Ring opening metathesis polymerization of cyclic alkenes containing heteroatoms

Abstract

The Ring Opening Metathesis Polymerization (ROMP) of a series of cyclic alkenes bearing heteroatom functionality has been performed using a classical WCl,-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 DielsAlder 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 h i d e 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.

ROMP of Norbornene Monomers Carrying Nonprotected Amino Groups with Ruthenium Catalyst

“…It is likely that the amino groups at the norbornene endo-positions hinder the coordination of the double bond to the ruthenium center of the catalyst, leading to the deactivation of catalyst. 16,19,[21][22][23][24] As described in the Introduction, most of metathesis catalysts are inactivated by compounds substituted with nonprotected amino groups, [15][16][17] and ruthenium complexes have not been able to polymerize norbornene derivatives with primary and/or secondary amino groups thus far. The ROMP of endo,exo-2,3bis(ethoxycarbonyl)norbornene with the Grubbs second generation catalyst is retarded by the addition of 150-300 equivalents of diethylamine, but it still gives a polymer in 80% yield.…”

“…As described in the Introduction, most of metathesis catalysts are inactivated by compounds substituted with nonprotected amino groups, − and ruthenium complexes have not been able to polymerize norbornene derivatives with primary and/or secondary amino groups thus far. The ROMP of endo,exo -2,3-bis(ethoxycarbonyl)norbornene with the Grubbs second generation catalyst is retarded by the addition of 150−300 equivalents of diethylamine, but it still gives a polymer in 80% yield .…”

“…A few studies have been reported regarding the ROMP of amino group-containing norbornene monomers, such as ROMP of 2-aminomethyl norbornene derivatives 14 and a cyclic alkene containing a tertiary nitrogen atom in the 2-position of norbornene skeleton 15 with tungsten/aluminum-based catalysts. However, ROMP of a norbornene monomer substituted with a nonprotected amino group was observed to be unsuccessful with a ruthenium catalyst.…”

Synthesis of a poly(2-azanorbornene) with a high degree of cis-TT-stereoregularity and a regular secondary solution structure

“…However, the polymerization of monomers with amine functionalities still faces challenges due to initiator deactivation, but, concomitant with the introduction of 3 rd generation Grubbs initiators, these days state-of-the-art ROMP offers the advantage of paramount functional group tolerance, including tertiary amines. 17,18 Hence, the incorporation of highly diverse chemical groups into the targeted materials is greatly facilitated and azanorbornenes are of topical interest for the synthesis of various bio-inspired agents. Studies on the tacticity and stereochemistry in polymers and also norbornene derivatives undergoing metathesis polymerization were published in the literature.…”

Influence of Microstructure on Properties of Polymers with High Glass Transition Temperatures obtained by Ring-Opening Metathesis Polymerization of Polycyclic Hydrocarbons

“…In order to increase the T g of these polymers copolymerizations of norbornene or dicyclopentadiene with rigid monomers carrying functionalities like norbornene anhydride, [15] norbornene lactone [16] and N-phenyl norbornene dicarboximide [17] were investigated. If pure hydrocarbon polymers are demanded, the glass transition can be raised by incorporation of tri-and tetracyclic hydrocarbons.…”