Cross Linking Condensation Polymerization of Rayon Fiber

الملخص

The degree of cross linking condensation polymerization of rayon molecule
under argon atmosphere is a function of temperature in the
range (200 – 230)°C with liberation of 10%, 10.5%, and 10.9% water respectively from
the fiber weight. Elemental analyses show increasing of carbon % on the expense of
hydrogen and oxygen percents in the same order. Above 230°C self-carbon dioxide is
generated. The fiber resulted from the polymerization shows fire resistance and
insoluble in sulfuric acid which is in opposite behavior to the untreated fiber. Also
treated fiber shows color change from white → yellow→ brown→ black depending on
temperature degree and duration of heating with smooth and oily surface appearance
due to the new bonding system and more close rayon molecules upon polymerization,
accompanied with what is called chemiluminescence phenomenon.
Polymerization under nitrogen atmosphere shows early liberation of carbon
dioxide gas beside water due to the presence of oxygen even in trace amount in the
nitrogen gas which attacks the rayon molecules at the above temperature.