Polyurethane aerogels synthesis for thermal insulation – textural, thermal and mechanical properties

Diascorn, Noémie; Calas, S.; Sallée, Hébert; Achard, Patrick; Rigacci, Arnaud

doi:10.1016/j.supflu.2015.05.012

Cited by 85 publications

(47 citation statements)

References 32 publications

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“…(2) to the data of Fig. 13 yields an exponent m between 3.0 and 3.5, in overall agreement with previous results on this class of materials [7,40,41]. We also note that the compression modulus is the lowest for N3300A-based aerogels and the highest for RC-based aerogels.…”

Section: Compression Modulussupporting

confidence: 91%

Density and shrinkage as guiding criteria for the optimization of the thermal conductivity of poly(urethane)-class aerogels

Członka

Bertino

Kośny

et al. 2019

J Sol-Gel Sci Technol

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We investigated the effect of gelation solvent, monomer type, and monomer concentration on the physical properties of freeze-dried poly(urethane)-poly(isocyanurate) (PUR-PIR) aerogels, with particular emphasis on their thermal conductivity. It was found that the gelation solvent considerably affects aerogel morphology and physical properties. Aerogels with the lowest thermal conductivity were obtained using a mixture of tetrahydrofuran (THF) and acetonitrile, in a 50% volume ratio. The influence on thermal conductivity of polyol and isocyanate structure and of their concentration was also investigated. Rigid precursors, phloroglucinol (POL), and an aromatic polyisocyanate based on toluene diisocyanate (Desmodur RC) yielded the lowest thermal conductivity. Our results were compared with recent work reporting on parameters that could be used as predictors of thermal conductivity and other physical properties of organic aerogels. None of these parameters were found to be satisfactory predictors of aerogel properties. For example, no systematic correlation between solvent solubility parameters and aerogel properties was observed. We also examined the role of the K-index. This index, defined as the ratio between porosity and contact angle, was shown recently to be a good predictor of the properties of polyurea aerogels. While the thermal conductivity scaled with the K-index, the scaling was different for each of the isocyanate monomers considered in our experiments. Thermal conductivity, instead, scaled well with the product of density and shrinkage of aerogels, independent of monomer type. The reasons of this dependence on shrinkage and density are discussed, and the use of these parameters to guide experimentation on other systems is discussed. Physical properties such as static and dynamic compression modulus and thermal stability of the most promising formulations were also examined.

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Section: Compression Modulussupporting

confidence: 91%

Density and shrinkage as guiding criteria for the optimization of the thermal conductivity of poly(urethane)-class aerogels

Członka

Bertino

Kośny

et al. 2019

J Sol-Gel Sci Technol

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“…Log (E modulus ) vs Log (bulk density) for different aerogel like materials[4][5][6][7][8][9][10][11][12][13][14][15][16].…”

mentioning

confidence: 99%

Reinforced and superinsulating silica aerogel through in situ cross-linking with silane terminated prepolymers

Iswar

Snellings²,

Zhao

et al. 2018

Acta Materialia

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“…The aerogel is a class of open cellular porous material with more than 80% porosity, in which the liquid in the gel is replaced with a gas . These materials have a high surface area (1100–4700 m 2 g −1 ) with very low apparent density (0.06–0.35 gcm −3 ) . The disadvantage of silica aerogel is fragility and nonflexibility.…”

Section: Introductionmentioning

confidence: 99%

Conductive shape‐memory polyurethane/multiwall carbon nanotube nanocomposite aerogels

Teymouri

Kokabi

Alamdarnejad

2019

J of Applied Polymer Sci

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Smart nanocomposite aerogels have promising applications. In this work, different percentages of multiwall carbon nanotube (MWCNT) added into synthesized polyurethane (PU) gel in the molten state, using a two-roll mill. By soaking the PU/MWCNT nanocomposite gel into the water, PU/MWCNT hydrogels containing more than 90 wt % of water were prepared. The obtained hydrogels were freeze-dried to produce aerogel counterparts. The aerogels were fully characterized using mercury porosimetry, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM). The electrical percolation threshold of conductive aerogel system was measured. The shape-memory behavior of PU/MWCNT nanocomposite aerogels was evaluated by dynamic mechanical thermal analysis (DMTA). The results of the DMTA showed that by adding 2.75 wt % of MWCNT, the recovery ratio and storage modulus of the PU/MWCNT nanocomposite aerogel increased 42 and 180%, respectively. The electrical conductivity of the system also increased three orders of magnitude at the percolation threshold.

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Polyurethane aerogels synthesis for thermal insulation – textural, thermal and mechanical properties

Cited by 85 publications

References 32 publications

Density and shrinkage as guiding criteria for the optimization of the thermal conductivity of poly(urethane)-class aerogels

Density and shrinkage as guiding criteria for the optimization of the thermal conductivity of poly(urethane)-class aerogels

Reinforced and superinsulating silica aerogel through in situ cross-linking with silane terminated prepolymers

Conductive shape‐memory polyurethane/multiwall carbon nanotube nanocomposite aerogels

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