Preparation and Characterization of Cellulose Acetate Propionate Films Functionalized with Reactive Ionic Liquids

Abstract

1-(1,3-diethoxy-1,3-dioxopropan-2-ylo)-3-methylimidazolium bromide (RIL1_Br), 1-(2-etoxy-2-oxoethyl)-3-methylimidazolium bromide (RIL2_Br), 1-(2-etoxy-2-oxoethyl)-3-methylimidazolium tetrafluoroborate (RIL3_BF4) ionic liquids were synthesized. Subsequently, the dense cellulose acetate propionate (CAP)-based materials containing from 9 to 28.6 wt % of these reactive ionic liquids were elaborated. Reactive ionic liquids (RILs) were immobilized in CAP as a result of the transesterification reaction. The yield of this reaction was over 90% with respect to the used RIL. The physicochemical properties of resultant films were studied using nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), atomic force microscopy (AFM), and thermogravimetric analysis (TGA). The RIL incorporation influenced the morphology of films by increasing their surface roughness with the rise of RIL content. The thermal stability of CAP-based membranes was dependent on the nature of the ionic liquid. Nevertheless, it was proven that CAP films containing RILs were stable up to 120–150 °C. Transport properties were characterized by water permeation tests. It was found that the type and the amount of the ionic liquid in the CAP matrix substantially influenced the transport properties of the prepared hybrid materials.

The Impact of Reactive Ionic Liquids Addition on the Physicochemical and Sorption Properties of Poly(Vinyl Alcohol)-Based Films

“…The synthesis was carried out according to the procedure described elsewhere [ 36 ]. The reaction yield was equal to 99% and 95% for RIL1_Br and RIL2_Br, respectively.…”

“…The RIL1_Br and RIL2_Br structures were confirmed by 1 H and 13 C NMR analysis. The detailed NMR results can be found in our previous study [ 36 ]. The number of protons determined via integration of peaks in the 1 H NMR spectrum, signals multiplicity and chemical shifts correspond to the proposed structure of RIL1_Br ( Figure 1 ) and RIL2_Br ( Figure 2 ).…”

“…The number of protons determined via integration of peaks in the 1 H NMR spectrum, signals multiplicity and chemical shifts correspond to the proposed structure of RIL1_Br ( Figure 1 ) and RIL2_Br ( Figure 2 ). Moreover, all carbon atoms in a different chemical environment were matched to the signals in the 13 C NMR spectrum [ 36 ].…”

“…The samples were sputtered with an Au/Pd conductive layer (80/20) with the 2–6 nm thickness. The detailed description of SEM measurements can be found elsewhere [ 36 , 37 ].…”

“…The PVA-RIL films surface topography was examined with an atomic force microscope (AFM) with a NanoScope MultiMode SPM System and NanoScope IIIa and Quadrex controller (Digital Instrument, Veeco, London, UK) and subsequently evaluated using root mean square roughness ( R q ) and arithmetic average height ( R a ) parameters. R q and R a parameters were determined for the 5 µm × 5 µm scanned sample area by using a Nanoscope v6.11 software (Bruker Corporation, Berlin, Germany) [ 36 , 38 ].…”