Showing papers on "Ring-opening metathesis polymerisation published in 1994"
212 citations
134 citations
TL;DR: In this article, the authors described the preparation of polystyrene macromonomers containing a norbornene unit and their living ring opening metathesis polymerization (ROMP) to produce comb graft copolymers.
64 citations
TL;DR: Poly(disilanyleneethynylene)s are obtained by ring opening metathesis polymerization of tetrasilacycloocta-3-7-diynes catalyzed by high valent Schrock carbyne complexes of the type (RO) 3 W≡CR' (RO= Me 3 CO, CF 3 Me 2 CO; R'= Me, Et) as mentioned in this paper.
Abstract: Poly(disilanyleneethynylene)s [Si(R) 2 Si(R) 2 -C≡C-Si(R') 2 Si(R') 2 -C≡C] n (R=, R'= Me, Et) are obtained by ring opening metathesis polymerization of tetrasilacycloocta-3-7-diynes catalyzed by high valent Schrock carbyne complexes of the type (RO) 3 W≡CR' (RO= Me 3 CO, CF 3 Me 2 CO; R'= Me, Et)
47 citations
TL;DR: In this paper, it was shown that the aqueous ROMP with these catalysts is not a living polymerization, since molecular weights are almost independent of the polymerization time and of the monomer to catalyst ratio.
41 citations
Patent•
10 Nov 1994
TL;DR: In this paper, a transition metal compound represented by the following formula is presented, and an olefin polymerization catalyst component having high polymerization activity can be formed from the transition metal compounds.
Abstract: Disclosed is a novel transition metal compound represented by the following formula: ##STR1## wherein M is a transition metal, X is halogen or the like, R1 is a hydrocarbon group or the like, R2 is an aryl group substituted with a halogenated hydrocarbon group, and Y is a divalent silicon-containing group or the like. Also disclosed are an olefin polymerization catalyst component comprising the transition metal compound, an olefin polymerization catalyst comprising the olefin polymerization catalyst component, and a process for olefin polymerization using the olefin polymerization catalyst. An olefin polymerization catalyst component having high polymerization activity can be formed from the transition metal compound. By the use of the olefin polymerization catalyst or the process for olefin polymerization, polyolefins having a high melting point and a high molecular weight can be prepared with high polymerization activity.
35 citations
TL;DR: In this article, homochiral norbornene monomers derived from amino acids undergo ring-opening metathesis polymerisation with [Mo(CHCMe2Ph)(NC6H3Pri2-2,6)(OBut)2] to give narrow molecular mass distributions.
Abstract: Homochiral norbornene monomers derived from amino acids undergo ring-opening metathesis polymerisation with [Mo(CHCMe2Ph)(NC6H3Pri2-2,6)(OBut)2] to give homochiral polymers with narrow molecular mass distributions.
32 citations
TL;DR: In this article, a number of 7-oxanorbornene derivatives with hydroxymethyl, methoxymethyl and acetoxylic acid functionalities were synthesised and investigated as monomers in ring-opening metathesis polymerisation (ROMP) catalysed by commercial ruthenium trichloride in aqueous ethanolic solvents.
Abstract: A number of 7-oxanorbornene derivatives with hydroxymethyl, methoxymethyl and acetoxymethyl functionalities were synthesised and investigated as monomers in ring-opening metathesis polymerisation (ROMP) catalysed by commercial ruthenium trichloride in aqueous ethanolic solvents. Comparison was made with related polymerisations of 7-oxanorbornene derivatives with anhydride, methoxymethyl and carboxylic acid functionalities. The structures of the polymers were investigated by 1H and 13C NMR and their molar masses and molar mass distributions by gel-permeation chromatography.
27 citations
TL;DR: A soluble liquid crystalline conducting polymer was obtained by metathesis cyclopolymerization of the compound (CH 2 C≡CH) 2 NCO(CH 2 ) 10 OPhPhCN.
