共查询到20条相似文献,搜索用时 31 毫秒
1.
In this study, the effects of the elastomer type—ethylene–propylene–diene monomer (EPDM), three kinds of ethylene vinyl acetate (EVA 9, EVA 18, and EVA 28, where the number is the vinyl acetate concentration), and styrene–butadiene–styrene—and content on the microstructure and mechanical and thermal properties of isotactic polypropylene (i‐PP) blends were investigated. Five different elastomer concentrations (3, 6, 9, 12, and 15 wt %) were added to i‐PP to produce polypropylene/elastomer blends. The yield and tensile strengths, elastic modulus, impact strength, hardness, melt flow index (MFI), and structural properties of the blends were investigated. The tensile and yield strengths, elastic modulus, and hardness decreased gradually, whereas the impact strength and MFI increased as the elastomer content increased. As a result, with respect to the impact strength, the most effective elastomers were EPDM with 15 wt % and EVA 28 with 15 wt % for higher impact strength values. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1445–1450, 2005 相似文献
2.
In this article, maleated–grafted ethylene‐co‐vinyl acetate (EVA‐g‐MA) was used as the interfacial modifier for polypropylene/polyamide‐6 (PP/PA6) blends, and effects of its concentration on the mechanical properties and the morphology of blends were investigated. It was found that the addition of EVA‐g‐MA improved the compatibility between PP and PA6 and resulted in a finer dispersion of dispersed PA6 phase. In comparison with uncompatibilized PP/PA6 blend, a significant reduction in the size of dispersed PA6 domain was observed. Toluene‐etched micrographs confirmed the formation of interfacial copolymers. Mechanical measurement revealed that the addition of EVA‐g‐MA markedly improved the impact toughness of PP/PA6 blend. Fractograph micrographs revealed that matrix shear yielding began to occur when EVA‐g‐MA concentration was increased upto 18 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99:3300–3307, 2006 相似文献
3.
Tuning the nano/micro‐structure and properties of melt‐processed ternary composites of polypropylene/ethylene vinyl acetate blend and nanoclay: The influence of kinetic and thermodynamic parameters
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The present study reports the dependence of the nano/micro‐structure and properties of polypropylene (PP)/ethylene vinyl acetate (EVA)/nanoclay ternary composites on the kinetics and thermodynamics of the melt‐mixing process. The size of dispersed EVA particles in the blends increased in the presence of the nanoclay particles, whereas in the ternary blend composites the size of the EVA dispersions decreased with increasing processing time. Intercalation and exfoliation were achieved more efficiently in ternary composites prepared with a longer EVA processing time. Moreover, the incorporation of the nanoclay particles within the EVA phase and interphase, as well as a long processing time stabilized the morphology. The degree of crystallinity, melting behavior, and crystallization temperature of PP in the ternary composites were not influenced by the presence of the nanoclay particles or by the duration of the melt‐mixing process. The thermal stability of the ternary composites improved with increasing melt‐mixing time. The rheological and thermomechanical properties were found to be dependent on the processing time and on the resulting structure. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45585. 相似文献
4.
Edson L. Francisquetti Vinicios Pistor Rudinei Fiorio Mara Z. Andrade Ademir J. Zattera Marly A. M. Jacobi 《应用聚合物科学杂志》2013,129(3):1117-1123
In this work, ethylene‐co‐vinyl acetate (EVA), poly(ethylene‐co‐octene) (POE), and poly(vinyl chloride) (PVC) blends were processed in a molten state process using a corotating twin‐screw extruder to assess both the balance of mechanical properties and physical interactions in the melt state. Tensile measurements, scanning electron microscopy, and oscillatory rheometry were performed. By means of flow curves, the parameters of the power law as well as the distribution of relaxation times were assessed with the aid of a nonlinear regularization method. The mechanical properties for the EVA‐POE blend approximated the values for POE, while inclusion of PVC shifted the modulus values to those of neat EVA. The rise in modulus was corroborated by the PVC phase dispersion as solid particles that act as a reinforcement for the ternary blend. The rheological properties in the molten state show that the POE does not present molecular entanglement effects and so tends both to diminish the EVA mechanical properties and increase the fluidity of the blend. However, the addition of PVC both restored the EVA typical pseudoplastic feature and promoted the increase in the viscosity and the mechanical properties of the ternary blend. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
5.
