Study of the aging process of corona discharge plasma effects on low density polyethylene film surface (original) (raw)
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Surface modification of polyethylene by diffuse barrier discharge plasma
Polymer Engineering & Science, 2013
Low-density polyethylene (LDPE) modified by atmospheric dielectric surface barrier discharge plasma in oxygen was investigated to improve surface properties and adhesion of LDPE to more polar polymers. The process of plasma modification was investigated using several methods-surface energy measurements, Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). The surface energy of LDPE increased significantly after activation by oxygen barrier plasma even at very short time of modification. The FTIR-ATR spectra manifested the presence of carbonyl functional groups on the surface of polymer pretreated by oxygen barrier plasma. It was shown by SEM, and AFM, that the topography of modified LDPE was significantly changed and the surface of modified polymer exhibited higher roughness in comparison with unmodified polymer. The surface energy of treated LDPE diminished in the course of ageing especially during the first 10 days after modification by barrier plasma. Hydrophilicity of the modified LDPE surface was stabilized by photochemical post-functionalization with 2,2,6,6-tetramethylpiperidin-4-yl-diazoacetate. POLYM. ENG. SCI., 53:516-523, 2013. ª
Modification of surface properties of polyethylene by Ar plasma discharge
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2006
Polyethylene (PE) surface was modified by Ar plasma discharge. The changes of surface morphology and surface wettability (characterized by contact angle) were followed using AFM microscopy and standard goniometry, respectively. The changes of chemical structure of PE polymeric chain were characterized by FTIR and XPS techniques. A nanoindenter was used to study mechanical properties (microhardness, elasticity module and microscratch test) of modified PE. After exposition to the plasma discharge a fast decline of the contact angle is observed. The decline depends on the discharge power and the time elapsed from the plasma exposition. FTIR and XPS measurements indicate an oxidation of degraded polymeric chains and creation of hydroxyl, carbonyl, ether, ester and carboxyl groups. Surface morphology of modified PE depends on the plasma discharge power and exposure time. Maximum microhardness and elastic module, observed on PE specimens exposed to plasma discharge for 240 s, may be connected with PE crosslinking initiated by plasma discharge.
Plasma Chemistry and Plasma Processing, 2008
The surface of a LDPE was modified by Ar, O 2 , N 2 , CO 2 gaseous plasma. The changes in surface morphology and surface wettability were investigated using AFM and SEM. The surface chemical changes of LDPE were also characterized by FTIR-ATR. The SEM and AFM results demonstrated variable changes in surface roughness for different types of plasma gas used, the changes being more for the Ar and N 2 plasma treatments. Considering the nature of the LDPE film, XRD studies were carried out to determine changes in the percentage crystalinity. The results showed that all low pressure O 2 , Ar, N 2 , CO 2 gas plasmas improved the wettability of LDPE films. Contact angles decreased significantly depending on the discharge powers and exposure times. Surface morphology was also found to vary with plasma discharge powers, exposure times, and the type of gas being used. Ar and N 2 gas plasmas in general produced more superior results.
DESCRIPTION Abstract: In the present work, high frequency (2.5 MHz) Dielectric Barrier Discharge (DBD) air plasma is used to investigate the effect of plasma treatment time on wettability and surface chemistry of polyethylene (PE). PE surface is exposed to air plasma for different time durations from 5-30 seconds. Treatment time for reduction in water contact angle from 101° to 45° was observed to be 10 seconds in this study, unlike in the case of 50 Hz AC DBD air plasma, where surface exposure time was 30 minutes to achieve water contact angle ~ 70° as reported in our previous work [1]. Beyond 10 seconds treatment time partial hydrophobic recovery (increase in water contact angle ±10 - 15°) is observed. Again after 25 seconds treatment time water contact angle is found to decrease. In this report, efforts have been made to understand the phenomena responsible for partial hydrophobic recovery during extended period of plasma treatment time. ATR-FTIR spectroscopy results confirm C-C ...
