Study On Safety Performance Of Hybrid Polymer Material Based On Silicate/Polyisocyanates And Heat Transfer During Expanding

With the rapid growth of China's economy and development of chemical industry,more and more polymer materials are applied in the daily life and play an importante role in the coal production.However,the polymer materials,consist of carbon and oxygen,are easy to be ignited and produce much heat,dense smoke and toxic gas.Building fires and safety production accident in coal mine are caused by polymer burning occasionally.In this article,in order to solve the the poor flame retardant performance,the hybrid polymer material with great flame retardant and mechanical properties is synthesized.The flame retardant and mechanical properties of hybrid polymer material is emphatically investigated.The main results and conclusions are as fellow:The hybrid polymer material is synthesized by the organic component(polyisocyanate)and inorganic component(sodium silicate)as the main ingredients.The differences of the flame retardant and mechanical properties among the samples are investigated.The results show that Si–O and Si–O–Si were introduced into the hybrid polymer material.When the ratio of organic component and inorganic component is 3:1,the mechanical property reaches optimal performance.The increasing contents of inorganic component lead to the decreasing of heat release rate and smoke density.While the production of CO2 and CO fluctuates.The apparent activation energy increases with the increasing amount of inorganic component and decomposition rate.In general,when the ratio of organic component and inorganic component is 3:1,overall performance of the material is the most excellent.In order to improve the mechanical property and safety factor,three size hollow glass microspheres(HGM)and glass fibers(GF)are used as fillers.The influence of various additive amount on the flame retardant and mechanical properties of hybrid polymer materials is investigated.The results show that the maxmum of the compressive strength and shear stress of materials will be improved with every additive alone,specifically,the GF have the greatest reinforcing effect.Among the HGM,the smallest additive works best.All kinds of the additives reduce the smoke density,heat release rate and decomposition rate in different degree.In general,overall performance of the GF1.5-320#HGM 3.0 SSP is the most excellent.In order to further improve the flame retardant property and reduce the damage of material by the fire,the expandable graphite(EG)is used as additive.The influence of EG on the flame retardant and the protective to the matrix is emphatically investigated.The results show that the addition of EG increases the brittleness,reduces the resistance to the stress and many broken particles and holes appear on the matrix of the material.When the materials suffer from heat radiation,the protective layer is formed and reduces the damage on the matrix.The flame retardant property,thermostability and apparent activation energy are improved obviously.In general,when 3 wt% EG is added to material,the flame retardant property can be improved obviously and the mechanical property can be kept.According to the experimental condition of the hybrid polymer material and the material with EG suffer from heat radiation,the temperature change in the matrix is simulated by finite analysis software.The results show that the temperature in the upper part rises rapidly.Conversely,the temperature grafient in the low part of the material is small and temperature rises slowly whether or not the material is ignited.The polymer composite based on the hybrid polymer material is applied in the Suozhou coal mine to reinforece the roadway.The results show that the material is filled in the cracks in the coal-rock and reinforces the roadway.The reaction temperature is very low and good to the safety production.