Water → Urea Urethane

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Reaction Steps

Eight-hundred parts of the prepolymer is charged to a reaction vessel and agitated. A mixture of 18 parts N,N-dimethylethanolamine and 786 parts water is then gradually added to the agitating prepolymer over a ten minute period, and the temperature is maintained between 25° to 31° C. Within one to two minutes after the completion of the addition of the N,N-dimethylethanolamine and water, a mixture of 9 parts 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane and 4 parts diethylene triamine and 112 parts water is gradually added to the prepolymer dispersion over a four to five minute period, and the temperature is maintained between 31° to 34° C. to form a colloidally dispersed urea-urethane polymer. The acetone and methyl ethyl ketone are then distilled from the dispersion to yield a stable, essentially organic solvent-free, aqueous colloidal polyurea-urethane ionomer dispersion with the following analysis: nonvolatile content of 34 percent by weight, pH of 8.4, and a viscosity of about 164 Stokes. The colloidal dispersion is only slightly opaque and is infinitely dilutable with water. Films from this product can be cured under ambient conditions to yield very high gloss films but optimum physical properties are attained when the films are cured at elevated temperatures. The polymer is a tough elastomeric material.

Provenance & Evidence