Sulfobetaine-based polydisulfides with tunable upper critical solution temperature (UCST) in water alcohols mixture,...

Area of Science:

• Polymer Chemistry
• Materials Science

Background:

• Sulfobetaine-containing polymers are known for their thermoresponsive properties.
• Polydisulfide backbones offer potential for stimuli-responsive degradation.
• Natural (R)-lipoic acid provides a chiral and biocompatible building block.

Purpose of the Study:

• To synthesize and characterize novel sulfobetaine-based polydisulfides.
• To investigate the tunable upper critical solution temperature (UCST) behavior of these polymers.
• To explore the stimuli-responsive depolymerization and surface wettability of the synthesized materials.

Main Methods:

• Synthesis of dithiolane derivatives and their polymerization into sulfobetaine-bearing polydisulfides.
• Characterization using UV-vis and circular dichroism (CD) spectroscopy.
• Investigation of UCST behavior in various aqueous alcohol mixtures and surface wettability studies.

Main Results:

• Polymers exhibited tunable UCST behavior, with cloud points increasing in lower polarity solvents and higher alcohol concentrations.
• Thermoresponsive behavior was repeatable, fully reversible, and showed negligible hysteresis.
• Monomer regeneration via depolymerization was controllable by temperature and sunlight.
• Tunable surface wettability was demonstrated on grafted polymer surfaces.

Conclusions:

• This study presents the first report of sulfobetaine-based polydisulfides with tunable UCST behavior and surface wettability.
• The synthesized polymers demonstrate potential for applications requiring stimuli-responsive materials.
• The combination of a cleavable polydisulfide backbone and thermoresponsive sulfobetaine groups offers versatile material design possibilities.