Naslov
How hydrotalcites function as PVC secondary stabilisers

Autori
Gilbert, Marianne ; Chin Ho, Kok ; Hitt, David J ; Vrsaljko, Domagoj

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Conference papers PVC 2011 / Melanie Boyce - Brighton : IOM Communications Ltd, 2011, 443-453

Skup
PVC 2011

Mjesto i datum
Brighton, Ujedinjeno Kraljevstvo, 12.04.2011. - 14.04.2011

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
PVC; UPVC; PPVC; degradation; Raman spectroscopy; UV/visible spectrophotometry; hydrotalcite

Sažetak
Hydrotalcites are increasingly used as secondary stabilisers for PVC and are believed to function by reacting with chlorine anions. Various concentrations of hydrotalcites Alcamizer P93 and Sorbacid 911 have been investigated in basic rigid (UPVC) and flexible (PPVC) formulations. Degradation at 180C has been assessed by colour change, UV spectroscopy and Raman spectroscopy and solubility changes. Before ageing, UPVC samples had similar UV/visible traces almost irrespective of hydrotalcite concentration but for PPVC unsaturation increased with concentration. In terms of colour, and unsaturation, addition of hydrotalcite improved the long term stability of PVC, with the best results obtained with 2phr Sorbitol. 5phr hydrotalcite produced intense colouration, but after 160min ageing the sample was fully soluble. Lack of crosslinking meant that long polyene sequences were present. For PPVC, no visible discolouration was observed until after 130min ageing, when the sample without hydrotalcite blackened rapidly. Colour, and the intensity of Raman C=C peaks decreased with increase in hydrotalcite concentration. For PPVC hydrotalcite appeared to prevent both crosslinking, and the formation of long sequences.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

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