Starch with glyoxal

Chlorinated and/or oxidized starches crosslinked with glyoxal were used to produce a high-strength size for paper.573 Coating adhesives were also prepared by crosslinking glycidyl esters.1385 In addition, esters of starch with inorganic acids (such as starch phosphates) were crosslinked with various aliphatic and aromatic aldehydes in the presence of urea, melamine and similar compounds.1322... 

A thixotropic starch was produced in reactions of POCl3-crosslinked starch with unsaturated aliphatic aldehydes.1361 Starch phosphates have been crosslinked by various aliphatic and aromatic aldehydes in the presence of urea, melamine, and similar compounds. Among several aldehydes tested[formaldehyde, propanal (propionaldehyde), glyoxal, glutaraldehyde, 2-hydroxyadipaldehyde (2-hydroxy -1,6-hexanedial), and some aromatic aldehydes], only those products that had reacted with glyoxal were insoluble in water.1322 Significant increases in viscosity occurred after starch phosphates having a low DS were treated with urea.1590... 

Water molecules are so small and cellulose and so hydrophilic that this solution usually affords only temporary protection. Formaldehyde, glyoxal, polyethylen-imine, and, more recently, derivatized starch (50) and derivatized cationic polyacrylamide resins (51) have been used to provide temporary wet strength. The first two materials must be applied to the formed paper, but the other materials are substantive to the fiber and may be used as wet-end additives. Carboxymethylcellulose-calcium chloride and locust-bean gum-borax are examples of two-component systems applied separately to paper that were used to a limited extent before the advent of the amino resins. Today three major types of wet-strength resins are used in papermaking polyamide-polyamine resins cross-linked with epichlorohydrin (52) are used in neutral to alkaline papers cationic polyacrylamide resins cross-linked with glyoxal are used for acid to neutral papers and melamine-formaldehyde resins are used for acid papers. 

Cellulose carbamate and its derivatives are able to immobilize enzymes easily with the help of dialdehydes such as dialdehyde starch, glutaraldehyde, and glyoxal [62]. Since cellulose triphenylcarbamate or tricarbanilate prepared... 

Sodium hydrogensulfite reacts with starch dialdehyde in a 1 1 ratio.527,528 Despite the fact that aldehydes react with hydrogensulfites, these compounds are described as adducts. Sodium sulfite degrades starch dialdehyde and the glyoxal liberated forms tetrahydrobenzoquinone.529... 

There are also patents for solid, water-insoluble products resulting from such a reaction.1276,1277 In addition there are reports of the strengthening of artificial silk, starches, and cellulose after contact with formaldehyde.1278 On the other hand model studies carried out by Tomasik and Schilling1279 on the reaction of maltodextrins with formaldehyde and pyruvaldehyde suggested that neither of these, in contrast to glyoxal and glutaraldehyde, acted as crosslinker. 

Chem. Descrip. Glyoxal CAS 107-22-2 EINECS/ELINCS 203474-9 Uses Crosslinking agent, water resist, aid for paper coatings Features Gives tissues temporary wet str. esp. effective when used with binders that contain amino or hydroxyl groups, such as starch, casein, or polyvinyl alcohol... 

Uses Starch insolubilizer in coatings for paper/paperboard in contact with dry food Regulatory FDA 21CFR 176.180 Glyoxal/urea polymer CAS 53037-34-6... 

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