Abstract: A soluble liquid crystalline conducting polymer was obtained by metathesis cyclopolymerization of the compound (CH 2 C≡CH) 2 NCO(CH 2 ) 10 OPhPhCN
27 citations
TL;DR: In this paper, a self metathesis of vinyltrimethylsilane in the presence of an oxygenated benzene solution of RuCl 2 (PPh3)3 and RuCl2(PPh4)4 follows an unusual course and yields two products, 1,2-bis(silyl)ethene (E) and 1,1-bis (sily l)ethenes, with products of dimerization, namely 1,4-bis-silylsbutenes-2 (E + Z) and butenylsilanes as
27 citations
TL;DR: Methyl-terminated polyenes containing up to 20 double bonds are synthesized by metathesis polymerization of conjugated acyclic diene or trienes.
Abstract: Methyl-terminated polyenes containing up to 20 double bonds are synthesized by metathesis polymerization of conjugated acyclic diene or trienes. The reactions are clean and high yields are obtained
Patent•
31 Aug 1994TL;DR: In this paper, the process for the polymerization of cyclic olefins by photochemical ring-opening metathesis polymerization by irradiation, using catalytic amounts of a heat-stable ruthenium or osmium catalyst which has at least one photolabile ligand, the other coordination sites being occupied by non-photolabelile ligands.
Abstract: Process for the polymerization of cyclic olefins by photochemical ring-opening metathesis polymerization by irradiation, using catalytic amounts of a heat-stable ruthenium or osmium catalyst which has at least one photolabile ligand, the other coordination sites being occupied by non-photolabile ligands.
Patent•
19 Aug 1994TL;DR: In this article, a process for the metathesis of olefins is described, where the olefs are reacted in contact with an improved catalyst comprising a niobium and/or tantalum compound and a rhenium compound on a porous support containing at least 75% alumina and having a surface area of at least 10 m 2 /g.
Abstract: A process for the metathesis of olefins, wherein the olefins are reacted in contact with an improved catalyst comprising a niobium and/or tantalum compound and a rhenium compound on a porous support containing at least 75% alumina and having a surface area of at least 10 m 2 /g.
TL;DR: The WCl 6 -SnR 4 catalyst system was shown to be active in the metathesis polymerization of 1,5-hexadiene yieding high purity 1,4-polybutadiene as mentioned in this paper.
Abstract: The WCl 6 -SnR 4 catalyst system is shown to be active in the metathesis polymerization of 1,5-hexadiene yieding high purity 1,4-polybutadiene
TL;DR: The cis living polymer [PHCH=CHPhCH 2 CH 2 ] n was obtained by the ring opening metathesis polymerization of [2.2]paracyclophan-1-ene catalyzed by Mo((NAr)(CHCMe 2 Ph)(OCMe(CF 3 ) 2 ).
Abstract: The cis living polymer [PHCH=CHPhCH 2 CH 2 ] n is obtained by the ring opening metathesis polymerization of [2.2]paracyclophan-1-ene catalyzed by Mo((NAr)(CHCMe 2 Ph)(OCMe(CF 3 ) 2
TL;DR: In this article, the ring-opening metathesis polymerization of norbornene and 5,5-dimethylnorbornene has been studied with a range of tungsten(VI) ring opening procatalysts containing chelating diolate ligands.
TL;DR: In this article, a fine balance between the electrophilicity of the metal center and steric interactions involving the approach of the monomer to the catalyst is attributed to the selectivity of 1-methylcyclobutene I.
TL;DR: In this paper, a ring-opening metathesis polymerization (ROMP) was applied to poly[norborn-5-ene-2,3-diyl bis(S-methyl xanthate) (polyl) to obtain complete trans connection of the repeating units, whereas the oxa analogue is not as stereoregular.
