Polyurethane Prepolymer

Product Description

Polyurethane Prepolymer Details

A polyurethane prepolymer is a reactive liquid intermediate — polyol pre-reacted with isocyanate — that a fabricator casts and cures into a finished PU part. Pepson supplies five prepolymer series across three polyol families (polyether PPG, polyether PTMG, and polyester PES) paired with TDI or MDI isocyanate, for shops that cast their own rods, sheets, wheels, and wear liners in-house.

Base chemistry decides how the cured part behaves. The two polyether grades, PPG and PTMG, cure into parts with strong water resistance and mold/mildew resistance — useful anywhere the part sees washdown or damp storage. The two polyester (PES) grades trade some of that water resistance for better resistance to solvents, oils, and heat, the usual tradeoff between polyether and polyester PU chemistry. TDI-cured grades give a caster a long pot life to work with before the mix sets; the MDI-cured grade sets up faster. Every grade is with good heat resistance and excellent machining performance, casting void-free with the abrasion resistance PU is known for.

These five grades exist to be cast into something else, not sold as a finished part. Fabricators use them to cast rods, sheets, and plates for further machining, PU and rubber wheels, seals, screen plates, cyclone separators, and grinding liners for mining and mineral-processing equipment, plus impellers and cushioning pads. That covers general industrial and machinery shops, mold and tooling work, and mining and mineral processing — anywhere a shop casts its own PU components in-house rather than buying a finished molded part.

Prepolymer Grade Specifications