Eco-friendly polymeric borate ester as a corrosion and scale inhibitor for carbon steel in 3.5% NaCl

Developing eco-friendly and high-performance corrosion inhibitors is crucial for carbon steel in WEDM cutting fluids. Herein, A novel water-based polymeric borate ester (PBE) was designed and synthesized as a corrosion and scale inhibitor. Compared to commercial borate ester, PBE offers better corrosion inhibition performance, multiple reactive sites, good film-forming ability, and high surface coverage. Electrochemical measurements, weight-loss methods, and surface analyses indicate that PBE demonstrates excellent corrosion inhibition efficiency (up to 99% for Q235 carbon steel in 3.5% NaCl solutions) and scale inhibition efficiency (up to 95.3% against CaCO 3 ). The adsorption behavior of PBE follows the Langmuir absorption isotherm model with a mixed absorption mechanism. Cost estimation further reveals low production cost ($1,400 per ton) of PBE. This research provides a promising green corrosion inhibitor with excellent potential for large-scale application in WEDM cutting fluids. • A polymeric borate ester was synthesized via a facile one-pot method. • It exhibits superior corrosion inhibition (99%) and scale inhibition (95.3%). • Electrochemical and surface analysis reveal its mixed adsorption and effective protective film formation. • The inhibitor offers a cost-effective and eco-friendly alternative to commercial counterparts.