V. F. Shumsky Y. Lipatov I. Getmanchuk A. Usenko P. Cassagnau G. Boiteux F. Melis J.‐M. Lucas 《应用聚合物科学杂志》2006,102(3):2700-2707
Blends of an ethylene/vinyl acetate copolymer (EVA) and polyisobutylene of various compositions were prepared by mechanical mixing at a temperature above the melting point of EVA (TmEVA) but below the upper critical solution temperature of 170°C for given blends. The rheological properties of the components and blends were studied in the region of small‐amplitude oscillating deformation at temperatures above and below TmEVA in the frequency range of 0.01–100 rad/s. At temperatures lower than TmEVA, the rheological properties were determined by the existence of the yield stress. With diminishing frequency, the viscosity increased, and the plateau in the relaxation spectrum at low frequencies broadened. The morphology of the blends depended on the conditions of sample heating. The introduction of a finely dispersed filler into the blends led to an anomalous drop in the viscosity. The morphology of the systems that arose by mechanical blending of the molten components was the important factor in the rheological behavior. The observed effects were examined in the framework of the concept of structural networks formed in melts by nonmelted crystallites of EVA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2700–2707, 2006 相似文献
6.
Structure and properties of nylon 1010/ethylene‐vinyl acetate rubber–based dynamically vulcanized thermoplastic elastomers filled with SiO2
下载免费PDF全文
![点击此处可从《Polymer Engineering and Science》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dynamically vulcanized Nylon 1010/ethylene‐vinyl acetate rubber (EVM)/SiO2 nanocomposites were prepared. Maleic anhydride grafted ethylene‐vinyl acetate copolymer (EVA‐g‐MA) and nano‐silica (SiO2) was used as a compatibilizer and a filler, and silane coupling agent (KH550, 3‐triethoxysilylpropylamine) was used to improve the dispersion of SiO2 in the nanocomposites. The nanocomposites were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), dynamic mechanical analysis (DMA), differential scanning calorimeter (DSC), and rheology analysis and mechanical properties test. SEM and AFM images showed that the compatibility between Nylon 1010 and EVM was improved by adding the compatibilizer. An increase in SiO2 content and the addition of the compatibilizer led to an increase in the tensile strength of the nanocomposite. A nanocomposite based on Nylon 1010/EVM/DCP (30/70/0.8) with tensile strength of 16.3 MPa and elongation at break of 180% was obtained by the addition of 15 phr EVA‐g‐MA and 40 phr SiO2. The non‐isothermal crystallization processes of Nylon/EVM blend were investigated by DSC. It was observed that EVM rubber could act as heterogeneous nuclei for Nylon which was more effective in Nylon/EVM/DCP blend than in Nylon/EVM blend. POLYM. ENG. SCI., 55:581–588, 2015. © 2014 Society of Plastics Engineers 相似文献
7.
Anton Marcin
in Eva Krmendy Marcela Hricov Andrej Rusnk Arun Pal Aneja 《应用聚合物科学杂志》2006,102(5):4222-4227
The article deals with method of preparation, rheological properties, phase structure, and morphology of binary blend of poly(ethylene terephthalate) (PET)/poly(butylene terephthalate) (PBT) and ternary blends of polypropylene (PP)/(PET/PBT). The ternary blend of PET/PBT (PES) containing 30 wt % of PP is used as a final polymer additive (FPA) for blending with PP and subsequent spinning. In addition commercial montane (polyester) wax Licowax E (LiE) was used as a compatibilizer for spinning process enhancement. The PP/PES blend fibers containing 8 wt % of polyester as dispersed phase were prepared in a two‐step procedure: preparation of FPA using laboratory twin‐screw extruder and spinning of the PP/PES blend fibers after blending PP and FPA, using a laboratory spinning equipment. DSC analysis was used for investigation of the phase structure of the PES components and selected blends. Finally, the mechanical properties of the blend fibers were analyzed. It has been found that viscosity of the PET/PBT blends is strongly influenced by the presence of the major component. In addition, the major component suppresses crystallinity of the minor component phase up to a concentration of 30 wt %. PBT as major component in dispersed PES phase increases viscosity of the PET/PBT blend melts and increases the tensile strength of the PP/PES blend fibers. The impact of the compatibilizer on the uniformity of phase dispersion of PP/PES blend fibers was demonstrated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4222–4227, 2006 相似文献
8.
