Modeling of the Migration of Glycerol Monoester Plasticizers in Highly Plasticized Poly(vinyl chloride)

Different migration models were evaluated on the basis of data from migration experiments carried out by Danisco in 2005. The migration experiments were set up to investigate the behavior of the three plasticizers GRINDSTED (R) SOFT-N-SAFE (SNS), GRINDSTED (R) ACETEM 95 CO (Acetem), and epoxidized soybean oil (ESBO) with regard to their migration from three different types of poly(vinyl chloride) into isooctane at 20, 40, and 60 degrees C. Diffusion coefficients derived from the experimental migration data were evaluated against diffusion coefficients estimated from a model based solely on the migration data for ESBO. The diffusion coefficient estimation model proved to be very good in estimating the diffusion coefficients at 20 degrees C but overestimated them at 40 degrees C and 60 degrees C. By using a migration model originally derived by Kontominas [Kondyli et al., Polymer, 34,2592 (1993)] and the estimated diffusion coefficients, it was possible to obtain a more satisfactory representation of the experimental migration data at 40 degrees C than that obtained with the commonly used migration model of Crank [Crank, Mathematics of diffusion, (1956)] based on the experimental diffusion coefficients. J. VINYL ADDIT. TECHNOL., 15:147-158, 2009. (C) 2009 Society of Plastics Engineers