Amide derivatives, cellulose, reaction

Amide derivatives, cellulose, reaction with formaldehyde and its, 52... 

Cellulose Reaction with Formaldehyde and Its Amide Derivatives... 

Figure 1 shows the repeating glucose units of cellulose with the carbons labeled, including those with the reactive 2, 3, and 6 hydroxyls. Ihe most important reactions of cotton cellulose commercially are esterification and etherification, with the products of etherification ranking first. It is generally agreed today among textile scientists that durable press cellulosic textiles ow their smooth-drying and resilient properties to the reactivity of formaldehyde and its amide derivatives with cellulose to produce crosslinks between adjacent cellulose chains (Figure 2). Hovever, the theory that crosslinking was responsible for increased resiliency developed only after the treatmaits were in wide use.

The possibility of crosslinking natural macromoleculcs, such as cellulose and proteic materials, via the Mannich reaction has also been inve.stigatcd. Cellulose derivatives, however, are mostly subjected to the analogous amidomcthylation reaction, " usually employing bis-methylol amides (urea, oxalyl, adipoyl derivativas, etc.) capable of reacting with the cellulose hydroxy groups. 

Amino polystyrene pyrazolone linker resin 58 provided various amide products 59 with a high conversion rate and good purity under mild conditions the resin linker was stable under the reaction conditions, resistant to hydrolysis, and reused repeatedly without loss of activity <03TL8063>. The preparation of pyrazoline derivatives 61 was accomplished with traceless solid-phase sulfone linker 60 with phenylhydrazine <030L1067>. Aniline cellulose-bound enaminones 62 reacted with phenylhydrazine under microwave irradiation to produce pyrazolocarboxylic acid derivatives 63 in high yields <03JCO465>. 

Apart from the reaction with halogen derivatives, use was also made, for the synthesis of silicon-containing cellulose esters, of the reaction of alcoholysis, with cellulose, of tetraalkoxysilanes or alkyl(aryl)trialkoxy-silanes and the amides of siliconic acids (64) ... 

The effect of the heating rate and the degree of transformation on such kineti c parameters as the activation energy and reaction order in the thermal degradation of phenyl- or pyridyl-carbamoylmethyl cellulose, indicated that the degradation reaction was very complex. Amidation of carboxymethyl-cellulose decreased the heat resistance and favoured the breaking of macro-molecular chains so that the supramolecular structure affected the heat stability of the derivative and the mechanism of thermal degradation. 

---