Viscoelastic Properties of Carboxyl-Terminated (Butadiene-co-Acrylonitrile)-Based Composite Rocket Propellant Containing Tris(2,3-Epoxypropyl) Isocyanurate as Bonding Agent

 

Saša Brzić

Gordana Ušćumlić

Aleksandar Milojković

Vesna Rodić

Marica Bogosavljević

 

 

The influence of tris(2,3-epoxypropyl) isocyanurate as a bonding agent on the polymer network characteristics as well as rheological properties of [carboxyl-terminated (butadiene-co-acrylonitrile)/polyglycidyl ether of glycerol and epichlorhydrin]-based composite propellant was investigated. Amplitude sweep tests have been run above the glass transition temperature to establish the linear viscoelastic range (LVR) in a rubbery phase of the composite propellant for the correct physical interpretation of DMTA data. Temperature dependencies of rheological behaviour parameters (storage modulus, loss modulus, loss factor and glass-rubber transition temperature) were analyzed. It was observed that all the tested propellants have shown two relaxation processes in the temperature range –80°C to +80°C. The first one, structural relaxation (α-transition) related to glass transition and the other one, secondary relaxation process. The activation energy for glass transitions was determined by the Arrhenius plot from dynamic properties measured at three frequencies (1, 5 and 10 rads^-1). The dynamic mechanical analysis showed that the tris(2,3-epoxypropyl) isocyanurate content did not affect the glass transition temperature of the tested propellants

Key words: composite rocket propellant, butadiene-co-acrylonitrile, isocyanurate, glass transition temperature.