L-tryptophan as an inhibitor of aqueous zinc corrosion

U teorijskom dijelu rada dan je prikaz osnovnih svojstava cinka te njegova primjena. Detaljno je opisan postupak vrućeg pocinčavanja te korozijska otpornost cinka u atmosferskim uvjetima i vodenim otopinama. Također, opisane su metode zaštite prevlake cinka inhibitorima korozije, s posebnim naglaskom na zaštitu organskim inhibitorima. U eksperimentalnom dijelu rada, provedena su istraživanja utjecaja inhibitora korozije na zaštitna svojstva pocinčanih vijaka u vodovodnoj vodi, 1 %-totnoj otopini NaCl, te destiliranoj vodi. Kao inhibitori koristili su se L-triptofan, VpCI-377, inhibitor 1240, te inhibitor 379/611. Ispitivanja su provedena elektrokemijskim tehnikama, kao što su metode linearne polarizacije i metoda Tafelove ekstrapolacije. Iz elektrokemijskih mjerenja određena je otpornosti materijala Rp, brzina korozije vcor, korozijski potencijal Ecor te je provedena analiza stvorenih filmova na uzorcima elektronskim skenirajućim mikroskopom (SEM).The theoretical part of work shows basic properties of zinc and its application in practice. Hot dip galvanization and corrosion resistance of zinc in both, atmospheric condition and water solution, have been described. Methods of protecting layers of zinc with corrosion inhibitors have also been described, having in the main focus the protection with organic inhibitors. In the experimental part of the thesis, influence of corrosion inhibitors on the protective properties of galvanized bolts in tap water, 1% solution of NaCl and distilled water was tested. L-tryptophan, VpCI-377, inhibitor 1240, and inhibitor 379/611 were used as inhibitors. With the electrochemical methods, few properties have been determined, such as polarization resistance Rp, corrosion speed vcor and corrosion potential Ecor. Also, an analysis of samples has been conducted using scanning electron microscope (SEM)