Polyhydrazides isotropic solutions

Solubility in Non-Agueous Solvents and Their Admixtures with Aqueous Organic Bases. Only optically isotropic solutions have been obtained with polyhydrazides in such solvents as dimethyl sulfoxide-LiCl or dimethylacetamide-LiCl. 

Another extended-chain polyhydrazide which contains no rings was prepared from oxalic di-hydrazide and trans,trans-muconvl dichloride (last formula of Table IV). The polymer had an Tinh value of 0.33 and dissolved in tetramethylammonium hydroxide to form only isotropic solutions. With a higher molecular weight sample, optically anisotropic solutions should be attained. Other possible components for this purpose are fumaroyl and acetylenedioyl (Table IV). ... 

Isotropic solutions are obtained likewise from polyhydrazides containing large proportions of linear polymethylene units, such as adipoyl or sebacoyl units. 

Copolyhydrazide-amides. Polyhydrazides with high proportions of amide links are poorly soluble in aqueous organic bases or at best yield isotropic solutions. As an example, 0-T polyhydrazide with 5 and 10 mole percent amide links derived from -phenylenedfamine formed optically anisotropic solutions in 10% and 25% tetramethylammonium hydroxide. At 20% modification, or above, only isotropic solutions or incomplete solubility was attained (Tables VI and VII). 

N-Substituted Polyhydrazides Several poly-hydrazides were prepared in which each hydrazide link had one N-methyl substituent (Table VIII). Only isotropic solutions were obtained in the aqueous organic bases. The nitrogen substituent presumably provides a more flexible type of amide link and changes the nature of the solvent association (see next section). 

J. R. SCHAEFGEN - DU PONT. I noticed in the solubility curves at the isotropic-anisotropic boxindaiy with the aqueoiis tetramethylammonium hydroxide and the 0-T polyhydrazide that the amount of base only increased slightly as the amount of polymer in solution increased. 

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