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An X‐ray study has been made of partially benzylated cellulose obtained from mercerized cotton yarn, in accordance with a recently developed technique. This study reports the formation of a new crystal lattice for benzylcellulose with a degree of substitution less than 1. This new lattice is indicative of a considerable distension of the original cellulose II unit cell present in the mercerized yarn. Attempts to benzylate ramie fibers under the same conditions resulted in destruction of the fibrous structure by the treatment. Application of heat and tension were found to cause considerable improvement in crystallinity and degree of crystallite orientation of the benzylated cotton. Application of pressure in preparing the sample for X‐ray analysis in the usual manner was found to affects the X‐ray diffraction pattern, due possibly to distortion of the greatly distended (101) interplanar spacing.

Cotton yarns were impregnated with 6% sodium hydroxide and reacted in the relaxed state with acrylonitrile at 60° ('. and different periods of time up to 60 min. to give products with degrees of suhstitution up to 2.6 cyanoethyl groups per anhydroglucose unit.As substitution increases, the x-ray diffraction pattern shows only slight alteration until substitution has exceeded 1.1, after which the crystalline structure rapidly gives way to ' an amorphous structure, complete at about DS = 2.0. At the same time density decreases nearly linearly with substitution. At the stage where the product becomes essentially amorphous, it can be annealed at temperatures of about 175° C. into a new pattern characteristic of cyanoethyl cellulose. This annealing is accompanied by a substantial density increase. Stress relaxation of the cyanoethylated yarns at a substitution of 1.1 suggests a glass-rubber transition point about 140° C. which becomes more distinct and moves to lower temperatures as substitution increases. At a substitution of about 2.0 the stress relaxation reaches its lowest value (about 4% of the value at 20° C.) at the highest temperatures tested (220° C.). With further substitution a minimum relaxation at an intermediate temperature is followed by increasing stress as the temperature is raised. This effect is associated with crystallization. Breaking strength increases slightly at low substitutions but decreases then to less than 50% for the highest substitutions. Elongation at break increases gradually, exceeding 100% above the control at DS = 2 and above.Tensile stiffness decreases to about 3% of its initial value. Work of rupture and recovery show considerable decreases below DS = 2, but sharp rises between 2.0 and 2.6. Immediate elastic recovery is little affected below DS = 2, but rises above this. Delayed elastic recovery shows continuous improvement as substitution increases, eventually exceeding the control by nearly 50%.

Ternary systems, such as alcohol. water, and sodium hydroxide, have been used in the pretreatment bath or have been added in fixed quantities to cotton prior to etherifi cation with benzyl chloride. Evidence has been obtained which supports an hypothesis that increased reagent solubility, coupled with control of the cellulose: sodacellulose equilibrium. can lead to essentially homogeneous cotton cellulose modifications. In addition, the experiments have resulted in the preparation of interesting fibrous cellulose ethers. These ethers retained many of the desirable mechanical properties of the original cotton and showed increases in elastic recovery, decreased permanent set, sub stantivity to disperse dyes, microbiological resistance, and a high degree of thermo plasticity.