تسجيل الدخول

تسجيل

Melamine-Formaldehyde Resins

المؤلف:  A. Ravve

المصدر:  Principles of Polymer Chemistry

الجزء والصفحة:  p493-494

2026-02-11

379

Melamine-Formaldehyde Resins

These resins are quite similar to urea-formaldehyde condensates and, probably, for that reason, find similar applications. Melamine reacts with formaldehyde under slightly alkaline conditions to form mixtures of various methylolmelamines :

Further heating causes condensation into resins. The rate of such resinifications is pH-dependent. Melamine-formaldehyde resins are also etherified for solvent solubility. Methanol is often used and hexamethyl ether of hexamethylolmelamine as well as higher homologues are available commercially. The hexamethyl ether can be shown as follows:

The ethers cleave upon acidification and network structures form. For methylolated melamines that are not etherified, acidification is not necessary and heating alone is often adequate for network formation. Melamine-formaldehyde resins have the reputation of being harder and more moisture resistant than the urea-formaldehyde ones.