| Chemical Industry-Epichlorohydrin |
 |
Epichlorohydrin
Epichlorohydrin (1-chloro-2,3-epoxypropane) is an important raw material for the production of epoxyresins. During the synthesis of epichlorohydin (EPI) allylchloride (3-chloropropene) is obtained as an intermediate product.
The production process starts with a substitution reaction between chlorine and propene.
CH3-CH=CH2 + Cl2 -> CH2=CH2-CH2Cl + HCl
Subsequently hydrochloric acid is removed via distillation from the obtained allylchloride.
In a second process step aqueous chlorine (sodium hypochlorite) is added. An addition reaction leads to the formation of dichlorohydrin (CH2Cl-CHOH-CH2Cl).
Finally hydrated lime - Ca(OH)2 - is added. The dichlorohydrin is converted into epichlorohydrin and calciumchloride during a dehydrochlorination reaction.
The final product epichlorohydrin (CH2(O)CH-CH2Cl) is seperated from the reaction mixture via a distillation.
Epoxy resins are generally obtained by a reaction between epichlorohydrin and bisphenol A, that takes place in the presence of caustic soda lye.
CH2(O)CH-CH2Cl + HO-C6H4-C(CH3)2-C6H4-OH ->
[ -O-C6H4-C(CH3)2-C6H4-O-CH2-CHOHCH2-] + HCl
oOOo
|
