## 3 Results
### DMA Results  
The storage modulus and tan \(\delta\) of pure PS, PS3 NaMt and PS3 OO@NaMt are shown in Figure 5a,d, respectively. The T\({}_{\text{g}}\), as well as the storage modulus (at 40 \({}^{\circ}\)C and 100 \({}^{\circ}\)C), are shown in Table 3. The T\({}_{\text{g}}\) values were calculated from the peak of tan \(\delta\). The storage modulus of the samples PS3 NaMt and PS3 OO@NaMt were found to be higher than that of pure PS for the whole temperature range of the experiment. The higher storage modulus of PS3 NaMt could be attributed to the stiffening effect of NaMt [32]. Our results are in good agreement with previous reports [32; 33]. The values of the Tg slightly increased with the addition of clay while the addition of oregano oil led to a decreased Tg, implying a plasticizing action [34]. The increased storage modulus observed after the addition of oregano oil has not been reported for the present system in the literature, but a similar behaviour has been reported in a different system consisting of whey protein isolate films incorporated with oregano oil [34]. In Figure 5b,e, storage modulus and tan \(\delta\) curves of PScoMA, PScoMa3 OO@NaMt and PScoMa5 OO@NaMt are shown. The storage modulus increased with the addition of clays. The highest storage modulus was obtained when 3 %wt. NaMtOO was added to the PScoMA matrix. The T\({}_{\text{g}}\) of the nanocomposite PScoMa5 OO@NaMt was increased by 4 \({}^{\circ}\)C compared to PScoMA while the T\({}_{\text{g}}\) of the PScoMa3 OO@NaMt was slightly decreased. The values are shown in Table 3.  
Figure 4: %Variation of [PERSON]’s Modulus-E values, tensile strength (\(\sigma\)) values, and %elongation at the break-%% values for all tested PS based active packaging films. In Figure 5c,f, storage modulus and tan \(\delta\) curves of PS3 OrgMt, PS3 OO@OrgMt and PS5 OO@OrgMt compared to the values of pure PS can be seen. The addition of clay increased the storage modulus while the T\({}_{\text{g}}\) slightly decreased, which is in good agreement with the results reported by [PERSON] and [PERSON] [35]. The same research group showed that as the clay content increased the polystyrene molecular weight decreased [35]. This  
Figure 5: Left part: Storage modulus of (**a**) pure PS, PS3 NaMt and PS3 OO@NaMt, (**b**) PScoMA, PScoMA3 OO@NaMt, PScoMA5 OO@NaMt (**c**) pure PS, PS3 OrgMt, PS3 OO@OrgMt and PS5 OO@OrgMt. Right part: Values of ta \(\delta\) of (**d**) pure PS, PS3 NaMt and PS3 OO@NaMt, (**e**) PScoMA, PScoMA3 OO@NaMt, PScoMA5 OO@NaMt and (**f**) PS, PS3 OrgMt, PS3 OO@OrgMt and PS5 OO@OrgMt. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sample** & **E\({}^{\prime}\) (40 \({}^{\circ}\)C)** & **E\({}^{\prime}\) (100 \({}^{\circ}\)C)** & **Glass Transition Temperature (T\({}_{\text{g}}\))** \\ \hline PS & 1739 MPa & 172 MPa & 105 \({}^{\circ}\)C \\ PS3 NaMt & 2034 MPa & 280 MPa & 107 \({}^{\circ}\)C \\ PS3 OO@NaMt & 2146 MPa & 510 MPa & 96 \({}^{\circ}\)C \\ PScoMA & 2121 MPa & 689 MPa & 112 \({}^{\circ}\)C \\ PScoMA3 OO@NaMt & 2799 MPa & 1542 MPa & 110 \({}^{\circ}\)C \\ PScoMA5 OO@NaMt & 2151 MPa & 1556 MPa & 116 \({}^{\circ}\)C \\ PS3 OrgMt & 2795 MPa & 356 MPa & 104 \({}^{\circ}\)C \\ PS3 OO@OrgMt & 1823 MPa & 356 MPa & 96 \({}^{\circ}\)C \\ PS5 OO@OrgMt & 2271 MPa & 683 MPa & 97 \({}^{\circ}\)C \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Storage modulus (at 40 \({}^{\circ}\)C and 100 \({}^{\circ}\)C) and T\({}_{\text{g}}\) values of all the tested films. may be a possible explanation for the slight decrease in Tg that was observed in PS3 OrgMt compared to pure PS. After the examination of PS3 OO@OrgMt and PS5 OO@OrgMt storage modulus curves, in a temperature range (85-100 \({}^{\circ}\)C and 75-110 \({}^{\circ}\)C, respectively) the storage modulus increased. This phenomenon has not been reported in the literature for such materials to the best of our knowledge. The modulus enhancement through antiplasticization has been explained by [PERSON] et al. [36; 37; 38; 39] for plasticization of PVC with tricresyl phosphate.