Evaluation of model compounds–polypropylene film interactions by Fourier transformed infrared spectroscopy (FTIR) method

Abstract

The interactions of methyl esters, methyl ketones and aldehyde compounds with polypropylene (PP) film were investigated. PP film, placed on a glass vial, was immersed in aqueous solution containing a model flavour compound. After a determined time at 45°C, the PP film was analysed by Fourier transform infrared spectroscopy (FTIR), allowing us to follow the speed of sorption and to quantify its relative rate.For PP films, we observed that the sorption strongly depended on the structure of sorbed molecules. For each functional group of flavour compounds, the sorption increased as the carbon chain number increased. A linear chain of 12-14 carbons favours the sorption more than a linear chain of eight carbons.Concerning functions, the rate of sorption usually decreases from esters to ketones and to aldehydes. We have a good correlation between the kinetic sorption by FTIR and the SP concept.

Sorption Phenomena in Packaged Foods: Factors Affecting Sorption Processes in Package–Product Systems

“…In the case of 2‐hexanal, its sorption by LDPE increased by a factor of 40 when the pH of the solution increased from 3 to 5. Lowering the pH to 3 increased the sorption of alcohols into LDPE . There is no significant change in the sorption of aldehydes, esters and alcohols in LDPE by the addition of a few drops of acetic acid in the flavoured aqueous solution .…”

“…Safa et al also observed that for the linear components and comparable mass the linear components and comparable mass, the sorption kinetic is appreciably the same, but the rate of sorption equilibrium varied according to the following order: ester > ketone > aldehyde . Ketones and aldehydes required a much shorter time, approximately 5 h, to reach equilibrium in comparison with esters which required 15–20 h. The sorption curves for ester groups indicated a high affinity of dodecyl acetate to PP film …”

“…the length of the carbon chain). The maximum sorption was observed with large chain length: the penetration behaviour of dodecyl acetate appeared higher than that of hexyl acetate …”

“…For example, limonene is a flavour compound found in citrus fruit. Because its polarity is relatively low, it is sorbed much faster by polyolefins compared with polymers such as polyethylene terephthalate (PET) or nylon, which has polar carbonyl functional groups in its repeating monomeric units . When the difference of dielectric constant between a polymer and an aroma compound decreases, vapour sorption of the aroma compound into the polymer increases …”

Tensile properties of polypropylene fibres

“…Owing to its hydrocarbon structure, especially the presence of a tertiary Tensile properties of polypropylene fibres [22,38] C-H bond, PP is relatively sensitive to thermal and photochemical oxidation. It cannot be processed, stored or used without stabilizers [44].…”