Research On Flame Retardancy And Energy Saving Performance Of HLS Modified Phosphor-silicon Synergistic Rigid Polyurethane Foam

With the improvement of people's awareness of saving and environmental protection,the application of thermal insulation materials has become a research hot spot.Rigid polyurethane has a very low thermal conductivity and is favored in the field of energy saving in construction.However,it is extremely flammable,and in the event of a fire,it will endanger people's safety and property.Research on polyurethane flame retardants has been carried out one after another.Phosphorus-containing flame retardants have excellent flame retardant effects and are non-toxic and harmless,and have received extensive attention.Among them,silicon-containing flame retardants have the characteristics of high temperature resistance and smoke suppression,and have broad research prospects.The raw materials of polyurethane are polyol and isocyanate petroleum-based raw materials.With the consumption of non-renewable energy oil,lignin,a renewable resource that exists in large quantities in nature,has become the object of substitute raw materials.Aiming at the shortcomings of poor flame retardant properties of polyurethane,this paper analyzes the flame retardant mechanism,selects flame retardants and conducts experimental research.First,ammonium polyphosphate was used to flame retardant polyurethane,and the effect of one-component ammonium polyphosphate on polyurethane foam and the optimal addition amount were explored.Various performance tests were carried out on the prepared polyurethane foam material.The results showed that when the addition amount of ammonium polyphosphate was 25%,the limiting oxygen index reached the maximum value of 25.9%,the flame retardant performance was improved,and the smoke emission TSR was 130.176m~2/m~2,compared with 132.008m~2/m~2of pure polyurethane,did not decrease significantly.In order to further improve the smoke suppression performance of the flame retardant,ammonium polyphosphate was used as the flame retardant,and nano-Si O₂was added at the same time to explore the performance changes of ammonium polyphosphate and nano-Si O₂during synergistic flame retardant,and to explore the best synergy match.Nano-Si O₂was prepared by sol-gel method,composite polyurethane material was prepared by one-step foaming method,and the performance was tested.According to the test results,when the addition amount of nano-Si O₂is 1%,the LOI reaches 26.3,the fire resistance of vertical combustion reaches V-0 level,the compressive strength reaches 0.847MPa,and the TSR at this time is104.777m~2/m~2Compared with pure polyurethane,it is reduced by 20.6%,indicating that the addition of nano-Si O₂is beneficial to suppress the smoke emission,and the flame-retardant and mechanical properties of polyurethane materials are improved to a certain extent.Ammonium polyphosphate and nano-Si O₂play a synergistic flame-retardant effect.In view of the problem of polyurethane petroleum-based raw materials,this paper uses the natural resource lignin as the research object,and uses sodium lignosulfonate as the raw material to prepare polyurethane,and explore the effect on various properties.First,the sodium lignosulfonate is modified,and then used to partially replace the raw material polyether polyol of polyurethane,and the optimal ratio of P-Si flame retardant is added to prepare the lignin-based phosphosilicate by one-step foaming method.The performance test results of synergistic flame retardant composite polyurethane foam show that the flame retardant performance of polyurethane has been improved after adding HLS.When the additions of nano-Si O₂and APP are 1.0%and 25%,respectively,and the addition of HLS is4%,the flame retardant effect is the best,the limiting oxygen index is 27.2%,PHRR and THR are 86.997k W/m~2,2.203MJ/m~2,Compared with pure polyurethane,the reductions were51.5%and 47.9%,respectively.The anti-compression performance also reached 1.109MPa,which was greatly improved compared with 0.419MPa of pure RPUF.From the scanning results of the electron microscope,it can be seen that the amount of residual carbon is large and the layer of residual carbon is thick and dense,which is conducive to blocking heat,so the flame retardant effect is improved.Using the method of software simulation,a three-story office building was taken as the research object,and the energy saved before and after the application of thermal insulation materials was calculated according to the calculation of energy consumption.Then compare the energy saved with the cost of insulation materials to explore its feasibility.According to the results of the study,after the application of the three thermal insulation materials,the standard coal amount that can be saved each year is 15.18t,15.34t,and 15.41t respectively.6.843kg/m~2,6.916kg/m~2,6.947kg/m~2.After deducting the cost of thermal insulation materials,the whole life cycle cost is reduced by 221.28 yuan/m~2,220.55 yuan/m~2,and 204.02 yuan/m~2respectively.The use of thermal insulation materials has good economic benefits and greatly improves the comfort and use of buildings.performance.For polyurethane thermal insulation materials,the cost is high,but the thermal conductivity is low,the thermal insulation performance is good,and the energy saving rate is the highest.