Abstract: exo,exo-Norborn-5-ene-2,3-diyl bis(S-methyl dithiocarbonate) (1) and exo,exo-norborn-5-ene-2,3-diyl bis(methyl carbonate) (2) were polymerized by ring-opening metathesis polymerization (ROMP) using Mo(CH-t-Bu)(NAr)(O-t-Bu) 2 . Depending on the bulkiness of the substituents, a higher stereoregularity of the polymer was achieved. Spectroscopic data (IR, NMR) of poly[norborn-5-ene-2,3-diyl bis(S-methyl xanthate) (polyl) show a complete trans connection of the repeating units, whereas the oxa analogue is not as stereoregular. Thermal properties of poly(1) offer interesting possibilities for application as a precursor polymer to poly(cyclopentadienylenevinylene)
TL;DR: A series of fluorinated homopolymers and block co-polymers have been synthesized using the four-coordinate molybdenum ring-opening metathesis polymerisation (ROMP) initiators as discussed by the authors.
Abstract: A series of fluorinated homopolymers and block co-polymers has been synthesised using the four-coordinate molybdenum ring-opening metathesis polymerisation (ROMP) initiators [Mo(CHR)(NAr)(OR′)2], where R = CMe2Ph, Ar = 2,6-C6H3-Pr2i and R′= CMe3 or CMe(CF3)2.
TL;DR: In this paper, a general route to 3,3-disubstituted cyclobutenes is described and a ring opening metathesis polymerisation (ROMP) is applied to 3-3-dipropylcyclobutene.
Abstract: A general route to 3,3-disubstituted cyclobutenes is described and 3,3-dipropylcyclobutene is subjected to ring opening metathesis polymerisation (ROMP) using the Schrock initiator, Mo(CHR)(NAr)(OR′)2, where R is C6H5C(Me)2-, Ar is 2,6-diisopropylphenyl and R′ is (Me)3C- to give a polymer which is completely regiospecific (HT) and stereospecific (trans); the polymer is reduced to poly[(1,1-dipropyl)butane-1,4-diyl], which shows evidence of unusual properties associated with the conformational control exerted by the quaternary centres.
TL;DR: In this article, the relation between structural parameters and reactivity in ring-opening metathesis polymerization of cyclo-olefins was studied from a kinetic point of view.
Abstract: Concerning the study on the relation between structural parameters and reactivity in ring-opening metathesis polymerization of cyclo-olefins, the “living” polymerization of norbornene initiated by Schrock's-type complexes was considered as a reference and studied from the kinetic point of view. First kinetic orders with respect to both monomer and active species allow the values of absolute rate constants of propagation to be determined. The thermodynamic parameters obtained from kinetic experiments performed at different temperatures seem to indicate that monomer coordination and metallacycle formation are rate-determining steps in the process studied. © 1994 John Wiley & Sons, Inc.
TL;DR: The ring opening metathesis polymerization of cyclic alkenes bearing heteroatom functionality has been performed using a classical WCl6-based catalyst system as mentioned in this paper.
Abstract: The Ring Opening Metathesis Polymerization (ROMP) of a series of cyclic alkenes bearing heteroatom functionality has been performed using a classical WCl6-based catalyst system. All of the alkenes studied exhibited significantly slower polymerization rates compared with the hydrocarbon monomer dicyclopentadiene (DCPD), this being most pronounced for monomers containing a tertiary nitrogen atom substituted at the 2 position of the norbornene skeleton. Cyclic alkene anhydrides, prepared by the Diels-Alder addition of cyclopentadiene to maleic and itaconic anhdrides, were found to be polymerizable with high yields giving cross-linked polymers which exhibited very high glass transition temperatures. Monofunctional cyclic imide derivatives of the cyclopentadiene-itaconic anhydride adduct were found to be polymerizable to moderate molecular weight thermoplastic materials with high glass transition temperatures, whilst difunctional cyclic imide derivatives led to cross-linked thermoset polymers. The solution copolymerizations of the cyclopentadiene-maleic anhydride adduct with DCPD, and of a cyclic imide derivative of the cyclopentadiene-itaconic anhydride adduct with DCPD, were carried out to form copolymers in high yields having glass transition temperatures intermediate between those of the respective homopolymers.
