Construction And Optimization Of Compound System For Fire Safety Of PIR-PUR Foam By Flame Retarding Of Marix And Fire Protecting Of Surface

Rigid polyurethane foam?RPUF?one of the most broadly used organic thermal insulation materials,has a bright future because of its multiple merits such as low density,low thermal conductivity etc.However,it has significant fire hazards when used as building external wall insulation material due to its high flammability.Hence,enhancing the fire safety of RPUF is an important subject.Expandable graphite stand out in large number of halogen-free flame retardenty,because of its high efficiency and low environmental pollution.At the same time,nitrogen and phosphorus containing flame retardanty have been widely used in rigid polyurethane foams,because of its high efficiency.Nowdays with the increasing requirement of fire rating,the efficiency of a single component for flame retardant has been unable to reach the standard,so how to improve the efficiency of flame retardant is an important subject.In this paper,a variety of phosphorus-oxidized of phosphorus-containing melamine salts were coated expandable graphite?EG?,and use it modified polyisocyanurate-polyurethane?PIR-PUR?foam,and then construct a fire protective coating in the surface of PIR,to construct the combination fire protection system,investigate the combustion performance and influencing factors,determine the optimal fire safety of fire protection system.In this paper,we synthesis various phosphorous-containning melamine salts?melamine 2-carboxyethyl?phenyl?phosphinic acid?MCEPPA?,melamine 1-hydroxyethylidene-1,1-diphosphonic acid?MHEDP?,melamine amino trimethylene phosphate?MATMP?and melamine amino phytic acid?MPHA??successfully,characterized its composition and structure,and its was encapsulate EG successfully,fabricated a synergistic flame retardant system with physical barrier,gas phase flame retardant and condensed phase flame retardant.The thermal degradation results showd that phosphorous-containning melamine salts can effectively reduced the degradation of EG,and improve the amount of residual carbon.In general,the thermal stability of EG coated with various phosphorus-containing melamine salt were improved significantly.A various phosphorus-oxidized of phosphorus-containing melamine salts coated EG were added to the PIR foam as an additive flame retardanty.As a contrast,the same amount of the same flame retardancy modified PIR foam was prepared by physical mixing,and the differences were discussed.The flame retardancy,thermal degradation,and combustion behaviours of each samples were investigated.Limiting oxygen index?LOI?results indicated that the EG coated phosphrous-containing melamine salt can effectively improve the flame retardancy of PIR foam,the LOI index increased by 0.5%or 1.0%compared with the physical mixing group.The two groups of phosphrous-containing melamine salt?MCEPPA and MATMP?,which are coated with EG,can not increase of carbon residue,but can reduce the heat release rate and the total heat release significantly,and inhibit the release of smoke effectively.The other two phosphrous-containing melamine salt?MHDP and MPHA?,it is beneficial to increase the carbon residue of PIR foam,although the inhibitory effect on the smoke is not obvious.But it can and also reduce the heat release rate and total heat release significantly,and improve the fire safety of the PIR foam.To obtain the coating of composite fire system with excellent fire resistance.The effects of different inorganic layered fillers on fire retardant coatings was studied.By preparing Zirconium phosphate??-ZrP?and aluminum phosphate?AlPO₄?,and choose the montmorillonite?MMT?and zirconia?ZrO₂?.its thermal stability was analyzed.The results of thermal degradation shows that ZrO₂ has excellent thermal stability,while the thermal stability of AlPO₄ is relatively poor.Four kinds of fire retardant coatings with different content?0.5%,1%,1.5%,2%?were prepared,and their mechanism of flame retardant and fire resistance performance were analyzed.In general,0.5%content of?-ZrP?IFC/?-ZrP0.5?has the optimal fire resistance.The fire hazard of PIR was successfully reduced by constructing fire protective coating on the surface of PIR.It is found that the addition of fire-retardant coating can delay the PIR ignition time,peak heat release rate and significantly reduce the total heat release.To the fire protection system of different filler coating and pure PIR,ZrO₂ group has the most excellent fire safety.The combustion performance of?-ZrP group and AlPO₄ group is roughly equivalent,and the combustion performance of MMT as filler is poor,but the inhibitory effect of smoke is most obviously;The fire safety of the IFC/?-ZrP0.5 and modified PIR with different phosphrous-containing melamine salt coated EG combination fire protection system was greatly improved,and the fire protection system?MCEPPA group?could not be ignited during the combustion test.