Three cellulosic materials with crystalline structures of cellulose I, cellulose II and mixture of cellulose I and III, respectively, are acetylated in a heterogeneous system consisting of a mixture of acetic acid and toluene in order to decrease their hydrophilic character. Different degrees of acetylation are achieved by carrying out the process for various times of reaction. The variation of water affinity of the acetylated fibres estimated from

Chemical modification of natural polymers (insoluble lignin and cotton cellulose) in radio-frequency cold plasma has been investigated. The treatments of polymers were carried out in a rotator cold plasma installation specially designed for the R. F. plasma treatment of powdery materials (i.e. insoluble lignin) and in a statically R.F. plasma device for cotton cellulose. Spectral, physical and chemical analysis proved the formation of the new products

The variety of physical structures taken by cellulose molecules in their different crystalline forms is one structural feature of cellulose that has not been examined systematically for its effect on biodegradation. In this paper was demonstrated that the enzymatic degradation reaction of cellulose is adequate not only to demonstrate the influence of the physical structure of the initial material on the heterogeneous reaction, but also to determine

The large availability of cellulose in nature and the low cost of cellulose derivatives make the cellulosebased hydrogels particularly attractive. New hydrogels were obtained by chemical cross-linking of different cellulose allomorphs (cellulose I, cellulose II and cellulose III) and xanthan with epichlorohydrin. The preparation conditions of the transparent cellulose hydrogels were established. The equilibrium swelling capacity of the obtained hydrogels

Amorphous cellulose was obtained from different types of celluloses (microcrystalline cellulose, dissolving pulp and cotton cellulose), by regeneration with ethanol from their solutions in an SO2-diethylaminedimethylsulfoxide (SO2-DEA-DMSO) solvent system. Different techniques, X-ray diffraction (XRD), FTIR spectroscopy and differential scanning calorimetry (DSC) were used to estimate the crystallinity degree. The values obtained for amorphous celluloses