Polypropylene rheology

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... 

Dialkyl peroxides Polyethylene cross-Unking Initiator for polystyrene polymerization Polypropylene rheology modification... 

Cook, R.F., Koester, K.J., Macosko, C.W., and Ajbani, M. Rheological and Mechanical Behavior of Blends of Styrene-Butadiene Rubber with Polypropylene, Polym. Eng. Set 45(11), 1487-1497, 2005. 

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. 

Shaban, H.I. and George, R.S., Rheological and extrudate behavior of polypropylene/latex reclaim blends, J. Blast. Blast., 29, 83, 1997. 

Lederer, K., Beytollahi-Amtmann, I., and Billiani, J., Determination and correction of peak broadening in size exclusion chromatography of controlled rheology polypropylene,. Appl. Polym. Sci., 54, 47, 1994. 

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... 

Demonstrations are given of the importance of extensional or elongational viscosity in the foam process. New polypropylenes are compared in extensional flow and it is shown how rheological differences allow the prodnction of low density foam on tandem extrnsion equipment. 6 refs. 

Various investigations have considered the effects of titanate treatments on melt rheology of filled thermoplastics [17,41]. Figure 10, for example, shows that with polypropylene filled with 50% by weight of calcium carbonate, the inclusion of isopropyl triisostearoyl titanate dispersion aid decreases melt viscosity but increases first normal stress difference. This suggests that the shear flow of the polymer is promoted by the presence of titanate treatment, and is consistent with the view that these additives provide ineffective coupling between filler particles and polymer matrix [42]. 

The viscoelastic properties of polypropylene melts containing magnesium hydroxide fire retardant fillers have been studied using parallel plate dynamic rheology [36]. In this work the filler variants differed in particle size, surface area and morphology, ranging from approximately spherical particles formed... 

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... 

C. Tzoganakis, J. Vlachopoulos, and A. E. Hamielec, Production of Controlled-rheology Polypropylene Resins by Peroxide Promoted Degradation during Extrusion, Polym. Eng. Sci., 28, 170-180 (1988). 

Fig. 14.3 Melt strand area and radius profiles in the melt drawdown region nylon 6 at 265°C and take-up velocity of 300m/min A, polypropylene (PP) at 262°C and take-up velocity of 350m/min. [Reprinted with permission from H. E Mark, in Rheology, Vol. 4, F. R. Eirich, Ed., Academic Press. New York, 1969.]...

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