Applications of Aldehyde-Crosslinked Starches

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 

Materials from starch crosslinked with melamine-formaldehyde, methylated melamine-formaldehyde, and other amine-aldehyde resins were patented as binders for filter paper,1336 milk filter sheet materials,1338 and aqueous papercoating compositions containing clay, titanium(IV) oxide, butadiene-styrene latex, and calcium octadecanoate.1396,1397 Foams for filters were developed.1398 A heatsetting adhesive was one of the first applications reported for starch crosslinked by urea-formaldehyde and phenol-formaldehyde resins.1331,1340-1342,1347,1372,1399 

Formaldehyde-crosslinked (hydroxyethyl)starch blended with borax was used to produce an adhesive,1401 and with silver halides to produce photochemical stencils.1402 The use of 1,5-pentandial instead of formaldehyde has been used to produce a so-called antifogging composition for optical applications.1357 Reinforced 

Starch dialdehyde acetalated with pullulan was applied as a cathode-mix binder in dry-cell batteries1363 and in contact lenses.1364 It was also reported that starch dialdehyde, after animation with ethylenediamine and crosslinking with 1,5-pentandial, immobilized trypsin.1411 This preparation was proposed as a component of wound dressing. 

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