The mould is filled with a prepolymer then the whole assembly is transferred to a flat substrate where the prepolymer is cross-linked and the mould removed.

The can contains isocyanate and polyol that have been mixed together to form a partially polymerized, low-molecular-weight prepolymer. As the foam is sprayed, the prepolymer reacts exothermically ...

Vinyl chloride is the prepolymer used to product polyvinyl chloride (PVC) plastic resins. Siloxanes are used to produce polysiloxane or silicone polymer resins. ASTM D1243 - Standard test method for ...

A PDMS mould is etched with a fluoride-containing substance (breaking Si--O bonds at the surface). The fresh PDMS surface then reacts with a prepolymer.