The Degradation Mechanism of NBR Invaded by High Concentration Chlorine Water

Abstract

In order to elucidate the degradation behavior of NBR caused by high concentration chlorine water, NBR samples corroded in 200 ppm chlorine water and in pure water were analyzed by means of EPMA, FT-IR and XPS. The degradation process of the NBR corroded in high concentration chlorine water is considered as follows: (1) an a-H of the butadiene double bond in NBR molecule is subject to substitution by chlorine; (2) the chlorinated NBR abstracts an a-H in another NBR molecule to cause the elimination of HCI, which generates polymer radicals; (3) the polymer radicals thus produced add to polybutadiene double-bonds in the other NBR. It is concluded that residual chlorine reacts with NBR by chlorination and oxidation mechanisms and that these reactions lead to hardening and degradation of NBR through the increase in the crosslinking density. 1.•• OE¾ •H•i •H•ê ‚âˆù‚âˆù-¿ •… •[ ‚Ä‚ñ•H•ê ‚È ‚Ç‚Å‚Í ŽE‹Û,'E •L ‚AE 'E-¡ ‚Ì-Ú "I ‚Å•‚ "Z"x ‚Ì ‰-'f •…‚ª40•`60•Ž ‚Ì ‰Á ‰·‚³ ‚ê ‚½‚ae ‚èOEµ ‚µ‚¢ ŠÂ‹« ‰º‚ÅŽg-p ‚³ ‚ê ‚Ä‚¢ ‚é.‚± ‚ê ‚ç ‚Ì ŠÂ‹« ‰º ‚ÅŽg-p‚³ ‚ê ‚é ƒSƒ€•Þ-¿ ‚Í •d ‰»‚µ,"¯ Žž‚ɃNƒ‰ ƒbƒN‚ð"-• ¶ ‚³ ‚¹,‚» ‚Ì OE‹ ‰Ê˜R‰Ê˜R•… "™ ‚Ì Ž-OEÌ‚ª • ¶ ‚ ¶,'å ‚« ‚È-â'è ‚AE‚È?‚Ä ‚¢ ‚é.‚Ü ‚½, ƒzƒeƒ‹ ‚Ì •~-[ "™ ‚Å ‚à •‚ "Z"x ‚Ì ‰-'f •…‚ð-p ‚¢ ‚½•HŠí ‚Ì •ô •ò ŽE ‹Û‚Å"¯-l‚Ì Ž-OEÌ‚ª '½"-‚µ‚Ä‚¢ ‚é.‰ä •X‚Í,•… "¹ •…' † ‚Ì Žc-¯ ‰-'f ‚É ‚ae ‚è ƒ_ƒ• •[ ƒW ‚ð Žó‚¯ ‚½‚AE •l ‚¦ ‚ç ‚ê ‚é-ò ‰» ŠÂ‹« ‚ÌˆÙ‚È‚ÌˆÙ‚È ‚é •" Ží ‚ÌNBR•» ƒ_ ƒCƒ" ƒt ƒ‰ ƒ€ ‚ð ‰ñ Žû ‚µ,Žc-¯‰-'f ‚É ‚ae‚é NBR‚Ì "î ‰»-ò ‰» ‚ª • ¶ ‚ ¶ ‚é ƒ• ƒJ ƒj ƒYƒ€ ‚ð‰ð-¾‚µ ‚½1).