Mechanical, morphological, and thermal properties of rigid polyurethane foams blown by distilled water

Seo, Won Ik; Jung, Hyun Chul; Hyun, Jae Chun; Kim, W. N.; Lee, Y.-B.; Choe, Kun Hyung; Kim, S.-B.

doi:10.1002/app.12238

Cited by 93 publications

(70 citation statements)

References 13 publications

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“…In contrast to the density decrease, strength and its anisotropy (strength ratio of parallel to perpendicular direction) smoothly increases with increasing concentration of surfactant with a maximum at 2 pphp (Figure 6). An earlier work showed simultaneous decreases of compression strength with increasing surfactant concentration [7]. It seems that the compression strength is closely related to the closed cell content and cell size when the density variation is insignificant…”

Section: Compression Strengthmentioning

confidence: 84%

“…Mechanical properties at room temperature were measured using a Universal Testing Machine (Ametek, Lloyd). Compression strength was determined by ASTM D 1621 at a crosshead speed of 3.0 mm/min with the sample dimension of 30×30×30 mm [7]. The force required for 10% deformation based on the original thickness has been taken as the compression strength of the foam.…”

Section: Characterizationsmentioning

confidence: 99%

“…To reinforce the foam, composites with particle, clays and fiber have been considered [17][18][19][20][21]. As far as the present authors are concerned, systematic investigations of the effects of surfactant on various properties of RPUF are sparse, perhaps except those blown with water [7,22].We synthesized various types of RPUFs from CMDI and polypropylene glycols (PPGs) with an environmentally friendly physical blowing agent, viz. HFC 365mfc (CF 3 CH 2 CF 2 CH 3 ), with a potential target application of insulation panel of LNG cargo where high compression strength as well as thermal insulation is highly desired.…”

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confidence: 99%

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Effects of silicon surfactant in rigid polyurethane foams

Lim¹,

Kim²,

Kim³

2008

Express Polym. Lett.

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Section: Compression Strengthmentioning

confidence: 84%

Section: Characterizationsmentioning

confidence: 99%

mentioning

confidence: 99%

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Effects of silicon surfactant in rigid polyurethane foams

Lim¹,

Kim²,

Kim³

2008

Express Polym. Lett.

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“…After mixing, the reactants were poured into an open mold (250 × 250 × 100 mm) to produce free-rise foams and were cured for 1 week at room temperature. 18,19 In order to investigate the effect of clay on the physical properties and thermal conductivity of PUF, neat PUF was also prepared and compared to PUF/clay composites. The PUF/clay nanocompisites were synthesized with and without ultrasound to study the effect of ultrasonic cavitation on PUF's properties.…”

Section: Methodsmentioning

confidence: 99%

Effects of organoclay on the thermal insulating properties of rigid polyurethane poams blown by environmentally friendly blowing agents

et al. 2007

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A process designed to synthesize rigid polyurethane foam (PUF) with insulative properties via the modulation of PUF cell size via the addition of clay and the application of ultrasound was assessed. The blowing agents utilized in this study include water, cyclopentane, and HFC-365mfc, all of which are known to be environmentallyfriendly blowing agents. The rigid PUFs were prepared from polymeric 4,4'-diphenylmethane diisocyanate (PMDI) and polyether polyol with a density of 50 kg/m 3 . In addition, rigid PUFs/clay nanocomposites were synthesized with clay modified by PMDI with and without the application of ultrasound. The PUF generated using water as a blowing agent evidenced the highest tensile strength. The tensile strength of the PUF/nanocomposites was higher than that of the neat PUF and the strength was even higher with the application of ultrasound. The cell size of the PUF/clay nanocomposites was less than that of the neat PUF, regardless of the type of blowing agent utilized. It appears that the higher tensile strength and lower cell size of the PUF/clay nanocomposites may be attributable to the uniform dispersion of the clay via ultrasonic agitation. The thermal conductivity of the PUF/clay nanocomposites generated with HCFC-141b evidenced the lowest value when PUF/clay nanocomposites were compared with other blowing agents, including HFC-365mfc, cyclopentane, and water. Ultrasound has also proven effective with regard to the reduction of the thermal conductivity of the PUF/clay nanocomposites with any of the blowing agents employed in this study. It has also been suggested that the uniformly dispersed clay particles in the PUF matrix function as diffusion barriers, which prevent the amelioration of the thermal insulation property.

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“…Nichol et al [8] reported the effects of equivalent weight and functionality of polyol on the properties of foams. Recently, Jung et al [9,10] compared the properties of rigid polyurethane foams blown by HCFC-141b with those by distilled water. In their work, however, the structure characteristics and dimensional stability of foams were not referred to, and all of data were only limited to the system water level ranging from 0.5 pph to 3.0 pph.…”

mentioning

confidence: 99%

Structures and physical properties of rigid polyurethane foams with water as the sole blowing agent

Cao

Zhang

2006

SCI CHINA SER B

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Rigid polyurethane foams blown by varying water level were prepared in this study. The structures and physical properties of rigid polyurethane foams blown by water were measured with FT-IR, universal testing machine (Instron3365), scanning electron microscope (SEM) and differential scanning calorimeter (DSC). The results show that polyurea and polybiuret were the typical characteristics, and the cream time and gel time were shorter for the fully water blown rigid foams than that for the fully cyclopentane blown foams. The density of foam samples decreased from 45.0 kg/m 3 to 27.4 kg/m 3 with the increase of water level from 3 pph to 7 pph. Compressive strength exhibited the similar behavior with density. The average cell size of foam samples ranged from 241 µm to 356 µm with the increase of water level from 3 pph to 7 pph, respectively. At the same time, poorer dimensional stability was encountered with the increase of average cell size due to fast diffusion rate of CO 2 out of the foam. The results of thermal analysis show that the glass transition temperature (T g ) shifted to a higher temperature with the increase of isocyanate level when more water was used as chemical blowing agent.

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Mechanical, morphological, and thermal properties of rigid polyurethane foams blown by distilled water

Cited by 93 publications

References 13 publications

Effects of silicon surfactant in rigid polyurethane foams

Effects of silicon surfactant in rigid polyurethane foams

Effects of organoclay on the thermal insulating properties of rigid polyurethane poams blown by environmentally friendly blowing agents

Structures and physical properties of rigid polyurethane foams with water as the sole blowing agent

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