Microwave-Assisted Cationic Polymerization of Turpentine: Change in Infrared and Ultraviolet Spectra

Abstract

Indonesia is a turpentine producer country. So far, only one factory is carrying out turpentine fractionation to increase its selling price. Chemical conversion is necessary to produce more valuable derivatives of this renewable biomass-based material. In this experiment, turpentine as the raw material and the four products: α-pinene, β-pinene, limonene, and δ-carene were reacted successively with sulfuric acid, hydrochloric acid, nitric acid, and ethereal boron trifluoride, respectively. The reaction products were further irradiated using a commercial microwave oven. The raw material composition, functional group, and ultraviolet absorption were analyzed using a gas chromatograph, Fourier transforms infrared spectrophotometer, and UV-Vis spectrophotometer, respectively. Half of the reaction products were neutralized with sodium bicarbonate whether or not it irradiated. All products which viscous colored liquid was examined on their ultraviolet and infrared spectrum. The turpentine reacted with sulfuric acid and boron trifluoride ethereal produced a brownish viscous liquid, but did not react with hydrochloric acid and nitric acid. The reaction products with sulfuric acid and boron trifluoride ethereal and microwave irradiation processes showed some shifts on the infrared spectra, particularly in C=C band due to to the polymerization and C=C reforming reaction. The products also demonstrate the presence of OH group in the infrared spectra.