Polyurethane hard Foam is a polymer made of isocyanate and polyether as the main raw materials, adding foaming agent, catalyst and other additives, mixed through special equipment, and foamed on-site through high-pressure injection. Polystyrene foam is made of polystyrene resin as the main body and added with additives such as foaming agent. It is a widely used cushioning material. Polystyrene foam is similar to polyurethane foam in many aspects such as insulation, strength, and stability. However, its disadvantages are that it has a narrow temperature resistance range, it easily emits toxic gases when exposed to open flames, and it easily loses its thermal insulation effect when it absorbs water. It is a product that is gradually being phased out.
The difference between rigid polyurethane foam and polystyrene plastic foam1：Different foaming mechanisms
Rigid foam polyurethane is a lightweight foam with a closed cell rate of up to90%. It is a thermosetting foam and a two-component liquid(commonly known as black and white materials)full After mixing, rapid chemical reaction and curing occurs(tens of seconds~ a few minutes ), in the foaming agent, catalyst, foam stabilizer It foams into a network structure under the action of additives.
polystyrene foam(EPS, XPS) is a granular structure of thermoplastic foam, which is heated and swollen by granular or powdery materials. After the foaming agent vaporizes and expands, it has secondary foamingPotential.
The difference between rigid polyurethane foam and polystyrene plastic foam2：The physical and chemical properties of foam are different
①Thermal insulation performance
Compared with rigid polyurethane foam, polystyrene foam has better thermal insulation properties. But its value is still relatively large, such as EPSboard≈0.04w/k·m, XPSboard≈0.031w/k·m, PURboard≈0.022 w/k·m. Under the premise of the same energy-saving indicators, the thickness of the insulation board can be reduced and the quality stability of the insulation system can be improved.
②Thermal stability
The thermal stability of rigid foam polyurethane can be as high as 120℃, while The thermal stability of benzene board is only 70℃. The outer surface temperature of exterior walls in China in summer is generally 70℃ or above can easily lead to secondary foaming of the styrene board and cracking of the board seams.
③Surface binding energy
The molecular chain of polyurethane has certain-OH-OH-OHKey is a hydrophobic material whose surface is difficult to blend with inorganic materials such as cement-based slurry. This is one of the main reasons for cracking and falling off of the benzene board external insulation system. .
④Combustion Principle
Rigid foam polyurethane is a thermosetting material that forms a carbonized layer after heating and burning, which hinders the further penetration of heat and oxygen, hinders further combustion of foam, and is less likely to cause fire spread accidents. Polystyrene foam is a thermoplastic material that shrinks and melts when heated, and then drips and burns. It does not produce a carbonization barrier and can easily cause flame spread accidents.
⑤Corrosion resistance
Polyurethane is waterproof, oil-resistant and solvent-resistant. Polystyrene is water-resistant but not solvent-resistant, and is resistant to benzene and ester solventsVerySensitive, EasyProduces rapid corrosion.
The difference between rigid polyurethane foam and polystyrene plastic foam3：Different application ranges
Polystyrene foam can only be extruded and foamed in a factory state, while rigid polyurethane foam can be sprayed, poured and foamed in a factory. Therefore, the application methods and scope of polyurethane foam are more convenient and diverse than polystyrene foam.
Note: The article comes from Shanghai Weigu Chemical Products Co., Ltd., which specializes in the production of polyurethane foam. Please indicate the source when reprinting .
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