In this study, a blend of polystyrene (PS)/ethylene vinyl acetate (EVA) (PS/EVA, 90 : 10 wt %) was compatibilized with three different block copolymers, in which their end blocks were compatible with either styrene or EVA. The compatibilized blends with different compositions were prepared using a twin‐screw extruder and injection molded into the required test specimens. Mechanical properties of the blends, such as tensile properties and Charpy impact strength, morphology of tensile fractured surfaces, rheological properties, and thermal properties, were investigated. The results show that the interaction between the dispersed and continuous phase can be improved by the addition of a compatibilizer. Appreciable improvement in the impact strength of the blend with 15 wt % of compatibilizer C (polystyrene‐block‐polybutadiene) was observed. Its mechanical properties are comparable to those of the commercial high‐impact polystyrene, STYRON 470. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2071–2082, 2004 相似文献
9.
To investigate the effect of interfacial interaction on the crystallization and mechanical properties of polypropylene (PP)/nano‐CaCO3 composites, three kinds of compatibilizers [PP grafted with maleic anhydride (PP‐g‐MA), ethylene–octene copolymer grafted with MA (POE‐g‐MA), and ethylene–vinyl acetate copolymer grafted with MA (EVA‐g‐MA)] with the same polar groups (MA) but different backbones were used as compatibilizers to obtain various interfacial interactions among nano‐CaCO3, compatibilizer, and PP. The results indicated that compatibilizers encapsulated nano‐CaCO3 particles, forming a core–shell structure, and two interfaces were obtained in the compatibilized composites: interface between PP and compatibilizer and interface between compatibilizer and nano‐CaCO3 particles. The crystallization and mechanical properties of PP/nano‐CaCO3 composites were dependent on the interfacial interactions of these two interfaces, especially the interfacial interaction between PP and compatibilizer. The good compatibility between PP chain in PP‐g‐MA and PP matrix improved the dispersion of nano‐CaCO3 particles, favored the nucleation effect of nano‐CaCO3, increased the tensile strength and modulus, but reduced the ductility and impact strength of composites. The partial compatibility between POE in POE‐g‐MA and PP matrix had little effect on crystallization and mechanical properties of PP/nano‐CaCO3 composites. The poor compatibility between EVA in EVA‐g‐MA and PP matrix retarded the nucleation effect of nano‐CaCO3, and reduced the tensile strength, modulus, and impact strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
10.
The photoinitiated crosslinking of halogen‐free flame‐retarded ethylene‐vinyl acetate copolymer (EVA) by the phosphorous‐nitrogen compound NP28 in the presence of photoinitiator and crosslinker and characterization of the related properties have been investigated by gel determination, heat extension test, thermogravimetric analysis (TGA), mechanical measurement, and thermal aging test. The photocrosslinking efficiency of EVA/NP28 blend and various factors affecting the crosslinking process, such as photoinitiator, crosslinker, NP28 content, and irradiation temperature, were studied in detail and optimized by comparison of gel content. The results show that the EVA/NP28 blend filled with 28.2 wt % NP28 with a thickness of 1.6 mm is homogeneously photocrosslinked to a gel content of above 80 wt % with 4.8 s UV‐irradiation under optimum conditions. The data from TGA, mechanical measurement, and thermal aging test give evidence that the thermal stability and mechanical properties of photocrosslinked EVA/NP28 blend are much better than those of the unphotocrosslinked one.© 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
11.
Waste polyurethane foam (w‐PU) and waste ethylene–vinyl acetate foam (w‐EVA) were used as fillers for the production of an ethylene–vinyl acetate (EVA) blend foam. Two different foaming techniques (single‐stage and heat–chill processes) were used for this purpose. The waste foam concentration was varied up to 30 wt % of the original EVA. The physical, mechanical, and morphological properties of the filled foam were studied. The single‐stage process produced blend foams with a lower density and a greater cell size than the foams obtained by the heat–chill process. The density and compression strength of the blend foam increased as the percentage of w‐PU foam increased. However, for the w‐EVA/EVA blend foams, the addition of w‐EVA foam did not significantly affect the density or compression strength compared to the original EVA foams. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44708. 相似文献
12.
