California Institute of Technology

Robert A Rhein

John D Ingham

A process for preparing dianhydrides that are miscible with hydroxyl prepolymers at moderate temperatures and can cure hydroxyl prepolymers to elastomers at moderate temperatures is disclosed. The dianhydrides are prepared by solution reaction of a prepolymer diol with excess dianhydride followed by removal of unreacted dianhydride. The prepolymer dianhydrides are miscible with hydroxyl substituted hydrocarbon prepolymers and cure the prepolymers to polyester-linked elastomers.

Prepolymer dianhydrides

Production of hydroxyl-containing curable liquid hydrocarbon prepolymers by ozonizing a high molecular weight saturated hydrocarbon polymer such as polyisobutylene or ethylene-propylene rubber, followed by reducing the ozonized material; e.g., by using reducing agents, preferably diisobutyl aluminum hydride, to form the above-noted hydroxyl-containing liquid prepolymers having a substantially lower molecular weight than the parent polymer. The resulting curable liquid hydroxyl-containing prepolymers can be poured into a mold and readily cured; e.g.; with reactants such as toluene diisocyanate, to produce highly stable elastomers having a variety of uses such as binders for solid propellants.

Growing community of inventors

La Canada, CA, United States of America

Robert A Rhein