Stability study of polyacrylic acid films plasma-polymerized on polypropylene substrates at medium pressure

• Published in: Applied surface science Vol. 257; no. 2; pp. 372 - 380
• Main Authors: Morent, Rino, De Geyter, Nathalie, Trentesaux, Martine, Gengembre, Léon, Dubruel, Peter, Leys, Christophe, Payen, Edmond
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2010; Elsevier
• Subjects: Acrylic acid; Carboxylic acids; Coatings; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Density; Deposition; Discharge; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; FTIR; Infrared and raman spectra and scattering; Monomers; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Organic compounds, polymers; Photoemission and photoelectron spectra; Physics; Plasma polymerization; Polymerization; Polymers; organic compounds; Polypropylenes; Stability; Water stability; XPS; XPS; Plasma polymerization; Water stability; Acrylic acid; FTIR; Atomic force microscopy; Medium pressure; Fourier transformation; Polymerization; Polymer films; Contact angle; Infrared spectra; FRIR; Polypropylene; Acrylic acid polymer; X-ray photoelectron spectra
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2010.06.080

Plasma polymerization of acrylic acid has become an interesting research subject, since these coatings are expected to be beneficial for biomedical applications due to their high surface density of carboxylic acid functional groups. However, the application of these monomers is counteracted by their low stability in humid environments, since a high stability is a required characteristic for almost any biological application. The present work investigates whether it is possible to obtain stable deposits with a high retention of carboxylic acid functions by performing plasma polymerization on polypropylene substrates with a dielectric barrier discharge operating at medium pressure. In order to obtain coatings with the desired properties, the plasma parameters need to be optimized. Therefore, in this paper, the influence of discharge power and location of the substrate in the discharge chamber is examined in detail. The properties of the deposited films are studied using contact angle measurements, X-ray photoelectron spectroscopy, atomic force microscopy and Fourier transform infrared spectroscopy. Moreover, to determine whether the obtained deposits are soluble in water, the coatings are once again analyzed after rinsing in water. This paper will clearly show that stable COOH-rich surfaces can be obtained at high discharge power and close to the monomer inlet, which might open perspectives for future biomedical applications.