Thermosetting resins are polymers that irreversibly harden during curing. Common thermosetting resins include casein, melamine-formaldehyde, phenol formaldehyde, phenol furfuraldehyde, and urea formaldehyde. These resins can only be heated and shaped once since they permanently harden. The document then provides details on the composition and properties of each resin type.

1. BUILDING MATERIALS - IV
THERMO SETTING RESINS

2. DEFINITION
A Thermosetting resin is a
pre polymer in a soft solid
or viscous liquid state that
changes irreversibly into
an infusible, insoluble
polymer network by
curing.
THERMO-SETTING RESINS CAN ONLY BE HEATED AND SHAPED ONCE

3. FOLLOWING ARE THE COMMONLY USED
THERMO-SETTING RESINS
 CASEIN
 MELAMINE-FORMALDEHYDE
 PHENOL FORMALDEHYDE
 PHENOL FURFURALDEHYDE
 UREA FORMALDEHYDE

4. CASEIN
 IT IS A PHOSPHOR PROTEIN.
 DERIVED BY PRECIPITATION OF MILK WITH ACIDS
 IT ABSORBS MOISTURE AND IS NOT VERY STRONG
 EASILY WORKABLE
 POSSESSES BRIGHT ATTRACTIVE APPEARANCE

5. USES

6. MELAMINE-FORMALDEHYDE
 MELAMINE IS OBTAINED FROM CALCIUM CARBIDE
 THE FORMALDEHYDE IS PREPARED SYNTHETICALLY FROM
METHANE
 THE MELAMINE WHEN REACTED WITH
FORMALDEHYDE.FORMS THIS RESIN
 HIGHLY RESISTANT TO WATER & ELECTRICAL ARCS

7. USES

8. PHENOL FORMALDEHYDE
 IT IS A CALBOLIC ACID
 IT IS EXTRACTED FROM COAL TAR WHEN REACTED WITH
BENZENE IT FORMS THIS RESIN
 HIGHLY RESISTANT TO HEAT
 POSSESSES MECHANICAL AND ELECTRICAL PROPERTIES
 NOT EASILY ATTACKED BY WATER

9. USES

10. PHENOL FURFURALDEHYDE
 THE FURFURALDEHYDE VAPOURS ARE FORMED BY DIGESTING
HUSKS OR RICE,SHELLS OF OAT OR GROUND-NUT,ETC.WITH
SULPHURIC ACIDS IN THE PRESENCE OF A CATALYST
 THESE VAPOURS,WHEN REACTED WITH PHENOL, FORM THIS
RESIN.
 IT IS DARK IN COLOUR
 RESISTS VERY HIGH TEMPERATURE

11. UREA FORMALDEHYDE
 THE UREA IS PREPARED FROM CALCIUM CYNAMIDE OR BY
HEATING UNDER PREASSURE,A MIXTURE OF LIQUID CARBON
DIOXIDE AND LIQUID AMMONIA
 THE UREA WHEN REACTED WITH FORMALDEHYDE FORMS
THIS RESIN
 POSSESSES EXCELLENT ELECTRICAL PROPERTIES
 NOT EASILY ATTACKED BY DILUTE ACIDS

12. USES

13. THANKYOU…