Micronized Shell-Bioaggregates as Mechanical Reinforcement in Organic Coatings

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Engineering

Background:

• Shells, composed of calcite and aragonite, offer potential as bio-based fillers.
• Enhancing organic coatings' mechanical properties is crucial for durability.

Purpose of the Study:

• To investigate the effect of micronized seashell powders on water-based coating properties.
• To evaluate the performance of Acanthocardia tuberculata and Mytilus galloprovincialis powders as coating fillers.

Main Methods:

• Incorporation of 5 wt.% Acanthocardia tuberculata and Mytilus galloprovincialis powders into a water-based coating.
• Testing abrasion resistance (Taber test), hardness (Buchholz), color, gloss, UV-B exposure, salt spray corrosion, and electrochemical impedance spectroscopy.

Main Results:

• Improved abrasion resistance and Buchholz hardness with seashell powders.
• No significant changes in color or gloss after UV-B exposure.
• Increased delamination in salt spray tests, indicating reduced isolation properties due to water penetration pathways.

Conclusions:

• Micronized shells enhance abrasion resistance and hardness but compromise coating isolation.
• Particle characteristics influence performance, necessitating further research for optimal bio-based filler applications.