ISSN:
0449-2951
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
A study has been made of the effect of concentration of the crosslinking agent, gelatin concentration, and pH on the rate of increase of viscosity with time, for gelatin solutions containing either formaldehyde or glyoxal. The results are consistent with the kinetic relationship: \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm Rate of crosslinking} \propto \left[ {{\rm Gelatin}} \right]^2 {{\left[ {{\rm Crosslinking agent}} \right]^n } \mathord{\left/ {\vphantom {{\left[ {{\rm Crosslinking agent}} \right]^n } {\left[ {{\rm H}^{\rm + } } \right]}}} \right. \kern-\nulldelimiterspace} {\left[ {{\rm H}^{\rm + } } \right]}} $\end{document} For formaldehyde, n is 2. For glyoxal, n is 1, as was expected for this bifunctional hardener. Initial formation of gelatin-methylol compounds is proposed in both cases. With formaldehyde, it is suggested that this leads to a methylene-ether crosslink between a gelatin amino-methylol compound and an unspecified gelatin-methylol compound, while in the case of glyoxal, there is evidence to suggest that the crosslinkage involves two side-chain amino groups and results in a charged crosslink.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1963.100010217
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