Use of Monomethyl Itaconate Grafted Poly(propylene)(PP) and Ethylene Propylene Rubber(EPR) as Compatibilizers for PP/EPR Blends (original) (raw)
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Polymer Testing, 2009
A new method was used to prepare thermoplastic elastomers based on polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr) with improved mechanical properties. An epoxy resin (EP) was used as a compatibilizing agent. The effect of EP on mechanical properties, swelling percentage and morphological characteristics of the blends was investigated with different blend compositions. The results showed that the incorporation of EP has improved the tensile strength, Young's modulus and elongation at break of PP/ NBRr-EP blends compared with PP/NBRr blends. The enhancement of tensile properties of PP/NBRr-EP blends is due to the better adhesion between the two phases with the incorporation of EP. This is quite evident by scanning electron microscopy of tensile fractured surfaces. PP/NBRr-EP blend exhibits lower stabilization torque and swelling percentage than PP/NBRr blends. The lower stabilization torque is an indication of better processing characteristics.
Influence of an ethylene-octene copolymer and of pollutants in PP/EPR blends
Journal of Applied Polymer Science, 2007
The objective of this work was to study the effectiveness of commercial compatibilizers (E-EA-MAH copolymer) on the morphology of blends of polypropylene/ ethylene polypropylene rubber (PP/EPR) (78/22) and metallocenic ethylene-octene copolymer (EOC) polluted by (poly (vinyl chloride) (PVC) and by an oil for engine. Blends of various compositions (with and without compatibilizer or pollutant), were prepared using a corotating twin-screw extruder. In both cases, the analyses of blend morphologies highlighted the poor adherence between the two phases in the uncompati-bilized blends. Compatibilized polluted blends display better adherence between phases. Dynamic mechanical thermal analysis and differential scanning calorimetry show that the compatibilizer improves the adhesion between both phases and enables stress transfer at the interface.
Graft-modified rubbers including maleic anhydride grafted ethylene propylene diene monomer (MAH-g-EPDM) and 49% methyl methacrylate grafted natural rubber (MMA-g-NR, i.e. MG49 rubber) were employed to toughen polypropylene (PP) and polystyrene (PS). The results showed that Charpy impact strength of the notched PP specimens and unnotched PS specimens at room temperature was improved markedly by addition of the graft-modified rubbers. Moreover, Charpy impact strength of the plastics increased with increasing graftmodified rubbers content and the incorporation of MAH-g-EPDM enhanced impact strength of the plastics more markedly than MG49. The result of thermogravimetric analysis (TGA) indicated that the addition of MAH-g-EPDM improved the thermal stability of PP, while the incorporation of MG49 reduced it. Good compatibility between the plastics and MAH-g-EPDM and saturation of EPDM could be responsible for these mechanical and thermal features. This preliminary work may also provide some information for oil-resistant modification of plastics due to the polar groups grafted onto the backbone of rubbers.
Polymer Engineering and Science, 2007
Dynamically vulcanized blends of polyoxymethylene (POM) and ethylene propylene diene terpolymer (EPDM) with and without compatibilizer were prepared by melt mixing in a twin screw extruder. Maleic anhydride (MAH) grafted EPDM (EPDM-g-MAH) has been used as a compatibilizer. Dicumyl peroxide was used for vulcanizing the elastomer phase in the blends. Mechanical, dynamical mechanical, thermal, and morphological properties of the blend systems have been investigated as a function of blend composition and compatibilizer content. The impact strength of both dynamically vulcanized blends and compatibilized/dynamically vulcanized blends increases with increase in elastomer content with decrease in tensile strength. Dynamic mechanical analysis shows decrease in tanδ values as the elastomer and compatibilizer content increased. Thermograms obtained from differential scanning calorimetric studies reveal that compatibilized blends have lower Tm values compared to dynamically vulcanized blends, which confirms strong interaction between the plastic and elastomer phase. Scanning electron microscopic observations on impact fractured surface indicate reduction in particle size of elastomer phase and its high level of dispersion in the POM matrix. In the case of compatibilized blends high degree of interaction between the component polymers has been observed. POLYM. ENG. SCI., 47:934–942, 2007. © 2007 Society of Plastics Engineers
Effect of addition of polyethylene on properties of polypropylene/ethylene-propylene rubber blends
Journal of Applied Polymer Science, 1996
