BACKGROUND

Solid rocket motors typically include a cast solid propellant. Solid propellant may include oxidizer, fuel, or both, held together with a binder. Ignition of the solid propellant generates high pressure gas, which is expelled through a nozzle to generate thrust.

SUMMARY

A solid rocket propellant according to an example of the present disclosure includes a binder having hydroxyl-terminated polybudadiene (HTPB) with a curative selected from the group consisting of isocyanate-terminated polyether, isocyanate-terminated polysiloxane, and combinations thereof.

In a further embodiment of any of the foregoing embodiments, the curative is the isocyanate-terminated polyether.

In a further embodiment of any of the foregoing embodiments, the isocyanate-terminated polyether is diisocyanate-terminated polyether.

In a further embodiment of any of the foregoing embodiments, the diisocyanate-terminated polyether is fluorinated.

In a further embodiment of any of the foregoing embodiments, the diisocyanate-terminated polyether is hexamethylene diisocyanate-terminated perfluoro-3,6,9-trioxaundecane-1,11-diol (FODI).

In a further embodiment of any of the foregoing embodiments, the diisocyanate-terminated polyether is hexamethylene diisocyanate-terminated polytetrahydrofuran (pTHF).

In a further embodiment of any of the foregoing embodiments, the curative is the isocyanate-terminated polysiloxane.

In a further embodiment of any of the foregoing embodiments, the isocyanate-terminated polysiloxane is diisocyanate-terminated polysiloxane.

In a further embodiment of any of the foregoing embodiments, the isocyanate is aliphatic diisocyanate.

In a further embodiment of any of the foregoing embodiments, the isocyanate is hexamethylene diisocyanate.

In a further embodiment of any of the foregoing embodiments, the binder has a ratio of the curative to the HTPB, by weight, of about 5:95 to about 40:60.

In a further embodiment of any of the foregoing embodiments, the curative is hexamethylene diisocyanate-terminated polyether, and the binder has a ratio of the curative to the HTPB, by weight, of about 5:95 to about 40:60.

In a further embodiment of any of the foregoing embodiments, the curative is diisocyanate-terminated polysiloxane, and the binder has a ratio of the curative to the HTPB, by weight, of about 5:95 to about 40:60.

A solid rocket motor according to an example of the present disclosure includes a motor case, a nozzle attached with the motor case, and a solid rocket propellant disposed in the motor case. The solid rocket propellant has a hydroxyl-terminated polybudadiene (HTPB) with a curative selected from the group consisting of isocyanate-terminated polyether, isocyanate-terminated polysiloxane, and combinations thereof.

In a further embodiment of any of the foregoing embodiments, the curative is diisocyanate-terminated polyether.

In a further embodiment of any of the foregoing embodiments, the diisocyanate-terminated polyether is selected from the group consisting of hexamethylene diisocyanate-terminated perfluoro-3,6,9-trioxaundecane-1,11-diol (FODI) and hexamethylene diisocyanate-terminated polytetrahydrofuran (pTHF).

In a further embodiment of any of the foregoing embodiments, the curative is diisocyanate-terminated polysiloxane.

In a further embodiment of any of the foregoing embodiments, the binder has a ratio of the curative to the HTPB, by weight, of about 5:95 to about 40:60.

A polymer composition according to an example of the present disclosure includes a hydroxyl-terminated polybudadiene (HTPB) with a curative selected from the group consisting of isocyanate-terminated polyether, isocyanate-terminated polysiloxane, and combinations thereof.

In a further embodiment of any of the foregoing embodiments, the curative is selected from the group consisting of hexamethylene diisocyanate-terminated perfluoro-3,6,9-trioxaundecane-1,11-diol (FODI) and hexamethylene diisocyanate-terminated polytetrahydrofuran (pTHF), and the binder has a ratio of the curative to the HTPB, by weight, of about 5:95 to about 40:60.

