Miscellaneous Aldehyde Polymers

A large number of polymers from aldehydes have been reported in the literature but, apart from those polymers already described, they are not of commercial importance. 

Care has to be taken in the polymerisation of aldehyde polymers in order to achieve reproducible results. It is also difficult to stabilise most of the products since thermodynamics frequently favour depolymerisation at temperatures a little above or at room temperature. 

In the immediate future it is unlikely that any of these polymers will attain commercial significance. Hopes that polyhaloaldehydes such as polychloral might be of some use because of their good acid stability have not been realised. This is because polymers prepared to date have poor alkali and thermal resistance, decomposing without melting. Chloral-dichloracetaldehyde copolymers have also proved similarly disappointing. 

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Miscellaneous Curing Reactions. Other functional groups can react with the thiol terminal groups of the polysulfides to cross-link the polymer chains and build molecular weight. For example, aldehydes can form thioacetals and water. Organic and inorganic acids or esters can form thioesters. Active dienes such as diacrylates can add to the thiols (3). Examples of these have been mentioned in the Hterature, but none have achieved... 

Biochemical and Miscellaneous.—3-Methyl-2-benzothiazolone hydrazone is incorporated quantitatively into the anticodon loop of t-RNA" from yeast. Reaction occurs by Schiff s base formation with the ribose aldehyde group remaining after excision of the base Y from the nucleotide. The reaction provides a method of chemically modifying the natural polymer, with retention of its biochemical activity." ... 

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