Poly(methyl methacrylate) and Poly(butyl methacrylate) Swelling in Supercritical Carbon Dioxide

Abstract

Swelling of poly(methyl methacrylate) and poly(butyl methacrylate) samples in supercritical carbon dioxide and propagation of diffusion fronts in the samples were studied in situ at various temperatures and pressures using direct optical observation. The difference in the appearance of diffusion fronts in these polymers with different glass transition temperatures was observed. The diffusion coefficients of carbon dioxide molecules in the polymers were determined both from swelling kinetics and from motion of diffusion fronts. A good agreement between these two values was found. The dependences of the diffusion coefficients and equilibrium swelling degrees of the polymers on pressure and temperature of supercritical carbon dioxide during sample exposure were determined and discussed.

Sorption and diffusion of dense carbon dioxide in a biocompatible polymer

“…To test and validate the new apparatus, some experiments were performed using PMMA, at 10 MPa and 313 K. The calculation of the diffusion coefficient of this polymer proved to be in the same order of magnitude of the literature, 10 −7 to 10 −5 cm 2 /s, depending on Mw of the polymer samples [17,18] validating our experimental method. Furthermore, the maximum sorption degree (16%) is also in very good agreement with literature data obtained by a spectroscopic in situ method [19].…”

A comparison between gravimetric and in situ spectroscopic methods to measure the sorption of CO2 in a biocompatible polymer

“…The manipulation of the physical properties of polymers as well as their selective control has become an area of interest in polymer science, particularly in polymer synthesis and processing using supercritical fluids [1].…”

“…The use of a quartzcrystal microbalance and a simple in situ gravimetric method or a barometric method are the most commonly used [10,11], Transmission IR spectroscopy has also been used to measure CO 2 sorption in polymers [12,13]. The direct optical observation of the sample's dimensions is usually widely used to study polymer swelling [1].…”

Raspberry-like Pt clusters with controlled spacing produced by deposition of loaded block copolymer micelles from supercritical CO2

“…This value was measured at 38°C and 250 bar, though according to Ref. [49] it would be even higher at 75°C and $750 bar, i.e. the conditions of the exposure in this experiment.…”

“…For diffusion coefficient of CO 2 in PMMA phase we can take the typical value of 0.6 Á 10 À10 m 2 /s from Ref. [49]. This value was measured at 38°C and 250 bar, though according to Ref.…”