Materials Research | |
Thermal aging of HTPB/IPDI-based polyurethane as a function of NCO/OH ratio | |
Luciene Dias Villar2  Thiago Cicaglioni1  Milton Faria Diniz2  Marta Ferreira Koyama Takahashi2  Luis Cláudio Rezende2  | |
[1] ,Departamento de Ciência e Tecnologia Aeroespacial Departamento de Ciência e Tecnologia Aeroespacial São José dos Campos SP ,Brazil | |
关键词: aging; HTPB; polyurethane; | |
DOI : 10.1590/S1516-14392011005000063 | |
来源: SciELO | |
【 摘 要 】
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.
【 授权许可】
CC BY
All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License
【 预 览 】
Files | Size | Format | View |
---|---|---|---|
RO202005130152659ZK.pdf | 342KB | download |