Thermal Instability of Fats Relative to Surface Wettability of Yellow Birchwood (Betula lutea)

Abstract

The surface wettability and fats of yellow birchwood were examined in an attempt to illustrate how heat-induced changes in wood fats might be related to changes in surface wettability. A marked reduction of surface wettability accompanied heating of yellow birchwood. The degree of water repellency imparted to the wood was highly dependent upon heating temperature and time. Acetone extraction of wood prior to heating to 105°C prevented a change in wettability and increased the surface wettability of wood heated at higher temperatures. Examination of the fats after heating indicated little hydrolysis and considerable oxidation of the unsaturated fatty acids and esters. The amounts of free fatty acids present in fresh, air-dried, or heated wood were far too low to approach amounts considered necessary to influence surface wettability. The preponderance of linoleic acid ester and its rapid oxidation suggest that oxidation products from this ester might be responsible for the observed changes in wettability.

Citation

Hemingway, Richard W. 1969. Thermal Instability of Fats Relative to Surface Wettability of Yellow Birchwood (Betula lutea). TAPPI 52(11):2149-2155