化學(xué)配方數(shù)據(jù)庫(kù)
| 配方類(lèi)型： |
MISCELLANEOUS |
| 配方說(shuō)明： |
Insolubilizing Technical Protein Colloids |
| 配方組成： |
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| 配制方法： |
Formaldehyde The reaction between T.P.C. and formaldehyde proceeds fastest under alkaline condition (pH 9) and slowest under acid conditions (pH 4). the exception is when ammonia is used as the alkali: ammonia appears to interfere with the proteinformaldehyde reaction.
Under all conditions, if excessive quantities of formaldehyde are used, even in the presence of plasticizers, the resulting product will be brittle.
Formaldehyde is purchased as commercial Formalin (40% aqueous solution) and must be diluted with water before use with T.P.C.s For example: a test product is saturated with T.P.C. solution and then immersed in a 3-5% formaldehyde bath. It is then dried, preferably with heat to hasten the cross-linking reactions.
Glyoxal Glyoxal and more recently glutaraldehyde, are gradually replacing formaldehyde for a number of reasons. Glyoxal is a dialdehyde as indicated, and the obnoxious odors incurred with formaldehyde are not present. The same rules generally apply in its use and application |
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