Modification of polyethylene tube surface in dielectric barrier discharge
- PDF / 456,157 Bytes
- 8 Pages / 584.957 x 782.986 pts Page_size
- 28 Downloads / 224 Views
ARTICLE Modification of polyethylene tube surface in dielectric barrier discharge Michał Młotek,a) Adam Błaszczyk, and Krzysztof Krawczyk Faculty of Chemistry, Warsaw University of Technology, Warszawa 0-664, Poland (Received 26 March 2018; accepted 13 June 2018)
The objective of the study was to modify the external surface of commercially produced polyethylene (PE) tubes made by Balton, Poland, to improve their hydrophilic properties. The process was conducted in a new dielectric barrier discharge reactor. The carrier gases were argon and air, whereas carbon dioxide and hydrogen were the doping gases. The influence of the gas composition in the plasma chamber on the surface free energy (SFE) of PE tubes was investigated. For the gas composition 50 vol% of Ar 1 50 vol% of CO2, the highest value of the SFE (53.4 mJ/m2) was obtained. It means an increase in SFE approx. 17% as compared to the unmodified sample (46.0 mJ/m2). Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) results indicates that on the surface of the tubes, carboxyl, carbonyl, and hydroxyl groups were formed. Those oxygen-containing groups could be responsible for the increase of the hydrophilic effect. The O/C ratio on the surface, measured by the X-ray photoelectron spectroscopy method, was three times higher in the case of the modified samples than in those which were not subjected to plasma treatment.
I. INTRODUCTION
For many years, plastics have been prevalent in daily life and constitute one of the most important materials in the industry. Currently, in technology, it is recognized that both the bulk and surface properties of materials are important for industrial processes such as bonding, catalysis, or printing.1 Innovations in the preparation of the materials determine the development of new methods for modifying the outer surface.2–4 The properties of the external surface are often different from the bulk properties. Modification of the external surface is used to prevent corrosion and improve the adhesion or bonding to other layers. This can be conducted by many methods such as plasma, chemical, mechanical, electrochemical, and radiative. There are problems in printing on polymers, gluing and laminating them or depositing metallic layers onto them for several reasons. First of all, their surfaces are smooth. Second, contaminants from ambient air deposit themselves on the polymer’s surface. Moreover, components such as lubricants, plasticizers, and antioxidants can migrate to the surface of the tubes.5 To increase the purity or surface free energy (SFE), the surface can be modified by a variety of chemical and physical methods.6,7 The main parameters changed during the modification are chemical composition, wettability, SFE, types of bonds in surface groups, and topography of the surface.8 a)
Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/jmr.2018.218 J. Mater. Res., 2018
Modification of the external surface of plastics using plasma methods have been investigated in recent
Data Loading...
