Electrokinetic and mechanical characterization of UV induced crosslinked acrylic copolymers

Carsten Wuertz, Alexander Bismarck, Jürgen Springer (Korresp. Autor*in), Rainer Königer

Veröffentlichungen: Beitrag in FachzeitschriftArtikelPeer Reviewed

Abstract

Functionalized copolymers for using as UV curable coatings were synthesized from three different monomers; methylmethacrylate, n-butylacrylate and glycidyl-methacrylate. The synthesis of functionalized copolymers consisted of two steps, the polymerization and the functionalization, and could be performed to high conversion rates as proved by gaschromatographical residual monomer detection. The synthesized coatings varied both in the polymer backbone composition as well as in the crosslink density. UV curing was performed in the presence of a commercially available photoinitiator system. The measured zeta (ζ) potential time dependence allows to study the swelling kinetics of the synthesized coatings in water. Physicochemical surface properties of the coatings were investigated by measuring the ζ-potential-pH dependence. The surfaces display a mostly hydrophobic character. Depending on the polymer composition, a change of the hydrophobic surface character towards a slightly acidic one was detected. For the various coatings, structure-property relationships could be observed. The isoelectric point, a measure of the surface acidity, decreases with increasing crosslink density, for instance, which indicates an increase in the amount of dissociable acidic surface functionalities. This can be attributed to lowered flexibility of the material. An analogous trend could be observed for the water uptake: the higher the crosslink density, the lower the water adsorption. With the technical applications in mind, some relevant data on the mechanical properties were obtained, as measure of hardness, flexibility and adhesion to bonder-plates. The expected correlation for the pendulum hardness and the Erichsen cupping (a measure for the flexibility) could be found. The increased glass transition temperatures leads to an enhanced hardness and a lowered flexibility. The cross-cut test of the polymeric coatings on bonder-plate surfaces showed medium to very good adhesion. The results indicate the existence of an optimal crosslink density as well as Tg range for the investigated copolymer system.

OriginalspracheEnglisch
Seiten (von - bis)117-129
Seitenumfang13
FachzeitschriftProgress in organic coatings
Jahrgang37
Ausgabenummer3
DOIs
PublikationsstatusVeröffentlicht - Dez. 1999
Extern publiziertJa

ÖFOS 2012

  • 104019 Polymerwissenschaften
  • 104015 Organische Chemie

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