Extreme durability of wettability changes on polyolefin surfaces by atmospheric pressure plasma torch Articles uri icon

publication date

  • October 2010

start page

  • 396

end page

  • 402

issue

  • 2

volume

  • 205

International Standard Serial Number (ISSN)

  • 0257-8972

Electronic International Standard Serial Number (EISSN)

  • 1879-3347

abstract

  • In the present work three common polyolefins: high density polyethylene (HDPE), low density polyethylene (LDPE) and polypropylene (PP) have been treated with an atmospheric pressure air plasma torch (APPT) in order to improve their wettability properties. The variations in surface energy (gammas), as well as the durability of the treatment are determined by means of contact angle measurements for different aging times after plasma exposure (up to 270 days) using five test liquids which cover a wide range of polarities. The introduction of new polar moieties (carbonyl, amine or hydroxyl) is confirmed by Fourier transform infrared spectroscopy in attenuated total multiple reflection mode (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). Furthermore, scanning electron microscopy (SEM) provides information on the morphological changes and variation on surface roughness, revealing that smoother, lamellar and semispheric micrometric structures are created on the LDPE, HDPE and PP surfaces, respectively. Results show that APPT treatment enhances both the total and polar components of the gammas under study, with an unprecedent stability (> 8 months) in time.

keywords

  • atmospheric pressure plasma; surface energy; hydrophilic durability; polyolefins