## 3 Results and Discussion
### Isothermal Oscillatory Rheological Behavior  
Oscillatory rheological measurements allow for the classification of matrix strength based on three factors: the difference between G\({}^{\prime}\) and G\({}^{\prime\prime}\), the average value of G\({}^{\prime}\) within the linear viscoelastic region (LVR, G\({}^{\prime}\)LVR), and the length of the linear region of the curve. Therefore, these matrixes could be categorized as strong (G\({}^{\prime\prime}\)/G\({}^{\prime}\) <0.1), weak (0.1 < G\({}^{\prime\prime}\)/G\({}^{\prime}\) < 1), or viscous sols (G\({}^{\prime\prime}\)/G\({}^{\prime}\) >1).  
Figure 3a shows that G\({}^{\prime}\) was higher than G\({}^{\prime\prime}\) (>50 Pa) within LVR indicating a gel-like property, and the CRW matrixes showed the largest oscillation strain limit (plateau region) of 0.32% and 2676100 Pa, respectively (Table 3). This critical point in LVR at which the curve of G\({}^{\prime}\) begin to deviate noticeable from the LVR (10%), provide information regarding the stability under strain sweep. Thus, the CRW matrix had the largest ductility and structural resistance to the applied strain when compared to  
other matrixes. Beyond the critical point, matrixes undergo permanent deformation, as reflected from the abrupt decrease in the G\({}^{\prime}\) and G\({}^{\prime\prime}\) values. This can be explained by a partial breakup of the matrix network triggering flow characteristics. Subsequently, at the cross-over point, the gel phase is transformed to a viscous sol (G\({}^{\prime}\) = G\({}^{\prime\prime}\)). CRW showed the highest G\({}^{\prime}\) at cross-over point suggesting a strong and a more stable network. The zone spanning between critical point and cross-over point is referred to as the yield zone and the CRW matrix had a large zone mainly attributed to the presence of mixtures of aliphatic esters and \(p\)-hydroxyl-cinnamic aliphatic diesters [29]. Furthermore, the CRW matrix was considered to be the only strong matrix since G\({}^{\prime\prime}\)/G\({}^{\prime}\) was always lower than 0.1, demonstrating that the solid-like properties strongly dominated over the liquid-like characteristics. Likewise, the CLW matrix displayed the second largest G\({}^{\prime}\) at critical point, although it showed the largest fall in G\({}^{\prime}\) with strain, reaching a cross-over point of 41659 Pa. Conversely, the OKW and BEW matrixes were much softer and yielded at much lower strain.  
Matrixes were then subjected to a frequency sweep in order to investigate their time dependent behavior (Figure 3b). Most of the matrixes showed a slight dependence on frequency from 0.1 to 100 rad/s, as indicated by a slightly positive slope at G\({}^{\prime}\) and G\({}^{\prime\prime}\) curves, especially for BEW matrixes, which is characteristic of weak networks. Other curves were mostly linear with G\({}^{\prime}\) > G\({}^{\prime\prime}\), indicating that these matrixes had good tolerance to the rate of deformation and that bonds forming the network were almost permanent within the time frame of the performed test. The poor fitting of CRW and CLW matrixes shown by an almost parallel trend with the x-axis indicates long-term stability at resting conditions. In contrast, the OKW matrix displayed a cross-over point between G\({}^{\prime}\) and G\({}^{\prime\prime}\) at low frequencies, indicating poor stability due to its weak colloidal nature where the viscoelastic behavior is elastic dominated at low frequencies (<1.6 rad/s), but viscous dominated at larger frequencies. Thereby, this matrix system was unstable at low amplitudes leading to the breaking up of the internal structure.  
Figure 3: Linear viscoelastic region (**a**); frequency sweep curves (**b**); heating temperature sweep (**c**); cooling temperature sweep (**d**); creep test of matrix systems (**e**); produced with representative waves: BEW, beewax matrix; CRW, carnauba matrix; CLW, candellilla matrix; OKW, ozokerite matrix.