| Descripción | Metallocene catalysts are revolutionising the polyolefin industry. They permit precision tailoring of polymers to give specific structures, which in turn give rise to new properties. Metallocene-catalysis of ethene and propene polymerisation has been investigated in particular depth. New metallocene polypropylenes and polyethylenes have been in use commercially for several years, particularly in film applications in blends. Market analysts are predicting huge growth in the markets for these new polymers over the next few years. In addition, there is speculation that metallocene-polyolefins could replace PVC in some medical applications.
In metallocene catalysis, polymerisation takes place at a defined transition metal centre, which provides a means to control monomer insertion and other reaction steps precisely. The variety of metallocenes available is increasing, the range includes titanocenes, hafnocenes, and zirconocenes with different symmetries, which give tailored polymers of totally different structures.
In this review the activation and deactivation of the metallocene catalysts are discussed, and the stability of metallocenes. In industrial processes metallocenes are generally used on supports such as silica, alumina or magnesium chloride. Each procedure for generating a supported metallocene affects the catalyst and thus the polymerisation process, affording new variations. The methods and effects of supporting metallocenes are discussed.
Professor Kaminsky is a world-renowned expert in the field of metallocenes and has been responsible for much of the pioneering work in this area. This review provides an excellent technical introduction to the subject of metallocene-catalysis of polymerisation, beginning with the background history and proceeding through the use of metallocenes in the polymerisation of ethene, propene, styrene, cyclic olefins, diene and methylmethacrylate monomers. The report reviews the suitability of different metallocenes, particularly for the production of polyethylene and polypropylene, and lists some of the structural variations and properties of these polymers synthesised using the different catalysts.
Metallocenes provide a tool for producing ‘designer polymers’, giving the polymer technologist the ability to vary structure and properties to match different applications. This review will be of particular interest to polymer technologists, the polyolefin industry, producers of film and foam, and to the chemical industry, where the applications of metallocenes are expected to advance in the near future.
A Rapra Review Report comprises a concise, expert overview of the state of the art, supported by an extensive bibliography. This review is accompanied by over 400 abstracts from the Rapra Abstracts database on the topic of metallocenes in polymerisation. This bibliography provides useful additional reading in this rapidly advancing field. |
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