The Unsaturated Polyester Via Ring-Opening Metathesis Polymerization (ROMP) of ω-6-Hexadecenlactone

2018 ◽  
Vol 15 (4) ◽  
pp. 566-571 ◽  
Author(s):  
Araceli Martinez ◽  
Mikhail A. Tlenkopatchev ◽  
Selena Gutierrez

Background: Ring opening metathesis polymerization of lactones using alkylidene catalysts is an alternative to obtain unsaturated linear polyesters with remarkable thermal and mechanical properties. Also, these polyesters have properties of biodegradability which opens up a wide range of applications as environmentally friendly thermoplastics and biomaterials. Objective: This research aims to present one route to obtain an unsaturated linear polyester poly(ω-6- hexadecenlactone) via ring opening-metathesis polymerization of ω-6-hexadecenlactone using the rutheniumalkylidene [Ru(Cl)2(=CHPh)(PCy3)2] (I), [Ru(Cl2)(=CHPh)(1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)( PCy3)] (II) and [Ru(Cl2)(=CH(o-isopropoxyphenylmethylene))(1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)] (III) and the ruthenium-vinylidene [RuCl2(=C=CH(p-C6H4CF3))(PCy3)2] (IV) catalysts. Conclusion: The high number-average molecular weights of the poly(ω-6-hexadecenlactone) between Mn = 114,800-155,400 g/mol and yields ranging from 96 to 98 % can be achieved by II and III catalysts. The catalysts II and III with the N-heterocyclic carbene ligand showed superior activity and stability upon catalysts I and IV bearing PCy3 ligands. The hydrogenation of poly(ω-6-hexadecenlactone) using Wilkinson catalyst [RhCl(PPh3)3] was studied. The percent crystallinity of the unsaturated poly(ω-6-hexadecenlactone) was 31% with a melting temperature 47.60ºC. Stress-strain measurements of several poly(ω-6-hexadecenlactone) were determined.

2006 ◽  
Vol 78 (10) ◽  
pp. 1877-1887 ◽  
Author(s):  
Christian Manfred Frech ◽  
Olivier Blacque ◽  
Heinz Berke

The treatment of benzene solutions of the cations [Re(NO)2(PR3)2][BArF4] (R = Cy and R = iPr; [BArF4] = tetrakis{3,5-bis(trifluoromethyl)phenyl}borate) with phenyldiazomethane afforded the moderately stable cationic rhenium(I) benzylidene dinitrosyl bis(trialkyl) phosphine complexes as [BArF4]- salts in good yields. The cationic rhenium dinitrosyl bisphosphine complexes catalyze the ring-opening metathesis polymerization (ROMP) of highly strained nonfunctionalized cyclic olefins to give polymers with relatively high polydispersity indices, high molecular weights, and Z configurations of the double bonds in the polymer chain backbones of over 80 %. The benzylidene derivatives are almost inactive in ROMP catalysis with norbornene and in olefin metathesis. NMR experiments gave first hints for the initial formation of carbene complexes when [Re(NO)2(PR3)2][BArF4] was treated with norbornene. The carbene formation is initiated by an unique reaction sequence where the cleavage of the strained olefinic bond starts with phosphine migration forming a cyclic ylid carbene complex. The [2+2] addition of a norbornene molecule to the Re=C bond leads to the rhenacyclobutane complex, which is expected to be converted into an iminate complex by attack of the ylid function onto one of the NNO atoms followed by Wittig-type phosphine oxide elimination. The formation of phosphine oxide was confirmed by NMR spectroscopy. This species is thought to drive the ROMP metathesis with alternating rhenacyclobutane formations and cycloreversions. The proposed mechanism is supported by density functional theory (DFT) calculations.


e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Xudong Lou ◽  
Christophe Detrembleur ◽  
Philippe Lecomte ◽  
Robert Jérôme

AbstractRing-opening polymerization (ROP) and ring-opening metathesis polymerization (ROMP) of an unsaturated ε-caprolactone, 6,7-dihydro-2(3H)-oxepinone (DHO2), are alternative routes to produce unsaturated aliphatic polyesters with the same molecular structure. Polymerization of DHO2 initiated by Al isopropoxide in toluene at room temperature or at 0°C proceeds by a coordination-insertion mechanism, although intramolecular transesterification takes place beyond complete monomer conversion. The molecular weight distribution is narrow as long as monomer conversion does not exceed 90%. Ring-opening metathesis polymerization of DHO2 initiated by Schrock’s Mo-based catalyst, 1, at 60°C allows higher molecular weight unsaturated polyester to be prepared, even though an intramolecular side reaction also operates. The structure of poly(DHO2) synthesized by ROP and ROMP is the same, as confirmed by 1H, 13C NMR, and FT-IR spectra. Copolymers of DHO2 with norbornene, cis-cyclooctene, and 1,5-cyclooctadiene have been successfully prepared.


