Multicomponent Polymerizations Provide Sustainable Sulfur (Selenium)-Containing Polyesters

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Chemistry

Background:

• Growing polymer industry creates sustainability challenges.
• Degradable plastics are crucial for environmental sustainability.
• Need for improved performance in degradable polyesters, particularly those with sulfur functional groups.

Purpose of the Study:

• To develop efficient multicomponent polymerization methods for synthesizing degradable polyesters.
• To incorporate sulfur/selenium functional groups into polyesters for enhanced properties.
• To achieve tunable structures and properties in novel degradable polymers.

Main Methods:

• Utilized multicomponent polymerization with readily available monomers like diols, diamines, H2O, diacrylates, carbonyl sulfide (COS), cyclic thioanhydrides, CO, and selenium powder.
• Conducted polymerization under mild conditions (60-90 °C, 2-12 h) using organobase catalysts or catalyst-free.
• Simultaneously incorporated in-chain ester and sulfur/selenium functional groups (thiocarbonate, thioether, thioester, thiourethane, selenoether).

Main Results:

• Synthesized diverse degradable polyesters with tunable structures and weight-average molecular weights up to 175.4 kDa.
• Achieved high thermal stability (>200 °C decomposition) and tunable performance (crystalline, thermoplastic elastomers, amorphous plastics).
• Demonstrated tunable glass-transition temperatures (-60 to 72 °C) and melting temperatures (43 to 274 °C), with polyethylene-like properties for long alkyl chain polymers.
• Incorporation of thiourethane/amide groups enhanced thermal and mechanical properties via hydrogen bonding.
• Polymers exhibited facile degradation via hydrolysis, oxidation, and other methods, yielding value-added products for potential repolymerization.

Conclusions:

• The multicomponent polymerization offers a facile and versatile route to sustainable polymers.
• The developed method allows for precise control over polymer structure, properties, and degradability.
• These novel polymers hold significant potential as environmentally benign plastics with enhanced performance and recyclability.