Extrusion International USA 5-2020

41 Extrusion International 5/2020 As the polypropylene is added it was verified that the maximum tension of the blends increases, the elonga- tion decreases and the modulus of elasticity increases, this behavior can be attributed to the degree of crys- tallinity of the polypropylene, however the results are inferior to the initial materials, (Noryl PPX and natural polypropylene). On an industrial scale, a tensile test was performed on the blend 50% Noryl PPX plus 50% Polypropylene and on pure Noryl PPX, the specimens were removed from a 6 mm extruded sheet. We can observe that with the addition of 50% polypro- pylene in the middle of pure Noryl PPX, there is a great increase in maximum tension, the elongation shows a significant reduction and the elasticity module increases considerably due to the high crystallinity of the polypro- pylene. Results obtained through mechanical impact tests can be compared according to Table 4. The behavior of the blends in relation to the impact toughness property follows the same logic obtained in the tensile tests, as polypropylene is added in different proportions, the impact resistance is reduced due to the increase in the degree of crystallinity. The analysis of the results obtained through thermal differential scanning calorimetry tests (Table 5) demon- strated an increase in the degree of crystallinity of the blends as the polypropylene was added. They are used as criteria for evaluating the miscibility in a blend, obtaining a single glass transition (Tg) and or changes in crystalline fusion temperatures (Tm). The immiscible blends have more than one Tg, the miscible ones have a single Tg and a single Tm and the partially miscible ones contain values close to that of pure poly- mers (QUENTAL, et AL., 2010). The first material tested was pure polypropylene (Figure 1). It was observed that the polypropylene showed a Tm evidenced by a large peak that proves the high degree of crystallinity of this polymer. The second sample analyzed was composed of 30% polypropylene and 70% Noryl PPX (Figure 2). There was a significant drop in the degree of crystallinity of the material due to the high Noryl PPX index in the blend composition. The third blend analyzed was composed of 40% poly- propylene and 60% Noryl PPX (Figure 3). This has a Tm of 165 ºC, and a small increase in the de- gree of crystallinity. The fourth sample that was analyzed was composed of 50% polypropylene and 50% Noryl PPX (Figure 4). It was found that the blend presented Tm around 165ºC, with a high degree of crystallinity due to the proportion of 50% polypropylene. The last sample analyzed was pure Noryl PPX (Figure 5). Figure 1: DSC Graph – 100%Polypropylene Figure 2: DSC Graph – 30%Polypropylene 70%Noryl PPX