Naslov
Study of Molecular Motion in the Glassy Styrene-Acrylonitrile Copolymers and Their Solutions by the ESR and DMESR Methods

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

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

Izvornik
Abstract Book: 5th European Polymer Federation Symposium on Polymeric Materials / - Basel : Congress Department, Kongreszentrum Messe Basel, 1994

Skup
5th European Polymer Federation Symposium on Polymeric Materials

Mjesto i datum
Basel, Švicarska, 09.10.1994. - 12.10.1994

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Moleclar motion; DMESR; ESR; Styrene-acrylonitrile copolymers

Sažetak
Random styrene-acrylonitrile copolymers with different compositions and their mixtures are studied over the wide range of rotational correlation times by the DMESR and ESR spin probe methods. The glassy polymers are studied by the DMESR method which is sensitive to very slow motions. Below 190 K, which marks the internal spin probe transition, molecular dynamics of the probe is determined by the density of chain packing. Above 190 K spin probe reflects local segmental and side group motions. The mobility of spin probe becomes faster with the increasing content of polystyrene. The ESR spectra of copolymers and their mixtures in dimethylformamide and tetrahydrofuran are recorded over the wide range of concentrations. The samples with high solvent concentration , corresponding to the temperatures above the glass transition exibit a two component ESR spectra. The fraction of of the slow motion component increases with the number of acrylonitrile segments in the copolymer indicating the presence of domains of different molecular mobility.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA