Catalog NumberHG-BULK121961204
CAS Number121961-20-4
CategoryPolymers
Poly(vinylbenzyl chloride) as Versatile Precursor for Poly(ionic liquid) Membranes in CO2 Capture
Nikolaeva, Daria, et al. Journal of Materials Chemistry A 5.37 (2017): 19808-19818.
Poly(vinylbenzyl chloride) (PVBC) serves as a readily available, modifiable polymer backbone for synthesizing poly(ionic liquid)s (PILs). Through post-polymerization quaternization and anion exchange, PVBC enables the fabrication of thin-film composite (TFC) membranes with tunable cationic structures for efficient CO2 separation from flue gas.
Synthesis and Membrane Fabrication: Commercial PVBC was quaternized with trimethylamine, 2-(dimethylamino)ethanol, or N-methylpyrrolidine, followed by metathesis with LiTf2N to yield three PILs: P[VBTMA][Tf2N], P[VBHEDMA][Tf2N], and P[VBMP][Tf2N]. TFC membranes were prepared by solvent casting a 4 wt% PIL solution onto a crosslinked porous support, then sealed with a PDMS top layer (≈3 μm). The selective PIL layer thickness was 2-6 μm.
Performance Evaluation: Under mixed-gas conditions (15/85 CO2/N2, 5 bar, 26 °C), PIL cation structure strongly affected separation. P[VBHEDMA][Tf2N] (hydroxyethylammonium) showed the highest CO2/N2 selectivity (41.6) with CO2 permeance 109 GPU, while P[VBMP][Tf2N] (pyrrolidinium) gave lower selectivity (17.2) but higher permeance (1334 GPU). Sorption studies confirmed that polar hydroxyl groups enhance CO2 affinity (ideal solubility selectivity ≈287 for P[VBHEDMA][Tf2N]). Importantly, humidified feed (90% RH) doubled CO2 permeance and increased selectivity by 20-30% compared to dry conditions, mimicking real flue gas.
Conclusion: PVBC is an excellent platform for designing PIL-based TFC membranes, with the hydroxyethylammonium derivative offering promising performance for post-combustion CO2 capture.
Poly(vinylbenzyl chloride) as Hydroxide-Conducting Polymer in Crosslinked Anion Exchange Membranes
Lu, Wangting, et al. Journal of Power Sources 248 (2014): 905-914.
Poly(vinylbenzyl chloride) (PVBC) serves as the hydroxide-conducting component in a novel crosslinked anion exchange membrane (AEM). Using a macromolecular crosslinker-poly(vinyl acetal) containing dimethylamino groups-combines the advantages of semi-interpenetrating networks and covalent crosslinking, yielding homogeneous, flexible membranes with suppressed swelling and high conductivity.
Fabrication Process: PVAc was synthesized from poly(vinyl alcohol) and 4-dimethylaminobenzaldehyde via acetalization. PVBC and PVAc were mixed in NMP (weight ratios 2:1, 3:2, 1:1) and heated at 80 °C to form crosslinks between benzyl chloride and dimethylamino groups. The membranes were treated with 1-methylimidazole/CH3I followed by 1 M KOH to convert remaining chloromethyl groups into imidazolium and quaternary ammonium hydroxides.
Performance Evaluation: FTIR and XPS confirmed crosslinking and quaternization. The PVAc(1)-c-PVBC(1)/OH membrane achieved IEC 1.26 mmol/g, water uptake 139%, swelling ratio 26.3%, and OH- conductivity 0.029 S/cm at room temperature (0.054 S/cm at 80 °C). Crosslinking effectively suppressed swelling at elevated temperatures. In an H2/O2 fuel cell at 40 °C, the membrane delivered an open-circuit voltage of 1.035 V and a peak power density of 124.7 mW/cm2. The OCV remained above 0.99 V for 120 h under continuous operation, indicating good oxidative stability.