Ultra-Tough Elastomers from Stereochemistry-Directed Hydrogen Bonding in Isosorbide-Based Polymers

Area of Science:

• Polymer Chemistry
• Materials Science
• Organic Synthesis

Background:

• Natural elastomers possess remarkable elasticity and tensile strength, properties difficult to replicate in synthetic counterparts.
• Conventional synthetic elastomers (rubbers) rely on covalent cross-linking, which impedes reprocessability.
• Existing reprocessable elastomers using physical cross-linking often compromise performance.

Purpose of the Study:

• To synthesize novel, ultra-tough, and reprocessable elastomers.
• To investigate the structure-property relationships of elastomers based on linear alternating polymers incorporating isohexide and urethane moieties.
• To explore the impact of stereochemistry on elastomer performance.

Main Methods:

• Synthesis of linear alternating polymers incorporating isohexide and urethane groups.
• Characterization of elastomer mechanical properties, including strain hardening and strain rate dependence.
• Analysis of optical clarity and strain recovery.
• Correlation of polymer regiochemistry and inter-chain hydrogen bonding with observed properties.

Main Results:

• Successfully synthesized ultra-tough, reprocessable elastomers with high optical clarity.
• Demonstrated exceptional strain hardening and strain rate dependent behavior.
• Observed superior tensile strength and strain recovery in isosorbide-based elastomers compared to isomannide-based ones.
• Attributed performance differences to regiochemical irregularities and inter-chain hydrogen bonding influenced by stereochemistry.

Conclusions:

• Linear alternating polymers with isohexide and urethane moieties offer a promising route to high-performance, reprocessable elastomers.
• Stereochemistry plays a crucial role in dictating polymer structure and inter-chain interactions, significantly impacting mechanical properties.
• These findings provide a new strategy for designing advanced elastomers with tunable properties for diverse applications.