Naslov
Molecular dynamics and heterogeneity of the styrene-acrylonitrile copolymers as viewed by electron spin resonance

Autori
Andreis, Mladen ; Veksli, Zorica ; Rogošić, Marko ; Mencer, Helena Jasna

Izvornik
Acta chimica Slovenica (1318-0207) 46 (1999), 1; 33-42

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
molecular mobility ; molecular heterogeneity ; styrene-acrylonitrile ; copolymers ; electron spin resonance

Sažetak
Molecular mobility and heterogeneity of statistical and alternating copolymers of styrene and acrylonitrile have been studied in the wide temperature range by the ESR spin probe method using two nitroxyl radicals, Tempo and Tempone. The temperature at which the maxima separation becomes 5 mT decreases with increasing styrene content. At higher temperatures above the glass transition temperature the copolymers with the smaller amount of styrene reflect motional heterogeneity. The motional difference between the statistical and alternating copolymers of a similar composition are reconciled on the basis of the sequence structure of copolymer chains. The packing of segments and the formation of motionally different domains can be explored by the adequately chosen probe even if the homopolymers have very similar glass transition temperature but differ in the polar and packing features.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Kemijsko inženjerstvo

POVEZANOST RADA