Mechanical and morphological characterization of polypropylene toughened with olefinic elastomer

Abstract

The effect of incorporating (C2-C8) ethylene-octene elastomer on the mechanical properties and morphology of polypropylene copolymers has been investigated employing two types of PP copolymer, with and without nucleating agent. The results were compared to the ones presented by a commercial PP heterophase (reactor impact modified PP/EPR). The addition of the elastomer increases the toughness of the blends but reduces their stiffness. PP blends in the low elastomer content region (< 20%) show low values of the Izod impact strength and both, elastomer content and impact strength, are directly proportional to the area under the β damping peak or its maximum intensity of the elastomer. The morphology is a continuous pattern of segregate elastomeric particles with average particle size in the range of 0.27 µm to 0.39 µm. The average particle size and particle size distribution plotted in log-normal distribution curves, increases slightly with the increase in the elastomer content. The reactor modified PP heterophase has a broader particle size distribution and an average particle size of 0.56 µm, at the lower limit but inside the range for good impact performance, as observed.

Development and characterization of post-consumer rubber tire powder, high density polyethylene and ethylene-octene-1copolymer ternary mixtures

“…Besides this, there is the chemical affinity with HDPE which makes the blend between them to be miscible, as showed by SEM images. This result agrees with that showed by Lotti et al [24] , where polypropylene/ C2C8 blends were studied, i. e., the increase in the concentration of this copolymer increases the blend toughness.…”

“…Thus, the ethylene-octene 1 copolymer does not act in the HDPE/ RTP interface. According to some works reported in literature [19,24] it is expected that elastomeric component envelops the dispersed phase and put itself up in the interface, but it did not happen in our study. This is explained by the fact that HDPE and C2C8 have great chemical affinity and it makes them miscible, according to SEM micrographs.…”

Potential and limits of dynamic mechanical analysis as a tool for fracture resistance evaluation of isotactic polypropylenes and their polyolefin blends

“…Its potential as a macroscopic toughness indicator has already been mentioned in several studies. Quantitative or at least qualitative relationships between the strengths of the principal or secondary relaxations and the fracture resistances have been found, [1][2][3][4][5][6][7][8][9][10][11][12] although the small strain, linear viscoelastic measurements in DMA differ fundamentally to the large strain, nonlinear behavior observed under impact conditions.…”

Natural Nanotubes Reinforcing Heterophasic Polypropylene

“…High-impact polypropylene (hiPP) is a type of polypropylene reactor blend formed by an array of isotactic polypropylene (iPP) in which an elastomeric copolymer (EPR) is finely dispersed, with much higher impact resistance at low temperatures than the polypropylene homopolymer, but with lower stiffness, modulus, density and glass transition temperature. It is widely used in injection molding of parts for the automotive industry, rigid packaging for household products, technical parts and coatings of steel pipes [1][2][3][4] . However, for broader applications it is necessary to further improve its stiffness/ toughness balance, increasing rigidity without sacrificing impact resistance, although the improvement of one of these properties generally compromises the other.…”

“…Halloysite polymer composites have attracted researchers' interest in recent years due to their unique structures and properties [11][12][13][14][15][16] . These nanotubes, with molecular formula Al 2 Si 2 O 5 (OH) 4 .nH 2 O, are naturally occurring multi-walled inorganic materials that have similar geometry to carbon nanotubes (CNTs). This aluminosilicate mineral clay can be found in different regions, varying in dimension.…”