| 摘要 |
a -b -Ethylenically unsaturated aldehydes, e.g. acrolein and/or methacrolein, are polymerized in aqueous medium in the presence of a Redox system comprising a peroxidic compound and metallic silver. Preferably, the peroxidic compound is potassium peroxydisulphate and the silver is a finely divided powder. The polyaldehyde so obtained may be oxidized in the presence of silver, in an alkaline medium, e.g. aq. NaOH, using oxygen or an oxygen-containing gas to give a solution of a polycarboxylic acid salt. Alternatively, the polyaldehyde in admixture with the silver may be caused to undergo the Cannizzoro reaction, e.g. to give the sodium salt of a polyhydroxy-polycarboxylic acid or reacted with formaldehyde. |
