Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

An efficient approach to surface-initiated ring-opening metathesis polymerization of cyclooctadiene.

ABSTRACT: Surface-initiated ring-opening metathesis polymerization of cyclooctadiene (COD), a low ring-strain olefin, is reported for the first time. Polymerization was carried out in the vapor phase, which is advantageous compared to conventional solution methods in terms of minimizing chain transfer by reducing polymer chain mobility at the vapor/solid interface. Attachments of a norbornenyl-containing silane and a Grubbs catalyst to silicon substrates were carried out before samples were exposed to COD vapor. The thickness of grafted 1,4-polybutadiene films was controlled by reaction time and reached approximately 40 nm after 7 h. The polymer films were further chemically modified to afford a new polymer, head-to-head poly(vinyl alcohol).

SUBMITTER: Feng J

PROVIDER: S-EPMC2515563 | biostudies-literature | 2007 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

An efficient approach to surface-initiated ring-opening metathesis polymerization of cyclooctadiene.

Feng Jianxin J Stoddart Stephanie S SS Weerakoon Kanchana A KA Chen Wei W

Langmuir : the ACS journal of surfaces and colloids 20070101 3

Surface-initiated ring-opening metathesis polymerization of cyclooctadiene (COD), a low ring-strain olefin, is reported for the first time. Polymerization was carried out in the vapor phase, which is advantageous compared to conventional solution methods in terms of minimizing chain transfer by reducing polymer chain mobility at the vapor/solid interface. Attachments of a norbornenyl-containing silane and a Grubbs catalyst to silicon substrates were carried out before samples were exposed to COD ...[more]

PMID: 17241005

Similar Datasets

Unsymmetrical difunctionalization of cyclooctadiene under continuous flow conditions: expanding the scope of ring opening metathesis polymerization.

Project description:Functionalized cyclooctenes (FCOEs) are important monomers in ring-opening metathesis polymerization (ROMP). Herein, a new library of disubstituted FCOEs bearing adjacent heteroatoms were synthesized and applied in ROMP. To address the issues associated with the handling of the reactive thienyl chloride intermediate, a two-step continuous flow method has been developed to prepare 5-thio-6-chlorocyclooctene compounds from abundant cyclooctadiene starting materials. These newly synthesized FCOE monomers were subsequently polymerized through ROMP, giving rise to a range of functionalized polymers with high molecular weights. Furthermore, we demonstrated that the thermal properties of these polymers could be fine-tuned by changing the functional groups in the FCOE monomers. We expect that this functionalization-polymerization strategy will enable the preparation of a range of polymeric materials with complex structures.

| S-EPMC5890785 | biostudies-literature

Z-Selective and Syndioselective Ring-Opening Metathesis Polymerization (ROMP) Initiated by MonoAryloxidePyrrolide (MAP) Catalysts.

Project description:We report the Z-selective and syndioselective polymerization of 2,3-bis(trifluoromethyl)bicyclo[2.2.1]hepta-2,5-diene (NBDF6) and 3-methyl-3-phenylcyclopropene (MPCP) by monoaryloxide monopyrrolide imido alkylidene (MAP) catalysts of Mo. The mechanism of polymerization with syn-Mo(NAd)(CHCMe(2)Ph)(Pyr)(OHIPT) (1; Ad = 1-adamantyl, OHIPT = O-2,6-(2,4,6-i-Pr(3)C(6)H(2))(2)C(6)H(3)) as the initiator is proposed to consist of addition of monomer to the syn initiator to yield a syn first insertion product and propagation via syn insertion products. In contrast, the mechanism of polymerization with syn-Mo(NAr)(CHCMe(2)Ph)(Pyr)(OTPP) (4; Ar = 2,6-i-Pr(2)C(6)H(3), OTPP = 2,3,5,6-Ph(4)C(6)H) as the initiator at -78 °C consists of addition of monomer to the syn initiator to yield an anti first insertion product and propagation via anti insertion products. Polymerizations of NBDF6 and MPCP at room temperature initiated by 4 led to polymers without a regular structure. We propose that the syndiotacticity of cis polymers is the consequence of the required inversion at the metal center with each insertion of monomer, i.e., stereogenic metal control of the polymer structure. We also propose that the two mechanisms for forming cis,syndiotactic polymers arise as a consequence of the relative steric bulk of the imido and phenoxide ligands.

| S-EPMC3074984 | biostudies-literature

A General Approach to Sequence-Controlled Polymers Using Macrocyclic Ring Opening Metathesis Polymerization.

