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.
Evidence is presented that all three theoretically predicted modes of phase separation take place in the ternary system polysulfone(PSf)/
N,
N-dimethyl acetamide(DMA)/water during the process of wet ...phase separation (WPS). The elementary process of solidification is reconsidered with regard to the (non-) equilibrium phase separation. Cast solutions with more than 15
wt% of PSf undergo nucleation and growth of the polymer lean phase with formation of separation membranes characterised by a cellular structure. When cast solutions with about 5–7
wt% of PSf undergo WPS, somewhere inside the ternary system conditions are established so that alongside other solidified PSf structures the bicontinuous spinodal structures superimposed by bead-like structures are also formed. Variety of lacy PSf structures with less/more polymer beads is the manifestation of the primary phase separation by the spinodal mode superimposed by the secondary phase separation taking place by heterogeneous nucleation and growth of the polymer rich phase mode. Latex formation during the WPS will also be explained. Skin formation on the cast solution – coagulation bath interface by direct accumulation of polymer is established regardless of the PSf content in the cast solution.
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.
We report on novel observations on the appearance of macrovoids in the ternary cellulose acetate (CA)/acetone (ACE)/water membrane forming system. The membranes are prepared by the wet phase ...separation whereby the cast solution is composed of ACE and polymer, and the coagulation bath is pure water only. It is found that the macrovoid formation in a 12.5
wt.% cast solution strongly depends on the cast solution thickness: macrovoids appear at the thickness of 500
μm but not at 150 and 300
μm.
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.
Isotactic polypropylene/styrenic rubber block copolymer blends (iPP/SRBC) as well as the iPP/talc/SRBC composites with 12
vol.% of aminosilane surface treated talc were studied by the measurement of ...mechanical properties (tensile properties and notched impact strength). Mechanical properties and their relation with the structure of polypropylene blends and composites were investigated as a function of poly(styrene-
b-ethylene-
co-butylene-
b-styrene) triblock copolymer (SEBS) and the SEBS grafted with maleic anhydride (SEBS-g-MA) content in the range from 0 to 20
vol.% as elastomeric components. Elongation at yield of the iPP/talc/SEBS-g-MA composites and impact strength of the iPP/talc/SEBS composites show synergistic effect at high elastomer content (20
vol.%). Higher molecular weight (and consequently higher viscosity, elasticity and impact strength) of thicker SEBS layers around highly oriented talc crystals and higher miscibility or interactivity of SEBS than SEBS-g-MA with iPP chains seem to contribute to enormous impact strength of the iPP/talc/SEBS composites. On the other side, a higher extent of encapsulation and disorientation of talc crystals by the SEBS-g-MA than by SEBS copolymer, and lower molecular weight of the SEBS-g-MA than SEBS copolymer may contribute to higher elongation at yield of the iPP/talc/SEBS-g-MA composite.
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