Synthesis, properties, and degradation behaviors of novel polysulfone-polysiloxane multi-block copolymers

The design and application of polysulfone-polysiloxanes block copolymers remains as a big challenge mainly owing to limited synthetic methods of sulfone prepolymers. In this contribution, vinyl-terminated poly (siloxane sulfone) (PSS) was applied as the hard segment to obtain novel polysulfone-polysiloxane multi-block copolymers by hydrosilylation with hydride-terminated polysiloxane (PDMS-H) for the first time. The new vinylfunctionalized sulfone prepolymers were prepared by ring-opening polymerization of benzylsulfonyl macroheterocyclosiloxane (BSM) using divinyltetramethyldisiloxane as end-capping reagent and KOH as a catalyst, which differs from the traditional condensation methods. Based on the polysulfone prepolymers, a better control of the molecular weight of the obtained polymers was achieved, affording relatively low PDI. Their morphological properties were investigated by atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS), which revealed a mild microphase separation in the copolymers. Their surface and fluorescence properties can be effectively tuned by changing the PSS content. Besides, the obtained copolymers exhibited high hydrolytic and thermal-oxidative stability, and underwent a controlled and effective degradation into the starting benzylsulfonyl macmheterocyclosiloxane with a high conversion of 85% in the presence of KHSO 4 at room temperature. This strategy may provide new ideas for the design and application of new polysulfone-polysiloxanes block copolymers.