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Blend Components (blend + component)
Selected AbstractsCompatibility and viscoelastic properties of brominated isobutylene- co - p -methylstyrene rubber/tackifier blendsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2008K. Dinesh Kumar Abstract Brominated isobutylene- co-p -methylstyrene (BIMS) rubber has been blended with hydrocarbon resin tackifier and alkyl phenol formaldehyde resin tackifier, and the compatibility between the blend components has been systematically evaluated. Dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) studies show that BIMS rubber and hydrocarbon resin tackifier blends are compatible at all blend proportions studied. However, BIMS rubber and phenol formaldehyde resin blends exhibit very limited compatibility with each other and phase separation even at very low phenolic tackifier concentration. Morphological studies of the rubber,resin blends by scanning electron microscopy (SEM) corroborate well with the DMA and DSC results. From the DMA frequency sweep and temperature sweep studies, it is shown that the hydrocarbon resin tackifier acts as a diluent and causes a decrease in the storage modulus values (by reducing the entanglement and network density) in the rubbery plateau region. On the other hand, phenol formaldehyde resin behaves in the way similar to that of the reinforcing filler by increasing the storage modulus values (by increasing the entanglement and network density) in the rubbery plateau zone. The relaxation time estimated from the different zones of frequency sweep master curves provides information about the influence of the two tackifiers on the viscoelastic properties of the BIMS rubber in the respective zones. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Solid state structure and mechanical properties of melt mixed poly(trimethylene terephthalate)/polycarbonate blendsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008I. González Abstract Poly(trimethylene terephthalate) (PTT)/poly (carbonate of bisphenol A) (PC) blends were obtained in the melt state by direct injection molding and also by extrusion followed by injection molding. The blends rich in PTT were monophasic, while the blends rich in PC were biphasic with the two components of the blends present in both phases. Both the monophasic and biphasic blends were partially miscibilized, and also partially reacted, as observed by FTIR. The extent of the reaction was greater in previously mixed blends. The observed synergism in the modulus of elasticity was attributed to the increased orientation of the blend components upon blending. Although decreases in elongation at break were observed and attributed to degradation of PTT, the blends were clearly ductile and compatible. This was a consequence of either their monophasic structure, or of the presence of the two components in the two phases of the blends. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Blends of high density polyethylene and ethylene/1-octene copolymers: Structure and properties,JOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2007Rameshwar Adhikari Abstract The morphology formation in the blends comprising a high density polyethylene (HDPE) and selected ethylene/1-octene copolymers (EOCs) was studied with variation of blend compositions using atomic force microscopy (AFM). The binary HDPE/EOC blends studied showed well phase-separated structures (macrophase separation) in consistence with individual melting and crystallization behavior of the blend components. For the blends comprising low 1-octene content copolymers, the lamellar stacks of one of the phases were found to exist side by side with that of the another phase giving rise to leaflet vein-like appearance. The formation of large HDPE lamellae particularly longer than in the pure state has been explained by considering the different melting points of the blend components. The study of strain induced structural changes in an HDPE/EOC blend revealed that at large strains, the extensive stretching of the soft EOC phase is accompanied by buckling of HDPE lamellar stack along the strain axis and subsequent microfibrils formation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1887,1893, 2007 [source] Immiscible Poly(L -lactide)/Poly(, -caprolactone) Blends: Influence of the Addition of a Poly(L -lactide)-Poly(oxyethylene) Block Copolymer on Thermal Behavior and MorphologyMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 7 2004Giovanni Maglio Abstract Summary: A binary blend of poly (L -lactide) (PLLA) and poly(, -caprolactone) (PCL) of composition 70:30 by weight was prepared using a twin screw miniextruder and investigated by differential scanning calorimetry (DSC), optical microscopy and scanning electron microscopy (SEM). Ternary 70:30:2 blends were also obtained by adding either a diblock copolymer of PLLA and poly(oxyethylene) (PEO) or a triblock PLLA-PCL-PLLA copolymer as a third component. Optical microscopy revealed that the domain size of dispersed PCL domains is reduced by one order of magnitude in the presence of both copolymers. SEM confirmed the strong reduction in particle size upon the addition of the copolymers, with an indication of an enhanced emulsifying effect in the case of the PLLA-PEO copolymer. These results are analyzed on the basis of solubility parameters of the blend components. Optical micrograph of M3EG2 blend melt quenched at 125,°C. [source] Design of Blends with an Extremely Low Viscosity Ratio between the Dispersed and Continuous Phases.MACROMOLECULAR SYMPOSIA, Issue 1 2007Dependence of the Dispersed Phase Size on the Processing Parameters Abstract Summary: This work deals with the development of the dispersed phase morphology in immiscible blends of poly(ethylene glycol)/polyamide 66 (PEG/PA) with an extremely low viscosity ratio. The blends were obtained, under different operating conditions, by melt blending in an internal mixer. The objective was to examine the influence of the main processing parameters on the particles size of the minor phase (PEG). A model was elaborated to describe the dependence of the particle size on interfacial tension, PEG concentration, shear rate and viscosity ratio between the two blend components. [source] Thermodynamic characterization of hybrid polymer blend systemsPOLYMER ENGINEERING & SCIENCE, Issue 6 2009Amos Ophir A thermodynamic model was used to predict the morphology of hybrid multicomponent polymer blend systems. Two systems were studied, both including two noncompatible polymers, a third compatibilizer polymer and layered, organo-treated clays. The polar and nonpolar contributions of the surface energies of the components of the systems were calculated using measurements