Polyurethane gas separation membranes with ethereal bonds in the hard segments

Self Cite

The increasing need for more efficient separation processes has motivated the development of polymer membranes that can provide fast and selective transport. In this work, cadmium‐based metal–organic framework (MOF) nanoparticles and a polyurethane–urea (PUU) elastomer were synthesized. New mixed‐matrix membranes (MMMs) were then fabricated from the nanoparticles and the PUU. SEM images verified that embedding the nanoparticles changes the morphology of the PUU and the nanoparticles disperse well in the PUU due to satisfactory compatibility of the polymer and nanoparticles. Fourier transform infrared spectroscopy and X‐ray diffraction analysis confirmed the dispersion of the nanoparticles in the soft segment of the PUU. With increased temperature, gas permeabilities of the MMMs improved but their sieving ability deteriorated. An MMM incorporating 2.5 wt % of the MOF showed a CO2 permeability of ~140 barrer and a CO2/N2 selectivity of ~30, which are 89 and 38% higher than those of the pristine membrane. Gas permeation tests showed that the higher CO2/N2 selectivity of the MMMs was due to improved solubility selectivity and the higher CO2 permeability was a result of improved CO2 diffusivity and solubility coefficients. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48704.

Section: Resultssupporting

confidence: 94%

“…The PUU was synthesized by a two‐step polymerization method in a glass reactor under nitrogen atmosphere at 75 °C . Figure shows the reaction steps.…”

Section: Methodsmentioning

confidence: 99%

Improved gas transport properties of polyurethane–urea membranes through incorporating a cadmium‐based metal organic framework

Sadeghi

Isfahani

Shamsabadi

et al. 2019

Self Cite

“…Samples with and without tridecanoic acid showed identical glass‐transition temperatures at −73 and 57 °C (Figure ). It is well known that the low glass‐transition temperature is attributed to the soft segment of the polyurethane, more specifically the long polyol 2‐ethyl‐1,3‐hexandiol. The 57 °C glass transition is attributed to the urethane group‐hard segment of the matrix made from each isomer of TDI .…”

Section: Resultsmentioning

confidence: 99%

Extending the working life of toluene diisocyanate‐based polyurethanes

Reardon

Carroll

Dumont

et al. 2019

This work demonstrates that the addition of tridecanoic acid to a toluene diisocyante (TDI)‐based polyurethane considerable increases its working life. Formulations with the additive exhibited little changes in chemistry, glass‐transition temperatures, and thermal stability as determined by Fourier transform infrared spectroscopy, rheology studies, nuclear magnetic resonance, solvent swelling tests, and thermal analyses. There was a slight increase in toughness of the additive formulation associated with an increase in engineering strain and a decrease in peak engineering stress. Molecular dynamics simulations indicated that the acid forms hydrogen bonding with the OH groups from the diols, slowing down the polymerization. These studies demonstrate that tridecanoic acid can be used to extend working time of a TDI‐based polyurethane with minimal changes to physical and chemical properties when compared to the pristine polyurethane. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47865.

“…PUs with different PEG/PDMS proportions were prepared by a two‐step polymerization, and the molecular feed ratios of the monomers are listed in Table . A typical procedure for the synthesis of PU‐d was as follows: PEG (24 g, 0.012 mol) and PDMS (24 g, 0.012 mol) were added to a 500 mL, three‐necked flask and stirred at 85°C for 1 hour under a nitrogen atmosphere.…”

Section: Methodsmentioning

confidence: 94%

“…found that PU membranes had a P CO2 of 96.83 Barrer at 25°C and 6 bar. Isfahani et al . reported that a diol‐based PU had the same chain‐extender length as a diamine‐based polyurethane–urea (PUU).…”

Section: Introductionmentioning

confidence: 99%

Synthesis and CO₂ separation of novel polyurethane membranes containing urea linkages

Zheng

Yang

et al. 2019

We synthesized novel polyurethane (PU) membranes from isophorone diisocyanate (IPDI), poly(ethylene glycol) (PEG) with a molecular weight of 2000, aminopropyl‐terminated poly(dimethyl siloxane) (PDMS) with a molecular weight of 2000, and 1,4‐butanediol (BDO) via a two‐step polymerization. The structure of each synthesized membrane was studied through Fourier transform infrared spectroscopy and gel permeation chromatography. The effect of the thermal behavior was determined by differential scanning calorimetry and thermogravimetric analysis. The gas‐permeability characteristics of the PU membranes were then tested for a single gas. The results show that the permeability of CO2 (PCO2) gradually increased with PDMS content. Among these PU membranes, PU‐d (PEG/PDMS = 1:1, PEG/PDMS/IPDI/BDO = 1:3:2) showed the best PCO2 (132.6 Barrer) at 25°C and 1 bar pressure. The gas‐permeability coefficients of each PU membrane at different operating temperatures were investigated, and the results show that PCO2 reached 302.6 Barrer at 65°C and 1 bar. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47723.