Swelling and tribological properties of poly (HEMA) hydrogels

In this work, the effects of crosslinking density and degree of swelling on the tribological behaviour of polyHEMA hydrogels, using the reinforcing polymer N-vinyl pirrolidone (NVP) (10% (w/w)) with 0, 5 and 10% (w/w) crosslinking agent (CA), were investigated. Tribological tests were conducted with distilled water as a lubricant and using stainless steel 316L as a counterface material. The friction values were relatively low, from 0.01 to 0.03, and the wear rate of hydrogels was in the range 10(-6) gm(-1) to 10(-5) gm(-1). The dominant wear mechanisms were adhesive wear and abrasive wear, respectively for hydrogels with 0% (w/w) CA and 10% (w/w) CA.