Renewable sulfur-containing thermoplastics via AB-type thiol-ene polyaddition

Polythioethers with molar masses up to 40 kDa were prepared by UV- or thermal initiated thiol-ene polyaddition polymerization of an aliphatic α-olefinic ω-thiol, an AB-type monomer derived from 10-undecenoic acid, which is a bio-sourced building block obtained from castor oil. The low polarity of the starting compound and the stability of the thioether functions formed during polymerization allowed for the synthesis of polymers with similar structures to existing bulk and engineering plastics such as polyethylene. The presence of the thioether functions offered the opportunity to oxidize these polyethylene analogues by hydrogen peroxide into sulfone linkages, resulting in polysulfones, which are valuable as engineering plastic in several application fields. Thermal analysis demonstrated the increased thermal stability and melting temperature (175 °C) of these polysulfones.