Alumina coatings on PMMA: optimization of adherence

Alumina is deposited on polymethyl methacrylate (PMMA) using the RF magnetron sputtering method. The adhesion is characterized by means of a 180° peeling test and a fragmentation test. The surface energy of the materials is determined by measuring the contact angles using the two liquids method. The plasma surface treatment of the polymer help to smooth it and increase its surface energy. The modifications of the dispersive and polar components of this energy depend on the type of the plasma-gas used. Oxygen rich plasmas, such as air or carbon dioxide, allow the surface polarity of the polymer to be increased by a superficial oxidation whilst limiting the reticulation. They give better adhesion values. The analysis by ATR-FTIR displays the reticulation phenomenon for the extended application of argon plasma at low power. The RBS analysis shows that the quantity of argon incorporated into the alumina deposit is dependent on the operating conditions, particularly the pressure in the sputtering chamber. Different values of surface energy are due to the variations in composition. The alumina films with the lowest percentage of argon have the highest polar component. Their adhesion to the PMMA is also the highest. The best adhesion of alumina on PMMA is obtained for a polymer activation during a short time (10 s), by means of an oxygen rich plasma (CO2) and for alumina coatings which have the lowest argon content (p = 1 Pa).

[1]  J. Donnet,et al.  Surface properties of high-energy solids , 1977 .

[2]  Y. Taga,et al.  Structures and properties of chromium thin films prepared by anisotropic‐emission‐effect sputter deposition , 1990 .

[3]  D. C. Agrawal,et al.  Measurement of the ultimate shear strength of a metal-ceramic interface , 1989 .

[4]  Katsuhiro Harada.  Plasma etching durability of poly(methyl methacrylate) , 1981 .

[5]  D. Clark,et al.  Selective surface modification of polymers by means of hydrogen and oxygen plasmas , 1983 .

[6]  L. Keer,et al.  Measurement of the intrinsic bond strength of brittle thin films on flexible substrates , 1990 .

[7]  A. Kinloch.  Adhesion and adhesives , 1987 .

[8]  J. Evans,et al.  The retention of Ar in low energy high fluence Ar-irradiated Mo and Si , 1989 .

[9]  J. Baglin.  Thin film adhesion: New possibilities for interface engineering , 1988 .

[10]  A. El-Shimi,et al.  Wettability of some low energy surfaces. I. Air/liquid/solid interface , 1974 .

[11]  R. S. Nowicki,et al.  Properties of rf‐sputtered Al2O3 films deposited by planar magnetron , 1977 .

[12]  T. Ogita,et al.  Surface Structure of Low-Density Polyethylene Film Exposed to Air Plasma , 1985 .

[13]  G. Wehner,et al.  Mass effects on angular distribution of sputtered atoms , 1979 .

[14]  L. Gerenser.  X-ray Photoelectron Spectroscopy of Modified Polymer Surfaces and Metal—Polymer Interfaces: Correlations with Adhesion , 1990 .

[15]  R. N. Wenzel.  RESISTANCE OF SOLID SURFACES TO WETTING BY WATER , 1936 .

[16]  L. Lavielle,et al.  Surface properties of graft polyethylene in contact with water , 1985 .

[17]  L. J. Bonis.  SURFACE ANALYSIS - "Interdisciplinary Aspects of Surface Phenomena" , 1964 .

[18]  P. Kettunen,et al.  Electrical insulating properties and thermal stability of r.f.-sputtered alumina coatings , 1985 .

[19]  L. J. Bellamy.  Advances in infrared group frequencies , 1968 .

[20]  J. Thornton.  High Rate Thick Film Growth , 1977 .

[21]  D. K. Owens.  Mechanism of corona–induced self-adhesion of polyethylene film , 1975 .

[22]  F. Fowkes.  ATTRACTIVE FORCES AT INTERFACES , 1964 .

[23]  I. Ritchie,et al.  Applications of ESCA to polymer chemistry. Part VI. Surface fluorination of polyethylene. Application of ESCA to the examination of structure as a function of depth , 1975 .

[24]  W. Possart,et al.  An XPS Investigation of the Interface between Thin Polymethylmethacrylate (PMMA) Films and Natively Oxidized Al , 1989 .

[25]  J. R. Dann,et al.  Forces involved in the adhesive process: I. Critical surface tensions of polymeric solids as determined with polar liquids , 1970 .

[26]  A. Gent,et al.  Effect of Wetting Liquids on the Strength of Adhesion of Viscoelastic Material , 1972 .

[27]  R. Lappalainen,et al.  Stoichiometry and impurities in sputtered alumina films on copper , 1991 .

[28]  D. W. Hoffman,et al.  The influence of discharge current on the intrinsic stress in Mo films deposited using cylindrical and planar magnetron sputtering sources , 1985 .

[29]  P. Natishan,et al.  Oxygen ion beam assisted thin film deposition , 1990 .

[30]  J. Pelletier,et al.  The etching of polymers in oxygen‐based plasmas: A parametric study , 1989 .

[31]  R. H. Hansen,et al.  Surface treatment of polymers for adhesive bonding , 1967 .