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Catalysis of the reaction of urea–formaldehyde precondensates on cellulose
Author(s) -
Steele Richard
Publication year - 1960
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1960.070041007
Subject(s) - cellulose , urea , catalysis , hydrolysis , chemistry , formaldehyde , ammonium hydroxide , polymer chemistry , urea formaldehyde , organic chemistry , adhesive , layer (electronics)
The reaction of dimethylol urea on cotton cellulose at 150°C. has been studied with NH 4 Cl and Na 2 CO 3 as catalysts. With the ammonium salt, 0.2 mmole/g. precondensate was required to attain the maximum level of fixed resin, while maximum resistance to hydrolysis by dilute acid required 0.3–0.4 mmole/g. The acid resistance is attributed to the crosslinking of the fiber, which is primarily responsible for the changes produced in resilience and other physical properties. The application of monomethylol urea with NH 4 Cl does not lead to changes in acid resistance or physical properties such as are attributed to crosslinking. Catalysis with Na 2 CO 3 does not appear to lead to crosslinking with dimethylol urea, since the treated cellulose remains soluble in cuprammonium hydroxide. There is very little difference in the effectiveness of monomethyl and dimethylol ureas for changing physical properties when they are applied with the alkaline catalyst. It is suggested that the curing step with Na 2 CO 3 leads to further condensation through methylene ether linkages rather than to reaction with the cellulose substrate.