Melt spun drawn fibers were prepared using a ternary blend of PP/PA6/PANI‐complex (polypropylene/polyamide‐6/polyaniline‐complex). Their electrical and mechanical properties were compared to those of binary blend fibers of PP/PANI‐complex. The results of the morphological studies on 55:25:20 PP/PA6/PANI‐complex ternary fibers were found to be in accordance with the predicted morphology for the observed conductivity vs. fiber draw ratio. The scanning electron microscopy (SEM) micrographs of the ternary blend illustrated at least a three‐phase morphology of a matrix/core‐shell dispersed phase style, with widely varying sizes of droplets. This resulted in a dispersed morphology that, in some parts of the blend, approached a bicontinuous/dispersed phase morphology due to coalescence of the small droplets. The matrix was PP and the core‐shell dispersed phase was PA6 and PANI‐complex, in which a part of the PANI‐complex had encapsulated the PA6 phase and the remaining was solved/dispersed in the PA6 core, as later confirmed by X‐ray mapping. When the ternary blend fibers were compared to the binary fibers, the formers were able to combine better conductivity (of an order of 10?3 S cm?1) with a greater tensile strength only at a draw ratio of 5. This indicated that the draw ratio is more critical for the ternary blend fibers, because both conductivity and tensile strength depended on the formation of fibrils from the core‐shell dispersed phase of the PA6/PANI‐complex. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers 相似文献
13.
Eduardo Ramírez‐Vargas Blanca Margarita Huerta‐Martínez Francisco Javier Medellín‐Rodríguez Saúl Snchez‐Valdes 《应用聚合物科学杂志》2009,112(4):2290-2297
Compatibility mechanisms between EVA and PP copolymers (C‐PP) blends have been studied as a function of the type of copolymer, using a heterophasic PP copolymer (PP‐EP) and a random PP copolymer (PP‐r‐EP), with similar ethylene content. The morphology and thermal and mechanical properties of PP/EVA blends with different levels of EVA containing 28% vinyl acetate (VA) were determined. The obtained results indicated compatibility for both systems showing interactions at the amorphous interfaces; however, this interaction was higher for the PP‐r‐EP/EVA, which showed a single glass transition temperature and changes in the PP crystalline fraction (changes in the fusion temperature and in the diffraction patterns). The evolution of the morphology from isolated spherical domains (20% EVA) to elongated shapes (40% EVA) was related to the observed changes in thermal and mechanical properties. The impact strength and deformation properties showed significant improvement with increasing EVA content above 40% where the highest values of elongation for the PP‐r‐EPand of impact strength for the PP‐EP were obtained. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
14.
The effect of epoxidized natural rubber (ENR) or polyethylene acrylic acid (PEA) as a compatibilizer on properties of ethylene vinyl acetate (EVA)/natural rubber (SMR L) blends was studied. 5 wt.% of compatibilizer was employed in EVA/SMR L blend and the effect of compatibilizer on tensile properties, thermal properties, swelling resistance, and morphological properties were investigated. Blends were prepared by using a laboratory scale of internal mixer at 120°C with 50 rpm of rotor speed. Tensile properties, thermal properties, thermo-oxidative aging resistance, and oil swell resistance were determined according to related ASTM standards. The compatibility of EVA/SMR L blends with 5 wt.% of compatibilizer addition or without compatibilizing agent was compared. The EVA/SMR L blend with compatibilizer shows substantially improvement in tensile properties compared to the EVA/SMR L blend without compatibilizer. Compatibilization had reduced interfacial tension and domain size of ethylene vinyl acetate (EVA)/natural rubber (SMR L) blends. 相似文献
15.
