Naslov
Determination of Polysulphide Crosslinks During Thermo- and Photo-Oxidative Ageing

Autori
Hrnjak Murgić, Zlata ; Jelenčić, Jasenka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Langzeitverhalten von Kunststoffen und Kunststoffprodukten / Osterreichisches Kunststoffinstitut - Beč : Osterreichisches Kunststoffinstitut, 1999

Skup
18th International H.F. Mark-Symposium, XXIst Colloguium of Danubian Countries

Mjesto i datum
Beč, Austrija, 04.10.1999. - 06.10.1999

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Natural rubber; NR; polyisoprene

Sažetak
The two different polymers with identical specification were formulated. Used polymers were natural rubber, NR and polyisprene, IR and the effect of thermo -and foto-oxidative ageing on their crosslink junctions were studied. Network changes occurring during oxidative ageing of sulphur/accelerated NR and IR vulcanizates have been characterised by treatment with thiol-amine proba followed by crosslink density measurement. Additional information was obtained from stress-strain measurement. At the initional process of crosslinking polysulphide junctions predominate which portion is reduced with vulcanization time in favour to mono-and disulphide crosslinks. During degradation there is also first conversion of residual polysulphide crosslinks to mono- and disulphide observed, and overall crosslinking density is reset. By further ageing the cleavage of crosslinks and of main polymer chains was present, as the oxidative processes take place. Consequence of such a chemical rearrangement of crosslinks in network is variations of mechanical properties of vulcanizates.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

POVEZANOST RADA