Sorption and diffusion of dense carbon dioxide in a biocompatible polymer

Abstract

Mass sorption and diffusion coefficients in one acrylate biocompatible copolymer contacted with supercritical (sc) carbon dioxide are reported. Equilibrium solubility of dense carbon dioxide in poly(methylmethacrylate-co-ethylhexylacrylate-co-ethyleneglycoldimethacrylate) (P(MMA-EHA-EGDMA)) was studied by a gravimetric method in a temperature range from 308 to 323 K and a pressure range from 10.0 to 20.0 MPa. The cross-linked copolymer presented Fickian behavior and Fick's diffusion model was applied to determine the amount of carbon dioxide present and the diffusion coefficients. Diffusion coefficients for the sorption under supercritical conditions and desorption at ambient conditions were determined and compared. Samples of P(MMA-EHA-EGDMA) with different thickness were used for comparison of the maximum sorption degree. Polymerization conditions were also varied in order to evaluate the influence of the molecular weight of the copolymer in the CO 2 sorption process. To investigate the possibility of impregnating this acrylate copolymer with an anti-inflammatory drug, a preliminary experiment was performed.

Solubility and binary diffusion coefficient of argon in polyethylene glycols of different molecular weights

“…5 and 6 and Tables 1 and 8. For different binary systems polymer/SCF similar conclusions were made [1,13,14,21]. From Fig.…”

“…[13][14][15][16] Up to a pressure of 0.25 MPa, the melting temperature of the investigated PEGs increases slightly (Fig. 13): 1 K for PEG 1500, 0.4 K for PEG 4000, 0.55 K for PEG 10 000 and 0.3 K for PEG 35 000 and reaches a maximum.…”

“…For designing and optimising processes of polymer processing using supercritical fluids, the knowledge of high-pressure equilibria, solubility, diffusivity, density and permeability is essential [3,[5][6][7] and were intensively researched in the past years [8][9][10][11][12][13][14][15][16]. Polymer processing includes micronisation, encapsulation, the present work, the behaviour of argon at supercritical conditions and its thermodynamic properties within a binary system with a polymer has been studied.…”

Supercritical fluid impregnation of a biocompatible polymer for ophthalmic drug delivery

“…Solubility data of flurbiprofen is reported previously [14] as well as the sorption of the carbon dioxide in the polymeric matrix [15,16]. Drug solubility is defined as the amount of solute (drug) that can be dissolved in a certain amount of solvent (supercritical fluid) at certain operational conditions (pressure and temperature).…”

Drug loading of polymer implants by supercritical CO 2 assisted impregnation: A review

“…Whereas the chain mobility is restricted below the T g , it increases above the T g which allows higher CO 2 sorption and swelling [76,77]. This effect can be counterbalanced by the decrease of CO 2 density with temperature under isobaric conditions [78][79][80] and by the CO 2 -induced recrystallization in semicrystalline polymers [81,82]. Nevertheless, if the temperature approaches the melting temperature of semi-crystalline polymers T m the crystals melt which increases the amorphous regions in the polymer and so the CO 2 sorption and the swelling [83].…”