Microstructural, Energy-Dispersive X-ray Spectroscopy, and Fourier-Transform Infrared Analysis of Inorganic-Platelet Polymer Composites for Sustainable Infrastructure
Year: 2026
Type: preprint
Abstract: Polymer matrix composites used in wet or thermally variable environments may change through moisture diffusion, polymer relaxation, swelling and plasticization, hydrolysis or leaching, microcracking, and progressive weakening of the reinforcement–matrix interface. This paper focuses on understanding the composition and morphology of a reinforcing phase, and determining whether its incorporation produces additional bulk-resolvable chemical features, which is important for interpreting composites used in wet or aggressive environments. The study presents a structural and spectroscopic characterization of a commercial glass-flake-reinforced unsaturated-polyester composite by combining energydispersive X-ray spectroscopy (EDS) with full-range Fourier-transform infrared spectroscopy (FTIR) against a neat unsaturated-polyester-resin control. EDS gives a composition consistent with a sodium–calcium silicate glass phase for the flake (17.4 wt% Si, 5.0 wt% Na, 2.2 wt% Ca, 1.1 wt% Al, 1.0 wt% Mg and 55.6 wt% O), whereas the polyester matrix and coat regions are dominated by carbon and oxygen (70–75 wt% C and 23–26 wt% O). Two representative flakes (n = 2) have apparent length-to-width ratios of 21.9 and 43.9. FTIR spectra collected over 428–4500 cm-1 show the same principal polyester-resin-associated bands at essentially identical wavenumbers in the composite and neat resin. Polymer-associated band intensities are 12–28% lower in the composite, while the band near the Si–O–Si network bending region changes by only −0.6%. No additional resolvable bulk absorption bands are observed. The results support a physically dispersed silicate-glass phase within the polyester matrix but do not exclude weak or spatially localized interfacial interactions below the resolution of the measurements. The spectra and elemental tables are released as a reusable dataset.
Source: ChemRxiv
Author: Parastou Kharazmi
Institution: KTH Royal Institute of Technology
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7221947510