Synthesis and characterization of polylimonene: Polymer of an optically active terpene

Radical polymerization of limonene (limonene) using benzoyl peroxide (BPO) as an initiator at 85 degrees C +/- 1 degrees C under an inert atmosphere of nitrogen in xylene as solvent was carried out. The system follows nonideal kinetics: Rp alpha[I]0.3 [M]1.4, due to both primary radical termination and degradative chain transfer reaction. The activation energy of the polymerization was estimated to be 22.97 kJ mol-1. 1H-NMR spectrum of polymer shows the presence of a triplet between 2 and 2.5 d, which reveals that beta-carbon of limonene is the active site in the polymerization of limonene. The FTIR spectrum of the polymer shows band at 1645 cm-1 due to gem disubstituted C = C stretching vibrations. The glass transition temperature (Tg) of the polylimonene of the polylimonene is 116 degrees C. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012