b-Pinene cationic polymerization using Keggin heteropolyacid catalysts

New and efficient Keggin heteropolyacid (HPA) catalysts were explored for b-pinene (PI) cationic polymerization. Among them, 12-phosphotungstic acid (PW12) dehydrated at 200 C exhibited high catalytic activity. The overall PI conversion was up to 96.53%, and the obtained polymer product yield was 60.85%. In order to study this new catalyzed reaction, special techniques of FT-IR, 1 H-NMR, XRD, and XPS were used in this paper, and it was shown that the crystal structure of the heteropoly anion was not destroyed during the reaction. The protons dissociating from the catalyst played an important role in the polymerization and the HPAs had two important functions: poly- merization initiator, and the counter-anion of the growing cation center.