Renewable Beta-Elemene Based Cyclic Carbonates for the Preparation of Oligo(hydroxyurethane)s

Area of Science:

• Polymer Chemistry
• Organic Synthesis
• Materials Science

Background:

• Biobased polymers offer sustainable alternatives to petroleum-derived materials.
• Non-isocyanate polyurethanes (NIPUs) are gaining interest due to safety and environmental advantages.
• β-elemene, a natural product, presents a potential renewable feedstock for polymer synthesis.

Purpose of the Study:

• To synthesize novel β-elemene dicarbonates.
• To investigate the step-growth polyaddition of these dicarbonates with various diamines.
• To evaluate the properties and potential applications of the resulting biobased oligo(hydroxyurethane)s.

Main Methods:

• Epoxidation of β-elemene followed by halide salt-catalyzed CO2 cycloaddition.
• Polyaddition reactions conducted under neat conditions at 150°C.
• Characterization of oligo(hydroxyurethane)s including molecular weight, dispersity, and glass transition temperatures.
• Scale-up of a selected polyhydroxyurethane and formulation for coating applications.

Main Results:

• Successful synthesis of β-elemene dicarbonates.
• Formation of non-isocyanate-based oligo(hydroxyurethane)s with molecular weights (M_n) between 1.3–6.3 kDa and dispersities (Đ) of 1.3–2.1.
• A wide range of glass transition temperatures (-59 to 84°C) were achieved depending on the diamine used.
• Scale-up to 43 g was successful, and the resulting material showed potential in coating formulations.

Conclusions:

• β-elemene can be effectively converted into dicarbonates for polymer synthesis.
• The developed biobased oligo(hydroxyurethane)s possess tunable properties.
• These materials demonstrate promise for the development of sustainable, high-performance coatings.