STUDIES ON THE CHANGES IN STRUCTURE AND DYEING PROPERTIES OF SOME CHEMICALLY MODIFIED CELLULOSIC POLYMERS

Abstract

In this part several samples of slack mercerized, ammonia-treated (prior to slack mercerization) ammonia-treated cotton cellulose fabric strips have been prepared. In order to gain more information about the supermolecular structural differences among these samples, extensive measurements have been carried out, comprising X-ray diffraction, and infrared absorption spectra both before and after chemical treatments. The cellulose crystalline phases, crystallinity of the ordered regions, apparent crystallite size or the average extension of lateral order, and IR band assignment were evaluated as a function of chemical treatments. It is to be noted, in this connection, that the extent of the cell form conversion and decrease in overall crystallinity depended on the experimental conditions.The extent of modification for ammonia-treated samples is found to be not as great as that for mercerized cellulose. Determination of cellulose accessibility and crystallinity has been extensively investigated. The results obtained were correlated and discussed in details, leading to valuable information about chemical modifications necessary to fabric strip industries.

The IR spectra of slack mercerized cellulose show a good resolved new crystalline phase (cellulose II), in addition to the presence of a partial retention of cellulose I. The IR spectroscopic data available on different treated celluloses have been critically re-examined in order to get the best