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

Abstract

It has been estimated that more than 8.3 billion tonnes of plastics have been produced over the past decades and about 60 % of plastics have ended up either in landfills or in 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 a cross-linker in UV curing reactions with acrylated epoxidized soybean oil. Two photoinitiators, 2-hydroxy-2-methylpropiophenone and ethylphenyl (2,4,6-trimethylbenzoyl) phosphinate, were tested in different quantities. Rheological properties of compositions were monitored by real time photorheometry. The obtained polymers were characterized by differential scanning calorimetry and thermogravimetry. Polymers possessed higher storage modulus and thermal characteristics due to the higher yield of insoluble fraction when ethylphenyl (2,4,6-trimethylbenzoyl) phosphinate was used as photoinitiator.