Naslov
Influence of MBS on the thermooxidative degradation of stabilized and nonstabilized PVC/MBS blends

Autori
Andričić, Branka ; Kovačić, Tonka

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

Izvornik
7th European symposium on polymer blends / Jean-Pierre Pascault - Lyon : INSA -Lyon, 2002

Skup
7th European Symposium on Polymer Blends

Mjesto i datum
Lyon, Francuska, 27.05.2002. - 29.05.2002

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
PVC/MBS blends; thermooxidative degradation

Sažetak
The thermooxidative degradation of PVC/MBS blends with/without thermal stabiliser for PVC was investigated by dynamic thermogravimetry in air. Thermooxidative degradation proceeds through three main degradation steps. The first one corresponds to the dehydrochlorination (DHC) of PVC followed by the polyene oxidation ; the second and the third steps correspond to the simultaneous degradation of PVC and MBS. It was found that, besides PVC, the thermal stabiliser stabilises MBS, too. The mass loss in the first degradation step is a few percents higher in stabilised PVC/MBS samples. Comparison of experimental and theoretical TG curves of the blends shows the stabilising effect of MBS on dehydrochlorination and the opposite effect on further degradation. This is more pronounced in stabilised blends with higher amount of MBS. Relative DHC rate in the blends with respect to pure PVC differs in stabilised and nonstabilised blends and implies additional stabilising effect of MBS in the stabilised blends. The kinetic parameters of the first degradation step were estimated by Kissingers equation. In both blend series the linear relationship between Arrhenius parameters E and A was found and the compensation parameter Sp* was taken as a measure of system reactivity, although there are many controversies about Sp*. Generally, the higher value of the parameter means the lower reactivity of the system. The lowest Sp* is exhibited by the samples with 15 and 20 phr of MBS in nonstabilised blends, and with 20 and 30 phr of MBS in stabilised ones. Glass transition temperature (Tg) of PVC in the blends, determined by DSC, shows no interaction of PVC with glassy phase of MBS. PVC in stabilised blends has lower Tg than in unstabilised blends due to the presence of heat stabiliser as a low molecular component miscible with PVC.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

POVEZANOST RADA