Mass transfer kinetics and diffusion coefficient estimation of bioinsecticide terpene ketones in LDPE films obtained by supercritical CO2-assisted impregnation

GOÑI, MARÍA LAURA; GAÑÁN, NICOLÁS ALBERTO; MARTINI, RAQUEL EVANGELINA; STRUMIA, MIRIAM CRISTINA

JOURNAL OF APPLIED POLYMER SCIENCE

JOHN WILEY & SONS INC

Año: 2017 vol. 134

0021-8995

elease kinetics of thymoquinone and R-(+)-pulegone impregnated in low-density polyethylene (LDPE) films into air and the effect of supercritical CO2-assisted impregnation process on the diffusional properties of these films were investigated. The incorporation of both ketones into LDPE films was performed under different conditions (pressure, depressurization rate, time, and initial ketone mole fraction). Release experiments were performed under controlled laboratory conditions (24 °C, 60% relative humidity), and the total release profile was determined gravimetrically, while the individual release of each ketone was quantified by Fourier transformed infrared. The experimental data were used to fit a mass transfer model based on the second Fick´s law for unsteady-state diffusion, and the diffusion coefficients of both ketones in LDPE were estimated, ranging from 2.35 × 10−13 to 5.53 × 10−13 m2 s−1 (thymoquinone) and from 1.24 × 10−13 to 4.52 × 10−13 m2 s&