Greener waterborne epoxy coatings with optimized UV-resistance

Author(s)

da Silva, Mauro Sergio ; de Souza, Alana Gabrieli ; Rosa, Derval dos Santos ; Valera, Ticiane Sanches ; Wiebeck, Helio

• Document type: Journal article
• Source: POLIMEROS-CIENCIA E TECNOLOGIA; v. 34, n. 3, p. 11-pg., 2024-01-01.

Abstract

The UV-resistance performance of waterborne epoxy coatings with different aminic-curable substances was evaluated to solve the widely known problem of poor weathering resistance of coatings. Samples were evaluated by color and gloss changes, FTIR, thermal properties, and macroscopic morphology. Results indicated that higher aminic values in curing agents degraded faster than lower aminic values (increases of similar to 3% in delta b and delta E between 5 and 20%). All samples showed a gloss variation varying between 40 and 70 G.U. FTIR and Tg indicated the resin degradation when using curing agents of unmodified aliphatic amine because of its rapid chemical degradation under a UV environment, as confirmed by microscopy images. The curing agents with aminic values between 200 and 300 KOH/g and the equivalent weight of amine hydrogen higher than 120 g/eq showed the best performance in epoxy coatings and good stability against accelerated aging, being promising options for future applications. (AU)

• FAPESP's process: 21/14714-1 - Multi-user equipment approved in grant 2020/13703-3: Cromatógrafo de Íons Modular 940 Professional IC Vario
• Grantee: Derval dos Santos Rosa
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 20/13703-3 - Environmentally friendly porous materials for the recovery and revaluation of metals reclaimed from contaminated water
• Grantee: Derval dos Santos Rosa
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 22/01382-3 - Cellulose hydrogels containing modified clays for the removal and recovery of metal ions present in contaminated water
• Grantee: Rafaela Reis Ferreira
• Support Opportunities: Scholarships in Brazil - Doctorate