Surface modification of poly (ethylene terephthalate) via hydrolysed erosion process

Abstract

Flexibility is one of the most important characteristics for the next generation of electronic devices in the application such as a touch-screen, flexible large screen, and solar energy membrane. Poly (ethylene terephthalate) (PET) has been recently used as a polymer matrix for electronic devices due to lightweight, as well as excellent optic and mechanical properties. Nonetheless, due to lack of surface tuneable functionality, surface modification of PET film is significantly required to increase its compatibility and reactivity with other electrode materials. In this study, hydrolysis in principle of a surface erosion process is conducted by using sodium hydroxide (NaOH) at varied hydrolysis time and NaOH concentration. The change of surface chemistry was investigated by using Fourier-transform infrared spectroscopy indicating the introduction of hydrophilicity group on the C-O bonds of carboxyl group surface chain in the PET backbone. The increase in hydrophilicity after modification was confirmed by the reduction of water contact angle from 84.20 (unmodified PET film) into the maximum at 53.80. Further, the hydrolysis at 1 M of sodium hydroxide solution showed an optimum hydrophilicity increase without affecting the transparency verified by UV-VIS Spectroscopy while giving insignificant weight loss (at only 7 %) and surface morphology.