Effect of plasma pretreatment on adhesion and mechanical properties of UV-curable coatings on plastics

Abstract An attempt was made to study the effect of plasma surface activation on the adhesion of UV-curable sol–gel coatings on polycarbonate (PC) and polymethylmethacrylate (PMMA) substrates. The sol was synthesized by the hydrolysis and condensation of a UV-curable silane in combination with Zr-n-propoxide. Coatings deposited by dip coating were cured using UV-radiation followed by thermal curing between 80 °C and 130 °C. The effect of plasma surface treatment on the wettability of the polymer surface prior to coating deposition was followed up by measuring the water contact angle. The water contact angle on the surface of as-cleaned substrates was 80° ± 2° and that after plasma treatment was 43° ± 1° and 50° ± 2° for PC and PMMA respectively. Adhesion as well as mechanical properties like scratch resistance and taber abrasion resistance were evaluated for coatings deposited over plasma treated and untreated surfaces.

[1]  G. Borcia,et al.  The surface oxidation of selected polymers using an atmospheric pressure air dielectric barrier discharge. Part I , 2004 .

[2]  P. Belleville,et al.  A scratch-resistant single-layer antireflective coating by a low temperature sol-gel route , 1994 .

[3]  Zhong Chen,et al.  Scratch resistance of brittle thin films on compliant substrates , 2008 .

[4]  K. S. Siow,et al.  Plasma Methods for the Generation of Chemically Reactive Surfaces for Biomolecule Immobilization and Cell Colonization ‐ A Review , 2006 .

[5]  Zhong Chen,et al.  A study towards improving mechanical properties of sol–gel coatings for polycarbonate , 2008 .

[6]  Deok‐Ho Kim,et al.  Scratch Resistant and Transparent UV-Protective Coating on Polycarbonate , 2003 .

[7]  T. Gengenbach,et al.  Quantitative Analysis of Polymer Surface Restructuring , 1995 .

[8]  J. Phalippou,et al.  Tribological properties of ormosil coatings , 1996 .

[9]  Young-Ze Lee,et al.  The study of atmospheric pressure plasma for surface cleaning , 2003 .

[10]  H. Schmidt,et al.  The Sol-gel process for nano-technologies : new nanocomposites with interesting optical and mechanical properties , 1998 .

[11]  C. M. Ryu,et al.  Investigation of crystallinity effects on the surface of oxygen plasma treated low density polyethylene using X-ray photoelectron spectroscopy , 2003 .

[12]  S. Koh,et al.  Altering a polymer surface chemical structure by an ion-assisted reaction , 2002 .

[13]  G. Wilkes,et al.  Abrasion-resistant coatings for plastic and soft metallic substrates by sol-gel reactions of a triethoxysilylated diethylenetriamine and tetramethoxysilane , 2000 .

[14]  B. Bae,et al.  Fabrication of Channel Waveguides by Photochemical Self-Developing in Doped Sol-Gel Hybrid Glass , 2001 .

[15]  J. Phalippou,et al.  Mechanical characterization of Ormosil films on plastics: Young's modulus determination by three points bending , 1994 .

[16]  S. Pavan,et al.  Hard UV-curable organo-mineral coatings for optical applications , 2006 .

[17]  H. Schmidt,et al.  UV curable hard coatings on plastics , 1999 .

[18]  A. Duri,et al.  Fracture study of organic–inorganic coatings using nanoindentation technique , 2004 .

[19]  H. Schmidt,et al.  Coatings for mechanical and chemical protection based on organic-inorganic sol-gel nanocomposites , 1994 .

[20]  C. P. Grover,et al.  Preparation and Optical Characterization of Thick-Film Zirconia and Titania Ormosils , 1999 .

[21]  Y. Shin,et al.  Hard coatings on polycarbonate plate by sol-gel reactions of melamine derivative, PHEMA, and silicates , 2008 .

[22]  Dezhen Wang,et al.  Surface modification of PE film by DBD plasma in air , 2008 .