A COMPARATIVE STUDY OF WETTABILITY RESPONSES OF POLYETHYLENE AND POLYMIDE SURFACES AFTER ION SHOWER TREATMENT

Abstract

Surface modification of polymers can be achieved by their exposure to different plasma systems in order to improve surface properties such as wettability and adhesion in a manner that can preserve desirable bulk properties. The paper presents the results concerning wettability responses after surface modification of low density polyethylene (LDPE) and Kapton polyimide (PI), using a DC ion shower system. Plasma source gases included argon and nitrogen, and wettability of the polymer surface after treatment was quantified in terms of the contact angle exhibited by water droplets on the polymer surface. Plasma treatment parameters investigated were accelerating voltage, exposure time and chamber pressure. The vicinity of the most promising setting from the initial variable screening experiments which used argon and nitrogen was further investigated using single-factor experiments (minimum of three levels per factor) to pinpoint more precisely a setting that would yield a minimum contact angle. Results showed that LDPE appears to be more resistant to surface modification than Kapton polyimide.