Abstract: An insulation system for use in rocket motors containing solid composite propellants is disclosed. Some composite rocket propellants are based on carboxyl-terminated polybutadiene (CTPB) and others on hydroxyl-terminated polybutadiene (HTPB) binders. An important requirement of such systems is the ability of the wall insulation to adhere to the combustion chamber and of the composite propellant to adequately adhere to the insulation system. With CTPB propellants, a sheet insulant comprising chrysotile asbestos fibers and floats dispersed in a CTPB polymeric binder has been successfully employed. However, the use of a similar sheet insulant based on HTPB polymeric binder has not proved to be compatible with HTPB propellants.

Abstract: A novel process for the preparation of flexible molded articles, such as head-end insulators for rocket casings, which are exposed to extremely high temperatures. The articles are cold-molded from shreds, discs or strips consisting of asbestos fibers and floats impregnated with a substantially uncured elastomeric binder comprising a carboxyl-terminated polybutadiene polymer.

Abstract: A method of bonding a solid rocket propellant to a motor casing using a flexible sheet insulant. The flexible sheet insulant is easily installed without intermediate adhesive on the metal or propellant side, retains its self-adhesive properties for long periods when stored at temperatures lower than 40.degree.F before installation and has improved resistance to erosion. The flexible sheet insulant comprises an elastomeric polymer binder in particular a carboxyl-terminated polybutadiene having dispersed therein from 50-80% preferably 65-75% by weight of a siliceous filler reinforcing material at least 50% of which is in the form of fibers. Preferably the filler consists of 50 to 80% asbestos fibers and 20% to 50% asbestos floats.