Use of Melamine-Formaldehyde Resin as Shell Material for Microencapsulation

MIGUEL, MARÍA DE LA PAZ

An Introduction to Melamine

NOVA SCIENCE PUBLISHERS, INC.

Lugar: Nueva York; Año: 2020; p. 1 - 204

Polymers are commonly used in the fabrication of protective coatings for metallic substrates. Research on self-repairing coatings based on the incorporation of microcapsules or nanocapsules loaded with corrosion inhibitors or film-former healing agents continues to increase because of potential economic benefits of this technology. This chapter deals with the use of melamine-formaldehyde resins as shell material for microcapsules. The microencapsulation of flaxseed oil as repairing agent was carried out via the in-situ emulsion polymerization method. Chemical composition of microcapsules is one of the key factors for keeping their physical integrity and stability in the course of their synthesis process, storage and handling operations to fabricate a coating. In this work, the melamine-formaldehyde resin was chosen to form the shell material due to its good thermo-mechanical and water-resistant properties. A comparison between the syntheses of microcapsules based on melamine-formaldehyde and urea-formaldehyde resins is included. Selection of emulsifiers is another key factor because the microcapsules formation is influenced by the emulsion stability. Therefore, a series of experiments was conducted changing the emulsifying system and a discussion of results is provided. The synthesis products were examined by optical microscopy and scanning electronic microscopy (SEM). Further characterization applied to a powder of microcapsules allowed to verify the effective repairing agent encapsulation.