• Elastomers and Composites
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• v.47 no.3
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• pp.246-253
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• 2012

This study was carried out to prepare a type of warm mix asphalt. Through urethane foam and emulsion asphalt preparation techniques a protocol of asphalt foam was made. Then three kinds of flame retardant agents were added in there to alleviate the inherent susceptability of asphalt and foam material to flame and thus flame retardant asphalt foam was made. The internal structure of form asphalt was composed of open cell. The higher the NCO% brought the larger the cell and the stronger also. Asphalt increased the strength of the foam. Among the flame retardant agents employed tritorylphosphate was the most effective.

• Macromolecular Research
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• v.11 no.2
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• pp.104-109
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• 2003

A microcellular, which combines a rubber with the conventional formulation of styrene/divinylbenzene/sorbitan monooleate/water system, was prepared using high internal phase emulsion (HIPE) polymerization. Although the open microcellular foam with low density from the conventional HIPE polymerization shows highly porous characteristics with fine, regular and isotropic structure, the one having much smaller cell size is desirable for various applications. In this study, a polybutadiene was introduced to reduce the cell size with comparable properties. Major interests were focused on the effects of rubber concentration and agitation speed on the cell sizes and compression properties. Scanning electron microscopy was used to observe the microcellular morphology and compression tests were conducted to evaluate the stress-strain behaviors. It was found that the cell size decreased as rubber concentration increased, reflecting a competition between the higher viscosity of continuous phase and the lower viscosity ratio of dispersed to continuous phases due to the addition of high molecular weight rubber into the oil phase of emulsion. A correlation for the average cell size depending on agitation speed was attempted and the result was quite satisfactory.

• Polymer(Korea)
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• v.25 no.4
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• pp.528-535
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• 2001

Polyurethane specimens were mainly composed of polyol, MDI, silicone surfactant, and water. The effects of ethylene glycol on the cell size, forming magnification, cream time, gel time, take free time, final free rising height, and reactive temperature were investigated. The cyclopentane was used for PU foam as a physical blowing agent. The components were hand-mixed at about 5000 rpm within 4 seconds at room temperature. The mixtures with various ethylene glycol contents were foamed in the wood mold. When the index of isocyanate was fixed, as the amount of ethylene glycol increased, cell size and thermal conductivity were decreased by about 5.1% and 14%, respectively.

• Polymer(Korea)
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• v.24 no.4
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• pp.564-570
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• 2000

The waste FRP occured in the fabrication of SMC (sheet molding compound) bathtubs and the waste polyurethane foam occured in electronic manufacture and waste insulator were applied as a soundproof and light weight pannel in the waste FRP unsaturated polyester matrix resin composites to recycle. The effect of filler contents on the mechanical properties and interfacial phenomena of the filler and matrix on the composites was evaluated. The tensile strength of composites reached its maximum value of 82.34 MPa when the filler content was 70 wt%, and the more content of reinforcement is increased, the more tensile modulus was decreased. The flexural strength and modulus of composites, reinforced 70 wt% with filler content, were dominant compared to the other samples to 72.5 MPa, 958.4 MPa respectively. When composite of reinforced 70 wt% with filler content, it was confirmed that pull out phenomena and cracks did not occur in the interface of reinforcement and matrix resin through the SEM observation. Also, waste FRP and urethane foam were dispersed well into matrix resin as filler.

• Polymer(Korea)
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• v.26 no.6
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• pp.759-766
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• 2002

Regular, spherical and isotropic open-microcellular foams having low density were prepared by the high internal phase emulsion (HIPE) polymerization mainly composed of styrene monomer and water The effects of Polymerization conditions. such as the content of water, divinylbenzene as a crosslinking agent and dodecane as a chain transfer agent, were investigated based on the tell size and foam properties. The microstructural morphology was observed using scanning electron microscopy (SEM) and the compression modulus of the foam was evaluated using compression test. The dropwise feeding of the aqueous phase into the oil phase was more effective than the batch feeding in producing the uniform and stable foam. Agitation speed and surfactant strongly influenced on the cell size and the window size between water droplets. Introduction of chain transfer agent increased the cell size, whereas it decreased the window size. Compression modulus increased with the crosslinking agent, but decreased with the chain transfer agent.

• Elastomers and Composites
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• v.48 no.4
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• pp.276-281
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• 2013

Polyester type polyurethane foam modified with acrylic polyol was prepared by quasi prepolymer method. Thermal and dynamic mechanical properties of polyurethane foam were analysed by thermal gravimetric analysis(TGA) and dynamic mechanical analysis(DMA). Also, glass transition temperature was measured by differential scanning calorimeter(DSC). As acrylic polyol contents were increased, thermal stability measured by TGA was slightly decreased. Storage modulus was increased and tan delta was decreased with increasing of acrylic polyol contents.

• Journal of the Korean Ceramic Society
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• v.40 no.7
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• pp.625-631
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• 2003

Recent work at USC has focused on strategies to enhance the toughness and overall mechanical performance of polymer foams for use in lightweight sandwich structures. Both mechanical and chemical approaches have been employed with reasonable success. Fiber reinforcement, though difficult from a processing perspective, can lead to substantial enhancements in toughness and strength, while reducing friability. Chemical modifications are also challenging from a processing perspective, but can produce similar enhancements in performance. Efforts to enhance performance of phenolic foam and PVC foam through fiber reinforcement and chemical modification are described, along with the resulting enhancements in performance.

• Journal of the Korean Applied Science and Technology
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• v.22 no.4
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• pp.355-361
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• 2005

The physical characteristics of polyurethane were examined by SEM, FT-IR tensile strength and mole % [NCO/OH]. Growing concerns in the environment-friendly architecture and public works have led to the development of solvent-free formulations that can be cured and foamed in air. Compared with general packing materials, this resin is much stronger in intensity and much longer in durability. Polyurethane foam resins were mainly composed of polyol, MDI, silicone surfactant, fillers, catalyst and blowing agent. The rigid foam of polyurethane in mechanical characteristics were due to chain extender and the increase of mole % [NCO/OH]. The change in the microstructure of polyurethane should be taken into account when considering the process of construction and durability through the polyurethane polymer resin in lots of industries.

• Macromolecular Research
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• v.15 no.5
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• pp.443-448
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• 2007

To improve the sound damping effect of flexible polyurethane foam, with an open-cell structure, various plate-like fillers, such as bentonite, organophilic clay and sodium montmorillonite intercalated with poly(ethylene glycol), were incorporated for the creation of nanocomposites. The plate-like fillers effectively improved the sound damping within the high frequency range. The structures of the nanocomposites and foam were examined using X-ray diffraction and scanning electron microscopy. The mechanical properties and flammability of the foams were also examined.

• Journal of the Korea Convergence Society
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• v.2 no.3
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• pp.1-6
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• 2011

Aluminum foam is one of the representative light-weight materials. In this study we analyzed the mechanical properties of the aluminum foam structures. Aluminum materials with pores have novel mechanical characteristics such as flame retardancy, damping, and energy absorption which are superior to those of polymer foam. Furthermore its reusable properties draw considerable interests. General properties, energy and acoustic absorption will be investigated and future research issues such as binding techniques of foam materials with other structures will be discussed through foam application examples.