Author(s): Luciene Dias Villar | Rafael Filadelfo da Silva | Milton Faria Diniz | Marta Ferreira K. Takahashi | Luis Cláudio Rezende
Journal: Journal of Aerospace Technology and Management
ISSN 1984-9648
Volume: 2;
Issue: 2;
Start page: 163;
Date: 2010;
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Keywords: Antioxidant | Composite propellant | HTPB propellant | Polyurethane resin | Storage
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Samples of 200 mL were stored in sealed 500-mL Erlenmeyer flasks under atmospheric pressure or vacuum and periodically withdrawn for physical and chemical analysis, infrared spectroscopy characterization and measurement of HTPB/IPDI (isophorone diisocyanate) reactivity, expressed as pot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.
Journal: Journal of Aerospace Technology and Management
ISSN 1984-9648
Volume: 2;
Issue: 2;
Start page: 163;
Date: 2010;
VIEW PDF
DOWNLOAD PDF Original pageKeywords: Antioxidant | Composite propellant | HTPB propellant | Polyurethane resin | Storage
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Samples of 200 mL were stored in sealed 500-mL Erlenmeyer flasks under atmospheric pressure or vacuum and periodically withdrawn for physical and chemical analysis, infrared spectroscopy characterization and measurement of HTPB/IPDI (isophorone diisocyanate) reactivity, expressed as pot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.