Ten-Year Aging of Elastomeric Vulcanizates in Panama, Alaska, and Illinois

Vulcanizates prepared from commercially available elastomers, many of which have been introduced since 1955, were exposed outdoors in Alaska; Rock Island, Illinois; and in the Panama Canal Zone to compare the effects of exposure in arctic, temperate, and tropic environments. Aging data collected on...

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Bibliographic Details
Main Author: Bergstrom, Edward W
Other Authors: ROCK ISLAND ARSENAL IL GENERAL THOMAS J RODMAN LAB
Format: Text
Language:English
Published: 1974
Subjects:
Elastomers and Rubber
*ELASTOMERS
*VULCANIZATES
ACCELERATED TESTING
ADDITIVES
AGING(MATERIALS)
ANTIOXIDANTS
ARCTIC REGIONS
COLD WEATHER TESTS
CRACKING(FRACTURING)
DEGRADATION
ELONGATION
ENVIRONMENTAL TESTS
EXPOSURE(GENERAL)
GRAPHS
MECHANICAL PROPERTIES
OXIDATION RESISTANCE
OZONE
POLYESTER PLASTICS
POLYMERS
POLYURETHANE RESINS
TABLES(DATA)
TEMPERATE REGIONS
TENSILE PROPERTIES
TROPICAL REGIONS
TROPICAL TESTS
UREIDES
ANTIOZONATS
Arctic
Alaska
Online Access:http://www.dtic.mil/docs/citations/ADB000996
http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADB000996
Description
Summary:Vulcanizates prepared from commercially available elastomers, many of which have been introduced since 1955, were exposed outdoors in Alaska; Rock Island, Illinois; and in the Panama Canal Zone to compare the effects of exposure in arctic, temperate, and tropic environments. Aging data collected on pads exposed as long as ten years are presented. The effects of rain forest vs. open sun exposure in Panama are compared as well as the effects of indoor vs. outdoor aging at Rock Island, Illinois. The ozone resistance of numerous vulcanizates was determined by exposures at the three sites, using ASTM D518, Method B, bent loop specimens. The resistance to cracking of numerous polyurethane vulcanizates exposed in Panama was also measured. Results show that aging is generally more severe in Panama than in Alaska or Rock Island, although some vulcanizates exhibit excellent aging resistance at all three sites. Polymeric antiozonants (EPDM) are more effective than chemical antiozonants in protecting SBR, NBR, and NR vulcanizates from ozone attack. Unstressed polyester urethane vulcanizates, even those containing hydrolysis inhibitors, deteriorate rapidly in Panama. Polyether urethane vulcanizates have also begun to show significant deterioration in Panama after seven years, while polyether urethane- urea vulcanizates remain relatively unaffected.

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