Preparation Of SiO₂ Aerogel Composite Cork And Its Flame Retardant Performance

In modern furniture materials,many materials have certain flammability and toxicity.Once a fire occurs,it is easy to cause greater safety hazards.Cork board has certain flame retardancy,and is comfortable to the touch,good in heat preservation,moisture-proof and waterproof,and has good application prospects in the fields of indoor and furniture materials.But the cork has a high calorific value,once it is ignited,the fire is easy to spread quickly.Therefore,it is particularly important to do fire-retardant treatment and evaluate the fire risk of cork,and it is of great application value to study the lightweight cork-based composites with excellent flame retardancy.In this paper,with the purpose of enhancing the flame retardancy of cork,a new type of lightweight cork-based board was prepared,thereby broadening the application of cork materials in the fields of furniture design and interior decoration materials.The main results are as follows:(1)The SiO2 aerogel composite cork was prepared by soaking the cork of different tree species in SiO2 aerogel suspension by positive and negative pressure cyclic impregnation.SiO2 aerogel can agglomerate in cork cells to form a multilayer pore structure.After dipping,the maximum aerogel loading rates of Quercus variabilis and Quercus suber were about 9%and 14%respectively.The method has the advantages of being simple and easy to implement,and has little damage to the cell structure and chemical components of the cork.(2)The flame retardant performance of the prepared particle board of SiO2 aerogel composite cork was studied.The experimental results showed that the flame retardancy and smoke suppression properties of Quercus variabilis and Quercus suber cork particleboard were significantly improved,of which THR decreased by 26.46%and 31.33%respectively,while TSR decreased by 85.60%and 52.04%respectively.This kind of composite cork can effectively inhibit the release of heat and smoke during the burning process of the cork,especially the smoke suppression effect of Quercus variabilis composite cork is more.Room fire simulation showed that the use of SiO2 aerogel composite cork can effectively inhibit the spread of indoor fires,and has good potential in furniture applications.(3)The flame retardant mechanism of the prepared Si02 aerogel composite cork was studied.The study showed that SiO2 aerogels in composite cork played a positive role in protecting the microstructure and chemical properties of cork during combustion,and could strengthen the thermal oxidation stability of the carbon layer,thereby improving the flame retardant properties of cork.At the same time,the physical insulation and adsorption effect of SiO2 aerogels filled in cork cells are considered to be important reasons for improving the flame retardancy and smoke suppression performance.Loaded with SiO2 aerogels can catalyze the free radicals and small gaseous molecules formed by pyrolytic cork,and then be captured on the surface or inside of SiO2 aerogels.In addition,the introduction of SiO2 aerogel has significantly changed the thermal stability and decomposition behavior of composite cork materials.The oxidation of-CH3 on the surface of SiO2 aerogels also affects the formation of carbon layer,thereby further enhancing the thermal barrier effect By improving the flame retardancy and thermal stability of cork,the added value of cork can be increased,and its market competitiveness as furniture cladding and sandwich material can be enhanced.