Freeze-Thaw Durability of Basalt Fibre Reinforced Bio-Based Unsaturated Polyester Composite
Abu T Shahid1, Mateus Hofmann2, Mário Garrido1
1Civil Engineering Research and Innovation for Sustainability (CERIS), Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal.
Materials (Basel, Switzerland)
|August 12, 2023
Summary
This study found that water immersion significantly degraded bio-based composites more than conventional ones. Freeze-thaw cycles had minimal impact, with some property recovery observed in the bio-composite.
Area of Science:
- Materials Science
- Polymer Composites
- Durability Testing
Background:
- Investigating the durability of fibre-polymer composites is crucial for their application.
- Bio-based resins offer a sustainable alternative to conventional oil-based unsaturated polyester resins (UPRs).
- Understanding material response to environmental stressors like freeze-thaw (FT) cycles is essential.
Purpose of the Study:
- To experimentally evaluate the wet freeze-thaw (FT) durability of a bio-based fibre-polymer composite.
- To compare the performance of a bio-based composite against a conventional oil-based composite.
- To assess the impact of water immersion preconditioning and FT cycles on composite properties.
Main Methods:
- Vacuum infusion was used to produce composites with bio-based and conventional UPRs reinforced with basalt fibres.
- Composites underwent water immersion preconditioning followed by up to 300 wet FT cycles.
- Mechanical (tensile, compressive, shear) and thermomechanical (DMA) tests, alongside gravimetric and SEM analyses, were performed.
Main Results:
- Water immersion preconditioning caused substantial property reductions (5–39%) in the bio-composite, exceeding those in the conventional composite (4–22%).
- Wet FT cycles alone had a minor effect on property degradation; some matrix-dominated properties, like interlaminar shear strength, showed recovery (12% in bio-composite).
- The bio-composite exhibited inferior overall performance compared to the conventional composite, primarily due to the hydrophilicity of its bio-based resin components.
Conclusions:
- The hydrophilicity of bio-based resin components significantly impacts composite durability during water immersion.
- Wet freeze-thaw cycles have a less detrimental effect than initial water saturation on these composites.
- Further development is needed to enhance the water resistance of bio-based composites for demanding applications.
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