Copolymerization of functional cyclotrisiloxanes – a reactivity comparison

Cypryk, Marek; Delczyk-Olejniczak, Bogumila

doi:10.14314/polimery.2010.503

Cited by 7 publications

(13 citation statements)

References 19 publications

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“…The rate constants of homopolymerization of

{normalD}_{3}^{Ph}

and

{normalD}_{3}^{normalF}

were independently determined by kinetic experiments (Tables and ). Notably, the values reported herein should be considered as the apparent reactivity ratios, which in fact may not be constant because the apparent rate constants may vary depending on the concentrations of the monomers and initiator; however, still may be useful for predicting the polymer composition in the limited range of concentrations of the monomers and initiator . The apparent reactivity ratios of

{normalD}_{3}^{Ph}

and

{normalD}_{3}^{normalF}

verified the differences in the reactivity when the copolymerization was initiated by CF 3 SO 3 H and Ph 2 Si(OLi) 2 , respectively; and one of the reactivity ratios greater than one for both the methods further indicated that the copolymers contained the gradient microstructures which was finally confirmed by 29 Si NMR, GPC, and DSC analysis.…”

Section: Resultsmentioning

confidence: 63%

“…Initiation was assumed to be instantaneous, although the model assuming rapid but not instantaneous initiation has also been examined. This complication did not have any significant impact on the results

- \frac{d true[{normalD}_{3}^{normalP normalh} true]}{d normalt} = k normalP normalP true[normalP normal* true] true[{normalD}_{3}^{normalP normalh} true] + k normalF normalP true[normalF normal* true] true[{normalD}_{3}^{normalP normalh} true]

- \frac{d true[{normalD}_{3}^{normalF} true]}{d normalt} = k normalP normalF true[normalP normal* true] true[{normalD}_{3}^{normalF} true] + k normalF normalF true[normalF normal* true] true[{normalD}_{3}^{normalF} true]

\frac{d true[{normalP}^{normal*} true]}{d normalt} = - \frac{d ([]|, F^{*})}{d normalt} = k normalF normalP true[normalF normal* true] true[{normalD}_{3}^{normalP normalh} true] - k normalP normalF true[normalP normal* true] true[{normalD}_{3}^{normalF} true]

…”

Section: Resultsmentioning

confidence: 99%

“…Polysiloxanes are important inorganic/organic materials possessing unique set of properties that make them useful in numerous applications . Siloxane chains present in polysiloxanes exhibit unusual static flexibility which in combination with low intermolecular forces leads to exceptionally low glass transition temperatures ( T g ) and small viscosity changes with temperature of polysiloxanes . Incorporation of polysiloxane segments into common organic polymers or different types of polysiloxane segments lead to the fabrication of the copolymers .…”

Section: Introductionmentioning

confidence: 99%

“…Siloxane chains present in polysiloxanes exhibit unusual static flexibility which in combination with low intermolecular forces leads to exceptionally low glass transition temperatures ( T g ) and small viscosity changes with temperature of polysiloxanes . Incorporation of polysiloxane segments into common organic polymers or different types of polysiloxane segments lead to the fabrication of the copolymers . Up until now, the copolymers with different siloxane units in the main chain have always attracted significant attention because different siloxane units in polysiloxanes are often necessary to obtain materials with tunable microstructures, physical properties, and required performances .…”

Section: Introductionmentioning

confidence: 99%

“…Compared with

{normalD}_{4}^{normalF}

, 1,3,5‐tris(trifluoropropylmethyl)cyclotrisiloxane (

{normalD}_{3}^{normalF}

) exhibits greater reactivity in polymerization initiated by an alkali due to higher ring strain in

{normalD}_{3}^{normalF}

. However, the mechanism involving reactivity difference of comonomers for simultaneous copolymerization has rarely been systematically and appropriately explored and gradient copolysiloxanes obtained through simultaneous copolymerization initiated by an acid have not been reported.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Synthesis of gradient copolysiloxanes by simultaneous copolymerization of cyclotrisiloxanes and mechanism for kinetics inverse between anionic and cationic ring‐opening polymerization

