UV Cross-Linked Poly(ethylene glycol)-Based Membranes with Different Fractional Free Volumes for CO₂ Capture: Synthesis, Characterization, and Thiol-ene Modification Evaluation

Abstract

CO2 separation is of paramount importance in CO2 capture from flue gas and natural gas sweetening. In this paper, the thiol-ene UV photopolymerization technique was employed to synthesize improved UV cross-linked amorphous poly­(ethylene glycol) (PEG)-based membranes using poly­(ethylene glycol) diacrylate (PEGDA) and poly­(ethylene glycol) methyl ether acrylate (PEGMEA) oligomers. To increase the fractional free volume (FFV) and consequently decrease the network cross-link density of PEGDA network, PEGMEA was incorporated to prepare the PEGDA-PEGMEA copolymer network. A tetrathiol cross-linker, namely, pentaerythritol tetrakis­(3-mercaptopropionate) (PETMP), was also utilized to alter the polymerization route from the chain-growth acrylate photopolymerization to step-growth free radical thiol-ene photopolymerization. The membranes were characterized by SEM, ATR-FTIR, DSC, TGA, and tensile analyses. Permeation measurements were carried out for CO2, CH4, N2, and H2 over wide ranges of temperature (308–348 K) and pressure (2–16 bar). It was revealed that a thiol-modified copolymer membrane, i.e., PEGDA-PEGMEA-PETMP, offers promising CO2 separation performance, more conspicuously at high temperatures.

Bio-Inspired Polydopamine-Modified ZIF-90-Supported Gel Polymer Electrolyte for High-Safety Lithium Metal Batteries

“…Specifically, the characteristic peak observed at 1635 cm –1 corresponds to the stretching vibration of CC in PEGDA, while the characteristic peak at 1723 cm –1 relates to the stretching vibration of CO . Regarding PETMP, the peak observed at 2567 cm –1 can be assigned to the sulfhydryl group (–SH) . Following the click polymerization reaction, the peak associated with the sulfhydryl group at 2567 cm –1 completely disappears, and the intensity of the vinyl group peak at 1635 cm –1 is significantly weakened, confirming the successful execution of the click reaction.…”

Radical Photopolymerization Using 1,4-Dihydropyrrolo[3,2-b]pyrrole Derivatives Prepared via One-Pot Synthesis

“…PyBN: bright red solid, 2.3 g, yield: 30%. 1 H NMR (400 MHz, DMSO-d 6 ): δ 8.2 (d, J = 8.8 Hz, 2H), 7.7 (d, J = 8.7 Hz, 2H), 7.5 (d, J = 8.8 Hz, 2H), 7.3 (d, J = 8.6 Hz, 2H), 6.9 (s, 1H). 13 C NMR (101 MHz, chloroform-d): δ 145.8, 138.9, 138.1, 135.2, 133.6, 132.9, 127.9, 126.8, 124.0, 120.5, 97.1, 58.5, 18.5.…”

“…Photopolymerization is a popular technique for curing materials used in applications such as three-dimensional (3D) printing, adhesives, and coatings. − Photoinitiated photopolymerization affords advantages such as low temperature, no usage of harmful solvents, a rapid curing rate, and spatial control of polymerization compared to the features of thermal curing. Radical photopolymerization has attracted increasing attention to obtain products with 3D structures by different additive manufacturing techniques − such as layer-wise and volumetric methods. , The curing principle of radical photosensitive resins is similar. , Generally, the photosensitive resin used for radical photopolymerization is composed of monomers and a prepolymer containing CC double bonds as well as a photoinitiator and co-initiator that matches a specific light wavelength. , (Meth)­acrylate resin is a commonly used photoactive material both in academic and practical applications that yields a good cross-linked polymer via radical polymerization. − …”

“…NMR and13 C NMR spectra were recorded to further analyze the products. As shown in Figure2e, the1 H NMR spectrum of PyBN shows a peak at 6.88 ppm, corresponding to the C−H of pyrrole, and a new peak at 6.99 ppm is observed after irradiation for 320 s. This indicates the formation of a new pyrrole[3,2-b]pyrrole structure. The peak at 5.75 ppm corresponds to the C−H of the alkene moiety generated after irradiation for 480 s. As shown in Figure 2f, the 13 C NMR spectrum shows peaks at 178.3 and 168.7 ppm for 320 and 480 s, confirming the presence of CO groups, respectively.…”

Hyperbranched polymers with step-growth chemistries from transfer-dominated branching radical telomerisation (TBRT) of divinyl monomers

“…3,4 The term telomerisation was first introduced over 70 years ago 5,6 and was defined as the reaction of a telogen, designated XY, to an unsaturated taxogen compound, Q, to form a telomer, X(Q) n Y. Many common reactions may be technically classified by the term telomerisation such as thiol-ene reactions 7 (addition of RS-H telogen across the CvC double bond of a taxogen), the addition of CO 2 , 8 water or hydroxyl functional small molecules to alkenes 9 and the Cysteine Lipidation on a Peptide or Amino acid (CLipPA) reactions. 10 Within the field of polymerisation, a telomer contains a distribution of products with a low number of Q residues within the final sample; specifically, the telogen fragments X and Y comprise the α and ω chain-ends of each oligomeric chain respectively.…”