R-NH-COO-R′ network + blowing agent
ChemistryPolyurethane foam is specified as R-NH-COO-R′ network + blowing agent. Density band 30–60 kg/m³ rigid boards.
What holds Polyurethane foam together is not the nickname. Formula R-NH-COO-R′ network + blowing agent, density 30–60 kg/m³ rigid boards.
Meters are atlas-relative. Grades are the SKUs buyers write.
Phases
Microstructure
OrderProcessing sets grain, crystallinity or fibre orientation — the reason two lots of Polyurethane foam can test differently.
Interfaces
SurfacesCoatings, oxide films, sizings or paper faces often decide weather and fire behaviour more than the bulk brochure.
Defects
FlawsInclusions, voids, knots, pinholes or residual stress start the failures that mill certificates do not list.
Grades
VariantsPolyurethane foam is a family. Grade names below are the ones buyers actually write on RFQs.
Ageing
TimeMoisture, UV, creep, hydrogen or carbonation shift properties in service. Design to the aged state.
Relative meters
Strength20
Strength is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Heat envelope36
Heat envelope is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Fire behaviour28
Fire behaviour is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Insulation88
Insulation is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Workability74
Workability is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Circularity32
Circularity is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Grades
Flexible slabstock
Furniture, auto.Furniture, auto.
Rigid PUR
Appliances.Appliances.
PIR board
Buildings, better fire index.Buildings, better fire index.
Spray closed-cell
Roofs, rim joists.Roofs, rim joists.
Elastofoam
Integral skin.Integral skin.
Bonds
Primary bonding
Polyurethane foam holds together by ionic/covalent networks.
Secondary forces
Hydrogen bonds, van der Waals stacks or grain-boundary cohesion set toughness and moisture uptake.
Composites & fills
Fillers, fibres, plasticisers or aggregates are part of the real product, not impurities.
Environment film
Oxides, chars, sizings or paints are the layer the world actually meets.
Change the grade, the coating or the moisture and you have a different material with the same English name.
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