Project description:A new and general strategy for the synthesis of sequence-defined polymers is described that employs relay metathesis to promote the ring opening polymerization of unstrained macrocyclic structures. Central to this approach is the development of a small molecule "polymerization trigger" which when coupled with a diverse range of sequence-defined units allows for the controlled, directional synthesis of sequence controlled polymers.

| S-EPMC4490773 | biostudies-literature

Resonance promoted ring-opening metathesis polymerization of twisted amides.

Project description:The living ring-opening metathesis polymerization (ROMP) of an unsaturated twisted amide using the third-generation Grubbs initiator is described. Unlike prior examples of ROMP monomers that rely on angular or steric strain for propagation, this system is driven by resonance destabilization of the amide that arises from geometric constraints of the bicyclic framework. Upon ring-opening, the amide can rotate and rehybridize to give a stabilized and planar conjugated system that promotes living propagation. The absence of other strain elements in the twisted amide is supported by the inability of a carbon analogue of the monomer to polymerize and computational studies that find resonance destabilization accounts for 11.3 kcal mol-1 of the overall 12.0 kcal mol-1 ring strain. The twisted amide polymerization is capable of preparing high molecular weight polymers rapidly at room temperature, and post-polymerization modification combined with 2D NMR spectroscopy confirms a regioirregular polymer microstructure.

| S-EPMC6993617 | biostudies-literature

Cis-selective ring-opening metathesis polymerization with ruthenium catalysts.

Project description:Cis-selective ring-opening metathesis polymerization of several monocyclic alkenes as well as norbornene and oxanorbornene-type monomers using a C-H activated, ruthenium-based metathesis catalyst is reported. The cis content of the isolated polymers depended heavily on the monomer structure and temperature. A cis content as high as 96% could be obtained by lowering the temperature of the polymerization.

| S-EPMC3278323 | biostudies-literature

Two-Dimensional Controlled Syntheses of Polypeptide Molecular Brushes via N-Carboxyanhydride Ring-Opening Polymerization and Ring-Opening Metathesis Polymerization.

Project description:Well-defined molecular brushes bearing polypeptides as side chains were prepared by a "grafting through" synthetic strategy with two-dimensional control over the brush molecular architectures. By integrating N-carboxyanhydride ring-opening polymerizations (NCA ROPs) and ring-opening metathesis polymerizations (ROMPs), desirable segment lengths of polypeptide side chains and polynorbornene brush backbones were independently constructed in controlled manners. The N2 flow accelerated NCA ROP was utilized to prepare polypeptide macromonomers with different lengths initiated from a norbornene-based primary amine, and those macromonomers were then polymerized via ROMP. It was found that a mixture of dichloromethane and an ionic liquid were required as the solvent system to allow for construction of molecular brush polymers having densely-grafted peptide chains emanating from a polynorbornene backbone, poly(norbornene-graft-poly(?-benzyl-l-aspartate)) (P(NB-g-PBLA)). Highly efficient postpolymerization modification was achieved by aminolysis of PBLA side chains for facile installment of functional moieties onto the molecular brushes.

| S-EPMC5617330 | biostudies-literature

Dewar Heterocycles as Versatile Monomers for Ring-Opening Metathesis Polymerization.

