Abstract
Structural hydrogel materials are being considered and investigated for a wide variety of biotribological applications. Unfortunately, most of the mechanical strength and rigidity of these materials comes from high polymer concentrations and correspondingly low polymer mesh size, which results in high friction coefficients in aqueous environments. Recent measurements have revealed that soft, flexible, and large mesh size hydrogels can provide ultra low friction, but this comes at the expense of mechanical strength. In this paper, we have prepared a low friction structural hydrogel sample of polyhydroxyethylmethacrylate (pHEMA) by polymerizing an entangled polymer network on the surface through a solution polymerization route. The entangled polymer network was made entirely from uncrosslinked polyacrylamide (pAAm) that was polymerized from an aqueous solution and had integral entanglement with the pHEMA surface. Measurements revealed that these entangled polymer networks could extend up to ∼200 μm from the surface, and these entangled polymer networks can provide reductions in friction coefficient of almost two orders of magnitude (μ > 0.7 to μ < 0.01).
Original language | English (US) |
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Article number | 042102 |
Journal | Journal of Tribology |
Volume | 138 |
Issue number | 4 |
DOIs | |
State | Published - Oct 1 2016 |
Keywords
- entangled polymer network
- friction
- hydrogel
- lubricity
- mesh size
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Surfaces and Interfaces
- Surfaces, Coatings and Films