## 3 Results and Discussion
### Characteristic of GE-EP@OIMs
#### 3.1.3 Thermostability and Inhibitor Loading Content of GE-EP@OIMs  
Figure 6 presents the thermogravimetric and heat loss curves of the OIM corrosion inhibitor, the carrier GE-EP, and the solid corrosion inhibitor GE-EP@OIMs. The thermal degradation of GE-EP and GE-EP@OIMs occurs in two distinct stages: the first stage (40-200 \({}^{\circ}\)C) is primarily characterized by the volatilization of free and bound water within the samples, while the second stage (200-500 \({}^{\circ}\)C) corresponds to the decomposition of the chemical components in the samples. These curves illustrate the thermal behavior and stability of the materials under increasing temperatures. Figure 5: FTIR spectra of pure OIM, GE-EP, and GE-EP@OIMs. The mass loss fractions of GE-EP and GE-EP@OIMs in stage 1 (40-200 \({}^{\circ}\)C) were similar, both significantly lower than those of OIMs, at 2.91% and 2.90%, respectively. In the second stage, both GE-EP and GE-EP@OIMs began to decompose at 200 \({}^{\circ}\)C, with the maximum degradation rates occurring at 332 \({}^{\circ}\)C and 327 \({}^{\circ}\)C, respectively. At 500 \({}^{\circ}\)C, degradation ceased in all samples, leaving 32.36% and 24.99% of undegraded substances, respectively. This demonstrates that the thermal stability of GE-EP@OIMs is further improved compared to that of PAM hydrogel, allowing it to be used in a corrosive environment at temperatures below 200 \({}^{\circ}\)C. The degradation process of GE-EP and GE-EP@OIMs in the second stage mainly involves (1) the breaking of the terminal aliphatic chain of the water-based epoxy resin (>300 \({}^{\circ}\)C) and partial cracking of the aromatic structure (>350 \({}^{\circ}\)C), leading to the generation of CO\({}_{2}\), H\({}_{2}\)O, phenol, or other aromatic substances [27] and (2) the degradation of the protein structure in gelatin, producing substances such as NH\({}_{3}\) and CO\({}_{2}\)[28; 29]. The degradation of GE-EP@OIMs also includes the thermal decomposition of the imidazole ring and hydrophobic carbon chain of the loaded OIM [30]. The degradation temperature of BaSO\({}_{4}\) exceeds 1500 \({}^{\circ}\)C, so the degradation process of GE-EP@OIMs will not result in the decomposition of BaSO\({}_{4}\)[31], the loading of OIMs in GE-EP is approximately 34.75%. During the first stage (40-200 \({}^{\circ}\)C), the mass loss fractions of GE-EP and GE-EP@OIMs exhibited a resemblance, both being substantially lower than that of the OIMs, with values of 2.91% and 2.90%, respectively. In the second stage, both GE-EP and GE-EP@OIMs initiated decomposition at 200 \({}^{\circ}\)C, with the peak degradation rates manifesting at 332 \({}^{\circ}\)C and 327 \({}^{\circ}\)C, respectively. Upon reaching 500 \({}^{\circ}\)C, the degradation processes of all samples ceased, leaving behind 32.36% and 24.99% of undegraded substances, respectively. This indicates that the thermal stability of GE-EP@OIMs has been further enhanced in comparison to that of PAM hydrogel, thereby enabling its application in corrosive environments at temperatures beneath 200 \({}^{\circ}\)C. The degradation mechanisms of GE-EP and GE-EP@OIMs during the second stage predominantly encompass (1) the rupture of the terminal aliphatic chain of the water-based epoxy resin (occurring at temperatures above 300 \({}^{\circ}\)C) and the partial fragmentation of the aromatic structure (taking place at temperatures above 350 \({}^{\circ}\)C), which subsequently leads to the generation of CO\({}_{2}\), H\({}_{2}\)O, phenol, or other aromatic substances as elucidated by [27] and (2) the degradation of the proteinaceous structure within the gelatin, resulting in the production of substances such as NH\({}_{3}\) and CO\({}_{2}\) as reported by [28; 29]. The degradation of GE-EP@OIMs also entails the thermal decomposition of the imidazole ring and the hydrophobic carbon chain of the loaded OIM as described by [30].