The Degradation Mechanism of EPDM Packing by Chlorine in City Water. (II).

Accession number;03A0073303
Title;The Degradation Mechanism of EPDM Packing by Chlorine in City Water. (II).
Author; KIKKAWA HARUHIKO (Chemicals Evaluation Res. Inst., Japan, JPN) NAKAMURA TSUTOMU (Sugakogyo Nagareyamagiken) HYAKUTAKE KEN'ICHIRO (Chemicals Evaluation Res. Inst., Japan, JPN) KOBAYASHI TOMOKO (Chemicals Evaluation Res. Inst., Japan, JPN) UEDA SHINJI (Chemicals Evaluation Res. Inst., Japan, JPN) MIYAGAWA RYUJI (Chemicals Evaluation Res. Inst., Japan, JPN) OTAKE YOSHITO (Chemicals Evaluation Res. Inst., Japan, JPN)
Journal Title;Journal of the Society of Rubber Industry, Japan
Journal Code:G0157A
ISSN:0029-022X
VOL.76;NO.1;PAGE.9-12(2003)
Figure&Table&Reference;FIG.6, TBL.4, REF.6
Pub. Country;Japan
Language;Japanese
Abstract;In order to elucidate the degradation mechanism of EPDM caused by a amount of chlorine in city water, EPDM used for about 3 years at 45 - 65 .DEG.C. in the water tank in Osaka City and the unused product were analyzed. The carbon black contained in them was FEF (Fast Extruded Furnace) which particle size is comparatively small. Their morphology changes were observed by SEM. The effect of the diffusion of chlorine was examined by EPMA. The degradation mechanism was studied by FT-IR and '13'C-NMR. As a result of FT-IR measurement, absorption of C=O bond (1720cm'-1') and C=C bond (1640cm'-1') were detected from the used product. As a result of '13'C-NMR measurement, in the used product, the peak of methyl group of main chain increased in comparison with the unused product. It was thought that generation of the C=O bond by the oxidation reaction caused the .BETA.-scission of the main chain to produce the C=C bond and the methyl group in the used product. Therefore, as the crossliniking density lowered, the used EPDM became brittle and collapsed. (author abst.)