Nonequilibrium Anionic Ring-opening Polymerization of Tetraphenyltetramethylcyclotetrasiloxane (D<sub>4</sub><sup>Me,Ph</sup>) Initiated by Sodium Isopropoxide

Gao, Xiyin; Wang, Qian; Sun, Hongjie; Tan, Yuanyuan; Zhang, Zhijie; Xie, Zuowei

doi:10.1080/10426507.2013.860534

Cited by 11 publications

(14 citation statements)

References 31 publications

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“…All polymers were prepared following a procedure based on literature protocols. [53][54][55] In a typical procedure, a Schlenk tube was charged with potassium hydroxide (0.051 g, 0.90 mmol), which was then tted with a septum. This was evacuated and relled with nitrogen three times.…”

Section: Synthesis Of Polydimethylsiloxane (Pd) and Poly(dimethylsilomentioning

confidence: 99%

“…promoter. 55 For the copolymerisation between octamethylcyclotetrasiloxane and octaphenylcyclotetrasiloxane, it was necessary to increase the reaction temperature to 90 C to obtain a homogenous, transparent mixture.…”

Section: Polymer Synthesismentioning

confidence: 99%

“…These observations are consistent with literature reports. 55,56 1 H NMR spectroscopy of the polydimethylsiloxane homopolymer revealed a signicant amount of unreacted D4 (or smaller cyclic compounds) as a signal at 0.75 ppm in addition to the polymer signal at 0.55 ppm (see Fig. S1 †).…”

Section: Polymer Synthesismentioning

confidence: 99%

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Enhancing the electro-mechanical properties of polydimethylsiloxane elastomers through blending with poly(dimethylsiloxane-co-methylphenylsiloxane) copolymers

Madsen

Boucher

et al. 2018

RSC Adv.

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In this work, improved electro-mechanical properties of silicone-based dielectric elastomers are achieved by means of adding so-called "voltage-stabilisers" prepared from phenyl-functional copolymers prepared using oxyanionic ring-opening polymerisation of octamethylcyclotetrasiloxane (D4) and either tetramethyltetraphenylcyclotetrasiloxane (T4) or octaphenylcyclotetrasiloxane (O4). The concentration of the voltage stabiliser was varied both by changing the molar ratio between methyl and phenyl groups in the copolymer and also by varying the amount of copolymer mixed into a PDMS-based elastomer. The phenyl-functional copolymers were generally found to disperse homogeneously in the PDMS matrix and this resulted in networks with improved mechanical and electrical properties. The developed elastomers were inherently extensible with enhanced tensile and tear strengths, due to phenyl-rich microphases acting as reinforcing domains. Furthermore, addition of phenyl-functional copolymers resulted in elastomers with increased relative permittivity and electrical breakdown strength compared to control elastomers while retaining a low dielectric loss. This demonstrates their efficiency as voltage stabilisers.a Phenyl content based on the added phenyl copolymer. b Residual mass fraction of the lm aer extraction and drying. c Mass fraction of the added phenyl copolymer. d Mass fraction of the phenyl copolymer in the extract, calculated from 1 H NMR. e Peak molecular weight of the early eluting peak. f Peak molecular weight relative to the late eluting peak.

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Section: Synthesis Of Polydimethylsiloxane (Pd) and Poly(dimethylsilomentioning

confidence: 99%

Section: Polymer Synthesismentioning

confidence: 99%

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Enhancing the electro-mechanical properties of polydimethylsiloxane elastomers through blending with poly(dimethylsiloxane-co-methylphenylsiloxane) copolymers

Madsen

Boucher

et al. 2018

RSC Adv.

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“…Inevitably, there is a portion of linear oligomers and cyclosiloxane, and it has a long reaction time and high energy consumption. Therefore, the novel efficient catalyst and polymerization system are the focus of AROP of polysiloxane in which polar aprotic solvents such as crown ether, tetrahydrofuran (THF), N , N ‐dimethyl formamide ( DMF), and N ‐methyl pyrrolidone ( NMP) are added to increase the polymerization rate and decrease the polymerization temperature.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of polysiloxanes containing trifluoroethylene aryl ether groups: The effect of promoters

