Study On Preparation And Performance Of Organosilicon-boron/24QP Coating Modified Phenolic Foam

Phenolic foam is widely used in the field of heat preservation and heat insulation because of its unique advantages such as wide use temperature,low thermal conductivity,and good fire resistance.Traditional phenolic foams are limited in application due to their high brittleness,high pulverization rate and low flame retardancy.Improving the heat resistance and strength of phenolic foam has become the main research direction of phenolic foam.By introducing inorganic structure and more heat-resistant resin,the flame retardancy and strength of phenolic foam can be improved at the same time,and phenolic foam with excellent comprehensive performance can be obtained.The modified phenolic foam with excellent flame retardant performance and high strength is higher than the current flame retardant standard,which can broaden the application of materials and promote the development process of flame retardant industry,and has broad development prospects.This article mainly studies the modification of phenolic foam from the following two aspects:(1)Through structural design and process optimization,the alkoxy-terminated silicone resin and boric acid with excellent flame retardant properties are introduced into the phenolic foam by the co-emulsification method,To prepare silicone-boron modified phenolic foam with high combustion grade,good fire resistance and high strength;(2)For the long-term use of phenolic foam,the outer layer is easy to be oxidized,and it is easy to smolder when exposed to fire.The problem,a phenolic compound 3,4,5-Trihydroxy-N-propylbenzamide POSS(24QP)was designed and synthesized,then combined with Fe³⁺to prepare a metal-phenol network flame-retardant coating on the surface of the phenolic foam.The coating has temperature response characteristics and can improve the flame retardancy,natural and high temperature aging of the foam.The following conclusions are drawn through testing and analysis:(1)When the silicone/boron/phenolic foam is added at 15 wt%and boric acid at 8 wt%,the microscopic morphology of the phenolic foam is spherical,and the strength of the material is obtained.Compared with the basic foam,the compressive strength is increased by 400%to 1.08MPa,and the bending strength is increased by 275%to1.21MPa.The powdering rate and water absorption rate reach the lowest values of 3.44wt%and 3.29 wt%,respectively.The thermal conductivity is only 18.18 m W/(m·K),the limiting oxygen index is increased by 10%compared with the basic foam value,reaching 38.59%,the rapid thermal decomposition temperature reaches 593.46°C.The above test results show that silicone The addition of boron and phenolic foam can greatly improve the material performance,thermal performance and fire resistance of phenolic foam;(2)After the silicon boron modified phenolic foam has a metal-phenol(MP)network coating,when the surface temperature of the foam exceeds 200?,The MP coating can respond quickly to the structure and form a 3D flame-retardant microlayer.This material layer can effectively inhibit the material exchange at the gas-solid interface,and at the same time,catalytic carbonization occurs,further improving the flame retardancy of the material surface and improving its anti-anion resistance burning ability.