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Preparation and Friction Force Microscopy Measurements of Immiscible, Opposing Polymer Brushes
Published on: December 24, 2014
Chain pullout and mobility effects in friction and lubrication
Science (New York, N.Y.)
|March 11, 1994
Summary
Interfacial shear stress measurements reveal that polymer segment mobility significantly impacts friction. Highly mobile materials on both sides of the interface result in lower stress, while thin tethered chains can increase friction.
Area of Science:
- Polymer Science
- Tribology
- Materials Science
Background:
- Understanding polymer interfacial behavior is crucial for applications like lubricants and polymer processing.
- Interfacial shear stress governs phenomena such as wall slip and melt fracture in polymers.
Purpose of the Study:
- To measure the interfacial shear stress between a mobile polymer network (elastomer) and an immobile (glassy) polymer surface.
- To investigate the influence of segment mobility and tethered chain layers on interfacial friction.
Main Methods:
- Sliding a highly mobile polymer network over a smooth glassy polymer surface coated with end-attached mobile chains.
- Ensuring no free chains at the interface for controlled slip experiments.
Main Results:
- Interfacial shear stress is strongly dependent on the segment mobility of polymers on both sides of the interface.
- Lower interfacial shear stress is observed when both materials are highly mobile.
- Thin layers of tethered chains can enhance interfacial friction.
Conclusions:
- Polymer segment mobility is a key factor in determining interfacial shear stress.
- Tethered chain layers can be utilized to modify interfacial friction properties.
- Findings have implications for lubricant performance and polymer processing challenges like wall slip.
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