Hydrolytic Degradation of Estane 5703
Relative to the unaged Estane{reg_sign} 5703, heating decreases the modulus and ultimate stress for both the dry and humid samples. The sample aged in dry air, quickly recovered to its original mechanical properties. The reversibility of the mechanical properties is a result of the reorganization of the hard segments into domains. For the Estane 5703 samples aged in humid air, the mechanical properties only partially recovered with time. Molecular weight data confirm that differences in the extent of the recovery for the samples aged under humid environments are likely due to the hydrolytic scission of the polyester soft segments. Since the tensile moduli are similar for the samples aged in both the dry and humid environments, it is believed that the phase behavior of the hard domains dictate the mechanical properties at low extensions. However, at higher elongations, the mechanical properties are dominated by the soft segments. Both the influences of morphological changes and chemical changes induced by heating must be considered in multiphase polymers when accelerated aging is utilized to predict long term polymer properties. After accelerated aging experiments, the morphology must be allowed to recover to equilibrium conditions in order to assess the extent of degradation and aging. Also, the effect of different humidities on the rate of hydrolytic degradation are presented.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 758888
- Report Number(s):
- LA-UR-99-1383; TRN: AH200031%%84
- Resource Relation:
- Conference: 22nd Aging Compatibility and Stockpile Stewardship Conference, Oak Ridge, TN (US), 04/27/1999--04/30/1999; Other Information: PBD: 27 Apr 1999
- Country of Publication:
- United States
- Language:
- English
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