TL;DR: The ring-opening metathesis polymerization (ROMP) of enantiomerically pure 2-substituted norbornenes carried out with Mo(CH-t-Bu)(NAr)(O-T-Bu)2 in chlorobenzene or with K2[RuCl5(H2O)] in aqueous solvents leads to polymers that show optical activity.
TL;DR: In this article, a ring opening metathesis polymerization (ROMP) using Mo(CHt-Bu) (NAr) (O-tBu)2 and other similar molybdenum-carbene catalysts in different solvents yielded optically active polymers with specific rotation [α]D depending on catalyst and solvent.
TL;DR: In this paper, a new polyacetylene precursor monomer (substituted tricyclo[4.02,5]deca-3,7,9-triene) was synthesized using ring opening metathesis polymerization (ROMP) with a tungsten alkylidine initiator.
Abstract: A new “Durham” polyacetylene precursor monomer (substituted tricyclo[4.2.2.02,5]deca-3,7,9-triene) was synthesized, and improved synthetic pathways to two existing precursor monomers were developed. Polymers of these three precursor monomers, as well as a bis-trifluoro substituted precursor monomer, were synthesized using ring opening metathesis polymerization (ROMP) with a tungsten alkylidine initiator. The kinetics of conversion (precursor polymer to polyacetylene) were studied for each of the four precursor polymers using differential scanning calorimetry (DSC). Percent age conversion vs. time data were fit to the Avrami expression often used to describe the kinetics of bulk of crystallization of polymers. The parameter K of the Avrami expression was assumed to depend on temperature according to an Arrhenius expression. In this way, an equation with three constants was obtained that completely describes the kinetics of conversion of a particular polyacetylene precursor polymer. Values for the constants depended on the type of substituent on the precursor polymer. Because the kinetics are well described by the Avrami expression, it is proposed that “nucleation” and “propagation” processes are involved in the conversion of the precursor polymers to polyacetylene.
TL;DR: In this paper, a ring-opening metathesis polymerization of the resulting monomers using Mo-carbene initiators gave highly stereoregular polymers with both allylic and benzylic carbon-hydrogen bonds.
Abstract: 11-(α-Phenylbenzylidene)benzonorbornadiene (3) and other similar monomers were synthesized by cycloaddition of dehydrobenzene with different fulvenes. Ring-opening metathesis polymerization of the resulting monomers using Mo-carbene initiators gave highly stereoregular polymers. Variation of the substituents allows control of the stereoregularity of these polymers. Poly[11-(α-phenylbenzylidene)benzonorbornadiene] is completely cis connected, whereas poly[11-(α-methylbenzylidene)benzonorbornadiene] is completely trans linked. The polymers contain two very reactive carbon-hydrogen bonds that are both allylic and benzylic. Elimination of these bridgehead hydrogens gives a fully conjugated polymer that can be described as having “fulvenoid” or “quinoid” geometry.
TL;DR: In this paper, a Re2O7/Al2O3 catalyst pretreated with Me4Sn also polymerizes norbornene but to a ROMP polymer favoring trans double bonds.
TL;DR: In this paper, the title monomers 1 and 2 were polymerized by Ru-, Ir-, Mo-, W- and Re-based metathesis catalysts to yield polymers with cis contents ranging from 10% to at least 90% for 1 and 23-60% for 2.
Abstract: The title monomers 1 and 2 were polymerized by Ru-, Ir-, Mo-, W- and Re-based metathesis catalysts to yield polymers with cis contents ranging from 10% to at least 90% for 1 and 23-60% for 2. Assignments of the 13 C NMR spectra were made. No significant head-tail bias was observed in either polymer. A high-trans polymer made from the optically active endo monomer ((-)-1) was atactic, while high-cis polymers could be either atactic or biased towards syndiotactic, depending on the catalyst