Abstract Composites are relevant to high-performance materials in the aerospace sector and have attracted the attention of the scientific and technological communities. Bentonites present very fine granulometry which enables their use in composites. This study showed the development of water absorbent composite based on sodium polyacrylate, bentonite coated by epoxy resin. Since there are gaps in the quantification of composite materials by near-infrared spectroscopy, especially by reflectance analysis (NIRA), this paper shows a quantification methodology (A7200/A5202) of sodium polyacrylate and bentonite. The methodology error found was 1.45% (95% of coefficient of determination). The effectiveness of the developed infrared methodology was verified showing that values are close to the nominal, especially for lower bentonite content. Besides, scanning electron microscopy (SEM) and universal attenuated total reflection (UATR) analysis evidenced the coating with the epoxy resin. Such development ensures rapid and precise methodologies that can be applied to the quality control of composite materials.

Abstract A variety of fiber-reinforced polymer (FRP) has been described in literature, with a considerable subset of studies focused on fiber surface treatment (sizing), performance enhancement of matrix and fibers both synthetic and natural, and development of more ecologically sustainable composites. The present review discusses the different types of fibers and matrices and their applications, depending on the chemical and mechanical properties of their composites. In order to evaluate the performance of FRP composites and explore the characteristics of the involved materials, some analytical techniques are considered paramount, such as thermal analysis, microscopy, Fourier transform-infrared spectroscopy (FT-IR), and others. On this basis, this review addresses the state-of-the-art of material characterization methodologies, provides a comprehensive overview of different types of FRP found in literature, as well as links the analytical techniques with the main applications contributing to future studies and research in this area.

Abstract The bicomponent fibers are a special class of fibers that consolidate two polymers in only one fiber in order to explore individual properties of each polymer and can be designed in a spatial configuration that allows the enhancement in application of this material. Thereby, an appropriate characterization of bicomponent fibers is very valuable to process monitoring, quality control and forensic investigation. The sheath-core bicomponent fiber composed by polyethylene (PE), polypropylene (PP) and titanium dioxide (TiO2) was analyzed by Fourier transform infrared (FT-IR) spectroscopy and other analytical methodologies. Results obtained by FT-IR using modern accessories showed efficiency to characterize the polymers of sheath (PE) and core (PP), moreover these polymers were confirmed by DSC (Differential Scanning Calorimetry). The morphology and elemental composition were also studied by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS). The thermogravimetric analysis (TGA) and colorimetric analysis allowed characterize and quantify the concentration of TiO2.