Extrinsic conditions for the occurrence & characterizations of self-healing polyurea coating

• Main Author: Choo, Wan Luoh
• Other Authors: Dong Zhili
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Materials::Material testing and characterization
• Online Access: https://hdl.handle.net/10356/147757
• Institution: Nanyang Technological University

Metal structures and polymers are susceptible to corrosion and degradation, which affect their mechanical properties, resulting in material failure. Protective coatings have been used widely to provide protection against corrosion and degradation caused by reaction in the presence of moisture and oxygen. However, because the maintenance and re-coating process of large ships and pipelines underwater are particularly difficult, there is still room for improvement in the role of the conventional coating. In addition, self-healing polyurea coating is gaining extensive attention due to its superior properties whereby manual maintenance is not required. Organic coating with microencapsulated drying oil as the healing agent has been extensively studied for its self-healing ability in air (atmospheric oxygen) but the study on its self-healing ability in water (dissolved oxygen) is still lacking. This paper presents the efficiency of microcapsules fabricated and the healing ability of Polyurea. During fabrication, it is found that the fabrication method is not optimal as shown by the SEM image of a clustered microcapsules, despite FTIR analysis showing that the healing agent is well encapsulated. In addition, the ratio, as well as the type of components used in the fabrication of polyurea is not optimal, which affects the flexibility of polyurea (PUA-p-PDA). Nevertheless, results obtained for polyurea coating of different components (PUA-P1000) possesses high elasticity of 267.7 N and it also shows promising ability to self-heal after being cut into half. The challenges and limitations faced for this project will enable future research to have a better reference to fabrication method and design of experiment.