of the contact angles. The morphology of the multicomponent systems and the relative position of the organo-clays within them, were predicted by calculating the interaction energies between the different components of the system and evaluating these values according to the Vaia and Giannelis thermodynamic model for polymer melt intercalation in organically modified layered silicates. The experimental results show good correlation with the prediction that the organo-clays will have higher affinity to the compatibilizer polymer component situated at the interface between the two noncompatible blend components. In addition, the presence of the organo-clays in this interface was found to have a significant additional compatibilizing effect between the two polymer phases. The results presented in this work support the idea that hybrid formation via polymer melt intercalation depends mostly on energetic factors that can be determined from surface energies of polymers and organo-modified layered silicates, also in the case of multiphase polymer system. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source] Modification of recycled high-density polyethylene by low-density and linear-low-density polyethylenes,POLYMER ENGINEERING & SCIENCE, Issue 1 2003N. Kukaleva The present study investigated mixed polyolefin compositions with the major component being a post-consumer, milk bottle grade high-density polyethylene (HDPE) for use in large-scale injection moldings. Both rheological and mechanical properties of the developed blends are benchmarked against those shown by a currently used HDPE injection molding grade, in order to find a potential composition for its replacement. Possibility of such replacement via modification of recycled high-density polyethylene (reHDPE) by low-density polyethylene (LDPE) and linear-low-density polyethylene (LLDPE) is discussed. Overall, mechanical and rheological data showed that LDPE is a better modifier for reHDPE than LLDPE. Mechanical properties of reHDPE/LLDPE blends were lower than additive, thus demonstrating the lack of compatibility between the blend components in the solid state. Mechanical properties of reHDPE/LDPE blends were either equal to or higher than calculated from linear additivity. Capillary rheological measurements showed that values of apparent viscosity for LLDPE blends were very similar to those of the more viscous parent in the blend, whereas apparent viscosities of reHDPE/LDPE blends depended neither on concentration nor on type (viscosity) of LDPE. Further rheological and thermal studies on reHDPE/LDPE blends indicated that the blend constituents were partially miscible in the melt and cocrystallized in the solid state. [source] Thermal and morphological properties of high-density polyethylene/ethylene,vinyl acetate copolymer composites with polyhedral oligomeric silsesquioxane nanostructurePOLYMER INTERNATIONAL, Issue 2 2010Patrícia Scapini Abstract The demand for improved properties of common polymers keeps increasing, and several new approaches have been investigated. In the study reported here, composites with a polymer matrix comprising a blend of high-density polyethylene with ethylene,vinyl acetate copolymer (EVA), and with polyhedral oligomeric silsesquioxane (POSS) as a nanostructure, were processed and characterized in terms of their thermal and morphological properties. For the preparation of the composites, the concentrations of the blend components (0, 50 and 100 wt%) and of the POSS (0, 1 and 5 wt%) were varied. X-ray diffraction results indicated that the presence of EVA in the composites led to the appearance of crystalline domains at lower POSS concentrations. Transmission and scanning electron microscopy showed that samples with 1 wt% of POSS had a homogeneous distribution in the polymer matrix with average dimensions of ca 150 nm. However, the formation of aggregates occurred in samples with 5 wt% of POSS. Differential scanning calorimetry and thermogravimetic analyses indicated that the POSS did not affect the melt and degradation temperatures of the polymer matrix. POSS underwent aggregation at higher concentrations during the composite processing, indicating a solubility limit of around 1 wt%. The presence of EVA in the composite favors POSS aggregation due to an increase in the polarity of the polymer matrix. Copyright © 2009 Society of Chemical Industry [source] Low density polyethylene and grafted lignin polyblends using epoxy-functionalized compatibilizer: mechanical and thermal propertiesPOLYMER INTERNATIONAL, Issue 12 2005RRN Sailaja Abstract Lignin was graft copolymerized with methyl methacrylate using manganic pyrophosphate as initiator. This modified lignin was then blended (up to 50 wt%) with low density polyethylene (LDPE) using a small quantity of poly[ethylene- co -(glycidyl methacrylate)] (PEGMA) compatibilizer. The mechanical properties of the blend were substantially improved by using modified lignin in contrast to untreated lignin. Differential scanning calorimetry studies showed loss of crystallinity of the LDPE phase owing to the interaction between the blend components. Thermogravimetric analysis showed higher thermal stability of modified lignin in the domain of blend processing. This suggested that there is scope for useful utilization of lignin, which could also lead to the development of eco-friendly products. Copyright © 2005 Society of Chemical Industry [source] Morphology and micromechanical properties of ethylene/1-octene copolymers and their blends with high density polyethylene,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 2-3 2005R. Adhikari Abstract The relationship between morphology and deformation behavior of selected ethylene/1-octene copolymers (EOCs) and their blends with high density polyethylene (HDPE) was investigated. The copolymers showed, depending on the 1-octene content, different morphologies ranging from lamellar to worm-like crystalline domains. The binary HDPE/EOC blends studied, which showed well phase-separated structures consistent with individual melting and crystallization behavior of the blend components, were characterized by a wide range of mechanical and micromechanical properties. The study of strain induced structural changes in an HDPE/EOC blend revealed that at large strains, the extensive stretching of the soft EOC phase is accompanied by rotation of lamellar stack along the strain axis and subsequent fragmentation of the crystals forming beaded-string-like structures. A significant depression in microhardness was observed in the copolymers. In their blends with HDPE, a deviation in microhardness behavior from the additivity law was observed. Copyright © 2005 John Wiley & Sons, Ltd. [source] | ||||||||||