Fei

Han

Liu

et al. 2015

J. Polym. Sci. Part A: Polym. Chem.

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Trifluoropropylmethylsiloxane-phenylmethylsiloxane gradient copolysiloxanes were synthesized by anionic and cationic ring-opening polymerization (ROP) of 1,3,5-tris(trifluoropropylmethyl)cyclotrisiloxane (D during the cationic ROP. AB and BAB type gradient copolymers were obtained because of a difference in the reactivity of the monomers. The microstructure of copolymers was characterized by 29 Si NMR spectroscopy, gel permeation chromatography, and differential scanning calorimetry. Furthermore, the mechanism for kinetics inverse of copolymerization was proposed based on the results of the optimized molecular configuration.

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“…The rate constants of homopolymerization of

{normalD}_{3}^{Ph}

and

{normalD}_{3}^{normalF}

{normalD}_{3}^{Ph}

and

{normalD}_{3}^{normalF}

Section: Resultsmentioning

confidence: 63%

- \frac{d true[{normalD}_{3}^{normalP normalh} true]}{d normalt} = k normalP normalP true[normalP normal* true] true[{normalD}_{3}^{normalP normalh} true] + k normalF normalP true[normalF normal* true] true[{normalD}_{3}^{normalP normalh} true]

- \frac{d true[{normalD}_{3}^{normalF} true]}{d normalt} = k normalP normalF true[normalP normal* true] true[{normalD}_{3}^{normalF} true] + k normalF normalF true[normalF normal* true] true[{normalD}_{3}^{normalF} true]

\frac{d true[{normalP}^{normal*} true]}{d normalt} = - \frac{d ([]|, F^{*})}{d normalt} = k normalF normalP true[normalF normal* true] true[{normalD}_{3}^{normalP normalh} true] - k normalP normalF true[normalP normal* true] true[{normalD}_{3}^{normalF} true]

…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Compared with

{normalD}_{4}^{normalF}

, 1,3,5‐tris(trifluoropropylmethyl)cyclotrisiloxane (

{normalD}_{3}^{normalF}

) exhibits greater reactivity in polymerization initiated by an alkali due to higher ring strain in

{normalD}_{3}^{normalF}

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Synthesis of gradient copolysiloxanes by simultaneous copolymerization of cyclotrisiloxanes and mechanism for kinetics inverse between anionic and cationic ring‐opening polymerization

Fei

Han

Liu

et al. 2015

J. Polym. Sci. Part A: Polym. Chem.

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Elastomers Based on Polynorbornene with Polar Polysiloxane Brushes for Soft Transducer Applications

Adeli,

Venkatesan,

Nüesch

et al. 2024

Helvetica Chimica Acta

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Elastomers based on cross‐linked bottlebrush polymers combine an extreme softness at low strains with a strain‐stiffening effect, which makes them attractive as active components in dielectric elastomer actuators (DEA). Their main disadvantage concerns the small relative permittivity, which lies in the range of 3.5, requiring relatively high driving voltage in actuators. We synthesized a bottlebrush polymeric elastomer with polar brushes, which exhibit an enhanced dielectric permittivity of 4.4. Anionic ring‐opening polymerization of a polar cyclosiloxane afforded telechelic polar brushes, while ring‐opening polymerization of a norbornene macromonomer gave a bottlebrush polymer which was cross‐linked to elastomers by a thiol‐ene reaction. Elastomers with a small elastic modulus below 100 kPa, strain at break exceeding 100%, attractive elasticity, and small mechanical loss factors (tanδ) were achieved. Temperature‐dependent impedance measurements revealed a transition temperature of ‐95 °C and an interfacial polarization. The multigram scale synthesis demonstrates the potential for scaling up, which opens the door to broader applications of these materials beyond actuators, such as capacitive sensors, batteries, and electroluminescent devices. Notably, these devices operate at extremely low voltages where the dielectric breakdown does not limit their functionality, but still, the softness and the increased dielectric permittivity are a plus.

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