FRICTION CONTROL WITH A GRAFT LAYER OF A THERMO-SENSING POLYMER

The lubricating mechanism of surfaces grafted with poly-N-isopropylacl ylamide (PNIPAAM) was investigated with a thrust collar apparatus. The coefficient of friction increases with temperature rise, because PNIP AAM changes its surface property from hydrophilic to hydrophobic. Conv ersely the friction coefficient decreases with temperature fall. The r ole of water in lubrication is discussed based on the experimental res ult that the thickness of the graft layer decreases with temperature r ise. A new technology is presented to control friction in water enviro nments.