The process of photopolymerization of acrylated soybean oil-based epoxides investigated by positron annihilation lifetime spectroscopy

The lifetime spectra of positrons annihilating in polymer matrices based on acrylated epoxidized soybean oil (AESO) and a mixture with vanillin-dimethacrylate (VDM) were measured. The chemical structure of the polymer series AESO and AESO-VDM was investigated by NIR spectroscopy. The semi-empirical quantum mechanical Tao-Eldrup model was used to estimate the sizes of individual free volumes in these matrices. Investigation of free-volume properties of polymer matrices based on natural oils, which are intended for the construction of amperometric biosensors, allows a better understanding of the relationship between the crosslinking densities of the matrices, i.e. microscopic characteristics, and the main operating parameters of the biosensors. The free volumes of the investigated matrices before, during and after the photopolymerization process were determined. The influence of vanillin-dimethacrylate (VDM) and photoinitiator (PI) on the final microstructural properties of the investigated matrices was evaluated.