Abrasive wear of selected plastics in solvent/corundum suspensions

A screening program to investigate the stability of plastics against wet abrasion was conducted. Plastic discs were spun in solvent/corundum suspensions at high speed and their wear was determined. Nine different plastics were investigated in water/corundum suspensions, and the three most stable were chosen for further studies in other liquids. Five common solvents were used to prepare corundum suspensions in which ultra-high molecular weight polyethylene, polyurethane 90Shore A and polyamide 6 discs were spun and abraded. Here we show that abrasion is solvent dependent. The abrasive power of the corundum/solvent mixture decreases as follows: methyl ethyl ketone>ethyl acetate>butyl acetate>water>isopropanol>ethanol, on average for the three plastics. The suspensions with solvents containing carbonyl groups display higher abrasive power than the ones with hydroxyl groups. For polyurethane the above ranking could be linked to swelling. For this polymer, a correlation exists between the degree of swelling and the abrasion in the respective solvent. The polymer with the best abrasion resistance in the suspensions tested is ultra-high molecular weight polyethylene.