High-Performance Nonisocyanate Thermoplastic Polythiourethane with High Hydrogen Bond Content

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Polymers

Background:

• Nonisocyanate polyurethanes (NIPUs) offer sustainability but face challenges with low reactivity and side reactions.
• Traditional NIPUs often compromise performance due to synthesis limitations.

Purpose of the Study:

• To develop high-performance nonisocyanate polythiourethanes (SPTU-DAs) using cyclic thiocarbonates.
• To enhance mechanical properties and overcome synthesis issues associated with NIPUs.

Main Methods:

• Synthesis of SPTU-DAs using bisphenol-S cyclic thiocarbonate and amino-terminated dimer-acid polyamides (DAPAs).
• Characterization of material properties using Differential Scanning Calorimetry (DSC), Wide-Angle X-ray Diffraction (WAXD), and Dynamic Mechanical Analysis (DMA).

Main Results:

• SPTU-DAs demonstrated crystallization and nanophase separation due to bisphenol-S hard segments and DAPA hydrogen bonding.
• Achieved high mechanical performance with a maximum strength exceeding 10 MPa.
• Rapid synthesis under mild conditions without side reactions was confirmed.

Conclusions:

• The developed SPTU-DAs exhibit superior mechanical strength compared to previously reported cross-linked NIPUs.
• Cyclic thiocarbonates offer an effective alternative to cyclic carbonates for high-performance NIPU synthesis.
• This work presents a significant advancement in achieving high-performance nonisocyanate polyurethanes.