Phenol Formaldehyde Resin Preparation Video Lecture | Chemical Technology - Chemical Engineering

preparation of a phenol-formaldehyde
resin attention formaldehyde is
carcinogenic on long-term exposure can
cause allergies and severe irritation of
the skin eyes and mucous membranes
resorcinol is toxic if swallowed can
cause severe irritation of the skin and
eyes and is very toxic to aquatic life
sodium hydroxide solution is corrosive I
don't take any responsibility for damage
done to persons or property caused by
the recreation of this experiment the
test tube is filled with about two
centimeters of resource in all then
distilled water is added until the
resorcinol is slightly covered after
that two milliliters of formaldehyde
solution with the concentration of 25 to
30 percent are added the mixture is
carefully heated with a Bunsen burner to
the resorcinol has dissolved when the
mixture has reached 50 degrees C or less
a long thin wooden stick is placed in
the test tube now four drops of a 10%
sodium hydroxide solution are added and
the solution is well mixed with a stick
this point the reaction can already
begin when this doesn't happen it is
heated again with a Bunsen burner while
stirring until the solution boils
without additional heat from this point
on it is only stirred strongly great
care has to be taken with this reaction
because it can easily become too
vigorous in some cases it can then be
cooled with an ice bath in the worst
case the mixture shoots out of the test
tube after a while the formation of
bubbles and the viscosity increase
the stick should touch the bottom of the
tube when the mixture solidifies
when it's solid enough it can be pulled
carefully out of the test tube with a
wooden stick this was the case after
about 30 seconds the test tube can then
be reused for other experiments this is
one of many different phenol
formaldehyde resins which is called reso
at the beginning it has a rubber like
consistency after about a day the mass
has become dark and brittle in addition
to that the volume has decreased phenol
formaldehyde resins were produced in
high amounts at the beginning of the
20th century here phenol and
hydrochloric acid were used instead of
resorcinol and sodium hydroxide solution
to make bakelite this was one of the
first polymers which has been used for
many different purposes until the 60s
even today sockets and light switches
made of bakelite can still be born the
resorcinol which is called the mono man
this reaction reacts with the
formaldehyde to form dimers
the dye must then react to form long
chains which are called polymers which
causes the mixture to become solid and
rubber like this is also called
polymerization
after that crossings are formed very
slowly which causes the material to
become solid and brittle
this was the preparation of a phenol
formaldehyde resin I hope you enjoyed
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