PBAN

PBAN - Polybutadiene Acrylonitrile copolymer. Also noted as Polybutadiene — Acrylic acid — Acrylonitrile terpolymer.

This was the binder formulation widely used on the 1960-70's big boosters (e.g., Titan III and Space Shuttle SRBs). It is also sometimes used by amateurs due to simplicity, very low cost, and lower toxicity than the more common HTPB. HTPB uses isocyanates for curing, which have a relatively quick curing time; however, they are also generally toxic.

PBAN is normally cured with the addition of an epoxy resin, taking several days at elevated temperatures to cure.