(407f) Mechanistic Study Of Surface-Modified Uhmw-Pe Using Pulsed-Dbd Plasma

An important aspect in the processing of polymer-polymer composites is the interphase between the polymer matrix and filler, such as UHMW-PE fibers and films. Because the filler and matrix are thermodynamically incompatible materials, poor adhesion arises due to interfacial discontinuities. To overcome this limitation, surface treatments using plasma have been implemented to form polar groups to enhance adhesion and to also promote surface roughening. Plasma has become an increasingly utilized technique in the area of surface modification, owing to short processing times and the ability to selectivity modify the surface structure while preserving the bulk properties. Traditionally, low-pressure plasma systems have been used but because of high costs associated with vacuum systems, the focus of attention has been shifted towards the use of alternative systems operating at atmospheric pressure. However, the change from low pressure to atmospheric pressure imposes change in the physics of the plasma, notably the non-uniformity of the treatment. In this work, nitrogen plasma operating at atmospheric pressure was used to study the degree of surface functionalization of nitrogen-containing groups and to characterize the surface properties. Plasma was initiated through the use of a high voltage power supply, creating short pulses, on the order of nanoseconds, to control the uniformity of the treatment. Surface analysis techniques used to characterize the treatments consisted of contact angle measurements, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), x-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). In order to optimize the treatment, it is imperative to understand the interaction that takes place between the plasma and the polymer to assess the structure-property relationship between the surface-modified filler-polymer matrix and the composite mechanical properties. Therefore, optical emission spectroscopy (OES) measurements were used to study the most probable reactions that take place in the plasma in the presence and absence of the UHMW-PE along with the implementation of ISS measurements.