Polymerisation of α-pinene using vanadium oxide (5 wt.% metal) supported on activated carbon was carried out at room temperature and 90°C. Polymers of low molecular weight were obtained after 100 h of reaction and 30% conversion was attained. The presence or absence of light has an important role in the reaction, suggesting that α-pinene polymerisation takes place via a radical mechanism. The role of the catalyst seems to be to increase the formation of radical initiator species such as peroxides. For the bulk catalyst (1.25 g) 50% conversion was obtained after 2 h at 90°C, and only isomerisation products of α-pinene, such as camphene and tricyclene. In situ XRD was carried out using the same experimental conditions of catalyst pre-treatment, and the phases identified for the supported and bulk catalyst was a mixture of V2O5/V6O13 and V2O5. The nature of vanadium species seems to be related to the catalyst behaviour.
- Carbon support
- Vanadium catalyst