Polythioesters Prepared by Ring-Opening Polymerization of Cyclic Thioesters and Related Monomers

Area of Science:

• Polymer Chemistry
• Materials Science
• Organic Synthesis

Background:

• Polyhydroxyalkanoates (PHAs) are biodegradable polyesters with potential as plastic alternatives.
• Incorporating sulfur into PHAs creates polythioesters (PTEs) with improved thermal, optical, and mechanical properties.
• PTEs are gaining attention for their enhanced versatility and applications.

Purpose of the Study:

• To review recent advancements in the synthesis of well-defined polythioesters (PTEs).
• To cover ring-opening polymerization (ROP) and ring-opening copolymerization (ROCOP) methods for PTE synthesis.
• To analyze monomer reactivity, catalyst systems, and control over PTE properties.

Main Methods:

• Ring-opening polymerization (ROP) of cyclic thioesters (thiolactones, S-carboxyanhydrides, thionolactones).
• Ring-opening copolymerization (ROCOP) of cyclic thioanhydrides or thiolactones with epoxides or episulfides.
• Anionic polymerization using various initiators/catalysts and some enzymatic reactions.

Main Results:

• ROP and ROCOP enable the synthesis of well-defined PTEs.
• Monomer ring-size (4- to 7-membered cycles) influences reactivity.
• Catalyst systems impact activity and control over PTE molar mass, dispersity, topology, and microstructure.

Conclusions:

• Recent advances in ROP and ROCOP provide effective routes to synthesize tailored PTEs.
• Understanding monomer and catalyst interactions is crucial for controlling PTE properties.
• PTEs represent a promising class of biodegradable materials with tunable characteristics.