Journal of Applied Polymer Science, 2008
The aim of this work was to study the durability of a polypropylene film plasma‐treated with an 80 : 20 methane–oxygen gas mixture. Three different storage conditions were used to evaluate the influence of the relative humidity and temperature on the aging process. The surface functionalization of the polypropylene film was analyzed with X‐ray photoelectron spectroscopy and attenuated total reflectance/Fourier transform infrared spectroscopy analysis, and the variations of the surface energy and its polar and dispersive components were also investigated. The effects of this plasma treatment were similar to those of a plasma polymerization process, the ablation and polymerization mechanisms taking place simultaneously at the treated surface, but in this case, we obtained hydrophilic properties. The obtained results indicated an improvement of wettability and high durability of the plasma‐treated polypropylene film. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polymers
In this work, the plasma was used in the dielectric barrier discharge (DBD) technique for modifying the high-density polyethylene (HDPE) surface. The treatments were performed via argon or oxygen, for 10 min, at a frequency of 820 Hz, voltage of 20 kV, 2 mm distance between electrodes, and atmospheric pressure. The efficiency of the plasma was determined through the triple Langmuir probe to check if it had enough energy to promote chemical changes on the material surface. Physicochemical changes were diagnosed through surface characterization techniques such as contact angle, attenuated total reflection to Fourier transform infrared spectroscopy (ATR-FTIR), X-ray excited photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Plasma electronics temperature showed that it has enough energy to break or form chemical bonds on the material surface, impacting its wettability directly. The wettability test was performed before and after treatment through the sessile drop, usi...
Polymers for Advanced Technologies, 2007
Low-density polyethylene modified by atmospheric dielectric surface barrier discharge in oxygen using several methods -surface energy measurements, ATR-FTIR spectroscopy, SEM, and AFM have been investigated. The activation of LDPE by oxygen barrier plasma increased significantly the surface energy and its polar component even at very short time of modification. The surface energy of treated LDPE diminished in the course of ageing especially during 10 days after modification by barrier plasma. The ATR-FT-IR spectra manifest the presence of oxygenic, i.e. carbonyl functional groups on the surface of polymer pre-treated by oxygen barrier plasma. It was shown by SEM, and AFM, that the topography of the modified LDPE significantly changed and surface of modified polymer became higher roughness as compared to unmodified polymer.
Comparison of low and atmospheric pressure air plasma treatment of polyethylene
Surface Engineering, 2013
Surface activation of polyethylene (PE) samples has been carried out using low pressure plasmas (at two different operating frequencies, namely, 40 kHz and 13?56 MHz) and dielectric barrier discharge (DBD) (50 Hz frequency and at atmospheric pressure), and the results are compared. The surface of the PE samples has been exposed to these different plasmas for various time durations ranging from 1 to 30 min. The treated samples have also been studied for their aging behaviour by exposing them to the ambient atmosphere for up to 7 days. The plasma induced morphological changes were studied using an scanning electron microscope and an atomic force microscope, while the formation of various functional groups was identified using Fourier transform infrared analysis. The surface energy values were observed to increase from 27?5 dyne cm 21 (of untreated PE) to 73?8 and 52?2 dyne cm 21 after low pressure 40 kHz and 13?56 MHz air plasma treatment respectively and to 35?6 dyne cm 21 after the DBD air plasma treatment. The low pressure plasma treatment at an operating frequency of 40 kHz has produced the best results in the surface activation of PE. During the aging process, the formation of C5C bonds was observed on the surface of PE.
The impact of DCSBD plasma discharge on polypropylene
IOP Conference Series: Materials Science and Engineering, 2020
The diffuse coplanar surface barrier plasma discharge (DCSBD) still belongs to specific methods of modifying (activating) the surface of polymeric materials. The present work deals with surface treatment of polypropylene foils by plasma discharge, investigation and subsequent identification of changes caused by mentioned discharge. The modified surface was examined by measuring the wetting angle. Film surface morphology and topography was investigated by scanning electron microscope (SEM) and atomic force microscopy (AFM), respectively. Subsequently, it was examined whether the modification of polypropylene by DCSBD plasma discharge only affects the surface of the investigated material or also changes structural properties in studied material, based on the obtained data from DMA analysis.
Journal of Applied Polymer Science, 1999
Modification of polyolefin surfaces is often necessary to achieve improved printability, lamination, etc. Although corona discharge and flame treatments can produce the higher surface energy needed for these applications, the properties of the resulting surfaces are not always optimal. Atmospheric pressure plasma is a surface modification technique that is similar to corona discharge treatment, but with more control, greater uniformity, and higher efficiency. Using an atmospheric pressure plasma unit with a dielectric barrier discharge generated using an asymmetric pulse voltage, the effects of different gases, powers, and linespeeds on polyethylene surface treatment were studied. Our results show that atmospheric pressure plasma can be used to achieve higher long-term wettability, higher surface oxygen and nitrogen, and a greater range of surface chemistries with better robustness versus standard corona treatment. Atomic force microscopy results suggest significant differences in the mechanism of surface functionalization versus etching and ablation depending on the gases used.