Facile Synthesis of High-Molecular-Weight Biobased Polythioethers with Outstanding Mechanical Properties and Intrinsic Antiultraviolet Performance

Common methods, including adding inorganic and organic ultraviolet (UV) absorbers, for preparing anti-UV polymers inevitably have the disadvantages of poor stability, low transparency, and coloration of samples. To overcome these shortcomings, high-molecular-weight polythioethers with excellent intrinsic anti-UV performance were prepared by anion ring-opening polymerization of episulfides derived from the biobased epoxides containing a substituted phenyl group. The mechanical properties, reprocessability, and anti-UV performance of polythioethers were significantly improved through copolymerization and cross-linking modification. A cross-linked copolythioether displayed a UV protection factor value of 91.8 and a light transmittance of over 68% in the visible range and moreover exhibited outstanding mechanical properties with a tensile strength of 17.9 MPa and an elongation at break of 534%. The mechanical properties and anti-UV performance of copolythioether decreased significantly after prolonged exposure to UV light, while the cross-linked copolythioether maintained good stability. This work provided a feasible method for preparing colorless, transparent, and high-performance intrinsic anti-UV polythioethers, which can be used in the manufacture of lenses and can effectively prevent UV-light damage to the eyes.