Thermal aging of HTPB/IPDI-based polyurethane as a function of NCO/OH ratio
| Autor: | Marta Ferreira Koyama Takahashi, Milton Faria Diniz, Thiago Cicaglioni, Luciene Dias Villar, Luis Claudio Rezende |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Materials science
Activation energy chemistry.chemical_compound symbols.namesake Polybutadiene Polymer chemistry medicine lcsh:TA401-492 General Materials Science Elastic modulus Tensile testing Polyurethane Arrhenius equation Mechanical Engineering aging Condensed Matter Physics chemistry HTPB Mechanics of Materials polyurethane symbols lcsh:Materials of engineering and construction. Mechanics of materials Isophorone diisocyanate Swelling medicine.symptom Nuclear chemistry |
| Zdroj: | Materials Research, Vol 14, Iss 3, Pp 372-375 (2011) Materials Research, Volume: 14, Issue: 3, Pages: 372-375, Published: 16 SEP 2011 Materials Research v.14 n.3 2011 Materials research (São Carlos. Online) Universidade Federal de São Carlos (UFSCAR) instacron:ABM ABC ABPOL |
| ISSN: | 1516-1439 |
| Popis: | Thermal aging of hydroxy-terminated polybutadiene/isophorone diisocyanate (HTPB/IPDI)-based polyurethane was studied as a function of NCO/OH ratio (1.0 and 0.85). Samples were aged in air ovens at 50, 60, 65, and 70 ºC for periods of time from 1 to 34 weeks. Changes in chemical (swelling testing and FT-IR spectroscopy) and mechanical (tension testing and hardness) properties were evaluated throughout the aging assays. Correlation between equilibrium swelling ratio and elastic modulus, coupled with changes in FT-IR spectra, indicated oxidative cross-linking as the dominant mechanism for both molar ratios investigated. However, determination of Arrhenius activation energy resulted in values of (82 ± 10) kJ.mol-1 and (156 ± 30) kJ.mol-1 for 1.0 and 0.85 NCO/OH ratios, respectively, thus revealing faster oxidative degradation kinetics for higher urethane linkage networks. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|