Influence of 1,4-butanediol on hydroxyl-terminated poly(butadiene) based composite propellant binder characteristics

1.4-butanediol, as a chain extender, was incorporated into a hydroxyl-terminated poly(butadiene) based composite rocket propellant binder composition. As curing agents, isophorone diisocyanate (IPDI) and toluene diisocyanate (TDI) were used. Composite propellant binder network and mechanical properties, influenced by a presence of 1,4-butanediol, were examined. Network characteristics, sol-gel content and crosslink density have been calculated and successfully correlated to the mechanical uniaxial tensile properties of the tested propellant binders. Differential scanning calorimetry studies showed that 1.4-butanediol content did not influence the glass transition temperature, however the uniaxial tensile properties were shown to be a function of the crosslink density.