Effect of the NCO/OH Molar Ratio on the Physical Aging and on the Electrochemical Behavior of Polyurethane-Urea Hybrid Coatings

Author(s)

Lopes de Oliveira, Mara Cristina ^[1] ; Antunes, Renato Altobelli ^[2] ; Costa, Isolda ^[3]

Affiliation

^[1] Technol Entrepreneurship & Innovat Ctr, Electrocell Ind Com Equip Elet LTDA, BR-05508000 Sao Paulo - Brazil

^[2] Fed Univ ABC UFABC, Engn Modeling & Appl Social Sci Ctr CECS, BR-09210170 Santo Andre, SP - Brazil

^[3] IPEN CNEN SP, BR-05508000 Sao Paulo - Brazil

• Document type: Journal article
• Source: International Journal of Electrochemical Science; v. 8, n. 4, p. 4679-4689, APR 2013.
• Web of Science Citations: 5

Abstract

Low volatile organic compounds (VOCs) coatings are increasingly attractive due to both environmental concerns and high protective performance. High solid systems play a central role in this scenario. In this work, 100% solids polyurethane-urea hybrid coatings have been prepared. The coatings were prepared using methylene diphenyl diisocyanate (MDI) for the synthesis process and different NCO/OH molar ratio. The effects of the structural characteristics on the physical aging behavior and on the electrochemical response of the hybrid coatings were evaluated using differential scanning calorimetry (DSC) and electrochemical impedance spectroscopy (EIS). The results showed that the coating with the highest NCO/OH ratio presented the best combination of properties, showing low susceptibility to physical aging and high corrosion resistance. (AU)