Influence of tert-amine groups on the solubility of polymers in CO2

Abstract

a b s t r a c tThere is a need to develop new, non-fluorous polymers that are highly soluble in CO 2 . Experimental evidence indicates that tertiary amine and pyridine groups may exhibit favorable Lewis acid-Lewis base type interactions with CO 2 . It is therefore reasonable to assume that incorporation of tertiary amines into the side chain or backbone of non-fluorous polymers may impart a degree of CO 2 -solubility to the polymer. We present experimental results for eight different tert-amine-containing polymers. Of these polymers, only propyl dimethylamine-functionalized poly(dimethylsiloxane) is soluble in CO 2 at temperatures and pressures accessible in our experiments, but even this polymer is less soluble than non-functionalized poly(dimethylsiloxane) at the same chain length. We have performed ab initio calculations on tertiary amine-containing moieties representative of some of the polymers examined experimentally. Our calculations confirm that amine-CO 2 interactions are indeed energetically favorable. However, we also find that the moiety self-interactions are typically more favorable than the CO 2 -moiety interactions. This indicates that the lack of solubility of amine-containing polymers in CO 2 is a direct result of strong polymer-polymer interactions.

Polymer nano-foams for insulating applications prepared from CO2 foaming

“…However, this seems to be rather the result of the polymer chains' flexibility [79,80]. According to Kirby and McHugh [81] and Nalawade and colleagues [82], CO 2 solubility in poly(dimethyl-) and poly(phenylmethyl-) siloxane is because the free volume fraction is higher than those of other polymers.…”

Quaternary ammonium membrane materials for CO2 separation

“…The gas solubility in polymers increases with increasing condensability [10], but also is highly influenced by specific interactions. Polyfluoroacrylates and polyfluorophosphazines are known for the very high CO 2 solubility [11,12]. Poly (dimethylsiloxane) (PDMS) has the highest solubility among the non-fluorinated polymers, due to low cohesive energy allied to low glass transition and high flexibility, as well as some contribution of Lewis acid-Lewis base interaction.…”

Metal Ions Extraction from Solid Matrix in Supercritical Carbon Dioxide with DMBP as Chelating Ligand

“…The effect of time on the extraction efficiency for DMBP was investigated at five different times (10,20,30,60, and 90 min). The pressure, temperature, and ligand to metal ratio were fixed at constant values of 25 MPa, 323 K, and 100, respectively.…”

“…However, direct extraction of metal ions by sc-CO 2 is known to be highly inefficient because of the charge neutralization requirement and weak solute-solvent interactions. A solution to this problem is to add a CO 2 -soluble chelating agent to produce a metal complex that can be extracted easily into sc-CO 2 from sample matrices [10][11][12][13]. Therefore, this chelation-SFE method might be a promising technology for the treatment of metal-contaminated waste materials.…”