Polysulfamates as "Macroisosteres" of Polyurethanes with Improved Degradability

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Chemistry

Background:

• Environmental persistence of plastics necessitates advanced polymers with both high performance and degradability.
• A lack of a general design blueprint has hindered the development of such materials.
• Bioisostere strategies in drug discovery offer inspiration for polymer design.

Purpose of the Study:

• To introduce a "macroisostere" design strategy for creating novel degradable polymers.
• To replace the carbonyl group in polyurethanes (PUs) with a sulfonyl group, forming polysulfamates.
• To evaluate the thermomechanical properties and degradability of these new polysulfamates.

Main Methods:

• A "macroisostere" approach was employed, substituting carbonyl (-CO-) with sulfonyl (-SO2-) groups.
• Sulfur(VI) Fluoride Exchange (SuFEx) polymerization was optimized for synthesis.
• Comparative analysis of a polyurethane and its polysulfamate analog was conducted.

Main Results:

• Ten polysulfamates analogous to common PUs were synthesized.
• Polysulfamates exhibited increased thermal stability and slightly lower glass transition temperatures compared to PUs.
• Similar hardness and reduced Young's modulus were observed, alongside significantly enhanced hydrolytic degradability.

Conclusions:

• The "macroisostere" approach is a viable strategy for designing high-performance, degradable polymers.
• Polysulfamates represent a promising class of materials as alternatives to traditional plastics.
• This method offers a generalizable blueprint for future sustainable polymer development.