Abstract
The effect of ferric chloride on solvent welding and wear of PMMA was determined in various solvents. FeCl3·6H2O mixed with methanol and ethanol enhanced the welding strength of PMMA because of increasing solubility of solvents. The strength of welding increased until X=0.1 and X=0.025 for FeCl3·6H2O mixed with methanol and ethanol, respectively. Further, bonding between the ester group of PMMA and Fe ion was found by FTIR. Large concentration of FeCl3·6H2O in solvents swelled PMMA so that bonding reduced. Maximum strength up to 12 MPa occurred at PMMA bonded by pure DMF. However, FeCl3·6H2O mixed with DMF decreased solubility of solvent so that welding strength was also degraded. Rising temperature of welding increased the plasticization effect of solvent so that welding strength was further increased. When solvent mixture was diluted by water, the effect of welding was poor. FeCl3·6H2O mixed with methanol, ethanol and DMF was transported in PMMA. After desorption, specimens with various concentrations of ferric chloride were slided against steel counterface with pin-on-disk configuration. With the addition of ferric chloride, wear of PMMA was larger than that treated by pure solvents. Hardness of polymers matched the wear behavior. FeCl3·6H2O mixed with methanol and ethanol promoted wear because increasing solubility weakened the structure of PMMA. Observation of the cleavage surface showed that the structure of PMMA was changed by ferric chloride. Ploughing surface showed abrasive wear mechanism. Low wear of PMMA treated with FeCl3·6H2O mixed with DMF was because adhesion of wear debris lubricated the surface. Wear can be reduced to 5.4*10^-4 mg/m for PMMA treated with pure DMF.