How is Epoxy resin made?

Answer 1

Firstly at 50⁰C in a conventional reactor, mix the reactants (epichlorohydrin and bisphenol A) under a molar ratio of bisphenol A to epicholorhydrin 1:14, then raise the temperature to 115⁰C over a period of time of 30 minutes. Conduct this reaction under a nitrogen gas environment.

Secondly add an alkaline catalyst (2 moles of NaOH), as 30% aqueous solution, drop wise. This usually takes several hours. The rate of addition is maintained as such the reaction mixture does not change the colour when phenothalein (an indicator) is added.

Thirdly carry out the reaction for an additional 30 minutes and then wash out the excess catalyst.

Next raise the temperature to 130⁰C and remove water by decanting (The remaining liquid is dried with anhydrous sodium sulfate or other dessicant)

Lastly remove excess epichlorohydrin by vacuum distillation.