| 摘要 |
N-Alkyl-N'-hydroxyethyl piperazines of formula (I) are new (where R1 is 1-3C alkyl and R2 is H, Me, or Et) as is their use as catalysts for the prepn. of polyurethanes. - Pref. (I) are N-methyl- N-methyl-N' hydroxyethyl piperazine and N-methyl-N'-(2-hydroxypropyl)-piperazine. Pref. (I) are prepd. by addn. of alkylene oxide to piperazine followed by Leuckart-Wallach reaction/reductive methylation. From 0.01-4 (0.05-3) pts. (I) are used per 100 pts. polyol, opt. together with triethylenediamine or organotin cpd. as co-catalyst, in prepn. of polyurethanes. - (I) have less unpleasant odour than dimethyl ethanolamine, are less toxic than certain morpholines, and their catalytic activity increases with temp. Soft polyurethane foams prepd. with (I) exhibit good extensibility without increased residual deformation on wet-compression at raised temp.
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