Estimation of the dispersive component of surface energy of polymer-grafted lignocellulosic fibers with inverse gas chromatography

Abstract

Surface energy has traditionally been obtained through contact angle measurements. Hygroscopic, chemically heterogeneous and short fibers, such as wood fibers, may present difficulties in obtaining meaningful results. Inverse gas chromatography (IGC) is an alternative technique which can circumvent this problem. Indeed, IGC is particularly well-suited to measurements with porous, short fiber substrates, and data can be acquired as a function of composition or temperature. Measurements are generally done with a solvent, called 'probe', at near infinite dilution in an inert carrier gas. Little solvent-solvent interaction is involved, which is different from classical wetting measurements. A comparison is made between dispersive components of the surface energy as obtained through contact angle analysis and IGC. The variation of the dispersive component of the surface energy of wood fibers grafted with poly(methyl methacrylate), as a function of the degree of grafting, as obtained with IGC is presented and compared with results of photoelectron spectroscopy and specific surface measurements.

Keywords:

• Inverse gas chromatography
• lignocellulosic surfaces
• surface energy
• specific surface
• acid-base interactions