Study On Vacuum Infiltration Modified EPS Board

Being a kind of evengranular insulation board with enclosed cavity,expanded polystyrene(EPS)plate is lightweight,less capacity of water absorption,excellent heat-insulating performance(a thermal conductivity of 0.041 W/(m·K)),acceptable mechanical strength and high toughness,high resistance to chemical attack and water,and is easy to cut and to form.But it also has some disadvantages such as bad aging resistance and poor fire resistance,along with the generation of poisonous fume during the burning process,which limits the applications of EPS plate in the area of thermal insulation.In order to improve the flame retardancy of EPS insulating board,a vacuum-enhanced penetration process was carried out to introduce adhesive agents which has better flame retardancy into EPS plate to form a covered layer.The work investigated.the type and penetration conditions of adhesive agents and their influence on the performance of modified EPS plated,including apparent density,mechanical strength,thermal conductivity and combustion performance.The results may provide theoretical supports and technical guides to solve the bad fire resistance and other problems of EPS plate.The paper arrives at conclusions as following:The vacuum-enhanced penetration realized the effective penetration of phenolic resin with moderate viscosity to the voids among the particles of EPS insulation board.After solidification,the phenolic resin effectively improved the fire resistance performance of EPS insulation board,which can reach more than 30%,although the corresponding thermal conductivity was slightly enlarged to no more than 0.0507 W/(m·K),along with an increased mechanical strength,which was of compliance with the relevant requirements of insulation materials.With the cooperation of anhydrous copper sulfate and sodium silicate compound,a combined agent of flame retarding was prepared and penetrated into the EPS board,which not only can improve the flame retardancy,but also can eliminate the poor water resistance effect of sodium silicate.Experimental results show that the combined flame retardant obtained with 200ml sodium silicate and 40 ml of 1 mol/L anhydrous copper sulfate solution behaved a resistance to water for 3 h.Compared with added no compound flame retardant,the retardant property of composite EPS board was greatly improved,and oxygen index of it was greater than 38%,The thermal conductivity and compression strength of EPS board were improved to a certain extent,that can meet the relevant standards.Through the cooperation of water-resisting powders and sodium silicate,a combined flame retardant was prepared by mixing 200ml sodium silicate with 60g of powder,which behaves a water resistance of 6h,which greatly improved the flame retarding performance of EPS composite board.Oxygen index of EPS composite board was greater than 38%.The thermal conductivity of EPS composite panel was about 0.0500W/(m K),which comply with the relevant requirements of the insulation material.Compressive strength of the composite EPS board also has been greatly improved.Comprehensive analysis the above experimental results proposes that by making used of vacuum-enhanced penetration,three kinds of modified EPS composite board were obtained,along with the oxygen index no less than 27%.All the products belong to flame retardant materials,and the heat insulation properties are similar to the pristine EPS board,while the corresponding mechanical properties can also comply with the relevant specifications.The work provides a feasible but effective way to solve the poor fire performance of EPS insulation board in the practical engineering applications.