• Polymer(Korea)
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• v.24 no.5
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• pp.589-598
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• 2000

In this study, various unsaturated polyester (UPE) resins were prepared from the condensation polymerization of mixtures of saturated (isophthalic acid : IPA) and unsaturated (maleic anhydride : MA) dibasic acids with propylene glycol (PG), neopentyl glycol (NPG). The critical surface tension (Υ$_{c}$) for the surface characteristics of a solid were estimated by Zisman plot, and the structure-property relationship was investigated by measuring the rheology of resins. The values of Υ$_{c}$ for glass of solid were 30.5 mNㆍm$^{-1}$ for UPE resin liquids. As the content of NPG in a PG/NPG glycol mixture increased, both the contact angle and the surface tension of the UPE resin liquids were found to decrease. The dynamic viscoelasticities of UPE resins with different glycol molar ratios were also measured. Shear rate dependence of viscosity and angular frequency dependence of storage, and loss modulus tended to decrease with increasing NPG content.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1066-1072
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• 1999

The physical properties of polymer concrete were investigated for development of high-performance construction materials. Various specimens of polymer concrete were prepared using unsaturated polyester resin as the polymer-binder with the various dosage of calcium carbonate as microfiller (5~20 wt %) and fine aggregate(10~50 wt %). For the evaluation of the physical properties of polymer concretes, tests such as compressive strength, flexural strength, water absorption test, hot water immersion test, acid resistance test and pore size distribution analysis were conducted. As a result, it is concluded that compressive and flexural strengths of polymer concretes increased up to 4 times than those of conventional cement concrete. Whereas the compressive and flexural strengths of polymer concretes tested after hot water immersion, compared with those of polymer concretes tested before hot water immersion, decreased about 67%, 47%, respectively. By hot water immersion, total pore volume and porosity(%) of polymer concretes were remarkable increased due to decomposition of polymer binder. And also, it is showed that water absorption(%) and weight loss(%) of polymer concrete specimens by acid immersion, compared with those of ordinary portland cement concrete, decreased about 1/100, 1/27, respectively.

• Polymer(Korea)
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• v.25 no.1
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• pp.15-24
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• 2001

In this study, the effects of different glycol molar ratios of unsaturated polyester(UPE) resins on the curing behaviors were investigated. The cross linking process was checked or monitored by differential scanning calorimetry(DSC) and by viscoelastic properties of rigid-body pendulum model. The knife-edge from which the pendulum is suspended, is immersed in a reaction mixture, and the change of the viscoelastic behavior brings on those of the period(T) and logarithmic decrement(${\Delta}$) of the damped free oscillations of the pendulum. The values of T and ${\Delta}$ obtained are related to the dynamic modulus(E') and modulus loss(E'). The information on the viscoelastic behavior of unsaturated polyester(UPE) resins during the curing process are shown to illustrate the usefulness of the techniques. As the content of NPG in a propylene glycol(PG)/NPG glycol mixture increased, both the cycle time during cure and the change of damping during cure of UPE resin decreased.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.107-112
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• 1998

The objective of this study was to develop a polymer mortar defensive block with high strength and durability using unsaturated polyester resin to complement defects of conventional cement mortar defensive block. Physical and mechanical properties of the polymer mortar defensive block were also investigated. Low absorptivity, high impact strength, and great bending strength of the polymer mortar defensive block was compared with those of the conventional cement defensive block. In conclusion, the polymer mortar defensive block is excellent and useful as industrial products for erosion control works.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.497-498
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• 2009

Unsaturated polyester(UP) and epoxy resin require 8${\sim}$11 hours long harding times and heating systems used by reinforcement liner. This study is to evaluate the effects of low temperature harding property of UP with methyl methacrylate(MMA) monomer mixing proportions.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.4
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• pp.124-129
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• 2000

The objective of this study is to develop a polymer mortar floor members for wine housing with high strength and durability using unsaturated polyester resin to complement defects of conventional cement concrete. Physical and mechanical properties of the polymer mortar floor members for swine housing are also investigated. Specimens with different panel thickness and FRP reinforcement are prepared, tested, and analyzed with respect to structural behaviors. Cracking moment is mostly affected by the thickness and reinforced FRP. Data of the study can be applied to the designing and planning of floor members for swine housing.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.330-335
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• 1999

The objective of this stu요 was to develop a polymer mortar guide block for the blind handicapped people. A high strength and a long durability polymer concrete using unsaturated polyester resin was used to developed the block and to improve the exiting cement mortar guide bloc. Physical and mechanical properties of the polymer mortar guide block were investigated with respect to absorptivity, impact strength, bending strength compared to those of the conventional cement guide block. The polymer mortar guide block was proven to have properties , indication that the block have better industrial applications.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.200-204
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• 2004

It is social demands that we are now wanting to be more cozier and clean by the enhancement of the living standard recently. Antimicrobial is essential to the interior materials to prevent bacteria from spreading through passenger using the electric railway called environmentally friendly. In this paper, ion exchanged zeolite was added to the unsaturated polyester resin reinforced glass fiber. To investigate the animicrobial performance. Staphylococcus aureus and Escherichia coli was used according to the FC TM-20-2003 method.

• Journal of the Korea Concrete Institute
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• v.13 no.1
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• pp.30-37
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• 2001

Generally, polymer mortar made with unsaturated polyester(UP) resin has a high curing shrinkage. This is an inadequate as repair material and construction products that have been widely used for years recently. To overcome these problems, polymer researchers and engineers have used shrinkage-reducing additives, which are usually specific thermoplastic polymers. The objective of this study is to evaluate the effects of shrinkage-reducing additive on the curing shrinkage and strengths of UP mortar. UP mortars are prepared with expanded polystyrene(EPS) ratio in styrene monomer(SM), (EPS/PS, PS=EPS+SM), and the ratio of total polystyrene resin(PS) to UP resin, (PS/UP). And it is tested for viscosity of UP resin, slump-flow, working life, flexural and compressive strengths, and curing shrinkage tests. From the test results, viscosity of resin for UP mortar increases with increasing PS content. Curing shrinkage of UP mortar is considerably smaller than that of plain UP mortar, nevertheless, reduction in the strengths is not recognized according to adding PS resin. In this study, we can obtain the optimum mix proportions of UP mortar using PS resin which made of waste expanded polystyrene.

• Journal of Power System Engineering
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• v.9 no.4
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• pp.137-142
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• 2005

The effects of temperature and initial crack length on impact fracture behavior of side plate material of 35 ton class FRP ship, which are composed by glass fiber and unsaturated polyester resin, were investigated. Impact fracture toughness of GF/PE composites displayed maximum value when the temperature of specimen is room temperature and $50^{\circ}C$, and with decrease in temperature of specimen, impact fracture toughness decreased. Impact fracture energy of GF/EP composites decreased with increase in initial crack length of specimen, and this value decreased rapidly when the temperature of specimen is lowest, $-25^{\circ}C$,. It is believed that sensitivity of notch on impact fracture energy were increased with decrease in temperature of specimen. As the GF/EP composites exposed in low temperature, impact fracture toughness of composites decreased gradually owing to the decrease of interface bonding strength caused by difference of thermal expansion coefficient between the glass fiber/polyester resin. Further, decrease of interface bonding strength of composites with decrease in specimen temperature was ascertained by SEM photograph of impact fracture surface.