The role of antioxidant on propellant binder reactivity during thermal aging
doi: 10.5028/jatm.2010.02027310

Luciene Dias Villar*
Instituto de Aeronáutica e Espaço
São José dos Campos – Brazil
ldvillar@iae.cta.br

Rafael Filadelfo da Silva
Universidade de São Paulo
Lorena – Brazil
rafael_fs1812@hotmail.com

Milton Faria Diniz
Instituto de Aeronáutica e Espaço
São José dos Campos – Brazil
miltond@iae.cta.br

Marta Ferreira K. Takahashi
Instituto de Aeronáutica e Espaço
São José dos Campos – Brazil
martat@iae.cta.br

Luis Cláudio Rezende
Instituto de Aeronáutica e Espaço
São José dos Campos – Brazil
lcrezende@iae.cta.br

*author for correspondence

Abstract:

Thermal aging of hydroxy-terminated polybutadiene (HTPB) stabilized with 2,6-di(tert-butyl)hydroxytoluene (BHT) was carried out at 60°C from 1 to 11 weeks. Samples of 200 mL were stored in sealed 500-mL Erlenmeyer flasks under atmospheric pressure or vacuum and periodically withdrawn for physical and chemical analysis, infrared spectroscopy characterization and measurement of HTPB/IPDI (isophorone diisocyanate) reactivity, expressed as pot life. Mechanical properties of the cured polyurethane, prepared from aged HTPB, were assayed by uniaxial tension tests. Despite the unchanged chemical structure, an increase in HTPB/IPDI binder reactivity was observed, being correlated with BHT depletion measured as color change (yellowing). Aging of HTPB showed no interference on mechanical properties of the cured polyurethane.

Keywords:

Antioxidant, Composite propellant, HTPB propellant, Polyurethane resin, Storage.

J. Aerosp.Technol. Manag., São José dos Campos, Vol.2, No.2, pp. 163-168, May-Aug., 2010
Received: 07/06/10
Accepted: 20/06/10