Water Immersion Aging of Epoxy Resin and Fique Fabric Composites: Dynamic-Mechanical and Morphological Analysis

Fiber-reinforced composites are among the most investigated and industrially applied materials. Many studies on these composites using fibers, especially with natural fibers, were made in response to an urgent action for ambient preservation. A particularly relevant situation exists nowadays in the area of materials durability. In this respect, no studies on water-immersion-accelerated aging in fique fiber-epoxy composites are reported. This work aimed to fill this gap by investigating the epoxy matrix composites reinforced with 40 vol% fique fabric. The epoxy matrix and the composite, both unaged and aged, were characterized by weight variation, water absorption, morphology, colorimetry (CIELAB method), Fourier transform infrared spectroscopy (FTIR) and dynamic-mechanical analysis (DMA). The main results were that degradation by water presents appearance of complex microfibril structures, plasticization of epoxy resin, and debonding of the fique fiber/epoxy matrix. The most intense color change was obtained for the water-immersion-aged epoxy by 1440 h. Cole-Cole diagrams revealed the heterogeneity of the materials studied.

Automated summary

Fiber-reinforced composites are widely investigated and applied materials. This study fills the research gap on water-immersion-accelerated aging in fique fiber-epoxy composites, finding that water degradation leads to complex microfibril structures, plasticization of epoxy resin, and debonding of fique fiber/epoxy matrix. Evaluating material durability is of great importance for material design and application.