• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.11a
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• pp.38-41
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• 2000

High temperature cure characteristics of polyester resin systems were investigated by isothermal and dynamic differential scanning calorimetries. During isothermal scanning, the experimental procedure was modified to reduce the initial Boss of heat. no kinetic equation from the isothermal experiment was compared with that from the dynamic experiment.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.1115-1120
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• 2000

The purpose of this study is to investigate toughening of unsaturated polyester resin by addition of liquid rubber. In general, unsaturated polyester liquid has strong brittleness in spite of if high strength Therefore; it is difficult use polyurethane liquid rubber for the place where impact resistance is demanded. In this study, it was evaluated strength, impact resistance and fracture toughness by adding to polyurethane liquid rubber(0~25%). As a result, it was found that a tendency to be increase bearing impact and fracture toughness as polyurethane liquid rubber increased but strength was decreased.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.588-593
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• 2012

Compatibility of unsaturated polyester (UP) and low profile agent (LPA) of polystyrene (PS) have been investigated under various mixing conditions such as the ratio of UP and LPA, mixing time, mixing temperature, and input amount of 2nd UP. It was possible to obtain mixture with small particle size and low phase separation in condition of 35 g of LPA, 25 g of 1st UP input, 5 min of mixing time, 1700 rpm of mixing speed, and 45 g of 2nd UP input. It was found that compatibility of UP and LPA was very sensitive to mixing conditions. In addition, molded sample using sheet molding compound prepared by stable mixing condition appeared good properties such as low water adsorption, low shrinkage, and high gloss.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.741-744
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• 2006

The study focuses on the mixture of materials for the development of porous concrete with unsaturated polyester resin. The materials used in the mixture include the coarse aggregates unsaturated polyester resin as binder, calcium carbonate and sand as a filler. An experimental procedure has been carried out to select the best combination of the materials that satisfy both the required permeability and compressive strength.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.1
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• pp.19-26
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• 2016

This study was performed to evaluate the strength and durability properties of modified epoxy composites with waste tire chip, recycled coarse aggregate, filler and modified epoxy to improve elongation and elasticity of epoxy. Additionally, for comparing to modified epoxy and unsaturated polyester resin as a binder, unsaturated polyester resin composites were developed in the same condition. The mix proportions were determined to satisfy the requirement for the workability and slump according to aggregate size and binder content. Tests for the compressive and flexural strength, freezing and thawing and durability for 20 % sulfuric solution were performed. The compressive and flexural strength of modified epoxy composites were in the range of 34.9~61.6 MPa and 10.2~18.3 MPa at the curing 7 days, respectively. Also, the compressive and flexural strength of unsaturated polyester resin composites were in the range of 44.2~77.8 MPa and 11.3~20.8 MPa at the curing 7 days, respectively. After 300 cycles of freezing and thawing, weight decrease ratio and durability factor of modified epoxy composites were in the range of 0.8~1.9 % and 95~98, respectively. Accordingly, modified epoxy composites will greatly improve the durability of concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 1992.04a
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• pp.35-40
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• 1992

Results of an experimental study on the manufacture, the workability and mechanical properties of steel fiber reinforced polyester resin composites utilizing industrial waste products are presented in this paper. The fly ash polyester resin composites using steel fiber, fly ash and calcium carbonic acid (CaCo3), unsaturated polyester resin, styrene monomer, cobalt octate and methyl ethyl ketone peroxide, fine and coarse aggregates are prepared with various filler~binder rations, binder rates and mixing conditions. As a test results, the workability of steel fiber reinforced polyester resin composites are considerably dropped with increasing fly ash-binder ratio and steel fiber volume. And compressive, flexural strength and bending toughness of the composites are remarkably improved with augmenting fiber contents.

• Journal of the Korea Concrete Institute
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• v.19 no.2
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• pp.163-169
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• 2007

This study is focused on the proper mixture design of materials for the porous concrete with unsaturated polyester resin. The materials used in the mixture include the single-grade aggregates, unsaturated polyester resin as binder, and calcium carbonate as a filler. An experimental procedure has been carried out to select the best combination of the materials that satisfy both the required permeability and compressive strength. Various kinds of gravel size, the ratio of binder, and F/B ratios are tried to get proper mixture, and the permeability coefficient and compressive strength have been measured to find out the best combination of materials based on the proper Korean Standards. A promix design satisfied the standards of rainfall runoff reduction system with $3.5{\times}10^{-1}$ (cm/sec) of permeability, 34 % of porosity, 11 MPa of compressive strength can be obtained.

• Elastomers and Composites
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• v.54 no.3
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• pp.247-251
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• 2019

Two different urethane acrylates (mono-acrylate and di-acrylate) were used to prepare unsaturated polyester-based hybrid gel-coats. The physical properties and surface characteristics of these gel-coats were investigated on the basis of the content and type of urethane acrylate. The set-to-touch time increased and the physical properties (surface hardness and tensile strength) decreased with an increase in the urethane acrylate content. However, the type of urethane acrylate did not affect these parameters. It was found that the optimal urethane acrylate content for the application of unsaturated polyester-based hybrid gel-coats is ~10 wt%.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.769-774
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• 2002

In this study, methyl methacrylate (MMA)- modified polyester polymer concrete, in which the MMA was added to the unsaturated polyester resin, was developed for improving the early-age strength and the workability of the conventional polymer concrete, binder of which was the unsaturated polyester resin. Then the fundamental properties of the polymer concrete such as workability and strength were surveyed. The experimental results showed that the workability was remarkably improved as the MMA contents increased, and the filler-binder ratio was turned out to be important factor for the workability. Slump prediction equation was derived by the regression analysis based on MMA content and filler-binder ratio. Furthermore, early-age strength was greater when the MMA content were increased in the range of 20-40 % but the strength rather showed a tendency of decrease when the MMA content was 50 %.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.2 s.13
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• pp.29-34
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• 2004

The time to ignition, heat release rate characteristics, and carbon monoxide yield of fiber reinforced and sandwich phenol resin were investigated with cone calorimeter. The fire characteristics of unsaturated polyester, mostly being applied to the existing passenger train, and phenolic resin were compared. DSC & TGA was used to monitor the degree of thermal decomposition and weight loss for the phenolic resin. According to the cone calorimeter data, the time to ignition was shorter, heat release rate, and CO yield was higher as the external heat flux increased. Under the same heat flux, the time to ignition of sandwich type phenolic resin was shorter than that of laminated. The result of comparison between unsaturated polyester and phenolic resin was that phenolic resin was shown to have better fire resistance than unsaturated polyester.