Polyurethane rigid foamrigid foam(PU) is a type of rigid foam plastic which has a rate of cell-closed above 92%.Its raw materials are isocyanate and polybasic alcohol. It has high compressive strength low water absorptionstable chemical propertiesacidity and alkalescence resistance long useful life good performance in thermal insulating.It is the best lightweight thermal insulation material at present. Main characters and design choice points (1) Working in heat, usually ranging from 100,after adding assist substance, its working temperature can reach to 120 (2) The foaming agent in polyurethane may have chemical reaction when it is exposed to the air. In this situation,we use the airtight material as the surface material such as staved steel to pack it up to abate or avoid this disadvantage. 3The polyurethane has the perfect capability of compression-resistance and heat-resistance, easy to fix. comparing with EPS is much better on thermal insulation of the house's surface . (4)Phenolic foam can be used in pipework (especially for Underground pipes) and roofing insulation, which should be protected from evaporation and moisture. Typically using the closed material as the protection layer is important being for the thermal conductivity increasing at any time. (5)It is not suitable for the internal insulation materials because of the low flammability degree ,the high smoke and the toxic gas emission. (6)As the thermal insulation material, it can not be used as the fireproof material, although it has low evaporating absorption. Item / NamePFPUPVCPSMax Temp.()18012012060Performance in limiting condition210Color change100Shrink140Intenerate80ShrinkThermal conductivity(w/m.k) 0.016 0.0360.022 0.0360.029 0.0350.033 0.045Loss of weight()371009594Degradation testingBestBadGoodBadResistance against chemicalsGoodGoodGoodBadRate of water absorptionkg/m30.020.030.030.2Crush resistance(kpa)21612733107Burning sec.sec303030Flame heightmm15100250250Oxygen index42Difficult to burn25(Easy to burn)25 27(Easy to burn)18 21(Easy to burn)Melt conditionNODrip with flameYESDrip with flameSmoke densityDm9516866Burn producepoisonous gas or notNOYESYESYES