Pre-treatments of polymers by atmospheric pressure ejected plasma for adhesion improvement

Abstract

Polymers such as rubbers generally have low surface energy, thus high hydrophobicity and inherent low bondability. An atmospheric pressure ejected plasma (APEP) source is developed for pre-treatments of polymers to overcome these intractable properties and improve the adhesion ability between polymers as environmental-friendly and simple alternative methods to conventional treatments in spite of several limitations until now. Proper operational conditions are found by T-peel tests performed with various plasma parameters and high peel strength up to 3.5 kgf/cm is achieved at those conditions. Optical emission spectroscopy revealed that the amount of oxygen radicals and gas temperatures are found to be higher at proper conditions in T-peel tests and Fourier transform infrared spectroscopy using attenuated total reflection. Scanning electron microscopy is used for the measurement of surface composition and morphology of pre-treated polymer specimen. These results established the advantage of pre-treatments by APEP source in proper operation conditions when compared to the conventional treatments in terms of improvement of the adhesion ability between polymers.