The hygroscopicity of cellulose and cellulosic
materials, e.g., cotton, wood, paper, etc., decreases
irreversibly, when they are heated at high temperatures
in a dry atmosphere accompanied by a loss of weight
(Urquhart, 1926 ; Stamm. 1964 j Kollman and Schneider,
1963 5 Salehuddin, 1970)• Several postulations have been
advanced’to explain the phenomenon. Stamm (1964), working
with wood, theorised that hemicelluloses in wood are
converted to furfural polymer which is less hygroscopic
than hemicelluloses, resulting in the overall lessened
hygroscopicity of wood. Kollman and Schneider (1963)
thought that heat induced changes in hemicelluloses and
sintering of lignin are responsible for the decrease in
the sorption capacity of wood. However, none of these
theories explain why pure cellulose also behaves in a
similar manner.