Polyolefin production

Sittig, M., Polyolefin Production Processes, Chemical Technology Review No. 79, New Jersey, Noyes Data Corp., 1976, p. 9. 

Since their discovery over a decade ago, late transition metal a-diimine polymerization catalysts have offered new opportunities in the development of novel materials. The Ni(II) catalysts are highly active and attractive for industrial polyolefin production, while the Pd(II) catalysts exhibit unparalleled functional group tolerance and a propensity to form unusually branched polymers from simple monomers. Much of the success of these catalysts derives from the properties of the a-diimine ligands, whose steric bulk is necessary to accelerate the insertion process and inhibit chain transfer. 

Polyolefin industry, catalysts in, 26 503 Polyolefin (PO) resins, 17 699-700 technologies and uses for, 17 707-708 Polyolefin products, Ziegler-Natta catalysts for, 26 533-544 Polyolefins, 10 518... 

Chevron Phillips Chemical Company LP, Spectroscopic method and apparatus for monitoring polyolefin production. Inventor D.R. Battiste. 1 Jan 2008. 47 pp. (inch 31 Hg.). Appl. 24 Sep 2004. Int. Cl. COIN 21/65 GOIJ 3/44. US Patent Specification 7,315,369 B2... 

Knowledge of the coordination polymerisation of olefins would not be complete without consideration of the types of process used in industry for polyolefin manufacture. Problems encountered in production influence developments in the area of catalysis in olefin polymerisation, an improvement in a catalyst being defined as leading to a reduction in the cost of making the polymer or giving better product properties. Therefore, the principal types of polyolefin production involving coordination catalysts of various types are dealt with briefly. Since modern polyolefin production processes offer a versatile range of polymers, the main commercially available olefin polymerisation products and their typical uses are also considered. 

PP/PA (polypropylene/polyallomer). These plastics are similar to polyethylene, but each unit of their chains has a methyl group attached. They are translucent, autoclavable, and have no known solvents at room temperature. They are slightly more susceptible than polyethylene to strong oxidizing agents. They offer the best stress-cracking resistance of the polyolefins. Products made of polypropylene are brittle at ambient temperature and may crack or break if dropped from benchtop height. 

A major application of these types of molded products would be for interior uses in automobiles, such as head liners, door panels, and dashboards. Although this is a low-cost, low-performance application, it represents a very laige-volume market. Indeed, wood is already utilized in applications of this type, but as a finely ground flour that serves as a filler (up to 40%) in extrusion-molded polyolefin products. The use of recycled fiber in this process and the one described above offers the potential of even greater cost reductions, combined with alleviation of solid waste disposable problems. 

Polyolefin Production Plastic Resin Polypropylene Production Polyethylene Production... 

Metallocene catalysts which are to be used as drop-in catalysts in existing plants for polyolefin production have to be heterogenized due to the fact that current... 

Titanium-based solid-state catalysts for the industrial production of polyolefin materials were discovered in the early 1950 s and have been continually improved since then (see Section 7.3). Due to the high degree to which they have been perfected for the production of large-volume polyolefin commodities, they continue to dominate the processes presently used for polyolefin production. Despite (or because of) this product-oriented perfection, only limited degrees of variability with regard to some relevant polymer properties appear to be inherent in these solid-state catalysts. 

Copolymers of ethylene with a-olefins, such as the short-chain branched LLDPE (linear low-density polyethylene) impact materials or the EPD (ethylene-propylene-diene copolymer) rubbers represent major percentages of the total polyolefin production, due to their desirable mechanical properties. Solid-state MgCl2-supported Ziegler-Natta catalysts however, have unfavourable reactivity... 

Section 7.2 Reviews on industrial polyolefin production K. S. Whiteley, G. T. Heggs, H. Koch, R. L. Mawer, W. Immel, Polyolefins, in Ullmann s Encyclopedia of Industrial Chemistry, sixth edition, VCH Weinheim, 2003, vol. 28, p. 393 G. Cecchin, G. Morini, F. Piemontesi, Ziegler-Natta Catalysts, in Kirk-Othmer Encyclopedia of Chemical Technology, John Wiley Sons, Inc, 2003 L. L. Bohm, Angew. Chem. Int. Ed. Engl. 2003, 42, 5010. 

Sittig, M. Polyolefin production Processes, Park Ridge, Noyes 1976... 

Figure 3. Typical process flow sheet for linear polyolefin production...

The commercial applications of the organometallic species are typically in the area of catalysis (see Chapters 33 and 34) and preparation of precursors for chemical vapor deposition [201]. An example of the synthetic usefulness of Grignard reagents is demonstrated in the preparation of the new breed of metallocene catalyst that are used for polyolefin production (Scheme 7) [106,202,203]. 

By homogeneous catalysis a wide spectrum of polyolefin products for a broad variety of applications can be produced [1-10]. Figure 2 shows the product portfolio in a map of copolymer composition vs. average molecular mass. 

The major processes for polyolefins production using Ziegler-Natta catalysts involve polymerization in the gas phase or in slurry, including bulk liquid monomer in the case of propylene. LLDPE is also produced via a solution process operating at temperatures in the range 130-250 °C. 

Rivaling polyolefin production, radical polymerization is most widely employed in industrial- and... 

The development of commercially useful polymers in the early 20th century ushered in an era where mass-produced, organo-polymeric materials have become a ubiquitous part of daily life. " Sixty years after the Nobel prize-winning discovery by Ziegler and Natta, " the scale of worldwide polyolefin production is massive. The current estimated aimual global production of polyolefins is over 150 million metric tons. However, the inherent chemical inertness of these substances causes them to persist in the environment centuries after they have been discarded. The detrimental environmental impact of a man-made waste problem of this scale has generated an interest in commercially viable, biodegradable alternatives. ... 

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