Norbornene

About: Norbornene is a research topic. Over the lifetime, 5628 publications have been published within this topic receiving 104495 citations. The topic is also known as: norbornylene & norcamphene.

Influence of the polymer microstructure on the thermal properties of cycloolefin copolymers with high norbornene contents

Abstract: This study involves research on possible relationships between the composition of ethylene/norbornene copolymers and their thermal properties. The copolymers were fully characterised by differential scanning calorimetry (DSC), 13 C NMR spectroscopy, Fourier transformation infra-red (FTIR) and Raman spectroscopy. The results of this study show that there is no linear correlation between the amount of norbornene incorporated in copolymers and thermal behaviour when copolymers containing high norbornene content and different microstructures are considered. The latter of which was found to be extremely sensitive to the catalyst used in its preparation.

Palladium-Catalyzed/Norbornene-Mediated ortho-Amination/N-Tosylhydrazone Insertion Reaction: An Approach to the Synthesis of ortho-Aminated Vinylarenes

Abstract: ortho-Aminated vinylarene derivatives were obtained via a reaction of aryl iodides, N-benzoyloxyamines, and N-tosylhydrazones. This approach involves a palladium-catalyzed, norbornene-mediated ortho-amination/N-tosylhydrazone insertion reaction. In this transformation, one C–N bond and one C–C bond are formed and an amine group is introduced at the ortho position successfully.

Ring-Opening Metathesis Polymerization in Emulsion

Abstract: Ring-opening metathesis polymerization (ROMP) of norbornene (NBE), catalyzed by water-soluble ruthenium alkylidenes 1, RuCl2(PCy2(C5H10NMe2Cl))2(CHPh), or 2, RuCl2(TPPTS)2(CHCO2Et) (TPPTS = tris(3-sulfonatophenyl)phosphine, sodium salt), has been carried out in emulsion. Polynorbornene latexes (PNBE) can be obtained in high yields, in the absence of floc, and with high solids, if Dowfax is used as surfactant. The nucleation mechanism of the polymerization has been found to be a continuous homogeneous nucleation. The resulting polymer particles are formed of aggregates of small primary particles, stabilized by the highly ionized chain ends. Typical particle sizes are ranging from 50 to 100 nm, even at higher solids. Less strained olefins, such as cyclooctene, COE, and 1,5-cyclooctadiene, COD, cannot be efficiently polymerized by catalysts 1 or 2. Nevertheless, these monomers are polymerized by a hydrophobic catalyst, 3, RuCl2(PCy3)2(CHPh). To form colloidal objects, the catalyst is dispersed into water thr...

Polymerization of acetylenes and cyclic olefins induced by metal carbynes

Abstract: : Trans-(bromotetracarbonyl(phenylmethylidyne)tungsten) and related metal-carbynes induce acetylenes and cycloalkenes to polymerize. The acetylenes include examples that are monosubstituted, disubstituted, and unsubstituted, as well as the first reported functionalized acetylenes in which the functional groups (the nitrile, ester, and halogen functions were studied) are not attached to the triple bond. The cycloalkenes yield polyalkenamers whose double bonds are largely cis. This last polymerization is speeded by the presence of oxygen. The stereochemistries of the polyacetylenes and the polynorborneamer produced when the initiator is the metal-carbyne are similar to those of the polymers produced when the initiator is pentacarbonyl(methoxyphenylmethylene) tungsten. A possible mechanism is presented to account for why the metal-carbynes behave as though they were sources of reactive metal-carbenes. (Author)