abstract |
Stabilized, catalyzed polyurethane systems are disclosed which are comprised of a polyurethane prepolymer, a tertiary amine catalyst and a stabilizing agent. To extend shelf life, and lend stability to the composition, the stabilizing agent is comprised of methane sulfonic acid. The stabilizer is suitable for use with most polyurethane systems catalyzed by tertiary amines, and produces longer shelf life or stability with lesser amounts than conventional stabilizers. In a particular embodiment requiring extended shelf life but quick curing times, a catalyst yielding these qualities is bis(2,6-dimethylmorpholino)diethylether. The catalyst, when incorporated in a polyurethane prepolymer coated on a flexible substrate, can be immersed in water, the material thereafter being wrapped about the portion of the patient's body to be immobilized, and cures rapidly, within about 15 minutes. The catalyst can optionally be combined with a stabilizer, such as methane sulfonic acid. When stored in the absence of moisture, such systems have exceedingly long shelf life. |