Swelling measurement of polymers in high pressure carbon dioxide using a spectroscopic reflectometer

Shinkai, Tomoaki; Ito, Kohzo; Yokoyama, Haruki

doi:10.1016/j.supflu.2014.09.003

Cited by 18 publications

(12 citation statements)

References 45 publications

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“…reported a swelling ratio of up to 25% at 300 bar. [ 35,36 ] It is within reason to assume that during the polymerization process the produced polymer is also swelling, making the growing polymer chains more accessible for propagation with fresh monomer.…”

Section: Resultsmentioning

confidence: 99%

“…One key difference between ScCO 2 properties and that of DMF is the viscosity, ScCO 2 has a viscosity of ≈0.05 cP being less viscous than DMF which as a viscosity of 0.67 cP at 40 °C, which may improve the diffusion and transfer of radical species and monomer mobility in the propagation steps, respectively. [31][32][33][34] Another effect that ScCO 2 has on [35,36] It is within reason to assume that during the polymerization process the produced polymer is also swelling, making the growing polymer chains more accessible for propagation with fresh monomer. At higher temperatures the deviation tends to increase significantly.…”

Section: Influence Of Temperaturementioning

confidence: 99%

See 1 more Smart Citation

RAFT Polymerization of a Biorenewable/Sustainable Monomer via a Green Process

Versteeg

Hegeman

Sebakhy

et al. 2022

Macromol. Rapid Commun.

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A biorenewable polymer is synthesized via a green process using the RAFT principle for the first time in supercritical CO2 at 300 bar and 80 °C. α‐Methylene‐γ‐butyrolactone polymers of various chain lengths and molecular weights are obtained. The molecular weights vary from 10 000 up to 20 000 with low polydispersity indexes (PDI <1.5). Furthermore, the monomer conversion in supercritical CO2 is substantially higher, respectively 85% for ScCO2 compared to ≈65% for polymerizations conducted in dimethyl formamide (DMF) solvent. Chain extensions are carried out to confirm the livingness of the formed polymers in ScCO2. This opens up future possibilities of the formation of different polymer architectures in ScCO2. The polymers synthesized in ScCO2 have glass transition temperature (Tg) values ranging from 155 up to 190 °C. However, the presence of residual monomer encapsulated inside the formed polymer matrix affects the glass transition of the polymer that is lowered by increasing monomer concentrations. Hence, additional research is required to eliminate the remaining monomer concentration in the polymer matrix in order to arrive at the optimal Tg.

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Section: Resultsmentioning

confidence: 99%

Section: Influence Of Temperaturementioning

confidence: 99%

RAFT Polymerization of a Biorenewable/Sustainable Monomer via a Green Process

Versteeg

Hegeman

Sebakhy

et al. 2022

Macromol. Rapid Commun.

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show abstract

“…The measurement of swelling in a carbon dioxide-poly(methyl methacrylate) system showed similar results. 82,83 Theoretical models [84][85][86] such as the statistical association fluid theory have been used recently for describing these experimental results. Fig.…”

Section: Sorption Of Ch 4 and Co 2 In Poly(alkyl Acrylates)mentioning

confidence: 99%

Sorption and Diffusion of Methane and Carbon Dioxide in Amorphous Poly(alkyl acrylates): A Molecular Simulation Study

2020

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Molecular simulations were carried out to understand the structural features, and the sorption and diffusion behavior of methane and carbon dioxide in amorphous poly(alkyl acrylates) in the temperature range of 300−600 K. The hybrid Monte Carlo/molecular dynamics approach was employed to address the effects of polymer swelling and framework flexibility on the gas sorption. Simulations show that the glass transition temperature decreases with side-chain length of poly(alkyl acrylate), consistent with experiments. This is due to the fact that the shielding of the polar ester groups increases with side-chain length. The simulated sorption isotherms for methane and carbon dioxide were in agreement with the experimental data. The polymer swelling becomes more pronounced, especially in the case of sorption of carbon dioxide. A significant swelling occurs possibly due to the greater interaction between carbon dioxide and the polar ester groups in the polymers. The uptake of methane and carbon dioxide by poly(alkyl acrylates) generally increases with side-chain length. Our simulations confirm the experimental findings that the diffusion coefficients of methane and carbon dioxide in poly(alkyl acrylates) increase with side-chain length. Interestingly, the activation energies of gas diffusion decrease with side-chain length.The diffusion coefficients of penetrants have an exponential relationship with the void fraction, which is in agreement with the free volume theory.

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“…Data such as CO 2 uptake, glass transition temperature depression, polymer swel-ling and so on are of great interest for a good control of polymer pro-cessing. Several works have already been reported on these topics [51][52][53][54][55] but more data on all the different systems used for drug for-mulation are needed.…”

Section: Knowledge Gaps/needsmentioning

confidence: 99%

Current situation and perspectives in drug formulation by using supercritical fluid technology

Badens

Masmoudi

Mouahid

et al. 2018

The Journal of Supercritical Fluids

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Supercritical fluid (SCF) technology has been applied to drug product development over the last thirty years and drug particle generation using SCFs appears to be an efficient way to carry out drug formulation which will form end-products meeting targeted specifications. This article presents an overview of drug particle design using SCFs from a rather different perspective than usual, more focused on chemical and process engineering aspects. The main types of existing processes are described in a concise way and a focus is put on how to choose the right operating conditions considering both thermodynamic and hydrodynamic aspects. It is shown that the operating conditions and parameters can be easily optimized so as to facilitate the further process scale-up. Furthermore, the new trends in particle generation using SCFs are introduced, related either to new types of drug medicines that are treated or new ways of process implementation methods.

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Swelling measurement of polymers in high pressure carbon dioxide using a spectroscopic reflectometer

Cited by 18 publications

References 45 publications

RAFT Polymerization of a Biorenewable/Sustainable Monomer via a Green Process

RAFT Polymerization of a Biorenewable/Sustainable Monomer via a Green Process

Sorption and Diffusion of Methane and Carbon Dioxide in Amorphous Poly(alkyl acrylates): A Molecular Simulation Study

Current situation and perspectives in drug formulation by using supercritical fluid technology

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