Effects of silicon surfactant in rigid polyurethane foams

Lim, Ho Sun; Kim, S. H.; Kim, B. K.

doi:10.3144/expresspolymlett.2008.24

Cited by 90 publications

(64 citation statements)

References 23 publications

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“…This indicated that the compressive strength of foam is closely related to the density. Numerous studies also showed that apparent density is a key factor for compressive strength [13]. The compressive strength of DPF foams and TPF foams reached its maximum value (0.110, 0.103 MPa, respectively) when the surfactant is 10 %.…”

Section: Microstructure Of the Foammentioning

confidence: 99%

“…Numerous studies showed that silicone surfactant has a lower surface tension than carbon hydrocarbon chain surfactant [12,13]. Additionally, the hydrophobic siloxane-chain may further increase the emulsifying efficiency of phenol-ureaformaldehyde resins, which would make the resin foam more quickly during the reaction [13,14]. Figure 2c shows the effects of various concentrations of surfactants on the tack-free of phenol-urea-formaldehyde resins.…”

Section: Foaming Dynamicsmentioning

confidence: 99%

“…In a study conducted by Zhang et al, the authors showed that increasing the proportion of polysiloxane/polyether in the silicone surfactant reduces the surface tension of the polyurethane foam and further reduces the size of cells that compose the foam [12]. 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%

See 2 more Smart Citations

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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Section: Microstructure Of the Foammentioning

confidence: 99%

Section: Foaming Dynamicsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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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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“…The compressive strength of the PU foams was obtained from 200 to 311 kPa. The mechanical properties of PU foams depended on several parameters such as density, cross-linking density, cell geometry and blowing efficiency [13,14]. The variation in compressive strength with foams density in Fig.…”

Section: Density and Compressive Strength Of Pu Foamsmentioning

confidence: 99%

Characterization of polyurethane foams prepared from liquefied sawdust by crude glycerol and polyethylene glycol

2018

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The aim of this study was to investigate polyurethane foams (PUF) properties obtained from crude glycerol (CG) and polyethylene glycol (PEG) based liquefaction of sawdust. The four types of foam were prepared by producing polyols from different weight loadings of PEG to CG as the liquefaction solvent. The produced polyurethane foams showed densities from 0.042 to 0.08 g/cm 3 and compressive strengths from 200 to 311 kPa. The foams obtained from CG/PEG based liquefaction, had more uniform and regular cell structure than foams derived from liquefaction by CG. Also with the increasing percentage of PEG to CG in liquefaction, closed cell content of the synthesized foams increased and the size of cells decreased. The thermal conductivity of the produced foams was between 0.031 and 0.040 W/m K. Foams produced from liquefaction by binary solvent had lower thermal conductivity. However all foams showed approximately similar thermal degradation curves; maximum thermal decomposition temperature was seen for the foam produced from higher weight ratio of PEG to CG in liquefaction. PU foams produced from PEG/CG based liquefaction process had improved properties over from foams derived from sawdust liquefaction by CG.

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“…PU has rapidly grown to be one of the most diverse and widely-used materials with a continuously increasing global market since its first lab synthesis in 1937 by Otto Bayer and co-workers (Vermette et al, 2001). Compared to conventional materials, e.g., wood and metals, polyurethane has its own unique merits, such as low density, thermal conductivity and moisture permeability, a high strength to weight ratio, and dimensional stability (Lim et al, 2008). In addition, the formulation and reaction conditions can be readily adjusted to synthesize PUs with desired properties for specific applications.…”

Section: Introductionmentioning

confidence: 99%