Project description:We report the utility of readily available heterocycles as precursors to unique ring-opening metathesis polymerization (ROMP) monomers. Photochemical valence isomerization reactions of pyridones, dihydropyridines, and pyrones dearomatize the parent heterocycles to their highly strained Dewar isomers, which readily engage in controlled ROMP reactions using Grubbs catalysts. This strategy is used to access polymer backbones that contain strained β-lactam and azetidine cores, which can be further derivatized using post-polymerization chemistries. We demonstrate this through the synthesis of water-soluble β-amino acid polymers that have potential applications as biomedical materials, along with the synthesis of highly-soluble poly(acetylene) derivatives, which have potential applications as organic conductive materials derived from bio-feedstock chemicals.

| S-EPMC8297915 | biostudies-literature

Optimization of Ring-Opening Metathesis Polymerization (ROMP) under Physiologically Relevant Conditions.

Project description:Ring opening metathesis polymerization (ROMP) is widely considered an excellent living polymerization technique that proceeds rapidly under ambient conditions and is highly functional group tolerant when performed in organic solvents. However, achieving the same level of success in aqueous media has proved to be challenging, often requiring an organic co-solvent or a very low pH to obtain fast initiation and high monomer conversion. The ability to efficiently conduct ROMP under neutral pH aqueous conditions would mark an important step towards utilizing aqueous ROMP with acid-sensitive functional groups or within a biological setting. Herein we describe our efforts to optimize ROMP in an aqueous environment under neutral pH conditions. Specifically, we found that the presence of excess chloride in solution as well as relatively small changes in pH near physiological conditions have a profound effect on molecular weight control, polymerization rate and overall monomer conversion. Additionally, we have applied our optimized conditions to polymerize a broad scope of water-soluble monomers and used this methodology to produce nanostructures via ring opening metathesis polymerization induced self-assembly (ROMPISA) under neutral pH aqueous conditions.

| S-EPMC8009303 | biostudies-literature

Creation of a PDMS Polymer Brush on SiO2-Based Nanoparticles by Surface-Initiated Ring-Opening Polymerization.

Project description:The incorporation of nanoparticles into soft matrices opens a broad spectrum of novel property combinations. However, one of the major challenges for these systems remains the compatibilization of particles with the surrounding matrix by proper surface functionalization. For silicon-based systems or liquid crystalline phases, polydimethylsiloxane (PDMS) brushes at the surface of particles increase the stability against particle agglomeration in such systems. Here, we report a novel approach for the functionalization of particles with a polysiloxane brush by surface-initiated ring-opening polymerization of a cyclosiloxane. For this purpose, surface hydroxy groups of silica and silica-coated hematite particles are used as initiators in combination with phosphazene bases as catalysts. The ring-chain equilibrium of a model-based solution polymerization is investigated in detail to find the appropriate reaction parameters. The corresponding molar masses are determined and compared by 1H-NMR and SEC measurements to confirm the underlying mechanism. In the resulting hybrid nanostructures, a covalently bound PDMS fraction is achieved up to 47 mass %.

| S-EPMC7240505 | biostudies-literature

Highly active ruthenium metathesis catalysts enabling ring-opening metathesis polymerization of cyclopentadiene at low temperatures.

Project description:Development of versatile ruthenium olefin-metathesis catalysts with high activity, stability, and selectivity is a continuous challenge. Here we report highly controllable ruthenium catalysts using readily accessible and versatile N-vinylsulfonamides as carbene precursors. Catalyst initiation rates were controlled in a straightforward manner, from latent to fast initiating, through the facile modulation of the N-vinylsulfonamide ligands. Trifluoromethanesulfonamide-based catalysts initiated ultrarapidly even at temperatures as low as -60?°C and continuously propagated rapidly, enabling the enthalpically and entropically less-favored ring-opening metathesis polymerizations of low-strained functionalized cyclopentene derivatives, some of which are not accessible with previous olefin-metathesis catalysts. To our surprise, the developed catalysts facilitated the polymerization of cyclopentadiene (CPD), a feedstock that is easily and commonly obtainable through the steam cracking of naphtha, which has, to the best of our knowledge, not been previously achieved due to its low ring strain and facile dimerization even at low temperatures (below 0?°C).

| S-EPMC6712042 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data