Turpentine as an alternative solvent for the extraction of gutta-percha from Eucommia ulmoides barks

Turpentine was used in the extraction of gutta-percha from Eucommia ulmoides barks. The Box-Behnken experimental design was used to optimize the extraction parameters. The optimized conditions were 25 mL/g liquid to solid ratio, 82.6 °C reaction temperature, and 1.0 h heating time, which resulted in a practical gutta-percha extraction efficiency of 80.46 ± 2.55 mg/g. The obtained samples of gutta-percha were analyzed by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR). The GPC results showed the molecular weight distribution (MWD) of gutta-percha from the barks was between 2.9 × 10 3 and 3.8 × 10 5 using turpentine as the extraction solvent, and the MWD was between 1.7 × 10 3 and 9.7 × 10 5 when petroleum ether was used as the extraction solvent. Turpentine showed promise as an alternative extraction solvent compared to traditional organic solvents for the extraction of gutta-percha from Eucommia ulmoides barks.