Preparation And Study On Properties Of Flame Retardant Rigid Polyurethane Thermal Insulation Materials

Rigid polyurethane(RPUF)has the advantages of low thermal conductivity,high strength and light weight,as well as waterproof,moisture,heat and cold.It has become one of the main thermal insulation materials for building energy saving engineering.However,the rigid polyurethane is easy to burn and prone to fire spread,with significant fire safety risks,and conventional physical or chemical flame retardant way will make the thermal conductivity of rigid polyurethane increased,lost its advantages as a thermal insulation material,Limiting its use in certain areas.In view of the existing problems of rigid polyurethane flame retardant,this paper proposes a new method of preparing new rigid polyurethane thermal insulation material from three aspects:energy storage,heat insulation and fire prevention.A modified polyether polyol containing both phosphorus(P)and polyethylene glycol(PEG)segments was synthesized by molecular design.After adjusting the acid value of diethanolamine,the final reaction was "reactive" The way into the rigid polyurethane system.In order to further improve its flame retardant properties,the flame retardant polyphosphate and melamine were introduced into the rigid polyurethane thermal insulation material in the form of "additive type",and the phase change energy storage performance of polyethylene glycol was combined with phosphorus-nitrogen The effectiveness of flame retardant fully coordinated,and strive to give rigid polyurethane flame retardant performance at the same time to maintain or even enhance its thermal insulation properties.(FTIR)was used to characterize the chemical structure of the flame-retardant rigid polyurethane thermal insulation materials.Using a differential scanning calorimeter(DSC),thermo-gravimetric analysis(TGA)study the thermal behavior of the flame retardant rigid polyurethane insulation material.The thermal hazard of flame-retardant rigid polyurethane thermal insulation materials was studied by Ozawa method.The thermal degradation of ordinary and flame-retardant polyurethane thermal insulation materials was studied by Ozawa method.The thermal hazard of flame-retardant rigid polyurethane thermal insulation materials was studied by Oxygen(LOI),horizontal vertical combustion,smoke density and flue gas toxicity behavior.The flame retardant mechanism,the preparation method,the combustion behavior and the thermal properties of the flame retardant rigid polyurethane thermal insulation materials were studied in depth.The main work is summarized as follows:1.Successfully synthesized containing both polyether polyol modified P element and the PEG segment.The chemical bond and molecular structure of FOCR were characterized by FTIR.It was found that the vibration absorption peak of new chemical bond POC was generated at 1011.58 cm-1,which proved that the coupling effect of polyethylene glycol segment in phosphorus oxychloride The success of the key to the ordinary polyether polyols;through the acid value and hydroxyl value of the test,proved to meet the reactivity requirements with the isocyanate.2.The modified polyether polyol was introduced into the rigid polyurethane system by the "one-step" foaming technology to prepare the phosphorus-containing rigid polyurethane thermal insulation material by adding a small amount of polyphosphoric acid Amines and melamine flame retardants further improve their flame retardancy.3.The thermal insulation performance and energy storage performance of flame retardant rigid polyurethane thermal insulation materials were studied by differential scanning calorimetry(DSC)and thermal conductivity test.It is found that the introduction of phase change energy storage material PEG-800 can make the RPUF material have higher phase change value at 22-42 ? and with the increase of PEG-800,the heating rate of RPUF material decreases,Thermal insulation performance.At the same time,the addition of flame retardant will increase the thermal conductivity of the material,but by the PEG-800 solid-liquid changes in the impact of energy storage,flame retardant rigid polyurethane insulation materials still have better than ordinary polyurethane materials Thermal insulation performance.4.The flame retardancy and thermal degradation behavior of flame retardant rigid polyurethane thermal insulation materials were studied by means of limit oxygen index(LOI),horizontal vertical combustion and tungsten weight loss(TGA).The Ozawa method was used to calculate the resistance The activation energy of the rigid polyurethane material was further analyzed,and the flame retardant mechanism of P element was further analyzed.The results show that the introduction of flame retardant element P makes the rigid polyurethane LOI significantly improved,with excellent self-extinguishing effect.Especially the introduction of a small amount of polyphosphoric acid amines and melamine,the formation of a PN synergistic flame retardant system in the rigid polyurethane system,LOI up to 31.3,the level of combustion can reach FH-1,the vertical combustion level can be achieved FV-0.5.The effects of phosphorus and nitrogen flame retardants on the amount of flue gas produced by polyurethane material and the amount of toxic gas in flue gas were studied by means of smoke density and flue gas toxicity test.The results show that both P and N flame retardants make the polyurethane material generate more flue gas in the fire,especially the P flame retardant is more obvious,but the amount of toxic gas in the flue gas will be with the P system The addition of the flame retardant is reduced.It is shown that P and N flame retardants will increase the amount of flue gas released during the fire of polyurethane material,but also reduce the amount of toxic gas in the flue gas and reduce the risk of fire.