Influence of PP content on mechanical properties, water absorption, and morphology in PA6/PP blend

Abstract

PA6/polypropylene (PP) blends are investigated for obtaining balanced strength and toughness. The focus of this study is to understand the effect of PP content on mechanical property, water absorption, impact strength, thermal behavior, and morphology of PP in the absence and presence of PP‐g‐maleic anhydride compatibilizer. In comparison to pure PA6, all blends have higher impact strength with 161 and 124% increase at 5 wt % PP content in uncompatibilized and compatibilized blends (UB and CB), respectively. Morphology of impact fractured samples shows brittle fracture in the case of CB. scanning electron microscope of cryogenically fractured samples show decrease in domain size and change in shape from ellipsoid to spherical, from UB to CB. Then, 75% reduction in water absorption is observed for 50 wt % PP content UB. Postwater absorption yield strength (YS) remains constant above 10 wt % PP in both UB and CB and decrease in YS is less at higher PP content in CB. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47690.

Effect of short carbon fiber content and water absorption on tensile and impact properties of PA6/PP blend based composites

“…Mostly PP was in spherical shape, and few PP droplets had higher radii, which resembles the morphology of compatibilized PA6/PP blend. [15] For composite CM1 ( Figure 7B), it is seen that PP domains are bigger and are mostly elongated elliptical in shape which corresponds to uncompatibilized blend as explained in our earlier study. [15] Cohesive failure is observed in Figure 7B that is, SCF is covered with matrix indicating better interaction between PA6/SCF, as also seen in FTIR of CM1 composite.…”

“…[15] For composite CM1 ( Figure 7B), it is seen that PP domains are bigger and are mostly elongated elliptical in shape which corresponds to uncompatibilized blend as explained in our earlier study. [15] Cohesive failure is observed in Figure 7B that is, SCF is covered with matrix indicating better interaction between PA6/SCF, as also seen in FTIR of CM1 composite. Hence it can be deduced that at lower SCF content, the reaction between PA6-epoxy on SCF (reaction 2, Figure 2) becomes more feasible than PA6 -PP/PP-g-MA (reaction 1, Figure 2).…”

“…Injection molding (Electronica Endura-90) was used to make all specimens with temperature range of 49 C to 249 C from the compression zone to the nozzle with cycle time of 40 seconds and injection pressure of 800 kg/cm [2] . [15,16]…”

“…Percentage of water absorbed was calculated based on the weight gain as mentioned in our earlier studies. [15,16] After completion of water absorption test, samples were wiped using tissue paper to remove surface water and considered as "wet" samples, which were further used for the tensile testing and FTIR.…”

“…The notchedizod impact test was conducted as per ASTM D256 standard on (CEAST 9050) pendulum type impact tester. [15,16] 2.6 | Fractography of blend and composites using SEM and OM Fractography of composite specimens was studied using SEM (ApreoS FE-SEM) after sputter coating with gold/ palladium on fracture surface. The tensile fractured sample (both dry and wet) and impact fractured sample (dry) of matrix blend and composites were studied.…”