Polypropylene polyolefin polymer

Ziegler-Natta catalyst (ZNC) A catalyst involved in creating highly structured (stereoregular) polyolefin polymer chains. Used to mass-produce polyethylene and polypropylene. 

N.S. Allen, A. Parkinson, F.F. Loffelman, and P.V. Susi, Photo-Stabilising action of ap-hydroxybenzoate compound in polyolefins. Part I. Thermal and photochemical behaviour in polypropylene film, Polym. Degrad. Stab. 1983, 5, 241-266. 

Although from our perspective, more than 60 years later, we see polyethylene and polypropylene as quite different polymers and industries, and the commercial value of each of these polyolefin polymers is appreciated, yet from the 1950s perspective of the new metal oxide and organo-metallic catalyst syntheses, they were just outcomes of a-olefin polymerization. That is why the early days of polyethylene and polypropylene and these metal oxide and organo-metallic catalysts are such entwined and convoluted histories. 

Polyolefin Blends as Models for High-Impact Polypropylene Co-polymers (HIPCs)... 

The focus in this chapter will be on the two main polyolefin polymers, namely polyethylene (PE) and polypropylene (PP). The latter especially has established itself as a very versatile fiber with unique applications in the textile and nonwoven industry. Polyethylene, on the other hand, has not been widely used as a fiber compared to other synthetic polymers such as PET, PP, and nylon, due in part to its low melting point. This chapter will, however, discuss ultra-high molecular weight polyethylene (UHMWPE) fiber that given its success and uniqueness in the synthetic fiber industry. 

Bokobza, L. Burr, A. Garnaud, G. Perrin, M. Pagnotta, S. (2004) Fibre Reinforcement of Elastomers Nanocomposites Based on Sepiolite and Poly(hydroxyethyl acrylate). Polym. Int. Vol.53, N0.8, pp.1060-1065, ISSN 0959-810 Bonduel, D. Mainil, M. Alexandre, M. Monteverde, F. Dubois, P. (2005) Supvported Coordination Polymerisation A Unique Way to Potent Polyolefin Carbon Nanotube Nanocomposites. Chem. Commun. Vol.l4, No.6, pp.781-783 Bruckner, S. Meille, S. Petraccone, V. Pirozzi, B. (1991) Polymorphism in Isotactic Polypropylene. Prog. Polym. Sci. 16, No.2-3, pp.361-404 Bryning, M. Islam, M Kikkawa, J. Yodh, A. (2005) Very Low Conductivity Threshold in Bulk Isotropic Single-Walled Carbon Nanotube-Epoxy Composites. Ado. Mater. Vol.17, N0.9, pp.1186-1191... 

Lee, S. H., Kontopoulou, M., and Park, C. B. 2010. Effect of nanosilica on the co-continuous morphology of polypropylene/polyolefin elastomer blends. Polymer 51 1147-1155. 

TPO materials are defined as compounds (mixtures) of various polyolefin polymers, semicrystalline thermoplastics, and amorphous elastomers. Most TPOs are composed of polypropylene and a copolymer of ethylene and propylene called ethylene—propylene rubber (EPR) [2]. A common rubber of this type is called ethylene propylene diene monomer rubber (EPDM), which has a small amount of a third monomer, a diene (two carbon-carbon double bonds in it). The diene monomer leaves a small amount of unsaturation in the polymer chain that can be used for sulfur cross-linking. Like most TPEs, TPO products are composed of hard and soft segments. TPO compounds include fillers, reinforcements, lubricants, heat stabilizers, antioxidants, UV stabilizers, colorants, and processing aids. They are characterized by high impact strength, low density, and good chemical resistance they are used when durability and reliability are primary concerns. 

With ever-increasing oil prices, recycled plastics are becoming an economical alternative for the production of a wide range of commodity plastic parts. Polyolefinic polymers, such as polyethylene (PE) and polypropylene (PP), contain approximately 14% hydrogen these materials could provide the hydrogen required for thermal coprocessing with biomass, which could lead to an increase of the liquid production of oligomers or short chain polymeric materials. 

Polypropylene Polyolefins Polybutadiene a-Olefin polymers Polyethylene... 

Niki E, Decker C, Mayo FR. Aging and degradation of polyolefins. Part I peroxide-initiated oxidations of atactic polypropylene. J Polym Sci Polym Chem Ed 1973 11 2813 5. 

AUen NS, Parkinson A, Loffelman IT, Susi PV. Photo-stabilising action of A /i-hydroxybenzo-ate compound in polyolefins. Part I thermal and photochemical behaviour in polypropylene film. Polym Degrad Stab 1983 5 241-b6. 

Similar reactions occur in the ozonization of polyolefins. Polymer alkyl radicals formed during ozonization of polypropylene react immediately with molecular oxygen to form polymer peroxy radicals (PO2) and can be detected by ESR spectroscopy [1777]. The reaction rates and concentrations of intermediate polymer peroxy radicals are proportional to the surface area and to the square root of the ozone concentration. 

Olefin fibers, also called polyolefin fibers, are defined as manufactured fibers in which the fiber-forming substance is a synthetic polymer of at least 85 wt % ethylene, propjiene, or other olefin units (1). Several olefin polymers are capable of forming fibers, but only polypropylene [9003-07-0] (PP) and, to a much lesser extent, polyethylene [9002-88-4] (PE) are of practical importance. Olefin polymers are hydrophobic and resistant to most solvents. These properties impart resistance to staining, but cause the polymers to be essentially undyeable in an unmodified form. 

Polyolefins are manufactured and used in much greater quantity than any other class of plastics. The principal polyolefins are polyethylenes of various densities (LDPE, LLDPE, HDPE) and polypropylene (PP) (see Olefin polymers). 

Some of the most difficult heterophase systems to characterize are those based on hydrocarbon polymers such as mbber-toughened polypropylene or other blends of mbbers and polyolefins. Eecause of its selectivity, RuO staining has been found to be usehil in these cases (221,222,230). Also, OsO staining of the amorphous blend components has been reported after sorption of double-bond-containing molecules such as 1,7-octadiene (231) or styrene (232). In these cases, the solvent is preferentially sorbed into the amorphous phase, and the reaction with OsO renders contrast between the phases. 

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