The effects of two metallocene ethylene-propylene-based elastomers (m-EPR1 and m-EPR2) differing in molecular mass and viscosity on mechanical, rheological and interfacial properties were compared. ...The m-EPR elastomers were added to iPP in 2.5, 5, 10, 15, and 20 vol.%. Torque values, elongation at break and impact strength measured of the iPP/m-EPR1 blends were higher than the iPP/m-EPR2 blends due to higher molten viscosity of m-EPR1 than m-EPR2 copolymer. Slight differences in Young moduli as well as in tensile strength at yield and at break might indicate that tensile properties of iPP/m-EPR blends were not significantly affected by difference in viscosity or molecular mass, miscibility and spherulite size. Optimization diagrams indicated the metallocene m-EPR copolymers are efficient impact modifiers for polypropylene and showed good balancing of mechanical properties in iPP/m-EPR blends.
Rheological and mechanical properties (tensile and impact properties) as well as the mechanical profiles of ternary isotactic polypropylene/silica/elastomer (iPP/SiO
2
/m-EPR metallocene catalyzed ...ethylene-propylene rubber) composites were investigated and discussed. The effects of two metallocene ethylene-propylene-based elastomers (m-EPR) differing in molecular weight/viscosity and their content on iPP/silica composites with different silica types differing in size (nano- vs. micro-) and surface properties (untreated vs. treated) were investigated. The two m-EPR elastomers were added to iPP/SiO
2
96/4 composites as possible impact modifier and compatibilizer at the same time in 5, 10, 15, and 20 vol% per hundred volume parts of composites. The effects of different silica fillers and two m-EPR rubbers were discussed within the context of structure-morphology-mechanical property relationships of these iPP/SiO
2
/m-EPR composites. Tensile and impact strength properties were mainly influenced by combined competetive effects of stiff filler and tough m-EPR elastomer so sinergistic effect was also observed. The ductility of these composites was affected additionally by spherulite size of the iPP matrix due to the difference in nucleation abilities of silica fillers enabled by prevailing separated morphology observed in iPP/SiO
2
/m-EPR composites.
Neat thermoplastic polyurethane (TPU), polypropylene (PP), and TPU/PP blends with different weight ratios that were prepared in a twin-screw extruder were investigated with differential scanning ...calorimetry and light and scanning electron microscopy. The results confirmed PP matrix to TPU matrix phase inversion in the concentration region between 60/40 and 80/20 TPU/PP blends. The total degree of crystallinity of the blends and the crystallization temperature of PP decreased with increasing TPU content. On the other hand, the addition of elastomeric TPU to PP significantly increased the spherulite size of PP. The TPU melt islands in the PP matrix prolonged the crystallization of PP during solidification, and this enhanced the growth of spherulites.
The effects of different silica (SiO
2
) types and different contents of two metallocene propylene-based m-EPR elastomers (differing in molecular weight and viscosity) on interfacial properties, ...structure and morphology of isotactic polypropylene/SiO
2
/m-EPR composites were investigated. Four silica fillers differing in size (nano- vs. micro-) and surface properties (hydrophilic vs. hydrophobic i.e. polar vs. non-polar) were chosen and added in 4 vol% to isotactic polypropylene. The m-EPR elastomers were added to iPP/SiO
2
96/4 composites as possible impact modifier and compatibilizer at the same time in 5, 10, 15, and 20 vol% per 100 vol% of composites (phr). The investigation confirmed the overall prevailing of separated morphology of ternary iPP/SiO
2
/m-EPR composites, i.e. selectivity of dispersed m-EPR and silica particles toward iPP matrix as was predicted on the basis of adhesion properties. The increase of crystallinity degree and spherulite size with addition of m-EPR elastomers indicated significant solidification effect of added elastomers in addition to opposite nucleation effect of silica particles owing to surface character of filler. The effects of different silica fillers and different contents of two m-EPR elastomers were discussed within the context of morphology/structure-adhesion property relationships of the iPP/SiO
2
/m-EPR composites.
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