Catalytic Polymerization and Post Polymerization Catalysis Fifty Years After the Discovery of Ziegler's Catalysts

Abstract

During the 1950's the discoveries of Ziegler's organometallic catalyst systems and Natta's stereoselective olefin polymerization set the stage for extraordinary progress in polymer science and technology. Today advanced catalyst systems are available for catalytic carbon carbon bond formation by means of polyinsertion, metathesis, coupling reactions, and controlled radical polymerization. Modern catalytic olefin polymerization processes and polyolefins are environmentally friendly and meet the demands of a sustainable development. The architectures of homo‐ and copolymers based upon olefin, cycloolefin, diene, styrene and arene feed stocks are tailored as a function of single site catalysts' ligand frameworks. Polymer properties are varied over a very wide range, e.g., liquid/solid, rigid/soft, crystalline/amorphous/rubbery, permeable/impermeable, opaque/transparent, moldable/thermosetting, insulating/conducting. Advanced polymerization reaction engineering, copolymerization processes, reactor granule and reactor blend technologies, tailor‐made single site catalysts, catalyst blends and tandem catalysis improve property profiles, stability, morphology, and melt processing. Tuned cycloolefin polymers are new functional materials for electronic applications. Catalytic chain transfer (CCT) and atom transfer polymerization (ATRP) produce a variety of new functional polymers, reactive oligomers, and block copolymers. Aqueous polyolefin emulsions are obtained when catalytic olefin polymerization is performed in nanodroplets of catalyst miniemulsions. The scope of catalytic polymerization and post polymerization catalysis is progressing well beyond the frontiers of commodity polyolefin manufacturing. Advanced catalytic processes produce polar polymers such as polyethers, polyketones, polyesters, polycarbonates, polyamides, polyaramids, and polyimides. The new phosgene free polycarbonate syntheses are based upon the palladium catalyzed oxidative carbonylation. This overview highlights history, recent progress and modern trends in catalytic polymerization and catalytic polymer modification illustrated by selected examples.

Uma revisão sobre polimerização de olefinas usando catalisadores Ziegler-Natta heterogêneos

“…Estes fragmentos são espalhados uniformemente, de forma que em torno deles é que as partículas poliméricas crescem, à medida que a reação prossegue [1,19,24] . Melhoramentos tecnológicos relacionados ao controle morfológico do polímero a partir das características morfológicas do catalisador proporcionaram um verdadeiro avanço na produção de resinas à base de polipropileno [4,11,25] . Este desenvolvimento tecnológico tornou possível o uso de misturas catalíticas que combinam catalisadores Ziegler-Natta heterogêneos com catalisadores homogêneos.…”

“…A aplicação destes sistemas catalíticos aos processos de polimerização propiciou o controle de características estéricas e estruturais das cadeias poliméricas, levando à obtenção de resinas poliolefínicas com propriedades completamente diferentes dos materiais anteriormente produzidos por outras rotas [1][2][3][4] . O termo Catalisadores Ziegler-Natta é usado para descrever uma grande variedade de catalisadores baseados em metais de transição, capazes de polimerizar e copolimerizar α-olefinas e dienos [5] .…”

Structural Characterization of the EtOH–TiCl4–MgCl2 Ziegler–Natta Precatalyst

“…6 Catalysts based on the Ziegler-Natta (ZN) concept are still massively used in the industrial production of plastics, and this puts the ZN catalysts among the most advanced industrial applications of catalysis. 7,8 Since the discoveries of Ziegler and Natta, numerous studies were devoted to the improvement of the activity (for ethylene and propylene homo-and co-polymerizations) and the selectivity (in particular the stereoselective polymerization of propylene) of the catalysts, leading to the modern ZN-catalysts.…”

Lattice sizes, crystallinities, and spacing between amorphous chains - characterization of ethene-/ɑ-olefin copolymers with various comonomers and comonomer contents measured by wide angle X-ray scattering

“…The breakthrough of single-site catalysts [1,2] in the late 1990s made it possible to synthesize materials with totally new properties. The high affinity of single-site catalysts towards higher olefins is used for producing ethene-/-olefin copolymers with a very high comonomer incorporation [3] and very long comonomers [4,5].…”