Chemical nature of water trees in cross-linked ethylene vinyl silane copolymer

Investigations on the aging of cross-linked ethylene vinyl silane copolymer

“…Some measurements using a micro beam wen: made on the wire samples to detect the radial changes in antioxidant concentration, oxidative s p i e s and polymser chain unsaturation. The changes in the characteristic IR absorptions of the methoxy and silane groups (1090, 1260 and 800 cm"') [2], of the olefinic double bonds (R.CH=C% at 908 cm-', R.CH=CH.R' at 965 cm" and KR'C=CH, at 888 c d ) > of the carbonyl groups at 1720 cm-' were monitored. :i'olvent extraction as per procedure .ASTM D2765 w3s performed on all aged samples.…”

“…The crosslinking of these ethylene vinyl silane copolymers (EVS) is essentially controlled by diffusion of water in the polymer [l]. There is experimental evidence to show its increased mistance to moisture induced degradation in the presence of an electric field attrinuted to its reactivity with water [2]. Mechanical measurements on EVS copolymer [3] have also indicated that more cross-links are formed within an already existing gel in an extended cross-linking time.…”