Contribution to the gas chromatographic analysis for both refrigerants composition and cell gas in insulating foams – Part II: Aging of insulating foams

Macchi-Tejeda, Hélène; Opatová, H.; Guilpart, J.

doi:10.1016/j.ijrefrig.2006.04.004

Cited by 11 publications

(7 citation statements)

References 8 publications

(12 reference statements)

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“…19 The K g of CO 2 and air at 298.15 K is 0.0166 and 0.0257 W m À1 K À1 , respectively. 20 Substituting the density of the 1 : 9-PPG-PEI-CO 2 blown polyurethane (62.4 kg m À3 , Table 5) and other parameters into eqn (1), one obtains the thermal conductivity of fresh foams (the trapped gas was CO 2 ) as 0.0286 W m À1 K À1 . However, with the replacement of CO 2 by air due to diffusion, the thermal conductivity nally increases to the value of an air-lled foam which is calculated as 0.0377 W m À1 K À1 .…”

Section: Possible Applications and Future Investigationsmentioning

confidence: 99%

“…Traditional blowing agents (CFCs, HCFCs and HFCs) on the one hand possess very low thermal conductivity (e.g. HCFC 141b: 0.01 W m À1 K À1 ; CFC 11: 0.0082 W m À1 K À1 ) 20 and on the other hand diffuse very slowly through polyurethane foams (the diffusion coefficients of CO 2 , N 2 and O 2 are two to three orders of magnitude higher than those of HCFCs and CFCs). 21 Therefore, the out-diffusion of traditional blowing agents can last for years, 22,23 helping to preserve the low thermal conductivity of the foams.…”

Section: Possible Applications and Future Investigationsmentioning

confidence: 99%

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A family of polypropylene glycol-grafted polyethyleneimines reversibly absorb and release carbon dioxide to blow polyurethanes

et al. 2016

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Section: Possible Applications and Future Investigationsmentioning

confidence: 99%

Section: Possible Applications and Future Investigationsmentioning

confidence: 99%

A family of polypropylene glycol-grafted polyethyleneimines reversibly absorb and release carbon dioxide to blow polyurethanes

et al. 2016

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“…Building from the GC methods outlined by Svanstrom and Ramnas (1995;1996) and others not included in this literature review (Ascough, 1989;Wan, Tyler, & Nienhuis, 1991) (Ascough, 1989;Wan et al, 1991), Macchi-Tejeda et. al.…”

Section: Gas Chromatography -Flame Ionization Detection (Gc-fid)mentioning

confidence: 99%

“…The samples were tested shortly after production and periodically for a total of 6 months. The aging period of 6 months is significantly shorter than the lifetime of the foam, however, it is the period where the most diffusion occurs (Macchi-Tejeda et al, 2007).…”

Section: Gas Chromatography -Flame Ionization Detection (Gc-fid)mentioning

confidence: 99%

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Microstructural and Chemical Analysis of Polyurethane and Polyisocyanurate Foam Insulations

Berardi¹

2023

Preprint

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For some closed cell foam insulation products, the thermal conductivity increases at low temperatures, contrary to single thermal resistance values provided by manufacturers. This phenomenon has been demonstrated in various polyurethane and polyisocyanurate insulations. The reduction in thermal performance has been attributed to the diffusion of air and blowing agent through the foam and to the condensation of blowing agent. Aging processes such as freeze-thaw cycling, moisture accumulation, and polymer degradation further increase thermal conductivity. The initial cell structure plays a role in dictating the thermal performance. To further understand the loss of thermal performance in closed cell foams, microstructure and chemical characterization was performed in this study. The aging behavior of foam insulations was analyzed by imaging foams with SEM and by measuring foam. Changes in the polymer physical attributes were identified and compared to increases in thermal conductivity. This project also used gas chromatography and quantified changes in pentane concentration in polyisocyanurate foams that have undergone aging

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Effect of the shape and the distribution of cells on the effective thermal conductivity of polyurethane foam

Hermama

Bensiali²,

Lahbabi

et al. 2023

Polymer Engineering & Sci

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To design foams with specific properties, it is important to be able to predict their effective properties. The objective of this study is to compare and quantify the effect of the geometrical parameters on the thermal properties. Then the study uses both analytical and numerical homogenization methods to connect micro-scale parameters to the macro-scale thermal behavior. Several statistical studies of the morphology have been used to model the different categories of PU foams. The foam is modeled by a periodic structure of open, closed, or mixed cells. For each type of cell, different idealized shapes of a single cell are used, while keeping a constant porosity for each category. In the case of mixed

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Contribution to the gas chromatographic analysis for both refrigerants composition and cell gas in insulating foams – Part II: Aging of insulating foams

Cited by 11 publications

References 8 publications

A family of polypropylene glycol-grafted polyethyleneimines reversibly absorb and release carbon dioxide to blow polyurethanes

A family of polypropylene glycol-grafted polyethyleneimines reversibly absorb and release carbon dioxide to blow polyurethanes

Microstructural and Chemical Analysis of Polyurethane and Polyisocyanurate Foam Insulations

Effect of the shape and the distribution of cells on the effective thermal conductivity of polyurethane foam

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