Yuan

Diao

Zhao

et al. 2020

Polymers for Advanced Techs

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Polysiloxanes with high molecular weight (M n > 100 000, M w /M n < 2.2) containing various quantity of trifluoroethylene aryl ether groups were prepared by anion ring opening polymerization (AROP) in the presence of promoters including N,Ndimethylformamide (DMF) and N-methyl pyrrolidone (NMP). The structures of monomers and polymers were characterized by FTIR and NMR. It was found that the addition of promoter could significantly increase the polymerization rate, decrease the polymerization temperature, and increase the molecular weight of the polymer.When DMF as the promoter, the optimal conditions for polymerization were as follows: The polymerization temperature is 100 C, the amount of catalyst is 2.0%, and the molar ratio of promoter to catalyst is 160:1. The optimal conditions for polymerization using NMP as the promoter were as follows: The polymerization temperature is 75 C, the amount of catalyst is 2.0%, and the molar ratio of promoter to catalyst is 70:1, which indicated that NMP is more effective on AROP than DMF. Thermogravimetric analysis (TGA) showed that the polymer has good heat temperature resistance. Differential scanning calorimetry (DSC) showed that the introduction of NMP in bulk polymerization could improve the randomness of polymer structure, which leads to the disappearance of crystal peak and improve the low temperature resistance of polymer. K E Y W O R D S alkali catalytic system, anion ring opening polymerization, polysiloxane, promoter, trifluorovinyl aryl ether group 1 | INTRODUCTION Perfluorocyclobutyl (PFCB) polymer is a novel class of semifluorinated polymers first reported by Babb et al 1 in 1993. PFCB polymers are mainly prepared by the [2π + 2π] thermocyclization of trifluoroethylene aryl ether (TFVE) monomer. 2 Recently, PFCB polymers have attracted extensive attention of researchers in various fields including electronics industry, 3-7 aerospace, 8 fuel cells, 9-13 optical waveguide materials, 14-16 and coatings 17 because of the unique properties such as low dielectric property, low hygroscopicity, high thermal stability, chemical solvent resistance, and low birefringence. However, most of the research interests are focused on the functionality of PFCB group. There are few researches about the thermocyclization of TFVE monomer.Silicone rubber is one of the largest and most widely used organosilicon products. The traditional vulcanization methods of silicone rubber mainly include the following three categories: peroxide vulcanization, hydrosiloxane vulcanization, and functional group condensation vulcanization. Peroxide vulcanization is described that vinyl polysiloxane is cured by radical reaction using peroxides as the initiators to form a cross-linked network. However, the residues of peroxide decomposition have negative effects on the properties of silicone

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“…Despite the good characteristics of this material, such as high flexibility at low temperature, very high radiation resistance, higher thermal stability and refraction, some gaps persist [14,15]. Very often, these characteristics can be improved by the substitution of dimethylsiloxane units with those of phenylmethylsiloxane in the PDMS chain (Scheme 1b) [16,17]. The production of polyphenylmethylsiloxanes is usually carried out by anionic or cationic ring opening polymerization of triphenyltrimethylcyclotrisiloxane (Scheme 1c) [18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Catalytic Activity of Maghnite-H+ in the Synthesis of Polyphenylmethylsiloxane under Mild and Solvent-free Conditions

Kherroub

Belbachir

Lamouri

et al. 2017

Period. Polytech. Chem. Eng.

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Nonequilibrium Anionic Ring-opening Polymerization of Tetraphenyltetramethylcyclotetrasiloxane (D₄^Me,Ph) Initiated by Sodium Isopropoxide

Cited by 11 publications

References 31 publications

Enhancing the electro-mechanical properties of polydimethylsiloxane elastomers through blending with poly(dimethylsiloxane-co-methylphenylsiloxane) copolymers

Enhancing the electro-mechanical properties of polydimethylsiloxane elastomers through blending with poly(dimethylsiloxane-co-methylphenylsiloxane) copolymers

Synthesis of polysiloxanes containing trifluoroethylene aryl ether groups: The effect of promoters

Catalytic Activity of Maghnite-H+ in the Synthesis of Polyphenylmethylsiloxane under Mild and Solvent-free Conditions

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Nonequilibrium Anionic Ring-opening Polymerization of Tetraphenyltetramethylcyclotetrasiloxane (D4Me,Ph) Initiated by Sodium Isopropoxide

Cited by 11 publications

References 31 publications

Enhancing the electro-mechanical properties of polydimethylsiloxane elastomers through blending with poly(dimethylsiloxane-co-methylphenylsiloxane) copolymers

Enhancing the electro-mechanical properties of polydimethylsiloxane elastomers through blending with poly(dimethylsiloxane-co-methylphenylsiloxane) copolymers

Synthesis of polysiloxanes containing trifluoroethylene aryl ether groups: The effect of promoters

Catalytic Activity of Maghnite-H+ in the Synthesis of Polyphenylmethylsiloxane under Mild and Solvent-free Conditions

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Nonequilibrium Anionic Ring-opening Polymerization of Tetraphenyltetramethylcyclotetrasiloxane (D₄^Me,Ph) Initiated by Sodium Isopropoxide