## 3 Results
### Work of Adhesion of Organic Solvents on Modified Copolymer
& R\({}^{2}\) \\ \hline n-hexane & \(W_{u}(T)=-0.80\) T + 380.26 & 0.80 & 380.26 & 477.77 & 0.999 \\ \hline n-heptane & \(W_{u}(T)=-0.66\) T + 326.22 & 0.66 & 326.22 & 497.51 & 0.997 \\ \hline n-octane & \(W_{u}(T)=-0.67\) T + 337.84 & 0.67 & 337.84 & 505.37 & 0.9958 \\ \hline n-nonane & \(W_{u}(T)=-0.69\) T + 335.3 & 0.69 & 383 & 509.53 & 0.9954 \\ \hline Benzene & \(W_{u}(T)=-0.78\) T + 397.1 & 0.78 & 397.1 & 508.39 & 0.996 \\ \hline Toluene & \(W_{u}(T)=-0.89\) T + 471.28 & 0.89 & 471.28 & 526.98 & 0.9958 \\ \hline Ethyl acetate & \(W_{u}(T)=-0.97\) T + 567.37 & 0.97 & 567.37 & 582.46 & 0.9976 \\ \hline Ethanol & \(W_{u}(T)=-1.66\) T + 862.63 & 1.66 & 862.63 & 520.85 & 0.9992 \\ \hline i-Propanol & \(W_{u}(T)=-1.49\) T + 795.55 & 1.490 & 795.55 & 533.78 & 0.9988 \\ \hline Dichlormethane & \(W_{u}(T)=-0.99\) T + 495.17 & 0.986 & 495.17 & 502.00 & 0.9989 \\ \hline \multicolumn{5}{c}{**10\% 5-hydroxy-6-methyluracil/S-DVB Copolymer**} \\ \hline Solvents & \(W_{u}(T)\) & \(\Delta S_{S}\) & \(\Delta H_{S}\) & \(T_{\text{data}}\). & R\({}^{2}\) \\ \hline n-hexane & \(W_{u}(T)=-0.76\) T + 361.98 & 0.76 & 361.98 & 476.48 & 0.9998 \\ \hline n-heptane & \(W_{u}(T)=-0.70\) T + 344.16 & 0.70 & 344.16 & 490.89 & 0.9996 \\ \hline n-octane & \(W_{u}(T)=-0.75\) T + 371.62 & 0.75 & 371.62 & 495.49 & 0.9993 \\ \hline n-nonane & \(W_{u}(T)=-0.80\) T + 396.43 & 0.80 & 396.43 & 497.78 & 0.9991 \\ \hline Benzene & \(W_{u}(T)=-0.87\) T + 438.65 & 0.87 & 438.65 & 502.58 & 0.9994 \\ \hline Toluene & \(W_{u}(T)=-1.08\) T + 562.98 & 1.08 & 562.98 & 522.63 & 0.9979 \\ \hline Ethyl acetate & \(W_{u}(T)=-1.02\) T + 585.03 & 1.02 & 585.03 & 573.90 & 0.9992 \\ \hline Ethanol & \(W_{u}(T)=-1.71\) T + 931.89 & 1.71 & 931.89 & 544.61 & 0.9998 \\ \hline i-Propanol & \(W_{u}(T)=-1.54\) T + 878.5 & 1.54 & 878.5 & 569.09 & 0.9995 \\ \hline Dichlormethane & \(W_{u}(T)=-1.01\) T + 503.78 & 1.01 & 503.78 & 499.09 & 0.9998 \\ \hline \multicolumn{5}{c}{**1\% 5-Fluouracil/DS-DVB Copolymer**} \\ \hline Solvents & \(W_{u}(T)\) & \(\Delta S_{S}\) & \(\Delta H_{S}\) & \(T_{\text{data}}\). & R\({}^{2}\) \\ \hline n-hexane & \(W_{u}(T)=-0.85\) T + 409.22 & 0.85 & 409.22 & 480.47 & 0.9 The values of \(\Delta H_{\rm S}\) and \(\Delta S_{\rm S}\) of the different organic solvents given in Table 4 for the modified copolymers at different modifier percentages led to linear relations between these surface parameters and the corresponding percentage (\(q\)) of melamine (noted Mela), 5-HMU, and 5-FU. The equations of \(\Delta H_{\rm S}(q)\) and \(\Delta S_{\rm S}(q)\) relative to the work of adhesion on the modified copolymers are given in Table 5 with the linear regression coefficients. The results in Table 5 led to the following general equations:  
\[\Delta H_{\rm S}(q)=aq+b \tag{20}\]  
\[\Delta S_{\rm S}(q)=cq+d \tag{21}\]  
where \(a\), \(b\), \(c\), and \(d\) given in Table 5 are constant coefficients, depending on the work of adhesion of the solvents on the modified S-DVB. The results presented in Table 5 show that the linearity of the variables \(\Delta H_{\rm S}(q)\) and \(\Delta S_{\rm S}(q)\) is not perfectly satisfied for all solvents, where the linear regression coefficients were found to be relatively low (around 0.9000). However, the general tendency of the linearity of \(\Delta H_{\rm S}(q)\) and \(\Delta S_{\rm S}(q)\) is satisfied for most solvents (about 90%) and solid materials. The relative weakness in the linearity of \(\Delta H_{\rm S}(q)\) and \(\Delta S_{\rm S}(q)\) shown in Table 5 for certain solvents is certainly due to the accumulation of uncertainties, beginning from the chromatographic measurements of the retention time, the free energy, and the values of \(\Delta H_{\rm S}(q)\) and \(\Delta S_{\rm S}(q)\)