Oligomer distribution in the polymerization of 2‐norbornene via metathesis

Reif, Lothar; Höcker, Hartwig

doi:10.1002/marc.1981.030020213

Cited by 20 publications

(8 citation statements)

References 8 publications

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“…In this degradation the C-C double bonds between c units reacted more readily, because oligomers with the unit a alone could scarcely be detected. These oligomers were found in a homopolymerization of I only after longer reaction times, which is in accordance with recent observations made by other authors [22].…”

Section: A) Polymerization Reactionssupporting

confidence: 93%

Some aspects of the synthesis and characterization of special polymers and oligomers by olefin metathesis

Stelzer

Graiman

Hummel

1982

Colloid & Polymer Sci

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Homopolymers of 2-norbornene and 2,3-bis(trifluoromethyl)-2,5-norbornadiene and copolymers of these bicyclic olefins with 1,5-cyclooctadiene and cyclopentene were prepared via ring opening metathesis polymerization. The molecular weight distributions of the polymers were estimated by gel permeation chromatography. The polymers were degraded in a cross metathesis reaction with E-4-octene; only poly[2,3-bis(trifluoromethyl),2,5-norbornadiene] was not degradable. All reactions were carried out with WC16/(CH3)4Sn as the catalyst system. The low molecular cyclic oligomers in the polymerization mixtures and the degradation products were analyzed by gas chromatography and identified using a gas chromatography/mass spectrometry coupling. The degradation experiments show reactivity differences for the double bonds situated in the polymer backbone. On the basis of these differences and the fact that this is the first time that a metathesis degradation of such polymers has been reported, the consequences on the ring opening metathesis copotymerization of cycloolefins are discussed in general terms, leading to some new aspects in the planning of the synthesis of special copolymers and oligomers.

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Section: A) Polymerization Reactionssupporting

confidence: 93%

Some aspects of the synthesis and characterization of special polymers and oligomers by olefin metathesis

Stelzer

Graiman

Hummel

1982

Colloid & Polymer Sci

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“…Höcker [220] and Thorn-Csànyi [221][222][223][224] investigated the complex equilibria involving cycoolefin monomer, macrocyclic ROMP oligomers, and linear polymers. The formation of linear polymers in ROMP requires a critical oligomer concentration which is influenced by the ring strain energy of the monomer and also the catalyst system and also the reaction engineering.…”

Section: Metathesis Polymerizationmentioning

confidence: 99%

“…In 1970 the role of metal carbene complexes and meallacyclobutane intermediates was recognized by Hérisson and Chauvin217 and confirmed later by the experiments of the groups around Ivin,218 Thorn‐Csànyi,219 and many others. Höcker220 and Thorn‐Csànyi221–224 investigated the complex equilibria involving cycoolefin monomer, macrocyclic ROMP oligomers, and linear polymers. The formation of linear polymers in ROMP requires a critical oligomer concentration which is influenced by the ring strain energy of the monomer and also the catalyst system and also the reaction engineering.…”

Section: Metathesis Polymerizationmentioning

confidence: 99%

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

Mülhaupt

2003

Macro Chemistry & Physics

275

193

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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.

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“…However, equilibrium is not achieved instantaneously in any case. In particular, for the ring-opening polymerization of norbornene, high polymers are obtained in the first place and a degradation of the polymer in the presence of active catalyst only occurs upon prolonged reaction times [8].…”

Section: Ring-chain Equilibriummentioning

confidence: 99%

Thermodynamic Recycling—On Ring-Opening Polymerization and Ring-Closing Depolymerization

Höcker

1993

Journal of Macromolecular Science, Part A

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The ring-opening polymerization of various cyclic monomers has been extensively investigated in the past, e.g., the cationic polymerization of tetrahydrofuran, the anionic polymerization of ecaprolactone, the metathesis polymerization of cycloalkenes, and the anionic or cationic polymerization of cyclohexamethyltrisiloxane and cyclooctamethyltetrasiloxane. In conjunction with ring-opening polymerization, monomer-polymer equilibrium (ceiling temperature) and/or the formation of a ring-chain equilibrium have also been studied. In the last few years we have studied extensively the anionic ring-opening polymerization and copolymerization of cyclic carbonates, the monomers mostly being provided by depolymerization of the polymers which were obtained by polycondensation polymerization. This fact has led to the development of a new polymer recycling concept by depolymerization and repolymerization, which we call thermodynamic recycling.

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Oligomer distribution in the polymerization of 2‐norbornene via metathesis

Cited by 20 publications

References 8 publications

Some aspects of the synthesis and characterization of special polymers and oligomers by olefin metathesis

Some aspects of the synthesis and characterization of special polymers and oligomers by olefin metathesis

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

Thermodynamic Recycling—On Ring-Opening Polymerization and Ring-Closing Depolymerization

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