Engineering Chemistry S Datta

POLYMERS 455
Monomers are:
(i)2, 2-(bis)-4-hydroxy phenyl propane [bis-phenol]
Preparation of bisphenol
NaOH
2 HO + CH 3 —COCH 3
HO
50 °C
CH 3
C
OH
Phenol
(ii)Epichlorohydrins
Acetone
CH 3
Bisphenol A
400 °C
2 3 2
—HCl
2 2
CH = CH—CH + Cl
Propylene
CH = CH—CH Cl
Allylchloride
CH = CH—CH Cl + HCl
300 °C HO+Cl 2 2
200 °C
2 2 .
CaO
2 2
O
Epichlorohydrin
(iii)Structure of epoxy resin
Cl CH —CH—CH Cl
OH
CH 3
CH —CH—CH —
2 2
O
C
OCH CHOH.CH
2 2
O
CH 3
n
CH 3
—O C
CH 3
O—CH —CH—CH
2 2
O
Flow diagram for the production of epoxy resin:
Epichlorohydrin
Brine
Bisphenol A
Reaction
Kettle
Purification
of resin
washing
with water
Resin
NaOH dry
or in solution
Recovered
epichlorohydrin
Water