Formaldehyde and its applications / Synthite Limited.

  • Synthite Limited.
Date:
[Between 1930 and 1939?]
Catalogue details

Licence: Public Domain Mark

Credit: Formaldehyde and its applications / Synthite Limited. Source: Wellcome Collection.

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    APPENDIX Formaldehyde H.CHO is the first aldehyde of the aliphatic series, and though it possesses many properties of aldehydes in general it differs from the rest of the series in several important characteristics. With ammonia, instead of forming the usual additive compound, it combines fiercely and quantitatively to form hexamethylene tetramine (CEE 0 N,, a ring compound of considerable stability. It isaa crystalline substance, very soluble in water, slightly so in alcohol, and is used in considerable quantities in the manufacture of synthetic resins and is also employed extensively in medicine. When formaldehyde is boiled with alkalies such as lime, it readily polymerises and condenses into sugar-like bodies, and on evaporation these are obtained as a sticky mass of considerable complexity. Formaldehyde reacts with most organic and many _ inorganic substances, the extreme activity and presence of a carbony] group enabling it to be employed in many organic syntheses, while its strong reducing properties also render it valuable in other applications. The gas is extremely soluble in water, a solution saturated at ordinary temperature containing approximately 50%; such a solution, how- ever, is not stable, especially in the absence of any alcohol, and hydrated paraformaldehyde is rapidly precipitated. Ordinary com- mercial 40°% formaldehyde is the strongest solution which can be handled satisfactorily without fear of undue polymerisation. It is however, questionable as to the actual H.CHO which normal ‘40% formalin’ contains, since the molecules so readily associate, and there is undoubtedly a large proportion of diformaldehyde or methylene glycol, CH. (OH), present in solution, together probably with a number of hydrated higher polymers as well.
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