ABSTRACT
Polybutadiene elastomers are versatile materials, being employed at several applications from rocket propellant binder to adhesives and sealants. The elastomers derived from hydroxyl-terminated polybutadiene are usually stabilised with antioxidants to prevent degradation. In this study, a comparative assessment among 2,2’-methylene-bis (4-methyl-6-tert-butylphenol) (AO2246), 2,6-di-tert-butyl-4-methylphenol (BHT), p-phenylenediamine (pPDA), and triphenylphosphine (TPP) regarding stabilisation of hydroxyl-terminated polybutadiene binder under accelerated ageing (six months at 65 °C) was carried out. Evaluation of antioxidants effectiveness was examined through Oxidation Induction Time, sol/gel extraction, swelling and mechanical testing, dynamic mechanical analysis, and mass variation measurement. AO2246 yielded the best performance, meanwhile BHT was poorly protective. TPP acted as prooxidant, causing a severe degradation of the binder, and pPDA was not manageable to be assessed due to the lower curing degree of the resulted polyurethane.
KEYWORDS
Ageing; Antioxidant; HTPB propellants; stabilisers