2018 ◽  
Vol 9 (42) ◽  
pp. 5179-5189 ◽  
Author(s):  
Chang-Geun Chae ◽  
Yong-Guen Yu ◽  
Ho-Bin Seo ◽  
Myung-Jin Kim ◽  
Mallela Y. L. N. Kishore ◽  
...  

Rod-like POSS-containing polynorbornenes with high molecular weights were synthesized using ROMP with molecular and kinetic control.


2019 ◽  
Author(s):  
Efthymia Vakalopoulou ◽  
Christian Slugovc

The effect of enhancing the crosslinking degree in polyHIPEs made from dicyclopentadiene by additionally using a crosslinking comonomer is described. Foams of 80% porosity with 10-40 w% comonomer content in the continous phase are prepared and show similar porosities and morphological characteristics as foams prepared with dicyclopentadiene alone. Assessing the mechanical properties reveals that the ductility is decreasing while the stiffness of the samples is increasing with increasing comonomer content. The foams containing the crosslinking comonomer take up at least five fold mass of toluene therby swelling to at least 30 v%. Upon drying of the swollen specimens, their initial shap and porosity are recovered. This feature distinguishes them from polyHIPEs made from dicyclopentadiene only.<br>


2020 ◽  
Author(s):  
Ting-Wei Hsu ◽  
Cheoljae Kim ◽  
Quentin Michaudel

Poly(p-phenylene vinylene)s (PPVs), a staple of the conductive polymer family, consist of alternating alkene and phenyl groups in conjugation. The physical properties of this organic material are intimately linked to the cis/trans configuration of the alkene groups. While many synthetic methods afford PPVs with alltrans stereochemistry, very few deliver the all-cis congeners. We report herein the first synthesis of all-cis PPVs with living characteristics via stereoretentive ring-opening metathesis polymerization (ROMP). Exquisite catalyst control allows for the preparation of homopolymers or diblock copolymers with perfect stereoselectivity, narrow dispersities, and predictable molecular weights. All-cis PPVs can then serve as light-responsive polymers through clean photoisomerization of the stilbenoid units.


2020 ◽  
Author(s):  
Ting-Wei Hsu ◽  
Cheoljae Kim ◽  
Quentin Michaudel

Poly(p-phenylene vinylene)s (PPVs), a staple of the conductive polymer family, consist of alternating alkene and phenyl groups in conjugation. The physical properties of this organic material are intimately linked to the cis/trans configuration of the alkene groups. While many synthetic methods afford PPVs with alltrans stereochemistry, very few deliver the all-cis congeners. We report herein the first synthesis of all-cis PPVs with living characteristics via stereoretentive ring-opening metathesis polymerization (ROMP). Exquisite catalyst control allows for the preparation of homopolymers or diblock copolymers with perfect stereoselectivity, narrow dispersities, and predictable molecular weights. All-cis PPVs can then serve as light-responsive polymers through clean photoisomerization of the stilbenoid units.


2019 ◽  
Author(s):  
Efthymia Vakalopoulou ◽  
Christian Slugovc

The effect of enhancing the crosslinking degree in polyHIPEs made from dicyclopentadiene by additionally using a crosslinking comonomer is described. Foams of 80% porosity with 10-40 w% comonomer content in the continous phase are prepared and show similar porosities and morphological characteristics as foams prepared with dicyclopentadiene alone. Assessing the mechanical properties reveals that the ductility is decreasing while the stiffness of the samples is increasing with increasing comonomer content. The foams containing the crosslinking comonomer take up at least five fold mass of toluene therby swelling to at least 30 v%. Upon drying of the swollen specimens, their initial shap and porosity are recovered. This feature distinguishes them from polyHIPEs made from dicyclopentadiene only.<br>


2011 ◽  
Author(s):  
Robert H. Lambeth ◽  
Joseph M. Dougherty ◽  
Joshua A. Orlicki ◽  
Adam M. Rawlett ◽  
Robert C. Hoffman ◽  
...  

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