## 1 Introduction  
The demand for both functional and aesthetically pleasing teeth has surged in recent years, leading to a rapid expansion in the utilization of resin-based composites. This growth can be attributed to the escalating aesthetic expectations of patients and the continuous advancements in material manufacturing technologies [1]. Resin-based composites are broadly categorized as hybrid or nanocomposite materials, primarily distinguished by their physico-mechanical attributes, such as filler type, filler particle size, and filler distribution within the composite structure [2]. These materials predominantly consist of a polymeric matrix comprising various high-molecular-weight dimethacrylates, including bisphenol-A-diglycidyl methacrylate (bis-GMA), bisphenol-A-ethoxy dimethacrylate (bis-EMA), triethyleneglycol dimethacrylate (TEGDMA), and urethane dimethacrylate (UDMA) [3]. Dental composites have physico-mechanical qualities and a survival rate comparable to enamel and dentin [4]; this is because the majority of these monomers can be transformedinto polymers during the polymerization phase [5]. The release of \"residual monomer\" may induce post-operative discomfort, secondary caries, and endodontic issues if monomer conversion does not occur adequately [6]. The utilization of resin-based composites in dentistry has revolutionized restorative dentistry practices due to their versatility, durability, and aesthetic appeal [7]. These materials offer clinicians a wide array of options to meet patients' specific needs, ranging from minor cosmetic enhancements to extensive restorations [8]. Furthermore, resin-based composites have gained popularity over traditional dental materials like amalgam due to their ability to mimic the natural color and translucency of teeth, providing patients with aesthetically pleasing outcomes [9]. Despite their widespread use and numerous advantages, resin-based composites present challenges related to polymerization shrinkage, polymerization stress, and the release of potentially cytotoxic by-products during polymerization [10]. These issues can compromise the longevity and integrity of restorations and contribute to post-operative sensitivity and secondary caries formation. Therefore, understanding the polymerization behavior and mechanical properties of resin-based composites is critical for optimizing their clinical performance and ensuring patient satisfaction. Recent advancements in material science and manufacturing techniques have led to the development of novel resin-based composite formulations with enhanced mechanical properties, reduced shrinkage, and improved biocompatibility [11]. These innovations have broadened the scope of applications for resin-based composites, extending beyond traditional direct restorations to encompass various aesthetic and functional dental procedures such as veneers, inlays/onlays, and even orthodontic appliances [10]. In addition to their clinical significance, resin-based composites play a pivotal role in dental research, serving as model materials for investigating fundamental principles of polymer science, dental material engineering, and biomaterial interactions [12]. By exploring the structure-property relationships of resin-based composites, researchers can uncover new insights into material design, performance optimization, and clinical application, ultimately advancing the field of restorative dentistry. Several spectroscopic techniques, including Nuclear Magnetic Resonance, Dynamic Mechanical Thermal Analysis, differential scanning calorimetry (DSC), and Fourier-transform infrared (FT-IR), are employed to measure the monomer transformation ratio of resin-based materials [13; 14]. FT-IR spectroscopy can be used to analyze organic molecules in different states of matter. Via bond characterization, the bonding status of functional groups in the structures of solid, liquid, or gaseous organic compounds can be identified, as well as whether the structure is aliphatic or aromatic [15].