| 摘要 |
<p>The condensates are prepd. by (a) adding chloracetic acid to a portion of the phenol in alkaline medium to form the chloropenoxyacetate; (b) adding the remainder of the phenol and sufficient acid to produce the pH required for the condensation; (c) adding the calculated amt. of HCHO; (d) raising the temp. of the reaction mixt. to 70 degrees C and effecting the reaction until all the HCHO has reacted with the phenol and a condensation melt is obtd.; (d) heating the mixt. to remove water of reaction; (e) finally raising the temp. to about 200 degrees C, and applying vacuum such that unreacted phenol is eliminated, the added acids are decomposed and a clear melt is left behind. After degassing, the melt may be used directly for melt-spinning fibres. The condensate gives clear, transparent, solid bodies on extrusion and cooling.</p> |
