Polyurethane
Isocyanates, polyols, prepolymers and curing agents for polyurethane foams, elastomers, coatings and adhesives. The flagship category of the platform: every grade listed here is matched against the CAS-verified product records buyers compare before requesting a quotation. Sits at the head of the taxonomy because flexible and rigid PU chemistry is where SupplierAssess has the deepest supplier coverage today.
2 sub-categories · 4 products published directly here
Sub-categories
Products
MDI
CAS 9016-87-9
Diphenylmethane diisocyanate (MDI, CAS 9016-87-9 for the polymeric grade) is the aromatic isocyanate that anchors rigid polyurethane chemistry. Polymeric MDI is a brown liquid mixture of monomeric 4,4′-MDI with higher oligomers, quoted by NCO content (typically 30.5-32.0%) rather than by purity. Its functionality above two builds the cross-linked network that gives rigid foam its compressive strength and dimensional stability, while pure 4,4′-MDI is used for thermoplastic polyurethane and cast elastomers. Buyers compare NCO content, viscosity at 25 °C, acidity, hydrolyzable chlorine and colour stability, and require drums purged under dry nitrogen because the product reacts with moisture.
0 suppliers · updated 2026-10-03
PPG
CAS 25322-69-4
Polypropylene glycol (PPG, polyether polyol, CAS 25322-69-4) is the polyol partner for MDI and TDI in the majority of polyurethane systems. It is made by base-catalysed ring-opening polymerisation of propylene oxide onto a starter such as glycerol, sorbitol or a diol, which fixes the functionality and hydroxyl value that a foam or elastomer formulator needs. Hydroxyl value, functionality, viscosity and water content are the buying parameters: hydroxyl value sets the stoichiometric isocyanate index, and residual water consumes isocyanate and releases carbon dioxide, so drum water content is usually specified below 0.1%. Di- and tri-functional grades cover flexible foam, rigid foam, sealants and coatings.
0 suppliers · updated 2026-10-03
PTMEG
CAS 25190-06-1
Polytetramethylene ether glycol (PTMEG, polytetrahydrofuran, CAS 25190-06-1) is the premium polyether polyol used where a polyurethane has to survive flexing cycles for years. Its regular, linear backbone and low unsaturation let the soft segment crystallise, so PTMEG-based spandex, TPU and cast elastomers deliver far better rebound, hydrolysis resistance and dynamic fatigue life than conventional PPG systems. Grades are sold by number-average molecular weight (most commonly 1000, 2000 and 3000 g/mol) with tight hydroxyl value, colour (APHA) and moisture limits. It is the polyol behind elastane fibres, roller and wheel compounds and high-performance copolyester elastomers.
0 suppliers · updated 2026-10-03
TDI
CAS 26471-62-5
Toluene diisocyanate (TDI, CAS 26471-62-5) is supplied as the 80:20 or 65:35 mixture of the 2,4- and 2,6-isomers and is the standard isocyanate for flexible polyurethane foam. The asymmetry of the 2,4-isomer makes the foam rise and cure fast enough for slabstock and moulded production, which is why TDI still dominates mattress, furniture and automotive seating foam despite its higher vapour pressure. The material is a respiratory sensitiser, so export lots ship in dedicated 250 kg drums or ISO tanks with strict handling documentation. Buyers compare isomer ratio, NCO content, acidity and total chlorine, and increasingly ask for lower free-TDI prepolymer grades.
0 suppliers · updated 2026-10-03
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