SynopsisBy impregnating cotton fiber with alkaline swelling agents and reacting with some chemical agents which can be substituted for the hydroxyl groups on cellulose molecules in the presence of alkali, highly accessible or decrystallized cotton fibers can be obtained. As the effective substitution reactions, acetylation by acetic anhydride and cyanoethylation by acrylonitrile were applied. The cotton fibers modified by these chemical treatments showed no decrease of tensile strength, and had moisture regain higher than the untreated cotton though the degrees of substitution were as high as 20-30 mol %. The resistance to heat or acid and the soil removal were improved. Dyeability for direct dye was increased, and dyeability for disperse or cationic dye was also given. Benzoylation and oleoylation were also investigated. Crease recovery of the cotton fabrics was somewhat improved and dyeability for disperse dye was given. The cotton fabrics oleoylated &r decrystallizing by alkali-acrylonitrile treatment had moisture regain almost the same as the untreated cotton, while high water repellency was given.

SynopsisSome physical and chemical properties of an ionic complex made from the weak polyelectrolytes carboxymethylated poly(viny1 alcohol) (PA) and aminoacetalized poly(viny1 alcohol) (PC) are investigated in comparison with those of another ionic complex made from the strong polyelectrolytes sulfated poly(viny1 alcohol) (PSA) and poly(viny1 alcohol) acetalized with diethoxyethyltrimethylammonium (PTC). It was found that when the complex PC-PA was heated at high temperatures, covalent amide bonding took place, whereas no significant change occurred in the case of the PTC-PSA complex. As a result of these structural changes, the degree of swelling of the PC-PA complex in water was markedly decreased, but that of the PTC-PSA complex was not changed by the treatment. The PC-PA complex was insoluble in water and in 1N HCl and 1N NaOH aqueous solutions even if not heat treated, but the PTC-PSA complex was soluble in such acidic and basic aqueous solutions but not in water if heat treated. The PC-PA and PTC-PSA films exhibited good mechanical properties.

SynopsisTo obtain highly accessible cotton by cyanoethylation with acrylonitrile after pretreatment with swelling agents, the effect of various swelling agents was examined. Swelling agents such as lithium hydroxide, sodium hydroxide, potassium hydroxide, ethylamine, triethylamine, ethylenediamine, piperazine, benzyltrimethylammonium hydroxide (BTMOH), urea, dimethyl sulfoxide, dimethylformamide, zinc chloride, and liquid ammonia were examined. It was found that the sodium hydroxide pretreatment or the dual pretreatment with either potassium hydroxide, ethylenediamine, or BTMOH, and sodium hydroxide prior to acrylonitrile treatment gave modified cottons having moisture regain as high as 14%. In such cases, maximum values of moisture regain were observed at the degrees of cyanoethylation of 5-8%.

SynopsisThe crystalline structure of decrystallized cotton, prepared by partial cyanoethylation with the use of sodium hydroxide aqueous solution and acrylonitrile, was examined by x-ray and IR data, in connection with such fabric properties as moisture regain. It was found that the moisture regain of the cotton fabric first increased, passed through a maximum at about 6 mole-% of cyanoethylation, and then slightly decreased with increasing degree of cyanoethylation. The increase of moisture regain in the region of the lower degree of cyanoethylation was well related to the decrease in the crystallinity of cotton. The x-ray diffraction studies revealed that the distension and disorder of the unit cell occurred primarily in the direction perpendicular to the (101) crystal plane as cyanoethylation proceeded.