Surfactant level influences on structure and properties of flexible slabstock polyurethane foams

Kaushiva, Bryan D.; McCartney, Stephan; Rossmy, G.; Wilkes, Garth L.

doi:10.1016/s0032-3861(99)00135-4

Cited by 100 publications

(80 citation statements)

References 21 publications

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“…Polyurethanes have fewer chances to build hydrogen bonds and they are not well-localized, and allow more freedom during the linkage of the carbamates. [35] As mentioned above, in polyurea elastomers intermolecular hydrogen bonds are formed between the active hydrogen atoms of one urea donor group (ÀNHÀ) and the acceptor carbonyl group from another urea motif (ÀCOÀ). The formation of hydrogen bonds with other carbonyl-type groups like esters, amides and carbamates, and rarely with alcohols or ethers, is also possible.…”

Section: Hydrogen Bonding In Polyetherurea Elastomersmentioning

confidence: 99%

Synthesis and Characterization of New Polyurea Elastomers by Sol/Gel Chemistry

Sánchez‐Ferrer

Rogez

Martinoty

2010

Macro Chemistry & Physics

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A series of elastomers based on polyurea chemistry is synthesized by crosslinking amino‐terminated polyethers with a triisocyanate using an appropriate solvent, which slowed down the reactivity of the amino groups. Control of the reactivity allows the shaping of the material, and films of defined thickness can be achieved for mechanical testing. The strength of the final network can be tuned by the crosslinking density of the network chemical constitution. The resulting materials show a good thermal stability and promising mechanical enhancement.magnified image

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Section: Hydrogen Bonding In Polyetherurea Elastomersmentioning

confidence: 99%

Synthesis and Characterization of New Polyurea Elastomers by Sol/Gel Chemistry

Sánchez‐Ferrer

Rogez

Martinoty

2010

Macro Chemistry & Physics

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“…Additionally, Lim et al demonstrated that silicon surfactants can reduce the surface tension of the foaming system, preventing adjacent cells from combining and making the closed cells of the polyurethane foam [13]. While a number of studies have been conducted to examine the effects of various surfactants on the cellular structure and mechanical properties of polyurethane foams [14][15][16][17][18][19], studies examining the effects of surfactants on phenol-urea-formaldehyde foam are much less common.…”

Section: Introductionmentioning

confidence: 99%

Effects of surfactants on the mechanical properties, microstructure, and flame resistance of phenol–urea–formaldehyde foam

Cheng

et al. 2015

Polym. Bull.

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To study the effect of surfactants on the foaming behavior of phenolurea-formaldehyde foam, silicone oil and Tween-80 surfactants were selected to study their effects on the mechanical properties, microstructure, and combustion characteristics of the foams. The results show that the surface tension of the phenol-urea-formaldehyde resins decreased with increasing surfactant concentration. Both the foaming temperature and foaming capacity of the phenol-urea-formaldehyde foam first increased and then decreased with increasing surfactant concentration. The compressive strength and oxygen index of the phenol-urea-formaldehyde foam first decreased and then increased with increasing surfactant concentration, which is probably related to the foaming capacity of the foam. The microstructure of the foams showed that the average pore diameters first increased and then decreased with increasing surfactant concentration. The combination of DC-193 and Tween-80 surfactants significantly improved the compressive strength, uniformity of the cells, and the number of closed cells in the final foam product.

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“…A higher agitation speed increased the nucleation of air microbubbles inside the polymer for a particular formulation. It should also be considered that as the volume of carbon dioxide (CO2) formed is the same at all agitation speeds, the amount of CO2 in each microbubble will be lower in the foam with a greater number of nucleated microbubbles, resulting in the formation of small cells with a greater amount of pores per area (Kaushiva et al, 2000).…”

Section: Pufs Synthesis and Characterizationmentioning

confidence: 99%

Synthesis, Characterization and Application of a Polyurethane-Based Support for Immobilizing Membrane-Bound Lipase

Soares

Rico

Andrade

et al. 2017

Braz. J. Chem. Eng.

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-This study conducted an assessment of polyurethane foams that were synthesized by one-shot process and used as a low-cost support to immobilize Mucor circinelloides URM 4182 whole-cells presenting high lipolytic activity. Polyols with different molecular weights (1100 to 6000 g mol ) were applied to synthesize the polymer matrix, and the agitation speed effect was used for controlling the average pore size of the investigated polyurethane foams. The physical and mechanical properties of the polymers were evaluated by standard test methods, and their morphology was identified by Scanning Electron Microscopy. The immobilization procedure efficiency was assessed by quantifying the capability of the matrices to attach the cells and the catalytic activity of the biocatalysts in both aqueous (olive oil hydrolysis) and non-aqueous media (ethanolysis of babassu oil) under single and consecutive batch runs. Although all synthesized matrices were suitable to immobilize the whole cells with high catalytic performance, a better set of parameters was attained when the polyol ether with molecular weight of 6000 g mol -1and 1100 g mol -1 was used. Both matrices yielded immobilized biocatalysts with high hydrolysis and transesterification activities, and exhibited a satisfactory operational stability with 96% and 81% retention of their initial hydrolytic and transesterification activities after three consecutive batch runs.

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Surfactant level influences on structure and properties of flexible slabstock polyurethane foams

Cited by 100 publications

References 21 publications

Synthesis and Characterization of New Polyurea Elastomers by Sol/Gel Chemistry

Synthesis and Characterization of New Polyurea Elastomers by Sol/Gel Chemistry

Effects of surfactants on the mechanical properties, microstructure, and flame resistance of phenol–urea–formaldehyde foam

Synthesis, Characterization and Application of a Polyurethane-Based Support for Immobilizing Membrane-Bound Lipase

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