Polypropylene system

Al-Malaika, S. and Amir, E.J., Thermoplastic elastomers Part III—Ageing and mechanical properties of natural rubber-reclaimed rubber/polypropylene systems and their role as solid phase dispersants in polypropylene/polyethylene blends, Polym. Degrad. Stab., 26, 31, 1989. 

M. LeBras., Mineral fillers in intumescent fire retardant formulations - Criteria for the choice of a natural clay filler for the ammonium polyphosphate/pentaeythritol/polypropylene system, Fire and Materials, vol. 20, pp. 39-49,1996. 

No.7, July 2003, p.84-5 MULTI-LAYER POLYPROPYLENE SYSTEM IMPROVES THERMAL PERFORMANCE AND DURABILITY... 

A detailed atomistic approach was used to investigate the molecular segment kinematics of a glassy, atactic polypropylene system dilated by 30%. ° The microstructural stress—dilation response consists of smooth, reversible portions bounded by sudden, irreversible stress jumps. But compared to the micro-structural stress—strain curve of the shear simulation, the overall trend more closely resembles macroscopic stress—strain curves. The peak negative pressure was in the neighborhood of 12% dilatation, with a corresponding secondary maximum in the von Mises shear stress. The peak negative pressure was re-... 

For a hydrophobic porous material with contact angle greater than 90°, the APc is >0 and depends on the liquid surface tension and the membrane pore size. As an example, considering water-air-polypropylene system, one can calculate that for a dry membrane with a pore size of 0.03 pim (30 nm) the critical entry pressure of water is more than 300 psi (>20 bar). 

An important documented effect specific to polypropylene systems should be mentioned here. Both groups working on the PP-PA-6 reinforcement [96,97] re-... 

Fusabond [DuPont]. TM for resin used for coupling in mineral-filled polypropylene systems. Works best with long glass fiber systems. The resins act to bond the filler into the polymer matrix. Also improves surface wetting and dispersion of the filler. It enhances tensile and impact strength of the composite. 

This paper studies multi-angle spectrophotometry as applied to integrally colored filled polyolefins for automotive applications. The paper begins by examining instrument capabilities and limitations using textured automotive parts. It also explores use of multi-angle spectrophotometiy to improve the quahty of automotive color matching in filled polypropylene systems. 

In polypropylene system, wide-angle XRD studies were carried out to analyze the effect of clay and compatibilizers on the thermodynamic stability of the monoclinic a-crystal of the PP. In general it was foimd that the monoclinic a-phase of PP is highly stable and not affected by the presence of compatibilizer or clays [ 15,21,28]. 

Many factors such as adhesion between components, fiber topography, and kinetic parameters of crystallization of semicrystalline matrix have been reported to influence transciystallinity. The transcrystallinity phenomenon in the natural fibers/polypropylene system is affected by the different type of chemical treatment of lignocellulosic materials. Moreover, the ability of natural filler to induce nucleation in polypropylene matrix is also dependent on the kind of chemical modification of surface fibers. Predominant nucleation ability was found for unmodified fibers. However, chemical modification of fiber surface slightly depressed the nucleation of polypropylene matrixes. 

To design a flame-retardant polypropylene system, the following key factors need to be determined ... 

Table 4.1 Flammability Assessment of Flame-Retarded Polypropylene Systems... 

Table 14.35 Effects of Best Additives on Flexural Modulus, HDT, and Impact Properties in Three Polypropylene Systems...

Having some experience with polypropylene systems and being aware of the current literature, it was easy to settle the titles for the book chapters and also to select and approach the most suitable potential contributors. Fortunately, many of my first-choice authors accepted the invitation to contribute. 

A molten polypropylene system (saturated with nitrogen at 220°C and 1 atm pres-... 

Figure 8.3 Variation of relative storage and loss moduli with volume fraction of filler in glass bead filled polypropylene system at frequency to = 1 rad/sec and strain y = 10%. (Reprinted from Ref. 8 with kind permission from Society of Plastics Engineers Inc., Connecticut, USA.)...

Le Bras, M. Bourbigot, S. Mineral tillers in intumescent Are retardant formulations criteria for the choice of a natural clay tiller for the ammonium polyphosphate/ pentaerythritol/polypropylene system. Fire Mater. 1996, 20, 39-49. 

Chemical coupling agents for glass and mica filled polypropylene systems. 

Borden KA, Weil RC, Manganaro CR. Optimizing properties of talc-filled polypropylene systems with a polymeric coupling agent. AN-TEC 1994 52(3) 2761. 

Karger-Kocsis J, Kall6 A, Szafner A, Bodor G and Sfenyei Zs (1979) Morphological study on the effects of elastomeric impact modifiers in polypropylene systems. Polymer 20 37-43. 

Y. Li, B. Li, J. Dai, H. Jia, and S. Gao, Synergistic effects of lanthanum oxide on a novel intumescent flame retardant polypropylene system. Polymer Degradation and Stability, 93(1) 9-16, January 2008. 

LEI Lei, Z., Ohyabu, H., Sato, Y., Inomata, H., and Smith Jr., R.L., Solubility, swelling degree and crystallinity of carbon dioxide-polypropylene system, J. Supercrit. Fluids, 40, 452, 2007. 

Figure 3 LTMA analyses of rigid and soft interphases (IP) at filler and elastomer inclusions respectively in a multicomponent polypropylene system...

T.Kitukani,J.Radhakrishnan,S.Arikawa,A.Takaku,N.Okui,X.Jin,F.Niwaand Y. Kudo (1996), High-speed melt spinning of bicomponent fibers Mechanism of fiber structure development in poly(ethylene terephthalate)/polypropylene system,/. Appl. Polym. Sci.,62,1913-1924. 

L. R. Aalund 1992. Polypropylene system scores high as pipeline anti-corrosion coating. Oil and Gas... 

To understand the subtle nature of tacticity, it is best at this point to examine the polypropylene system, the formation of which is shown below. 

The output of the extruder as a function of the screw speed is depicted in Fig 6. An average throughput over a period of 5 min is shown in Fig. 6. For a given screw speed, the barrier screw 5tielded approximately 18% more output relatively to the metering screw. In addition, the barrier screw was more efficient from power consumption point of view as shown in Fig 7. These results along with the extrusion stability data discussed previously certainly render a barrier screw the preferred screw design of polypropylene systems similar to that studied in this work. 

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