STUDIES ON RAYON GRADE BAMBOO PULP

Abstract

The authors have successfully prepared pulp from East Pakistani bamboo on an industrial scale. Emphasis of the present study is laid on hemicellulose of bamboo, and the following observations are made:(1) The pentosan content in the inner zone of the bamboo culms, in which there exists coarsely scattered buscular bunds and dense parenchymatous cells, is higher than that in the outer one.(2) From the result of paper partition chromatography, it is found that large part of hemicellulose of bamboo is pentosan (xylan) and there exists a small quantity of araban, but no free monosaccharides.(3) During the prehydrolysis of bamboo chips in water, araban is readily removed and then xylan is changed to furfural by stepwise degradation. Also a part of pentosan togather with a part of lignin is changed into resineous substance which is soluble in hot alkali solution.(4) The rayon grade pulp prepared from bamboo by the sulfate prehydrolysis and the multistage bleaching (including chlorine dioxide treatment) contains xylan and a small quantity of araban.The rayon filaments spun from the viscose prepared from the bamboo pulp contain a small quantity of xylan, a large part of which exists in amorphous region of the bamboo fibers.The removal of xylan in rayon seems to be more difficult than in the case of wood pulp.