Ligand effects on the directed polymerization of butadiene by palladium salts in aqueous media

Canale, A. J.; Hewett, William A.

doi:10.1002/pol.1964.110021108

Cited by 19 publications

(2 citation statements)

References 3 publications

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“…Beside radical polymerization, several attempts have been made to use other polymerization mechanisms in aqueous emulsion polymerization, e.g., initiator systems allowing a stereospecific heterophase polymerization and hence a control of the molecular structure (modes of addition of the monomer molecules, branching, and isomerism). First experiments in this direction are reported in the sixties where dienes have been polymerized with rhodium and palladium salts 118–120. Recently, the emulsion polymerization of ethylene with organo‐nickel metal complexes has been reported for the first time 121,122.…”

Section: Benefits Of Heterophase Polymerization Processes (Hpp) and Tmentioning

confidence: 99%

90 Years of Polymer Latexes and Heterophase Polymerization: More vital than ever

Antonietti

Tauer

2003

Macro Chemistry & Physics

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An attempt is made to give an overview on the historical and possible future development of heterophase polymerization techniques in liquid continuous media to prepare polymer dispersions. Polymer latexes play an essential role in our daily life as they are present visibly or hidden in a variety of products such cosmetics, detergents, newspapers, or paints and lacquers. More than 10 million tons of polymers are produced by heterophase polymerization techniques worldwide yearly. The majority of heterophase polymerizations is carried out in water as continuous phase and hence, they are belong to green chemistry with increasing importance due to environmental reasons. The compartmentalization of the reaction volume into domains of colloidal size (between a few nm3 and μm3) is the characteristic feature and relates both to the problems and the potential promises of this class of polymers. Special emphasis is placed with regard to the development of new heterophase polymerization techniques, the adoption of new polymerization mechanism to the particular conditions of heterophase polymerization, the synthesis of block copolymers and nanoparticulate hybride structures, the development of new stabilizers and polymerization aids, and the usage of specialty latexes as model systems to learn more about complex matter.

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Section: Benefits Of Heterophase Polymerization Processes (Hpp) and Tmentioning

confidence: 99%

90 Years of Polymer Latexes and Heterophase Polymerization: More vital than ever

Antonietti

Tauer

2003

Macro Chemistry & Physics

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“…Once again, the experience with iridium is not parallel with that of rhodium. W e have observed only minor erratic rate effects from formic acid co-Palladium Use of palladium salts a s structure regulators in the polymerization of butadiene (3,35) and as catalysts for the polymerization of norbornene and norbornadiene (36), has been described. Catalytic properties for polymerization similar to palladium salts are shown by complexes of palladium and will be discussed briefly.…”

Section: Iridiummentioning

confidence: 99%

Polymerizations catalyzed by noble metal‐olefin complexes

Rinehart

1969

J. polym. sci., C Polym. symp.

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Several noble metal‐olefin complexes were prepared and studied as polymerization catalysts. Catalytic behavior of complexes toward specific monomers is invariably a property of the metal atom. Polymerization rates may depend upon ligands associated with the metal, but ligands do not alter the course of reaction. Olefin complexes of rho‐dium(I) chloride are superior catalysts for the emulsion polymerization of 1,3‐butadiene to crystalline trans‐1,4‐polybutadiene. The rates of polymerization are dependent to some extent upon the olefinic ligands. In all cases rates can be increased by addition of certain hydride donors. Chelating diolefins, such as 1,5‐cyclooctadiene and norbornadiene, can serve as stabilizing ligands in catalytically active complexes. When added as free diolefin to polymerizing recipes containing either salts or complexes of rhodium, however, chelating diolefins are effective inhibitors of polymerization. Olefin complexes of iridium(I) chloride do not polymerize butadiene, but are effective catalysts for the ring‐opening polymerization of norbornene in bulk, solution, or emulsion. Polymermerization rates are very sensitive to the nature of the ligands within the complex; the more unstable complexes give the faster rates. Specific hydride donors do not usually enhance catalytic activity of iridium complexes, and may lead instead to complete deactivation of the complexes. The selective behavior of complexes of various noble metals toward specific monomers is strikingly illustrated by polymerization of norbornadiene. Three different polymer structures are obtained from complexes of the three metals rhodium, iridium, and palladium. From rhodium polymer consists of nortricyclene units, from a 1,5‐addition. Iridium leads to ring‐opened oxygenated polymer, whereas palladium catalyzes formation of 1,2‐addition polymer.

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