Sulfobetaine-Modified Poly(butylene succinate) with Fine-Tuned Mechanical and Lubricating Properties in Melted Film Discs

A series of sulfobetaine-modified poly(butylene succinate) copolymers (P(BSn-<i>co</i>-cBSm)-S-SBp) were synthesized by varying the feed ratio of unsaturated <i>cis</i>-butene-1,4-diol (cBS). Six bulk disc films were fabricated, exhibiting a minimum compressive strength exceeding 30 MPa when the sulfobetaine content was between 1% and 2.5%. Notably, the zwitterionic side chains enhanced hydrophilicity and surface wettability, improving lubricity (low friction). Albumin adsorption tests revealed a 43% suppression compared to the unmodified film. The films remained stable, with cumulative weight loss ranging from less than 1% to 10% over a 45 day period under ambient hydrolytic conditions. These results highlight the potential of sulfobetaine-functionalized PBS for future utility in load-bearing or supportive materials.