Dithioketal Polymers Via Radical Polymerization of γ-Dithiobutyrolactone

Area of Science:

• Polymer Chemistry
• Materials Science

Background:

• Polymers with dithioketal groups exhibit unique properties like reactive oxygen species (ROS)-responsiveness and vitrimer behavior.
• Previous synthesis of dithioketal polymers relied on step-growth polymerization or polyaddition methods.

Purpose of the Study:

• To report the first instance of chain polymerization for synthesizing dithioketal polymers.
• To investigate the copolymerization of gamma-dithiobutyrolactone (DTBL) with conjugated monomers.
• To elucidate the factors influencing ring-retention versus ring-opening during polymerization.

Main Methods:

• Radical copolymerization of gamma-dithiobutyrolactone (DTBL) with various conjugated monomers.
• Density Functional Theory (DFT) calculations to analyze polymerization mechanisms.
• Demonstration of DTBL incorporation into diverse polymer architectures.

Main Results:

• Successful synthesis of dithioketal polymers via chain polymerization, preserving ring structures.
• DFT calculations revealed electronic effects governing DTBL's polymerization behavior compared to its analogue, gamma-thionobutyrolactone (TBL).
• DTBL was shown to impart degradability to thermosets, latexes, and complex architectures synthesized via RAFT.

Conclusions:

• Chain polymerization offers a new route to dithioketal-containing polymers.
• Understanding the electronic properties of monomers is crucial for controlling polymerization outcomes.
• DTBL is a versatile building block for creating degradable advanced polymer materials.