Surface degradation of polyethylene terephthalate induced by UV-evanescent field

Abstract

Poly(ethylene terephthalate), PET, is a commercial polymer with various applications in many industries such as textile, food and automotive industries. However, PET has hydrophobic property, thus it is not appropriate for some applications. Surface degradation induced by UV-evanescent is a novel technique for improving hydrophilic property of PET. The degradation was initiated under the total internal reflection of the UV radiation at the interface of specimen that contacted with internal reflection element(UV-ATR). This technique induces surface degradation and creates hydrophilic species on the exposed side of PET surface only, but it cannot induce the degradation of opposite side. These chemical changes were investigated by attenuated total reflection Fourier Transform infrared(ATR FT-IR) spectroscopy and FT-Raman spectroscopy. Since the change only occurs at the surface of PET (nanometer level), the mechanical properties of the degraded PET under UV-evanescent field are expected to be unchanged.