《Journal of Adhesion Science and Technology》2013,27(14):1561-1571
Two types of wax were added to a ethylene vinyl acetate (EVA) copolymer/aromatic hydrocarbon resin (tackifier) blend in the molten state and the miscibility, viscoelastic and adhesion properties of ternary blends as hot-melt adhesives (HMAs) were investigated. Miscibility and viscoelastic properties were studied using differential scanning calorimetry (DSC), Brookfield viscometry and dynamic mechanical thermal analysis (DMTA), and their adhesion strength was determined in terms of single lap shear strength. DSC thermograms of both types of waxes showed their melting peaks in a similar region to that of EVA/tackfier blend. It was difficult to evaluate the miscibility of ternary blends using DSC because the melting peaks of the waxes overlapped with those of the EVA/tackifier blend, although the glass transition temperature (T g) of the ternary blend systems slightly increased with increasing wax concentration. However, their storage modulus (E′) increased slightly and loss tangent (tan δ) showed different peaks when two types of wax were added to the EVA/tackifier blend. Therefore, the miscibility of EVA/tackifier blend altered with addition of waxes. In addition, their melt viscosity decreased with increasing wax concentration. Furthermore, the adhesion strength of the ternary blends decreased with increasing wax concentration, despite the increment of storage modulus. These results suggested that the ternary blends of EVA/tackifier/wax were heterogeneous. 相似文献
16.
The effect of calcium carbonate (CaCO3) on the mechanical properties (with heat treatment) and thermal properties of polypropylene and isotactic polypropylene (i‐PP)/ethylene vinyl acetate (EVA) blends was investigated. CaCO3, in five different concentrations (3, 6, 9, 12l, and 15 wt %), was added to i‐PP/EVA (88/12) to produce ternary composites. The mechanical properties, including the yield and tensile strengths, elastic modulus, Izod impact strength for notch radii of 0.25 and 1 mm, and hardness with and without an annealing heat treatment, and the thermal properties, such as the melting point and melt‐flow index, of the composites were investigated. The annealing heat treatment was carried out at 100°C for three different holding times: 75, 100, and 150 h. On the basis of the results, attempts were made to establish a relationship between the CaCO3 content, the annealing holding time, and the mechanical and thermal properties to obtain the best results. The tensile test results showed that the heat treatment was not effective for the ultimate tensile strength, and the yield strength and tensile strength decreased gradually as the CaCO3 content increased. However, CaCO3 was effective for higher elastic modulus, impact strength, and hardness values. A considerable increase in the elastic modulus was found with a 3% CaCO3 concentration for a holding time of 100 h. The maximum impact strength for a notch radius of 1 mm was obtained with 3% CaCO3 with annealing for a holding time of 100 h, whereas a 9% CaCO3 concentration produced higher toughness values for a notch radius of 0.25 mm. The fracture surfaces also supported the results from the Izod impact tests. Similarly, hardness values increased with the annealing heat treatment and increasing CaCO3 content. However, different holding times showed similar effects on the hardness values. The increased CaCO3 content caused the melting point to increase 5°C, whereas the melt‐flow index showed a sharp decrease as the CaCO3 content increased to 3%. Taking into consideration the mechanical and thermal properties and the annealing holding time, we recommend a CaCO3 concentration of 3% with an annealing heat treatment for 100 h for optimum properties of such ternary composites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1126–1137, 2005 相似文献
17.
José M. Mata‐Padilla Francisco J. Medellín‐Rodríguez Carlos A. Ávila‐Orta Eduardo Ramírez‐Vargas Gregorio Cadenas‐Pliego Mario Valera‐Zaragoza Sofía M. Vega‐Díaz 《应用聚合物科学杂志》2014,131(20)
Polypropylene (PP)‐ethylene vinyl acetate (EVA)/clay nanocomposites were prepared via reactive blending using dicumyl peroxide (DCP) as an initiator with the goal of enhancing the interaction between both phases and modified nanoclay. The effect of the reactive blending and clay incorporation strategies (direct and masterbatch) on the blend and nanostructure morphology, and chain mobility of nanocomposites were studied. The chemical analysis showed the chemical bonding of PP‐EVA, which helped to enhance the interaction in the nanocomposites. The nanocomposites obtained from the direct clay strategy presented a co‐continuous morphology of bordering intercalated and agglomerated nanoclay sheets, while the nanocomposites obtained from the masterbatch strategy showed that blend morphology change from droplet to co‐continuous with the increase of EVA concentration, with intercalated/exfoliated nanoclay sheets located in the EVA domains and at the interface. The dynamic mechanical and creep‐recovery results showed different behavior for the both strategies in terms of chain mobility and relaxation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40897. 相似文献
18.
