EPOXY RESIN
SYNTHESIS
RUSHIKESH DIXIT
180030037
MECHANICAL BRANCH
UNDER THE GUIDANCE OF:Prof. RAJESH RAO MALAKALAPALLI
INTRODUCTION
2
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Epoxy resins are low molecular weight pre-polymers or higher
molecular weight polymers which normally contain at least two
epoxide groups. The epoxide group is also sometimes referred to
as a glycidyl or oxirane group.
•
The raw materials for epoxy resin production are today
largely petroleum derived, although some plant derived sources are
also used. Epoxy resins are polymeric or semi-polymeric materials.
High purity grades of epoxy resins can be produced using a
distillation purification process.
•
In this experiment we are using Bisphenol A to combine with
Epichlorohydrin to give bisphenol A diglycidal ether. Increasing the
ratio of bisphenol A to epichlorohydrin during manufacture produces
higher molecular weight linear polyethers with glycidyl end groups,
which are semi-solid to hard crystalline materials at room
temperature depending on the molecular weight achieved. Curing
agent used here is Isophoronediamine(IPDA) as a hardener.
•
High purity grades can be produced for certain applications, e.g.
using a distillation purification process. One downside of high purity
liquid grades is their tendency to form crystalline solids due to their
highly regular structure, which require melting to enable processing.
•
Applications of Epoxy resins involve Paints and
Coatings,Adheisves,Industrial toolings and composites,Wind
turbine technology composites,Electrical systems and
electronics,Electrical systems and electronics,Petroleum and
petrochemicals,Consumer and marine applications,Aerospace
applications,Biological applications and for Art and decoratives.
•
Other curing methods include
Homopolymerisation,Amines,Anhydrides,Phenols and Thiols.
PROCEDURE
3
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Make 10% aquaeous Sodium hydroxide by taking 7.04 gm of NaOH pellets in
70 gms of water.
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Take 20gm of Bisphenol A in a round bottom flask with the above prepared
Sodium hydroxide solution,
•
This mixture is heated to about 45°C under continuous stirring by magnetic
stirrer until the temperature is reached in solution.
•
And after its done add Epichlorohydrin in 1:10 molar ratio with Bisphenol A,here,
it comes out to be 81.05 gms. Pour it into the mixture slowly such that it takes
approx. 15 mins to completely fall into the round bottom flask.
•
The reaction mixture is heated to 95°C and maintained for about 30 mins under
using magnetic stirrer.
•
Later on the reaction mixture is allowed to cool down to reach room
temperature.
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Separate the aquaeous layer and wash the resin with water atleast 3 times until
it becomes neutral.
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Remove the excess of Epichlorohydrin by vacuum distillation and dry the
remaining resin in vacuum. Keep the resin then after in a suitable container.
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Take 0.2 gm of the epoxy resin in a round bottom flask and ad 2mL of HCl .To
this,add 25mL of pyridine under stirring. Heatthe reaction mixture to reflux for 45
mins.
•
Allow the solution to cool to room temperature. Estimate the unreacted acid
present in it by back titration with standard NaOH solution (0.1N) using
phenolphthalein indicator.
•
Carry out a blank under the same reaction conditions and find the epoxide
equivalent = N x (V/w), where N is strength of alkali, V is the volume of alkali
used up and w is the weight of the resin.
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Take 5.98 gms of Isophoronediamine(IPDA) and pour it into the epoxy resin
mixture. Stir until the mixture starts to harden. Add organic colouring like
methylene blue if required.
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Pour the epoxy resin into a mould and wait for it to harden completely.
CHEMICAL
REACTIONS AND
CALCULATIONS
4
Reaction between Bisphenol A and Epichlorohydrin
CALCULATIONS
o
Mass of Bisphenol A = 20 gms
o
Molar mass of Bisphenol A = 228.9 gms
o
Moles of Bisphenol A = 20/228.9 = 0.0876
o
Mass of NaOH = 7.04 gms
o
Mass of Epichlorohydrin (1:10 molar ratio with Bisphenol A) = 10 x 92.52 x
0.0876 =81.05 gms
o
Mass of Epoxy resin after distillation = 26 gms
o
Epoxide Equivalent = 185
o
Mass of IPDA = ( (Molar mass of IPDA / No. of Acidic hydrogen) / Epoxide
Equivalent ) x 100 x ( Mass of Epoxy resin after distillation / 100 )
o
Mass of IPDA = ((170/4)/185) x 100 x (26/100) = 5.98 gms
RESULTS
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Epoxy resin solid was made in the shape of a CUBOID and a
PYRAMID using proper moulds.
DISCUSSION
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Epoxy resin can be moulded into various shapes quickly, safely,
easily and with a good yield.
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The method which we used for synthesis is profitable when we are
not doing it on a large scale just making a sample.
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Length of the polymeric chain of Epoxy resin can be controlled and
desired physical properties of the Epoxy resin being made can be
obtained.
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Also the resin we obtain after the whole process is non-reactive
with common materials we use daily and also with human skin