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Polymer Blending (polymer + blending)
Selected AbstractsSmart blending technology enabled by chaotic advectionADVANCES IN POLYMER TECHNOLOGY, Issue 3 2006D. A. Zumbrunnen Abstract Polymer blending has been typically regarded as a mixing process rather than a structuring process so polymer blends and composites are not necessarily optimized with regard to structure, properties, and composition. In this article, a new smart blending technology is described whereby melt components and solid additives are more controllably organized into micrometer-scale and sub-micrometer-scale shapes and arrangements to improve properties or impart functionality to extruded plastics. Chaotic advection is an enabling recent subfield of fluid mechanics for smart blending. It provides a method to controllably stretch and fold melt domains and evolve a multilayered structure leading to derivative morphologies, or indirectly manipulate solid additives. Recent advances in fluid mechanics have thereby been implemented to reconsider how blending is done. A variety of structured plastic materials are producible with a single smart blending device with no device alterations. Several examples and their improved physical properties are shown or discussed. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25:152,169, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20073 [source] Morphological and fractal studies of polypropylene/poly(ethene-1-octene) blends during melt mixing using scanning electron microscopyPOLYMER INTERNATIONAL, Issue 3 2008Xinhua Xu Abstract BACKGROUND: Polymer blending creates new materials with enhanced mechanical, chemical or optical properties, with the exact properties being determined by the type of morphology and the phase dimension of the blend. In order to control blend properties, morphology development during processing needs to be understood. The formation and evolution of polypropylene/poly(ethylene-1-octene) (PP/POE) blend morphology during blending are qualitatively represented by a series of time-dependent scanning electron microscopy (SEM) patterns. The area diameter and its distribution of dispersed phase domains are discussed in detail. In order to characterize the formation and evolution of phase morphology quantitatively, two fractal dimensions, Ds and Dd, and their corresponding scaling functions are introduced to analyze the SEM patterns. RESULTS: The evolution of the area diameter indicates that the major reduction in phase domain size occurs during the initial stage of melt mixing, and the domain sizes show an increasing trend due to coalescence with increasing mixing times. The distribution in dispersed phase dimension obeys a log-normal distribution, and the two fractal dimensions are effective to describe the phase morphology: Ds for dispersed phase dimension and Dd for the distribution in it. CONCLUSIONS: The fractal dimensions Ds and Dd can be used quantitatively to characterize the evolutional self-similarity of phase morphology and the competition of breakup and coalescence of dispersed phase domains. It is shown that the fractal dimensions and scaling laws are useful to describe the phase morphology development at various mixing times to a certain extent. Copyright © 2007 Society of Chemical Industry [source] A novel miniature mixing device for polymeric blends and nanocompositesPOLYMER ENGINEERING & SCIENCE, Issue 11 2009Martin Sentmanat A new miniature mixer has been developed to monitor and optimize the preparation protocol of various polymeric compounds and blend systems. The effect of mixing time and other basic processing parameters on the shear and extensional rheological properties of said compounds and blends is examined to understand the effect of undermixed and/or overmixed conditions on the rheological properties and thus the quality of the final products. Results from the new miniature mixer are compared with the results from other conventional mixing techniques to assess the scalability of the new mixing protocol. Two examples are used, those of polymer blending and nanocomposite formation. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers. [source] In-line optical detection in the transient state of extrusion polymer blending and reactive processing,,POLYMER ENGINEERING & SCIENCE, Issue 1 2005Tomás Jeferson A. Mélo Using an opticaldetector we followed the transient state of blends and composites, including a reactive blending during extrusion. The detection system is composed of a slit-die with transparent windows fixed at the extruder exit, an optical arrangement with a W incandescent light microbulb with fixed luminescence, and a CdS photocell. As the tracer passes though the light path, it absorbs and backscatters part of the light, reducing the total transmitted light intensity. This is followed by changes in the voltage induced by the photocell to an electric circuit. We calibrated the response of the photocell at room temperature using a set of various films with a second phase dispersed, and obtained a logarithmic relationship. The tracers were particulate (phthalocyanine, TiO2) and polymeric (PS, PA6) phases that absorb and scatter light, producing a residence time distribution (RTD) curvelike trace. Measurements were taken from a twin-screw extruder Werner-Pfleiderer ZSK 30 equipped with K-Tron gravimetric feeders operating at various screw configurations and speeds, and feeding rates. The transient state of PP/PA6 blends can be easily detected optically and recorded using one of the components (either PP or PA6) added as a pulse in a steady-state flow of the other component. With the simultaneous addition of a compatibilizer (polypropylene grafted with acrylic acid (PP-g-AA)) with the PA6, the intensity of the detector signal is substantially increased as a result of the PA6/PP-g-AA reaction. Quantitative off-line infrared spectroscopy of the total amide group corroborated the in-line measurements. These observations suggest that an in-line optical detector may be a fast and simple way to study the flow behavior of blends and composites, including reactive processing. POLYM. ENG. SCI. 45:11,19, 2005. © 2004 Society of Plastics Engineers. [source] | ||||||||||