Naslov
ESR Study of NR/montmorillonite Nanocomposites

Autori
Didović, Mirna ; Valić, Srećko ; Klepac, Damir ; Meera, A.P. ; Thomas, Sabu

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

Izvornik
Book of Abstracts / Musić, Svetozar ; Ristić, Mira ; Krehula, Stjepko - Opatija, 2008, 159-159

Skup
XXIX European Congress on Molecular Spectroscopy (EUCMOS)

Mjesto i datum
Opatija, Hrvatska, 31.08.2008. - 05.09.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
ESR; spin probe; natural rubber; clay; nanocomposites

Sažetak
Nanocomposites of natural rubber (NR) containing 2, 5 and 10 phr of organically modified clay (montmorillonite) were prepared in order to study the influence of the filler content on the local chain dynamics and motional heterogeneity of the composite system via electron spin resonance (ESR) and to correlate the ESR results with those obtained by other methods. The dispersion of the clay in the polymer matrix was examined by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Thermal behaviour of the composite material, as well as of the pure clay, was investigated by differential scanning calorimetry (DSC). ESR spectra were measured in the temperature range from -100 º C to 130 º C, using the spin probe method. ESR spectra reflect significant differences in the local chain dynamics and motional heterogeneity of the composite material in comparison with the pristine NR, especially in the high temperature region. The shape of the spectra varied with the filler content and with the type of distribution of the clay particles, in accordance with SEM results. An increase in the amount of the broad component is observed at the temperatures above 100 º C, indicating hindered motion of the chain segments. DSC results of the composite material indicate that Tg is not affected by addition of the clay ; DSC curve of the pure clay shows an endothermic peak around 40 º C, which corresponds to the melting of the clay and is shifted towards higher temperatures when clay is incorporated in the polymer matrix. Hence, hindered motion of the chain segments observed at higher temperatures can be related to the melting of the clay particles.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA