Plasma surface treatment of PCL/PC blend sheets

Surface treatments using glow discharge plasmas from O-2 and Ar were applie d to blend sheets of poly(epsilon -caprolactone)-polycarbonate (PCL/PC), wh ich had been produced by extrusion from melts of the mixture at various ble nd ratios. As to the reactivity of these two plasmas, O-2-plasma forms the oxidative species to be reactive in general, while Ar-plasma is non-oxidati ve. Weight loss by the oxidative O-2-plasma etching increased with the cont ent of PCL in the polymer blends. The surface became hydrophilic by plasma treatment, and the changes were affected also by the blend ratio. PC and th e PC-rich blend sheets became more hydrophilic than the PCL-rich blends aft er plasma treatments. The O-2-plasma treatments were more effective than no n-oxidative Ar-plasma treatment in increasing the hydrophilicity. Hydrophil ic change was related to the increase in the polar contribution of surface energy.