Banca de QUALIFICAÇÃO: TATIANA DE LIMAS SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : TATIANA DE LIMAS SANTOS
DATE: 27/03/2026
TIME: 13:30
LOCAL: Google meet
TITLE:

Effects of aging on the physical-mechanical properties of natural fiber-reinforced composite materials

KEY WORDS:

fibrous composites, natural fibers, aging, and mechanical properties.

PAGES: 12
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUMMARY:

The growing demand for sustainable materials drives research into composites reinforced with natural fibers, such as sisal and curauá. Due to their high specific strength, low cost, and abundance in Brazil, these fibers are ideal candidates for lightweight structural applications. However, moisture sensitivity and limited adhesion to the polymer matrix represent crucial challenges for their long-term reliability. In this context, this study investigated the influence of hygrothermal aging on the mechanical properties of natural fiber composites, comparing the performance of two matrices: epoxy resin (synthetic) and castor oil resin (a natural and renewable polyurethane). The composites were produced with different volume fractions of sisal and curauá fibers and subsequently subjected to accelerated moisture aging conditions to simulate environmental degradation. Performance was evaluated through tensile testing. The results confirmed that hygrothermal aging is the primary limiting factor, with the test condition—whether humid or steam environments—being the most determinant factor in the reduction of mechanical properties as demonstrated by statistical analysis. The comparative analysis revealed that epoxy resin provided greater mechanical stability and a more effective barrier against moisture diffusion, allowing the curauá/epoxy composite to maintain the highest strength and stiffness after aging. Conversely, while the castor oil resin offered a more sustainable profile, it exhibited a greater loss of properties under moisture, resulting in more ductile behavior. Regarding fiber performance, curauá fibers provided higher specific strength, whereas sisal fibers resulted in greater deformation. In summary, this work contributes to the understanding of degradation mechanisms and reaffirms the importance of the fiber–matrix–environment interaction. Although the curauá/epoxy system is more promising for structural durability, the sisal/castor oil system stands out for its sustainable character. To achieve an ideal balance, future strategies should focus on the surface treatment of fibers to mitigate moisture sensitivity.

BANKING MEMBERS:
Presidente - 1691537 - TULIO HALLAK PANZERA
Externo ao Programa - 3469890 - HULISSES BONETI MARCON
Externo ao Programa - 1803678 - FABIANO BIANCHINI BATISTA