A one‐pot synthesis of comb polymers and hydrogels by the ring‐opening metathesis polymerization reaction

Bell, Brian; Hamilton, James G.; Law, Edwina E.; Rooney, John J.

doi:10.1002/marc.1994.030150615

Cited by 26 publications

(18 citation statements)

References 28 publications

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“…Water-soluble polymers and hydrogels have also been made by ring-opening metathesis polymerization. [89][90][91][92] One would also expect that it is possible to form stable hydrogels based on polyamides and other polymers formed by condensation chemistry, which might form tough microstructures.…”

Section: Chemical Fabrication Of Gelsmentioning

confidence: 99%

Hydrogels for Soft Machines

2009

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Hydrogels have applications in surgery and drug delivery, but are never considered alongside polymers and composites as materials for mechanical design. This is because synthetic hydrogels are in general very weak. In contrast, many biological gel composites, such as cartilage, are quite strong, and function as tough, shock‐absorbing structural solids. The recent development of strong hydrogels suggests that it may be possible to design new families of strong gels that would allow the design of soft biomimetic machines, which have not previously been possible.

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Section: Chemical Fabrication Of Gelsmentioning

confidence: 99%

Hydrogels for Soft Machines

2009

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“…The stereochemistry of the polymers obtained (PNBE, PNBE-COOME, PVNBE and the soluble part of PNBD) was determined by 1 H and 13 C NMR [28][29][30][31][32]. tt).…”

Section: Polymer Microstructurementioning

confidence: 99%

“…Substrates having strongly coordinating substituent groups (-COOH, -OH, -CN) deactivate 1, while those with softer ones (-COOMe, -CH=CH 2 ) are quantitatively polymerized, albeit with lower rates than NBE (Table 1, C NMR spectra prevents the estimation of the cis-content [29,30]. In the case of PVNBE, the peak at 5.30 ppm suggests that the ring-strained C=C bond is cleaved, while the vinylic one is left intact.…”

Section: The Relative Proportions Of Double-bond Pair Sequences Reprmentioning

confidence: 99%

“…The overlapping signals of the olefinic protons of the polymeric chain with the vinylic ones prevent the stereoregular assignment for the same reasons as above [30]. NBE-COOMe has been polymerized by a variety of catalytic systems (Mo, W, Re, Ru, Os, Ir) with yields varying from 20% to quantitative and molecular weights higher than 800,000 [29]. In contrast, there is only one report for the polymerization of VNBE, namely with the [(OC) 4 W(µ-Cl) 3 W(GeCl 3 )(CO) 3 ] (4) complex under controlled conditions, giving high yields of PVNBE along with small amounts of side products (~10%) [31].…”

Section: The Relative Proportions Of Double-bond Pair Sequences Reprmentioning

confidence: 99%

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Ring Opening Metathesis Polymerization of Norbornene and Derivatives by the Triply Bonded Ditungsten Complex Na[W2(µ-Cl)3Cl4(THF)2]·(THF)3

et al. 2012

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Abstract:In this study, the reactions of the bimetallic compound Na 3 ) with norbornene (NBE) and some of its derivatives (5-X-2-NBE; X = COOH (NBE-COOH), OH (NBE-OH), CN (NBE-CN), COOMe (NBE-COOMe), CH=CH 2 (VNBE); norbornadiene (NBD)) are described. Complex 1 contains a tungsten-tungsten triple bond, bearing three halide bridges and two labile THF ligands, in a cisoidal relationship along the metal-metal axis. The complex was found to be a highly efficient room temperature homogeneous and heterogeneous unicomponent initiator for the catalytic ring opening metathesis polymerization (ROMP) of most substrates. NBE provides polynorbornene (PNBE) of high molecular weight (M w ) in high yields, soluble in organic solvents. The reaction proceeds with high cis-stereoselectivity (80%-86% cis), independently of the reaction conditions. Strongly coordinating pendant groups (-COOH, -OH, -CN) deactivate 1, whereas substrates bearing softer ones (-COOMe, -CH=CH 2 ) are quantitatively polymerized. NBD gives

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“…Water-soluble polymers and hydrogels have also been made by ring-opening metathesis polymerization [77][78][79][80]. It would also be expected that it is possible to form stable hydrogels based on polyamides and other polymers formed by condensation chemistry that might form tough microstructures.…”

Section: Chemical and Physical Formation Of Gelsmentioning

confidence: 99%

Polymer Gel Actuators: Fundamentals

Calvert

2009

Biomedical Applications of Electroactive Polymer Actuators

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One view of materials development is to search for what materials correspond to empty spaces on a hypothetical multi-dimensional map of the properties of available materials. Following a biomimetic philosophy, for instance, it can be seen that tough ceramics and moldable short fiber composites with high moduli are possible but absent from the list of available synthetic materials. Likewise artificial muscle is missing, where the properties are defined as a developed stress of over 300 kPa, a linear contraction of 25 % and a response time of below one second. Currently dielectric elastomers come closest but have disadvantages [1,2].The actin-myosin muscle system provides the performance target for electroactive polymer actuators [3,4]. The process is driven chemically by the energy change from hydrolysis of the polyphosphate bond as ATP (adenosine triphosphate) binds to myosin and is converted to ADP (adenosine diphosphate) and phosphate. A simple chemical analogy suggests that muscle-like gels should be feasible but it is now clear that the task is much harder than it seems.Early work on gel actuation by Katchalsky-Katzir demonstrated that engines could be built using the chemical energy in diluting a lithium bromide solution to drive contraction and expansion of a collagen belt [5]. In essence, the collagen expands to take up the salt solution or contract to exclude the water. This change is both a molecular conformation change and a volume change. Other chemically driven gels, for instance polyacrylic acid fibers [6] which respond to a pH change, also rely on a solubility change giving rise to a volume change.

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A one‐pot synthesis of comb polymers and hydrogels by the ring‐opening metathesis polymerization reaction

Cited by 26 publications

References 28 publications

Hydrogels for Soft Machines

Hydrogels for Soft Machines

Ring Opening Metathesis Polymerization of Norbornene and Derivatives by the Triply Bonded Ditungsten Complex Na[W2(µ-Cl)3Cl4(THF)2]·(THF)3

Polymer Gel Actuators: Fundamentals

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