Polypropylene rheological properties

Medintseva, T.I., Dreval, V.E., Erina, N.A., and Prut, E.V., Rheological properties thermoplastic elastomers based on isotactic polypropylene with an ethylene-propylene-diene terpolymer, Polym. Sci. A, 45, 2032, 2003. 

Blends of poly (ethylene terephthalate) (PETP) and polypropylene (PP) with different rheological properties were dry blended or compounded, and extrusion foamed using both physical blowing and chemical agents, and the foam properties compared with those of foam produced from the individual components in the absence of compatibilisers and rheology modifiers. The foams were characterised by measurement of density, cell size and thermal properties. Low density foam with a fine cell size was obtained by addition of a compatibiliser and a co-agent, and foamed using carbon dioxide. The presence of PP or a polyolefin-based compatibiliser did not effect... 

Fridman ML (1970) Rheological properties and high-speed extrusion of polypropylene. Summary of the thesis, INHS, Ac. Sci. USSR, Moscow... 

Nam GJ, Yoo JH, Lee JW (2005) Effect of long-chain branches of polypropylene on rheological properties and foam-extrusion performances. J Appl Polym Sci 96 1793-1800... 

A suitable system to consider initially is polypropylene, which has a hydrogen atom on the tertiary carbon atom that is available for abstraction to form a polymer-backbone radical. This is also of practical significance since controlled scission of polypropylene has been used to produce polymers with controlled molar-mass distribution and rheological properties (Brown, 1992). 

This standard covers measurement of the rheological properties of polymers with both stable and unstable melt viscosity parameters at various temperatures and shear rates. The test procedure lists typical test temperature conditions for polyethylene 190°C, for polypropylene 230°C, for poly(vinyl chloride) 170-205°C, however, this indicates that the most useful data are generally obtained at temperatures consistent with processing experience. The test method also prescribes using the Rabinowitsch shear rate correction (see above) and indicates that the basic rheology equations (17.10), (17.15) and (17.16) yield true shear rate and true viscosity for Newtonian fluids only for non-Newtonian fluids only the apparent shear rate and viscosity are obtained. 

Mishra, J. K., Hwang, K.-J., and Ha, C.-S., Preparation, mechanical and rheological properties of a thermoplastic polyolefin (TPO)/organoclay nanocomposite with reference to the effect of maleic anhydride modified polypropylene as a compatibifizer. Polymer, 46, 1995-2002 (2005). 

Sepehr, M., Ausias, G., and Carreau, P. J., Rheological properties of short fiber filled polypropylene in transient shear flow, J. Non-Newtonian Fluid Mech., 123,19-32 (2004). 

A systematic study of the basic rheological properties for a wide variety of polypropylene melts has been made by Minoshima et al. [89]. These authors measured shear viscosities at low shear rates in a Rheomatrics mechanical spectrophotometer and at high rates in an Instron capillary rheometer. The principal normal stress difference, Ni, was measured in the mechanical spectrophotometer with a cone and plate device. The elongational viscosity, of special importance to fiber formation, was measured in an apparatus built by Ide and White [90],... 

Complex viscosity (t) ) of polypropylene (PP)/polyethylene (PE)-2 and PBT/PE-2. For PP/PE-2 (a), the effect of fibril concentration is compared. For PBT/PE-2 (b), the effect of morphology is compared. The dependence of concentration is also compared. (Reproduced from Hong, J. S., J. L. Kim, K. H. Ahn, and S. J. Lee. 2005b. Morphology development of PBT/PE blends during extrusion and its reflection on the rheological properties. Journal of Applied Polymer Science 97 1702-1709, with permission.)... 

Kurzbeck, S., F. Oster, H. Munstedt, T. Q. Nguyen, and R. Gensler. 1999. Rheological properties of two polypropylenes with different molecular structure. Journal of Rheology 43 359-374. 

Azizi, H., Ghasemi, I., Karrabi, M. (2008). Controled-p>eroxide degradation of polypropylene rheological properties and prediction of MWD from rheological data. PolyntTest, 27, 548-554... 

Maiti, S. N., Singth, G., Ibrahim, M. N. (2003). Rheological properties of calcium silicate-filled isotactic polypropylene. /, Apply. Polym. Sci, 8, 1511-1118... 

Maria Omastova and Ivan Chodak prepared conductive polypropylene/ polypyrrole composites using the method of chemically initiated oxidative modification of polypropylene particles in suspension by pyrrole. In order to prepare the composite, polypropylene particles were dispersed in water-methanol mixture and FeCb was added to be used for chemical oxidation. Addition of pyrrole started formation of polypyrrole particles in polypropylene suspension. The electrical and rheological properties of the composite were compared with polypropylene/polypyrrole composite prepared by melt mixing of pure polypropylene with chemically synthesized polypyrrole and with polypropylene/carbon black composites also prepared by melt mixing. Elemental analysis verified presence of polypyrrole in polypropylene matrix. The conductivity studies show that even a very small PPy amount present in composites results in a significant increase in... 

Rheological Properties of Surface Treated Glass Fiber Reinforced Polypropylenes in Molten State... 

Rheological properties of surface treated short glass fiber reinforced polypropylenes... 

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