Toughening of polypropylene was carried out by adding two types of ethylene-propylene rubber (EPR) having different ethylene content, and three commercial types of EPR containing high density polyethylene (PE). The concentration of EPR was varied from 0-30%. Globular morphology of the dispersed phase was observed at all concentrations. Average particle size of the dispersed phase (EPR) was about 2-4 pm with about 10% within the 0.5-1 pm range. Although most of the properties were not affected by the presence of polyethylene, high notched Izod impact strength was achieved only with samples containing PE. Melt flow rate, yield strength and modulus were found to decrease almost linearly with increasing elastomer concentration in the blend. Elongation a t break was enhanced by the addition of EPR, particularly those containing PE. The contribution of P E to the properties was explained by the specific EPR/PE particle morphology (core-shell or interpenetrating)
Journal of Applied Polymer Science, 2015
This research analyzes the effect of ground tire rubber (GTR) and a novel metallocene-based ethylene-propylene copolymer (EPR), with high propylene content, on the morphology and mechanical behavior of ternary polymer blends based on a highly flowable polypropylene homopolymer (PP). The PP/EPR blends morphology, with very small domains of EPR dispersed in the PP matrix, indicates a good compatibility among these materials, which leads to a significant improvement on elongation at break and impact strength. The incorporation of EPR on the rubber phase of thermoplastic elastomeric blends (TPE) based on GTR and PP (TPE GTR) has a positive effect on their mechanical performance, attributed to the toughness enhancement of the PP matrix and to the establishment of shell-core morphology between the rubber phases. The mechanical properties of the ternary blends reveal that TPE GTR blends allow the upcycling of this GTR material by injection molding technologies.
Polymer, 2005
Ethylene-propylene rubber (EPR) functionalised with glycidyl methacrylate (GMA) (f-EPR) during melt processing in the presence of a co-monomer, such as trimethylolpropane triacrylate (Tris), was used to promote compatibilisation in blends of polyethylene terephthalate (PET) and f-EPR, and their characteristics were compared with those of PET/f-EPR reactive blends in which the f-EPR was functionalised with GMA via a conventional free radical melt reaction (in the absence of a co-monomer). Binary blends of PETand f-EPR (with two types of f-EPR prepared either in presence or absence of the co-monomer) with various compositions (80/20, 60/40 and 50/50 w/w%) were prepared in an internal mixer. The blends were evaluated by their rheology (from changes in torque during melt processing and blending reflecting melt viscosity, and their melt flow rate), morphology scanning electron microscopy (SEM), dynamic mechanical properties (DMA), Fourier transform infrared (FTIR) analysis, and solubility (Molau) test. The reactive blends (PET/f-EPR) showed a marked increase in their melt viscosities in comparison with the corresponding physical (PET/EPR) blends (higher torque during melt blending), the extent of which depended on the amount of homopolymerised GMA (poly-GMA) present and the level of GMA grafting in the f-EPR. This increase was accounted for by, most probably, the occurrence of a reaction between the epoxy groups of GMA and the hydroxyl/carboxyl end groups of PET. Morphological examination by SEM showed a large improvement of phase dispersion, indicating reduced interfacial tension and compatibilisation, in both reactive blends, but with the Tris-GMA-based blends showing an even finer morphology (these blends are characterised by absence of poly-GMA and presence of higher level of grafted GMA in its f-EPR component by comparison to the conventional GMA-based blends). Examination of the DMA for the reactive blends at different compositions showed that in both cases there was a smaller separation between the glass transition temperatures compared to their position in the corresponding physical blends, which pointed to some interaction or chemical reaction between f-EPR and PET. The DMA results also showed that the shifts in the T g s of the Tris-GMA-based blends were slightly higher than for the conventional GMA-blends. However, the overall tendency of the T g s to approach each other in each case was found not to be significantly different (e.g. in a 60/40 ratio the former blend shifted by up to 4.5 8C in each direction whereas in the latter blend the shifts were about 3 8C). These results would suggest that in these blends the SEM and DMA analyses are probing uncorrelatable morphological details. The evidence for the formation of in situ graft copolymer between the f-EPR and PET during reactive blending was clearly illustrated from analysis by FTIR of the separated phases from the Tris-GMA-based reactive blends, and the positive Molau test pointed out to graft copolymerisation in the interface. A mechanism for the formation of the interfacial reaction during the reactive blending process is proposed.