Quasi-prepolymers are defined as NCO-terminated products prepared from diisocyanates and polyols with NCO contents between 16 and 25 percent. Three such quasi-prepolymers are Baytec® MP-210, Baytec® ME-120 and Baytec® ME-230. These products are liquid at ambient temperature, can be processed like one-shot elastomers and yield elastomer properties that come close to hot-cast prepolymer systems. Quasi-prepolymers Baytec MP-210 and Baytec ME-230 have important advantages over conventional hot-cast elastomer systems in that they:
are low viscosity liquids at 25°C
have favorable mix ratios
are processable at room temperature or slightly above
are processable using simple metering equipment
result in elastomers with excellent overall physical properties