SynopsisThe reaction of carbon dioxide with aniline using triphenyl phosphite in pyridine is greatly facilitated by the addition of hydrochlorides of tertiary amines such as pyridine and triethylamine, and has been successfully applied to the preparation of polyureas of high molecular weight from carbon dioxide and aromatic diamines. The presence of a catalytic amount of pyridine hydrochloride significantly increased the inherent viscosity of the resulting polymers, the highest value being obtained with about an equivalent of the chloride. Optimal temperatures and pressures varied with diamines used, and were M " C and 40-50 atm of carbon dioxide. The polycondensation reaction was also affected by the solvent compositions of pyridine and N-methylpyrrolidone, its optimum being dependent on diamines used.
SynopsisIn a model reaction of terephthalic acid with aniline by using triphenyl phosphite in a mixed solvent of pyridine and N-methylpyrrolidone (NMP), mono-and dianilides were produced with relative yields varying with the content of pyridine in the solvent. The polycondensation of terephthalic acid with aromatic diamines was found to proceed more favorably via monoamidation, and highmolecular-weight polyterephthalamides were prepared by controlling initiation conditions (selective activation of carboxylic groups), such as initial solvent systems, including the amount and kind of pyridines and initiation temperatures.
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