Žc-¯ ‰-'f ‚É•N ‚³ ‚ê ‚½NBR‚AE "¯-l‚È"î ‰»-ò ‰» OE»•Û‚Í,•… "¹ •…‚Å Žg-p ‚³ ‚ê ‚Ä‚¢ ‚é,EPDMƒp ƒbƒL ƒ"‚Å‚à Ž¦ ‚³ ‚ê ‚Ä‚¢ ‚é2).ˆê •õ ‚±‚̘_‚±‚̘_ • ¶ ‚ðŽc-¯ ‰-'f ‚É‚ae‚éNBR‚Ì-ò ‰» ‚ÉŠÖ ‚· ‚é 'ae2•ñ ‚AE ‚· ‚é. 'ae1•ñ ‚Í,"ú-{ƒSƒ€‹¦ ‰ï Ž•,77,301(2004) *1 ‡Š ƒp ƒ"ƒEƒH ƒV ƒ… ƒOE ƒbƒg(• §802-0823-k ‹ã •BŽs•¬'q"ì ‹ae•' ƒ-‹u1-1-1) *2•à'c-@ •l ‰» Šw •¨ Ž¿•] ‰¿ OE¤ ‹ †‹@i•\i(• §345-0043•é‹ÊOE §-kŠ‹•üOES •™ OEË '¬‰º •‚-ì1600) *3'· •è'å Šw 'å Šw ‰@ • ¶ŽY ‰È Šw OE¤ ‹ †‰È •¨ Ž¿‰È Šw •ê•U(• §852-8521'· •èŽs • ¶‹³ '¬1-14) 98 •û ‚ÅEPDMƒp ƒbƒLƒ"‚ª500ppm‚Ì •‚ "Z"x ‚Ì Žc-¯‰-'f ‚É ‚³ ‚ç ‚³ ‚ê ‚é ‚AE ‹t ‚É•d ‰»-ò ‰» ‚· ‚é ‚± ‚AE ‚ª •ñ •• ‚³ ‚ê ‚Ä‚¢ ‚é3).-{OE¤‹ † ‚Å‚Í,'O •ñ1)‚Å •ñ •• ‚µ‚½Žs •ê ‰ñ Žû•i ‚AE "¯ ˆêŽðOEÈ • ‡ ‚ÌNBRŽŽ OE± •Ð ‚ð•ì •¬ ‚µ,ŽÀ •Û‚ÉŽg-p‚³ ‚ê ‚Ä‚¢ ‚é •ê • ‡ ‚AE "™ ‚µ‚¢ •‚ "Z"x ‚Ì ‰-'f •…‚É•Z ‚¹ ‚« ‚µ,‹-• § "I ‚É-ò ‰»‚³ ‚¹,Še Ží •ª •Í Žè-@ ‚É ‚ae‚Á‚Ä-ò ‰» ‰ð •Í ‚ð•s ‚¢,•‚ "Z"xŽc-¯ ‰-'f •Z‚¹ ‚« ‰º‚Å"-OE» ‚· ‚é-ò ‰» OE» •Û ‚ð"c ˆ¬ ‚· ‚é ‚AE"¯ Žž‚É-ò ‰» ‹@•\ ‚ɂ‚¢ ‚Ä•l Ž@ ‚µ ‚½. 2.ŽÀ OE± 2.1ŽŽ-¿ 'O•ñ ‚ÅŽg-p‚µ‚½NBR•» ƒ_ƒCƒ" ƒt ƒ‰ ƒ€Žs•ê ‰ñ Žû•i ‚Ì 'g •¬ •ª •Í ‚ð ŽÀŽ{ ‚µ,‚» ‚Ì OE‹‰Ê ‚ð ‚à ‚AE‚É"z • ‡ ‚µ ‚½NBR‚É ‚Ä, 2mmOEú ‚Ì ‰Á-°ƒV•[ ƒg‚ð•ì •»,-ò ‰» •ˆ-•‚Ì ŽÀ OE±‚É‹Ÿ ‚µ ‚½. "z • ‡ •\ ‚ðTable1‚É Ž¦ ‚·.ƒS ƒ€‚Ì •… •ª ‹z '… •« ‚AE"¯ Žž‚ÉŽc-¯ ‰-'f ‹z '…‚É'½'å ‚È‰e ‹¿ ‚ð‹y ‚Ú‚· ƒJ •[ ƒ{ ƒ"ƒu ƒ‰ ƒbƒN ‚Ì Ží-Þ3) ‚Í,Žs •ê ‰ñ Žû•i ‚Ì "M •d-Ê •ª •Í '• 'u(TG)‚É ‚ae‚é ƒJ •[ ƒ{ ƒ"ƒu ƒ‰ ƒbƒN "R•ÄŠJŽn‰· "x'ª 'è ‚© ‚ç,'¼ ‚Ì ƒJ •[ ƒ{ ƒ"ƒuƒ‰ ƒbƒN‚AE "ä ‚×-± ŽqOEa‚ª20•`25nm‚AE •¬ ‚³ ‚-,•… •ª ‹z '… •« ‚ª ‹-‚¢ISAF ‚Å‚ ‚é ‚± ‚AE‚ðŠm"F ‚µ‚Ä"z • ‡ ‚µ ‚½. (20)