**6.3. Mechanical properties**

To evaluate the effect of maghnite (Algerian MMT) catalyst in APAm, we prepared five samples with the same procedure. Tensile tests were conducted using a LLoyd LR/10KN Universal Machine at room temperature and crosshead speed of 50 mm min−<sup>1</sup> for the determination of tensile modulus and yield strength, according to the standard ASTM D638.

**Sample Catalyst** 

**(w%)**

**Young's modulus** 

Maghnite — 1.23 54.36 43.26- — APAm (pure) — 0.68 42.91 33.91 70.45 APAm-1/Magh 1 0.64 35.56 35.13 62.05 APAm-2/Magh 2 0.86 30.42 33.80 65.66 APAm-3/Magh 3 0.95 29.35 31.28 67.33 APAm-4/Magh 4 1.45 31.22 31.22 70.88 APAm-5/Magh 5 1.29 54.03 57.55 85.09 APAm-6/Magh 7 1.81 46.47 48.37 84.12 APAm-7/Magh 12 1.72 41.44 41.44 83.56

**Figure 13.** Proposed mechanism for obtained anionic polyacrylamide catalyzed by maghnite-Na<sup>+</sup>

**Deformation at break (%)**

**Maximum stress** 

http://dx.doi.org/10.5772/intechopen.80033

.

**Yield strength (MPa)**

123

**(MPa)**

Synthesis and Characterization of Polymeric Material Consisting on Acrylamide Catalyzed…

**(GPa)**

**Table 7.** Mechanical properties of APAm/maghnite samples.

Compared with PAm prepared by other catalyst such as Lewis acid and under conventional method, the Young's modulus and yield strength are greatly enhanced as shown in (**Table 7**). It shows that the mechanical properties depend on amount of catalyst.

The tensile test was carried out to evaluate the tensile properties of the various samples compositions in order to determine the influence of the addition of the clay on the tensile properties of the virgin matrix. Young modulus, tensile strength and elongation at break were evaluated as a function of the mass fraction of clay in all series of samples. The test pieces are maintained during the test by pneumatic jaws preventing any sliding of the test piece during the traction. The initial strain rate was set at 5 mm min−<sup>1</sup> . From these results, it can be deduced that the incorporation of the clay into the APAm matrix, with different percentages, has significantly improved all of its tensile properties. Thus Young's modulus increased in compositions with the highest clay contents, (1–12 w%). The composition of clay (5 w%) in APAm has the highest tensile values. This is attributed to the interactions between the polymer chains and the nanometric layers of the clay with a decrease in the value of the Young's modulus. This composition is the most tensile resistant with a maximum stress of 57.55 MPa, the most flexible (E = 1.89 GPa) and the most ductile (ε<sup>r</sup> = 54.03%). This result confirms the exfoliation of maghnite clay in polymer (APAm) which is in agreement with the literature [56].
