Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5204973 | Polymer Degradation and Stability | 2006 | 11 Pages |
Abstract
A polyester polyurethane, was subjected to humid and dry aging conditions at 70 °C with 75% and 0% relative humidity, respectively. Differences in molecular weight and quasi-static tensile strength between humid- and dry-aged samples are attributed to hydrolysis of the humid-aged polymers. A phase-separation study was performed on selected samples from the aging matrix. Polymer samples were subjected to 110 °C for 10 min, by mixing the polyester (soft) and the polyurethane (hard) domains, then rapidly cooled to room temperature, initiating the phase-separation process. Uniaxial tension, dynamic shear and infrared spectra of these samples were measured as a function of time providing insight into the effects of hydrolytic degradation and the relationship of mechanical and molecular-level properties. An Avrami-type analysis shows two distinct processes whose characteristics vary as a function of increased hydrolysis. LA-UR 04-6447.
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Authors
Darla Graff Thompson, Jill C. Osborn, Edward M. Kober, Jon R. Schoonover,