Polymerization of β-pinene by using natural montmorillonite clay as a green catalyst

β-Pinene issued from pine trees is an essential compound for the fine chemical industry. It is the precursor of non-toxic and inert poly(β-pinene) used as additive for rubbers, food packaging and casting industries and in the production of chewing gums. In this paper, the authors report an efficient and environmentally friendly method to produce poly(β-pinene). The authors have used a montmorillonite clay (Maghnite) as a heterogeneous non-toxic catalyst to initiate β-pinene polymerization. Spectroscopic methods such as Fourier-transform infrared spectroscopy, proton (¹H) nuclear magnetic resonance, gel permeation chromatography and viscosimetric measurements were used to confirm the structure of the obtained poly(β-pinene). In order to find the optimal reaction conditions, the effects of temperature, reaction time, amount of catalyst and solvent on the yield of the reaction and on the average molecular weight (M _v) of the resulting poly(β-pinene) were studied. The thermal properties (differential scanning calorimetry) of the resulting poly(β-pinene) were also studied.