A study on high oxygen pressure autoclave testing for the oxidative resistance of polyolefin-based geosynthetics
- Testing of the oxidative resistance of polyolefin based geosynthetics in autoclaves at high oxygen pressure has been suggested as an alternative method to conventional forced-air oven aging. The intention is to shorten considerably the testing time and to ensure that aging is performed under the condition of rate-controlled and not diffusion-limited oxidation. We compare data from high pressure autoclave tests (HPAT) with data from oven aging and water immersion tests at 80 °C. For this, the stabilization of the samples has to be taken into account. Polyolefin based geosynthetics are usually stabilized by two types of “packages” of antioxidants (AO), designated here as P1 and P2. P1 consists of phenols and phosphites, P2 of hindered amine stabilizers (HAS) in addition to a marginal stabilization P1 of the resin for the manufacturing process. Phenolic and phosphite AO are quickly consumed in the HPAT. Failure time is tremendously reduced compared to forced-air oven aging orTesting of the oxidative resistance of polyolefin based geosynthetics in autoclaves at high oxygen pressure has been suggested as an alternative method to conventional forced-air oven aging. The intention is to shorten considerably the testing time and to ensure that aging is performed under the condition of rate-controlled and not diffusion-limited oxidation. We compare data from high pressure autoclave tests (HPAT) with data from oven aging and water immersion tests at 80 °C. For this, the stabilization of the samples has to be taken into account. Polyolefin based geosynthetics are usually stabilized by two types of “packages” of antioxidants (AO), designated here as P1 and P2. P1 consists of phenols and phosphites, P2 of hindered amine stabilizers (HAS) in addition to a marginal stabilization P1 of the resin for the manufacturing process. Phenolic and phosphite AO are quickly consumed in the HPAT. Failure time is tremendously reduced compared to forced-air oven aging or water immersion. The results are discussed within the framework of a basic autoxidation scheme (Wise et al., 1997). The reduction is much greater than expected from theoretical considerations. Therefore, a direct and degrading reaction of oxygen with the AO has to be assumed. In case of HAS, the time dependence of the degradation of tensile properties in the HPAT is significantly different from the dependence observed in conventional forced-air oven aging and their effectiveness is likewise strongly reduced. A conclusive interpretation of HPAT results needs a better understanding of what happens to the AO at high oxygen pressure.…
Autor*innen: | Werner Müller, Andreas Wöhlecke |
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Persönliche Herausgeber*innen: | Y. G. Hsuan, S. K. Bhatia, T. Y. Soong |
Dokumenttyp: | Beitrag zu einem Tagungsband |
Veröffentlichungsform: | Graue Literatur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | Proceedings of Geo-Chicago 2016 |
Jahr der Erstveröffentlichung: | 2016 |
Herausgeber (Institution): | ASCE |
Verlag: | ASCE |
Verlagsort: | Reston, USA |
Jahrgang/Band: | Geosynthetics, Forging a Path to Bona Fide Engineering Materials, GSP 275 |
Erste Seite: | 332 |
Letzte Seite: | 341 |
DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |
Freie Schlagwörter: | Autocalve testing; Geosynthetics; Oxidative resistance |
Veranstaltung: | Geo-Chicago 2016 |
Veranstaltungsort: | Chicago, IL, USA |
Beginndatum der Veranstaltung: | 14.08.2016 |
Enddatum der Veranstaltung: | 18.08.2016 |
DOI: | 10.1061/9780784480182.030 |
URL: | http://ascelibrary.org/doi/book/10.1061/geochicago2016 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 19.09.2016 |
Referierte Publikation: | Nein |