Fully Bio-Based Polymers Derived from Acrylated Epoxidized Soybean Oil by Thiol-ene Reaction

Researchers estimate that more than 8.3 billion tonnes of plastic has been produced over the past decades and about 60 % of plastic has ended up in either a landfill or the natural environment. With the rapid growth of consumerism, research on innovative starting materials for preparation of polymers may help to reduce the negative impact of petroleum-based plastic materials on the global ecosystem and on animal and human health. Therefore, photochemical thiol-ene coupling reaction of squalene was performed to obtain thiol functional groups. Then, hexathiolated squalene was used as cross-linker in UV curing reactions with acrylated epoxidized soybean oil. Two photoinitiators (2-hydroxy-2-methylpropiophenone and ethylphenyl (2,4,6-trimethylbenzoyl) phosphinate) in different quantities were tested. Rheological properties of compositions were monitored by real time photorheometry. The obtained polymers were characterized by differential scanning calorimetry and thermogravimetry. Polymers had higher rheological and thermal properties due to highest cross-linking density when ethylphenyl (2,4,6-trimethylbenzoyl) phosphinate was used in the compositions.

Acknowledgements. This research was funded by the Research Council of Lithuania (project No. S-MIP-20-17).