β-Pinene cationic polymerization using Keggin heteropolyacid catalysts

Abstract

New and efficient Keggin heteropolyacid (HPA) catalysts were explored for b-pinene (PI) cationic polymerization. Among them, 12-phosphotungstic acid (PW 12 ) 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: polymerization initiator, and the counter-anion of the growing cation center.

Cationic polymerization of isobutylene at room temperature

“…Thus, heteropolyacids or their salts represent an interesting and promising type of catalysts for the cationic polymerization at room temperature. Apart from IB, these catalysts were used recently for the cationic polymerization of styrene78 and β‐pinene79 at ambient temperatures (−10 to 20 °C).…”

Room temperature cationic polymerization of β-pinene using modified AlCl3 catalyst: toward sustainable plastics from renewable biomass resources

“…Among Lewis acids investigated, 2,3 aluminum chloride (AlCl 3 ) or its derivatives (ethylaluminum dichloride, EtAlCl 2 ) were the most effective and therefore commonly used in the commercial production of poly(b-pinene)s. 3 However, these catalysts resulted in low molecular weight polymers (M n £ 4000 g mol -1 ) with poor thermal properties (T g £ 65 • C) even at low reaction temperatures (0 • C to -40 • C) 5-7 that limited the commercial application of poly(b-pinene)s (terpene resins) as pressure-sensitive adhesives, hot-melt coatings or tackifying additives. 3,8 Neither the use of the inifer technique 9-11 or even living cationic polymerization 4 nor the use of heteropolyacid as a catalyst 12 could improve the molecular weight of the polymers obtained.…”

Heteropolycompounds as catalysts for biomass product transformations

“…Polymers formed from terpenes are called terpene resins, and can be used in many industrial applications: as pressure-sensitive adhesives, holt-melt coatings, tackifying agents and additives in rubber, among others 351 . In some cases heteropolycompounds may act as initiators, in others they are the catalysts 352 , while in other cases they play the two roles: as both the initiator and the catalyst 353 .…”