Experimental and numerical study of sorption/diffusion of esters into polypropylene packaging films

Abstract

The sorption and diffusion of four esters into polypropylene packaging ®lms immersed in four different solutions have been studied by the FTIR method at 45°C. Kinetic curves have been generated for these systems to compute diffusion coef®cients. The calculated results are discussed in terms of size and shape of diffusing molecules into a polymer ®lm. Isovalues and pro®les of liquid concentrations have been calculated by solving Fick's diffusion equation using a numerical method based on a two-dimensional ®nite element method.

Measurement of transport phenomena of volatile compounds: A review

“…This technique was also applied to calculate the diffusion coefficient of several esters into polypropylene in the presence of water and/or fats. The results, however, were not compared to those obtained with other techniques (Safa & Abbes, 2002). The main drawback of the FTIR technique is its low limit of detection and a potentially high level of overlapping bands in the study of multi-component diffusion, making identification or analysis difficult.…”

“…FTIR spectroscopy was recently introduced to determine the diffusion of aroma compounds through packaging films(Cava, Lagaró n, Ló pez-Rubio, Catalá, & Gavara, 2004;Cava, Catala, Gavara, & Lagaron, 2005;Safa & Abbes, 2002).…”

The Role and Potential of Vibrational Spectroscopy in the Study and Characterization of Traditional and Novel Food Packaging Structures

“…31,32 There is also a recent study performed using transmission FT-IR spectroscopy, where the sorption and diffusion of several esters in PP were investigated in a stepwise manner, but no comparison was made with other methods. 33 The use of an ATR accessory has the advantages, over typical measurements in transmission, of offering the possibility of the simultaneous study of accurate sorption and diffusion processes during sorption, of characterizing the effect of temperature over sorption, and of the estimation of swelling rate and swelling rate factors. On the other hand, the technique has the drawbacks of only measuring the properties near the surface of a polymer (in some cases, obtained by casting from solution to achieve and ensure a good adhesion between the ATR crystal and the film) and of having a complex relationship between absorbance and concentration.…”

Ethyl hexanoate transfer in paper and plastic food packaging by sorption and permeation experiments

“…Inverse gas chromatography (IGC) was also used to a lesser extent to determine thermodynamic and kinetic parameters linked to aroma compounds and packaging film interactions (Gavara et al, 1996a(Gavara et al, , 1997. Fourier transform infrared (FT-IR) spectroscopy was recently introduced to determine aroma compound diffusion through packaging films (Cava et al, 2004(Cava et al, , 2005Safa and Abbes, 2002) and seems to be a promising technique. The determination of the transport coefficient is made during desorption of aroma compounds from packaging films.…”