Sulfur-rich polymers from elemental sulfur-derived polysulfide salts and bisepoxides

Abstract

The obtainment of polymeric materials out of green, renewable, or sustainable building blocks is an ongoing research area. Due to its large-scale derivation as a by-product of the petroleum industry and natural abundance, elemental sulfur is a prospect to ensure the sustainable production of diverse functional polymeric materials. In the present study a simple yet efficient synthesis of sulfur-rich polymers from elemental sulfur-derived polysulfide salts and bisepoxide monomers was reported. Nucleophilic ring opening step growth polymerization of bisepoxide compounds with bifunctional sulfur derivative sodium pentasulfide (Na2S5) allowed tailorable access to novel linear copolymers with polysulfide chains in the backbone and hydroxyl groups at the side chains. Functional copolymers in the range from 14.8 kDa to 24.5 kDa molecular weights (Mn) were obtained with relatively high monomer conversions (69–91 %). By simple alteration of employed bisepoxide monomers, structurally diverse copolymers were obtained. The polymerizations were efficiently conducted at ambient temperature without the need of any catalyst. Obtained copolymers incorporated alternating hydroxyl functionalities at polymer side chains which were employed as reactive handles for post-polymerization modification. By employing a multifunctional epoxide crosslinker, chemically crosslinked polymers were also fabricated. These crosslinked polymers were shown to be utilized as adsorbents for mercury removal from water. The obtained results in this study demonstrated that the proposed methodology can be employed to synthesize and fabricate structurally diverse sulfur-rich polymers that might find potential use in various material applications.