Urea formaldehyde is a thermosetting condensation polymer that is produced by reacting urea and formaldehyde in an alkaline medium. It is primarily used as a wood adhesive but also has applications as a fertilizer, foam insulation, and more. The polymerization process involves the elimination of water and results in a hard resin. However, the resin can decompose in humid conditions or at high temperatures, limiting its uses. It is manufactured through a condensation reaction of urea and formaldehyde in an aqueous alkaline solution.

1. UREA Formaldehyde
Polymers Manufacture

2. Review

7. CHEMCAD Flow sheet

8. UREA FORMALDEHYDE
• A non transparent resin, used for a variety of
applications. Wood glue.

9. • urea formaldehyde resins are prepared by
treating urea with formaldehyde in an alkaline
or neutral medium to produce dimethylol
urea, which then undergoes
polycondensation, a chemical process that
results in a polymer, when heated in an acidic
medium.
• This resin is primarily used as an adhesive

10. UREA FORMALDEHYDE
A condensation polymer is one in which the repeating unit lacks
certain atoms,
which were present in the monomer(s) from which the polymer
was formed or to which it can be degraded by chemical means.
Condensation polymers are formed from bi- or poly
functional monomers by reactions which involve elimination of
some smaller molecule.
Examples:
1- Thermoplastics :Polyesters and polyamides are examples of
such thermoplastic polymers.
2- Thermosetting condensation polymers
Phenol-formaldehyde, Urea-formaldehyde resins are
thermosetting condensation polymers.
All these polymers are directly synthesized by condensation
reactions.

11. • MAJOR APPLICATIONS Molding
resins, adhesives, coatings,
treatment of paper and textiles,
automobile tires
• PROPERTIES OF SPECIAL INTEREST
Hardness, non-flammability,,
thermal properties, light fastness

12. Urea Formaldehyde as
1- Fertilizer (slow Nitrogen release)
2- Glue (Wood Glue)
3-Foam insulation

13. • The major drawback of this resin is that it
hydrolyzes, or decomposes, in extremely
humid conditions and at high temperatures.

14. Condensation of urea with formaldehyde leads to products of
various structures and properties according to the
experimental conditions (pH, temperature, reaction time,
molar ratio of components).
The condensation is generally carried out in basic medium,
resulting essentially in the formation of hydroxymethyl
compounds; some oxymethylene groups are also formed,
particularly on heating. Mono-, di-, and trihydroxymethyl-
urea have been proved to be primary products of this
condensation; whether tetrahydroxymethyl-urea is also
formed is as yet uncertain:

17. • Urea-formaldehyde resins are generally prepared
by condensation in aqueous basic medium.
Depending on the intended application, a 50-
100% excess of formaldehyde is used. All bases
are suitable as catalysts provided they are
partially soluble in water. The most commonly
used catalysts are the alkali hydroxides. The pH
value of the alkaline solution should not exceed
8-9, Since the alkalinity of the solution drops in
the course of the reaction, it is necessary either
to use a buffer solution or to keep the pH
constant by repeated additions of aqueous alkali
hydroxide. Under these conditions the reaction
time is about 10-20 min at 50- 60 °C

21. UREA FORMALDEHYDE