Composite foams have been prepared from blends of Kerimid 601 polyimide resin and different types of glass microbubbles. Kerimid 601 is an addition type polyimide that offers many processing advantages over other types of polyimides. In an addition reaction, no volatiles are evolved during cure and weight loss and shrinkage during cure are small. Also, since the resin is a powder that melts and flows before curing, low density foams can be prepared. Processes were developed to blend, mold, and cure the foam formulations. The powered resin and glass microbubbles were mixed together in a twin shell blender. Three methods of molding were considered: a sintering process, vacuum bag molding, and compression molding; however, all of the foams were made by the vacuum bag method. The standard cure recommended by the manufacturer of Kerimid 601 was used to cure and postcure the foam samples. Test results show that foams with compressive strengths ranging from 500 to 26,000 psi (3.45 to 179 MPa) can be prepared depending upon the type of GMB used and the density of the foam composite. Foam made from B40A glass microbubbles had the best strength to weight ratio, but the lowest foam density possible using themore » B40A bubbles is only about 0.35 g/cm/sup 3/. Low density composites require low density glass microbubbles. Foams with densities of about 0.2 g/cm/sup 3/ were made with the B18A bubbles, but the compressive strength was about 500 psi (3.45 MPa).« less