Complexes of Diamines with Cellulose: Study of Symmetrical and Unsymmetrical Terminal Group Effects

Abstract

Cellulose formed complexes of limited stability with a di-secondary diamine, symmetrical dimethylethylenediamine, and with a diamine containing primary and tertiary amine groups, unsymmetrical dimethylethylenediamine. Pretreat ment of the cellulose with liquid ammonia was required for complex formation. X-ray diffractometer tracings were obtained of the complexes. More stable complexes were formed between cellulose and each of two diamines, N-methyl- ethylenediamine and N-methyl-1,3-propanediamine, both of which contain primary and secondary amine groups. Pre treatment with liquid ammonia was not required for formation of these complexes. Unit cell determinations were made of the latter complexes. A di-tertiary diamine, N,N,N',N'-tetramethylethylenediamine, did not form a complex with cellulose even when the cellulose was preswollen with liquid ammonia. A complex formed with cellulose and diethyl enetriamine confirmed the results of previous workers who found that crosslinkage of the cellulose chains occurs through primary and secondary amine groups when the complex is washed with carbon tetrachloride after vacuum distillation. However, if the complex is not washed, the terminal primary amine groups bond with the cellulosic hydroxyl groups with greater distention of the 101 interplanar spacing of the complex. Nitrogen content of the complexes corresponded to a 1:1 ratio of diamine molecules to anhydroglucose units. Thermal studies were made of the more stable complexes.