Thermo-Mechanically Driven Hierarchical Evolution in Polyurethane Elastomers Subjected to Compression Fatigue.
Min Wang1,2, Yushu Tian1,2, Jihang Yu1,2
1State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China.
ACS Applied Materials & Interfaces
|October 20, 2025
Summary
Polyurethane elastomers (PUEs) with high microphase separation resist fatigue by managing heat and maintaining structural integrity. Low separation PUEs fail faster due to heat buildup and structural collapse.
Area of Science:
- Materials Science
- Polymer Science
- Mechanical Engineering
Background:
- Polyurethane elastomers (PUEs) are vital for demanding applications but degrade under compressive fatigue due to heat accumulation.
- The complex interplay between heat, mechanics, and microstructural changes in PUEs under fatigue is not fully understood.
Purpose of the Study:
- To investigate the thermo-mechanical behavior and microstructural evolution of PUEs with varying degrees of microphase separation under cyclic compression.
- To establish a structure-property relationship for designing fatigue-resistant PUEs.
Main Methods:
- Design and synthesis of PUEs with low (LP) and high (HP) microphase separation.
- Synchronized temperature-field monitoring and multiscale characterization techniques.
- Analysis of microstructural changes (hard segment domains, spherulites) under cyclic compression.
Main Results:
- LP-PUEs exhibited rapid heat buildup, disordered hard segment domains, and spherulite fragmentation leading to structural collapse and a 17.2% compression set.
- HP-PUEs demonstrated stress distribution via lamellar reorientation and controlled spherulite fragmentation, preserving structural integrity.
- HP-PUEs showed superior fatigue durability with a significantly lower compression set (6.2%).
Conclusions:
- The study elucidates the distinct thermo-mechanical evolution pathways in PUEs based on microphase separation.
- A clear structure-property relationship was established, highlighting the importance of ordered hard-segment networks for fatigue resistance.
- Findings provide a basis for designing advanced PUEs with enhanced durability for high-stress applications.
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