Catherine Joubert Philippe Cassagnau Alain Michel Lionel Choplin 《Polymer Engineering and Science》2002,42(11):2222-2233
The elaboration of a TPV based on copolymer of ethylene and vinyl acetate (EVA) and polypropylene (PP) as thermoplastic phase was investigated in a batch mixer. The crosslinking reaction is carried out through a transesterification reaction between ester groups of EVA and alcoxysilane groups of the crosslinker agent tetrapropoxyorthosilicate (TPOS). The main advantage of this crosslinking reaction is that it can be well controlled and suitable for different processing conditions. The aim of the present study is to get a better understanding of the dispersion mechanism and of the phase inversion of the EVA major phase during its dynamic vulcanization into the PP minor phase. It was proved that the initial viscosity ratio, λ = ηpp/ηEVA, between EVA and PP plays an important part in the morphology development of the reactive blend. The viscosity ratio must be close to the critical ratio expressed by Utracki's model of phase inversion mechanism. Furthermore, the influence of different processing parameters on the variation of the morphology and on the mechanical properties of the ultimate TPV was investigated. The main conclusion of this study is that the characteristic time of crosslinking must be of the same order than the time of mixing. Indeed, better mechanical properties are obtained when a progressive phase inversion occurred and when it is controlled by rheological aspects and transient morphology equilibrium of the two phases and not by the mechanical fragmentation of the crosslinked EVA. For example, in our experimental conditions (concerning the amounts of catalyst and crosslinker reagents), high shear rates can be avoided ($ {\rm \dot \gamma} $ < 80 s?1) as the self‐heating of the blend under shear considerably increases (ΔT ≈ 50°C for $ {\rm \dot \gamma} $ = 225 s?1), leading to faster kinetics and consequently to a phase inversion controlled by the fragmentation of the crosslinked EVA phase. 相似文献
19.
Jing‐hui Yang Ting‐ting Zhang Yong‐sheng Zhang Nan Zhang Ting Huang Yong Wang 《Polymer International》2020,69(3):228-238
Carbon nanotubes (CNTs) and barium titanate (BaTiO3) (BT) were simultaneously introduced into the immiscible blend poly(ethylene‐co‐vinyl acetate)/thermoplastic urethane (EVA/TPU), and the EVA/TPU/CNT/BT quaternary polymer composite blends with core–shell structured island TPU domain were successfully prepared, in which CNTs in the TPU domain act as the core and the BT spheres at the interface of the TPU and EVA act as the shell. A core–shell structured island can lead to the formation of micro‐capacitors and further accumulate electron storage owing to the incorporation of CNTs and BT; on the other hand, a BT shell can be assembled along the TPU spheres, reducing the possibility of formation of a conductive CNT network, resulting in suppressed dielectric loss. Therefore, CNTs and BT were tailor‐made into blend composites with a core–shell structured domain, which can achieve an increased dielectric constant by 176% and decreased low dielectric loss by 80% compared with the blend composites with only CNTs in the TPU domain. © 2019 Society of Chemical Industry 相似文献
20.
This paper describes a study of melt-rheological properties of the binary blend of isotactic polypropylene (PP) and ethylene–vinyl acetate copolymer (EVA) at varying blending ratios (from 0 to 40 wt % EVA content) and using three samples of EVA containing different vinyl acetate contents (VA %), viz. 9, 12, and 19%. Measurements made on a capillary rheometer at three different temperatures (210, 220, and 230°C) in a shear stress range of 104–106 Pa (shear rate 101–104 s?1) are presented and discussed for the effects of blend composition and shear stress on the flow curves, melt viscosity and melt elasticity. Morphology of the blend studied through scanning electron microscopy revealed distinct differences in size and number density of dispersed EVA droplets, which are discussed in terms of the variation of average size and number density of the dispersed EVA droplets as a function of blend composition and shear stress. Melt-rheological properties and morphology of dispersion are correlated and found quite consistent. 相似文献