p-toluenesulfonyl isocyanate

p-Toluenesulfonyl isocyanate (CAS 4083-64-1), commonly known as tosyl isocyanate or PTSI, is a reactive isocyanate reagent used across coatings, adhesives, and polymer systems. It functions primarily as a crosslinking agent and moisture scavenger, reacting with hydroxyl and amine groups to build or stabilize polymer networks in various industrial applications.

In polyurethane coatings and adhesives, PTSI acts as a crosslinker that improves chemical resistance and film hardness without requiring elevated cure temperatures for the final product. Sealant and elastomer formulators use it to scavenge residual moisture from systems sensitive to premature gelation, extending pot life and improving shelf stability during storage.

In textile and leather finishing, it enables durable bonding of functional coatings to fiber substrates by reacting with surface hydroxyl groups to create a strong chemical bond. Plastic and polymer manufacturers incorporate PTSI as a reactive building block in specialty monomers where controlled isocyanate functionality is required for specific material properties.

p-Toluenesulfonyl isocyanate is supplied as a clear to pale yellow liquid. Technical grade is the standard commercial form, with purity specifications typically ranging from 97% upward. Packaging options generally include small reagent quantities through to drum-scale volumes for industrial procurement, ensuring flexibility for both laboratory and large-scale manufacturing needs.