Poly(chloroaldehydes). I. Polychloral stabilization

Abstract

Polychloral diol, unlike polyoxymethylene diol, is not readily capped in the presence of alkali catalysts. Polychloral is capped under acid conditions by acid anhydrides and chlorides and does not appear to undergo degradation during the process. Evidence for end‐capping is provided by infrared analysis in the case of the low DP polychloral, metachloral. End‐capped polychlorals possess good stability towards hot dimethylformamide and good stability at elevated temperatures (255°C.). From the melting points of copolymers, polychloral itself is estimated to have a melting point of about 460°C. The high melting point is consistent with the rigidity of the polymer chain. A means of estimating the DP of the polymer is proposed, based on a form of endgroup analysis. By this technique, metachloral is estimated to have a DP of about 50.

Haloaldebyde Polymers. I. Chain Termination in Anionic Chloral Polymerization

“…Under these circumstances, the determination of the degree of polymerization of polychloral There is also a suggestion in the literature that this method has been successfully used for the determination of molecular weights of polychloral. 4 In our hands, polychloral once made and isolated, cannot be endcapped, no trace of carbonyl group is observed after acetylation with acetic anhydride or acetyl chloride and exhaustive extraction of the polymer sample with acetone.…”

“…Very little is known about the end groups of chloral polymers, particularly of the homopolymer, although it has been reported that chloral polymers are like the polymers of formaldehyde, substituted polyoxymethylene glycols which can be acetylated to the corresponding acetates. 4 We found that anionic chloral polymerization can be carried out readily in the presence of strong acylating agents and that acylation occurs in the form of a chain termination reaction. This method provided a new way to introduce stable end groups into polychloral.…”

Tuning the hydrophobic cores of self-immolative polyglyoxylate assemblies

“…44 Chloral (C) is not a glyoxylate, but has three chloro groups a to the aldehyde, making it susceptible to polymerization while at the same time being hydrophobic. 45 EtG was purchased and purified as previously reported. 40 C was purchased as its hydrate and then distilled over P2O5 to afford the aldehyde.…”