Condensation polymers from diisocyanates with dihydrazides and hydrazine

✍ Scribed by Tod W. Campbell; Veronika S. Foldi; John Farago

• Publisher: John Wiley and Sons
• Year: 1959
• Tongue: English
• Weight: 686 KB
• Volume: 2
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1959.070020504

✦ Synopsis

The versatility of the reaction of the isocyaiiate group with various active hydrogen compounds, and some polymers made by this type of reaction, have been discussed recently. Among the unusual active hydrogen compounds which have not been adequately investigated as polymer formers with diisocyanates are hydrazine2 and dihydrazides, which should give linear polymers with structures (I) and (11) 0 0 II II [-R-NH--CNH-NH--CNH-]~ (I) and -R-NH-L NH-NH-88 R--NH-NH-L NH-Jn (11)

a polyureylene, and a poly (acylsemicarbazide), respectively.

The chemistry of the reactions of monoisocyanates with hydrazines and hydrazides has been investigated by a number of workers. Thus, Curtius and Burkhardt3 noted that hydrazine hydrate reacted with phenyl isocyanate rather violently with evolution of heat. The main products of the reaction were hydrazidicarbanilide (CeHh-NH .-CO .NH .NH .CO .NH-c&k), some carbanilide, and only a small amount of phenyl carbazide Busch and Frey4 obtained 1,4-diphenyl semicarbazide in very pure form when an equimolecular amount of phenyl isocyanate in cold ether solution was slowly added to a cold ether solution of phenylhydrazine. Phenyl isocyanate and symdimethyl-hydrazine6 reacted violently to give (CSH~NHCONHNH~).

CeHSNHCONCHaNCHaCONHCeHS

Van Gelderens studied the reactions of 4-bi-phenylyl isocyanate with a series of aromatic hydrazine derivatives in benzene, toluene, or petroleum ether. In all cases, the 1,4-~ubstituted semicarbazides resulted. 0 RNH.NH2 + R"CO -RNHNHJNHR!