Synthesis of Some Nonionic Polymeric Surfactants Based on Aminolized PET as Corrosion Inhibitors

Abstract

The present work deals with the preparation of nonionic polymeric surfactants based on aminolytic degradation of PET by using diethanolamine (DEA) in the presence of Na-acetate as a catalyst to produce bis(4-hydroxyethylene)terephthalamide (B4HETA) monomer. The monomer produced was reacted with stearic acid and poly (ethylene glycol) with different number average molecular weights, namely 600, 2000 and 4000 gmol⁻¹, to produce nonionic polymeric surfactants having different hydrophile–hydrophobe balances. The molecular weights and polydispersity of the prepared surfactants were determined by the GPC technique. Surface tension as a function of concentration for different solutions of the prepared surfactants was measured at 298, 308, and 318 K to calculate surface and thermodynamic properties of the investigated compounds. Furthermore, corrosion inhibition efficiency of the investigated nonionic polymeric surfactants was thoroughly studied.

Keywords:

• aminolysis
• corrosion inhibitors
• nonionic surfactant
• PET
• thermodynamic parameters

Notes

*CMC in mol L⁻¹; γ_CMC in mNm⁻¹.

*Γ_max in mol cm⁻²; A _min in nm² (molecule)⁻¹; Π_CMC in mNm⁻¹.

−ΔG _mic and ΔH _mic in KJ mol⁻¹.

−ΔG _mic and ΔH _mic in KJ mol⁻¹.