The interaction of a low-temperature oxidizing plasma with modified cellulose

Abstract

The influence of a low-temperature low-frequency glow discharge air plasma on the surface and physicomechanical properties of wood cellulose I was studied. Cellulose was formed as a paper sheet treated with an organic surface-active substance on the basis of a disubstituted alkylaromatic acid. The total effective surface energy of the initial sample was 31 mJ/m2. Treatment in an air plasma decreased the hydrophobic properties of the surface. The total effective surface energy substantially increased, largely because of an increase in its polar component by many times. Treatment was accompanied by a decrease in the content of hydrogen and hydroxyl groups, which caused the destruction of macromolecules and the formation of functional carbonyl (aldehyde and ketone) groups. In the near IR range, bonds most probably related to epoxide groups were observed. Macromolecules in a very thin surface layer experienced chemical modification, and this layer likely became amorphous. The high degree of sample crystallinity in the bulk did not change. The mechanical properties of samples worsened only under intense plasma actions.