Polypropylene copolymers

In the early stages of development of polypropylene rubbers, particularly butyl rubber, were used to reduce the brittleness of polypropylene. Their use declined for some years with the development of the polypropylene copolymers but interest was greatly renewed in the 1970s. This interest has been centred largely around the ethylene-propylene rubbers which are reasonably compatible in all proportions with polypropylene. At first the main interest was with blends in which the rubber content exceeded 50% of the blend and such materials have been designated as thermoplastic polyolefin elastomers (discussed in Section 11.9.1). There is also increasing interest in compounds with less than 50% rubber, often referred to as elastomer-modified thermoplastics. It is of interest to note... 

TPO applications are in automotive bumpers and dashboards because of their higher toughness than conventional polypropylene copolymers. 

Figure 18.5 Formation of an isotactic-atactic polypropylene copolymer from a bis(phenylindenyl)zirconium complex.

Fig. 9.27 Fully contained ATR/FTIR instrument rated for operation at the depth of 500 m in the ocean. The ATR sensing element is AgCl fiber coated with polyethylene/polypropylene copolymer (reprinted from Kraft et al., 2003)...

Figure 9. Distribution of nitroxyl radicals concentration by thickness of sample underwent thermo-oxidative destruction at 120°C a - poly(acrylonitril-butadiene-styrene (ABS) copolymer), thickness of sample is 3,8mm b - polypropylene copolymer with polyethylene, thickness of sample is 3,4mm. The inset is the example of EPR-spectrum of nitroxyl radical in ABS-copolymer.

Fig. 1. Tensile creep and recovery of rubber-modified plastics, showing axial strain (x), lateral contraction ( ), and volume strain (o) for ASA polymer and polypropylene copolymer at 20 °C...

Lu, B. Chung, T.C. New maleic anhydride modified polypropylene copolymers with block structure synthesis and application in PP/nylon blends. Macromolecules 1999, 32, 2525. 

Fujiyama, M. Wakino, T. Molecular orientation in injection-molded polypropylene copolymers with ethylene. Inter. Polym. Proc. 1992, VII (2), 159. 

Fig. 10 Strain at break Vs. UV exposure time for polypropylene copolymer bars made from (a) virgin polymer (V) (b) virgin polymer + undegraded recyclate (U) (c) virgin polymer + photodegraded recyclate (P). Results for blends with recyclate contents of 10% and 25% are shown. (More details in Craig, I.H. White, J.R. Mechanical properties of photo-degraded recycled photo-degraded polyolefins. J. Mater. Sci. 2006, in press.)...

We carried out experiments to define the optimal conditions in a reactive extrusion process, and to obtain maleic anhydride grafted polymers of polypropylene copolymers (3050 MN 4 supplied by ATOCHEM). The previous studies were carried out in a batch mixer (HAAKE RHEOCORD), at a temperature of 220° C and a mixing speed of 64 rpm, during 20 minutes. Three different systems were tested i. with pure maleic anhydride ii. in the presence of a solvent (toluene or chorobenzene) iii. by introduction... 

PIB), PE and polyethylene-block-polypropylene copolymer (PE-PP) (referred as B20 in the literature). At temperatures <145°C, primary scattering peak and second-order peak are observed at q = 0.07 nm-1 and q2 = 0.14 nm 1, indicative of an ordered lamellar phase with a repeat distance of 90 nm. The experimental intensity near the second peak was fit by Eq. (7.1). 

Polypropylene—copolymer (3-5). Good resistance to WVP but poorer gas barrier. Not easy to control when thermoforming due to higher temperature involved, but improving with specialist grades. 

A comparison between different LMW-HALS in a dark gray colored high impact polypropylene copolymer is shown in Table 17.9. In this case the HALSs with the lowest molecular weight performed best. 

U.S. Pat. No. 6,743,507 [40] discloses cellulose-fiber-reinforced composites comprising a matrix polymers such as polyethylene, polypropylene, copolymers, terpoly-mers and mixture thereof in an amount ranging from about 25 to 99% by weight, and cellulose pulp having an a-cellulose purity of greater than about 80, 90, or 98% by weight. 

The question regarding the mechanism(s) of the action of maleated coupling agents was approached via studying the crystallization kinetics in wood-fiber-filled polypropylene in the presence and the absence of a maleated polypropylene copolymer... 

This chapter presents a discussion of the multiphase polypropylene copolymers with emphasis on the commercially important blends. The discussion will be more narrowly focused on the composition, structure, and phase morphology of these... 

Chapter 12 Multiphase Polypropylene Copolymer Blends 359 Table 12.2 Berstorff Twin-Screw Corotating Extruder Conditions. 

Eor the typical commercial polypropylene copolymer systems the viscosity of the matrix phase is quite high, and the molecular diffusion and solubility of the minor phase component in the matrix phase are relatively high. These factors tend to favor the evaporation/condensation, that is, Ostwald ripening, mechanism and suppress the coalescence mechanism in these systems. Mirabella and coworkers studied a series of multiphase systems, including a hiPP (30), a high density polyethylene (HOPE)/ hydrogenated polybutadiene (HPB) blend, (31) and an unbranched PE molecular... 

Figure 12.8 Scanning electron microscopy photomicrographs of quiescently coarsened and ice water quenched specimens of impact polypropylene copolymer (hiPP). Magnifications are given above each photomicrograph. (From Reference 28 with permission from John Wiley Sons, Inc.)...

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