###### Abstract  
In previous studies, a new methodology was developed to determine the free dispersive and polar energies, the surface energies, and Lewis acid-base parameters of a polystyrene-divinylbenzene (S-DVB) copolymer modified by melamine, 5-Hydroxy-6-methyluracil, and 5-fluorouracil. In this paper, we were interested in the determination of the work of the adhesion of solvents on the modified copolymer as a function of temperature and for the different modifiers with the help of inverse gas chromatography at infinite dilution. The variations in the London dispersive and polar surface properties of copolymers against the temperature led to the determination of the different acid-base components of their surface energies. Using [PERSON]'s equation, [PERSON]'s relation, and [PERSON]'s concept, we obtained the variations in the dispersive and polar works of the adhesion of the different solid surfaces, and the corresponding forces of interaction  
approaches and functional group insertions have also been shown to drastically alter surface polarity and molecular interactions, improving compatibility with organic and bioactive molecules [5; 6; 7; 8]. These advancements underscore the importance of molecular-level surface design in tuning adhesion and dispersion forces--principles central to the present study on 5-fluorouracil-modified S-DVB copolymers. Incorporating such knowledge helps align our methodology with broader efforts to develop polymer surfaces with controlled physicochemical properties for use in separations, biomedical applications, and responsive materials [7; 8; 9; 10]. The most important parameter that governs such interfacial interactions is the work of adhesion (W\({}_{\text{a}}\)), which quantifies the energy required to separate two phases in contact, a solid or a liquid solvent, and a solid polymer surface [11; 12]. Understanding the thermodynamics and molecular mechanisms that dictate solvent adhesion to polymer or copolymer surfaces is essential for controlling wettability, solvent uptake, film stability, and interfacial compatibility [13; 14]. The strength of adhesion to a solid surface can be estimated from the value of the thermodynamic \"work of adhesion\", \(W_{a}\), a concept first introduced by [PERSON] [15] using the various surface tensions intervening when a liquid adheres to a solid. The adhesion process was described in classical interfacial thermodynamics, using surface tensions and contact angle measurements and utilizing the work of [PERSON] [5] and the Young-Dupre equation [16; 17]. Later, models were proposed by [PERSON] [18], [PERSON] [19], and [PERSON] et al. [20; 21], taking into account intermolecular forces, including dispersive, polar, and acid-base interactions [18; 19; 20; 21]. These models provided a more comprehensive understanding of the thermodynamic equilibrium at the solid-liquid interface, especially when dealing with chemically complex or functionalized polymer surfaces. Polymers and copolymers, such as polystyrene, polymethyl methacrylate (PMMA), and styrene-divinylbenzene (S-DVB) resins, exhibit different chemical functionalities, crosslinking densities, and very interesting morphologies. These properties play a key role in how solvents interact at the surface and in the bulk [22; 23]. Moreover, the choice of solvent, characterized by its polarity, hydrogen bonding capacity, and molecular size, directly influences its adsorption behavior and the resulting adhesion energy [23; 24]. The synergy between solvent properties and polymer surface energetics thus determines the degree of solvent penetration, polymer swelling, and final desorption dynamics [25]. Despite the crucial role played by adhesion, a rigorous understanding of solvent-polymer adhesion remains elusive due to the complex interplay of a large number of physical, mechanical, thermodynamic, and chemical factors.