Cationic polymerization of β-pinene in the presence of alkylaluminum chlorides as catalysts

Abstract

Cationic polymerization of β-pinene, a naturally occurring monomer, was studied in the presence of different alkylaluminum chlorides ((iBu)3Al2Cl3, Et3Al2Cl3 и Мe2AlCl) in the solvent mixture dichloromethane/methylcyclohexane (DCM/MCH) at –78 °C. The effect of catalyst concentration [(iBu)3Al2Cl3] and various electron donors on the polymerization rat and molecular-weight characteristics of synthesized poly(β-pinenes) was investigated. Controlled cationic polymerization of β-pinene was carried out in the presence СumCl/Мe2AlCl initiating system. The polymers with controlled molecular weight up to 6400 g/mol and relatively low polydispersity (Mw/Mn < 1.42) were synthesized. Microstructure of synthesized poly(β-pinene) was investigated by 1H NMR spectroscopy.

Keywords

• β-pinene
• cationic polymerization
• alkylaluminum chlorides
• controlled cationic polymerization
• electron donor
• proton trap