Ring-opening polymerization of decamethylcyclopentasiloxane initiated by a superbase: Kinetics and rheology

Pibre, Guillaume; Chaumont, Philippe; Fleury, Étienne; Cassagnau, Philippe

doi:10.1016/j.polymer.2007.11.017

Cited by 35 publications

(18 citation statements)

References 30 publications

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“…25,26 More recently, a chemorheology study on organocyclosiloxane anionic ROP showed the possibility to build up a model able to predict the viscosity variation knowing the monomer conversion and the complex shear modulus variation during the polymerization. 27 Thus, the use of a rheometer as a chemical reactor enables the monitoring of the chemical reaction by measuring the viscoelastic behavior of the reactive media while the polymerization occurs. Furthermore, such models can be used to calculate the polymerization kinetics (conversion versus time) from inverse rheological methods.…”

Section: Journal Of Polymer Science: Partmentioning

confidence: 99%

“…This model was successfully developed in our previous work to the viscosity change during ROP of e-caprolactone 23 and decamethylcyclopentasiloxane. 27 In the case of this study, we assume that the free-volume correction factor can be neglected (a u ¼ 1) as the polymerization temperature is far above the glass temperature of PGA. As previously defined, M c is the critical molar mass for the viscosity in bulk, M c % 11,000 g/mol.…”

Section: Kinetics From Inverse Calculationmentioning

confidence: 99%

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Synthesis and rheology of biodegradable poly(glycolic acid) prepared by melt ring‐opening polymerization of glycolide

Gautier

Fuertès

Cassagnau

et al. 2009

J. Polym. Sci. A Polym. Chem.

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Ring-opening polymerization (ROP) of glycolide was studied in melt conditions and in the presence of two different initiators: 1-dodecanol and 1,4-butanediol and tin(II) 2-ethylhexanoate as catalyst. Its subsequent polymerization provided poly (glycolic acid) with controlled molar masses ranging from 2000 to 42,000 g/mol with well-defined structures characterized by NMR. Their thermal properties were evaluated by DSC analysis, and a glass transition temperature at infinite molar mass (T g1 ) of 44.8 C was thus calculated. From rheological data, the critical molar mass for entanglement, M c , was estimated to be near 11,000 g/mol. Furthermore, in situ polymerizations were also performed between the plates of the rheometer within a same temperature range from 210 to 235 C. The variation of the storage and loss moduli during the polymerization step have been monitored by time sweep oscillatory experiments under an angular frequency x ¼ 10 rad/s. Finally, the development of an inverse rheological method allowed to calculate the bulk polymerization kinetics in the temperature range 200-230 C.

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Section: Journal Of Polymer Science: Partmentioning

confidence: 99%

Section: Kinetics From Inverse Calculationmentioning

confidence: 99%

Synthesis and rheology of biodegradable poly(glycolic acid) prepared by melt ring‐opening polymerization of glycolide

Gautier

Fuertès

Cassagnau

et al. 2009

J. Polym. Sci. A Polym. Chem.

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“…With the molar masses and Equation (8 Since the polymerization rate for the ROP of cyclosiloxanes increases with the size of the counterion [21,26], the performance of two different phosphazene bases, P 4 -t-Bu (ionic radius = 4.7 Å [55], pK BH + = 41.9 [56]) and P 2 -t-Bu (ionic radius = 3.3 Å [55], pK BH + = 33.5 [56]), is investigated. The ROP of M 4 is performed in toluene at constant monomer concentration (([M 4 ] 0 = 0.96 mol•L −1 ) with P 4 -t-Bu and P 2 -t-Bu (B'), respectively, and varying n M / n I .…”

Section: Molar Mass Controlmentioning

confidence: 99%

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

et al. 2020

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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 %.

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“…We are interested in the polymerization of D8 (Scheme 1a) by Maghnite-H + . The polymerization of siloxane monomers was carried out previously by different catalysts as phosphazene bases [11,12], strong bases [13,14], dodecylbenzenesulfonic acid [15], triflic acid [16], tris(pentafluorophenyl)borane [17] and trifluoromethanesulfonic acid [18].…”

Section: Introductionmentioning

confidence: 99%

Green Polymerization of Hexadecamethylcyclooctasiloxane Using an Algerian Proton Exchanged Clay Called Maghnite-H+

Kherroub¹,

Belbachir

Lamouri

2017

Bull. Chem. React. Eng. Catal.

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The purpose of this study was to synthesize polydimethylsiloxanes by heterogeneous catalysis, based on the polymerization of the hexadecamethylcyclooctasiloxane (D8) by an environment-friendly solid catalyst (Maghnite-H + ). Maghnite-H + is a natural Algerian clay of the montmorillonite type, prepared by activation with sulfuric acid, the impact of this activation was observable in the XRD spectrum, by the increase in the interlayer spacing (d001) resulting from the intercalation of hydronium ions between layers. The molecular structure of the obtained polymer was determined by different chemical methods of analysis such as IR, 1 H NMR, and 13 C NMR. The thermal behavior of the polysiloxane obtained was confirmed by DSC. In order to achieve the best possible yield and at the same time to get a polymer of high molecular mass, the operating conditions have been set at t = 8 h and T = 70 °C after the reaction was repeated several times. The average molecular mass and the polydispersity index were measured by GPC. A reaction mechanism has been suggested to show the action of the Maghnite-H + during the reaction.

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Ring-opening polymerization of decamethylcyclopentasiloxane initiated by a superbase: Kinetics and rheology

Cited by 35 publications

References 30 publications

Synthesis and rheology of biodegradable poly(glycolic acid) prepared by melt ring‐opening polymerization of glycolide

Synthesis and rheology of biodegradable poly(glycolic acid) prepared by melt ring‐opening polymerization of glycolide

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

Green Polymerization of Hexadecamethylcyclooctasiloxane Using an Algerian Proton Exchanged Clay Called Maghnite-H+

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