurethane foam with the density of about 31kg / m<3> and has relatively good compression strength and high-low temperature size stability. The oxygen index of the polyurethane foam is increased to 23.9% from 19.2% of oxygen index of a blank sample; and the oxygen index of polyisocyanurate foam is increased to 25.2% from 20.3% of oxygen index of a blank sample. The flame retardant can be applied to the fields of rigid polyurethane foam, elastomers, synthetic leather slurry and the like.

Description

technical field [0001] The invention relates to the synthesis of a reactive halogen-free phosphorus-containing flame retardant for polyurethane and the application of the phosphorus-containing flame retardant in polyurethane. Background technique [0002] Polyurethane is a material with relatively comprehensive properties, which has the advantages of good physical and mechanical properties, excellent weather resistance and elasticity. At present, the total output of polyurethane in the world has exceeded 10 million tons, and its output and variety are increasing year by year. However, polyurethane is flammable in air and presents a certain fire hazard. Therefore, the research on flame retardant technology of polyurethane materials has attracted more and more people's attention. [0003] The molecular structure of DOPO contains biphenyl ring and phenanthrene ring structure, which has higher thermal stability and chemical stability than organic phosphate without ring formati...

AI Technical Summary

Problems solved by technology

However, the flame retardant is a glassy solid at room temperature, and it is an additive type flame retardant, which has the disadvantage of being easy to decompose during processing.

[0004] From the current published literature, it has not been seen that DOPO or its derivatives are used to synthesize a hydroxyl-terminated flame retardant for polyurethane materials that is liquid at room temperature.