• Journal of Adhesion and Interface
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• v.22 no.2
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• pp.63-68
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• 2021

Unsaturated Polyester Resin (UPR) is in general used as a resin to prepare for composite materials with reinforcing materials such as glass fibers. UPR, a thermosetting resin, is used in industry to prepare for sheet molding compound (SMC) molding prepreg that has excellent productivity and is advantageous for mass production among various molding methods of composite materials. The fiber-reinforced composite material using UPR as a matrix material is light and has the advantage of excellent physical properties, but it is weak against impact and is fragile. Four types of polyurethane were synthesized and added to UPR resin to overcome the shortcomings.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.343-348
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• 1999

The purpose of this study is to evaluated the effects of added expanded polystyrene on the basic properties of UP mortar. Polyester resin mortars are prepared with expanded polystyrene ratio in styrene monomer (EPS/PS), and the ratio of total polystyrene resin to UP resin (PS/UP). And it is tested for viscosity of UP resin added PS resin, slump-flow test, working life, flexural and compressive strengths, and curing shrinkage test. From the test result, Viscosity of resin for polymer 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 polymer mortar using PS resin.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.283-290
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• 2002

Generally polymer mortar and concrete using unsaturated polyester resin has high strengths and good chemical resistance. However it also has high brittleness and because of this reason, it is not used for the purpose that demands high resistance to impact. The purpose of this study is to improve the brittleness of unsaturated polyester mortar(UPE mortar) which could be used for the flooring material with recycled aggregates and UPE. Polyurethane liquid rubber(PU) and recycled aggregates were used to complement the brittleness and to recycle the resources respectively. The characteristics of mortar were investigated according to the molecular weight and substitution rate of PU. As the molecular weight and PU substitution rate were increased, the viscosity was increased, working life became fast and curing shrinkage was reduced. Compressive and flexural strengths were also reduced but tile brittleness was improved. Therefore, it is seemed that the improved WE mortar could be obtained by using polyurethane liquid rubber with the polyol of molecular weight 2000, 3000.

• Composites Research
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• v.36 no.1
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• pp.37-41
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• 2023

The treated water inside the ballast electrolytic cell creates a highly alkaline atmosphere due to hydroxide generated at the DSA(Dimension Stable Anode) electrode during electrolysis. In this study, a composite material that can replace the weakness of the PE-coated steel pipe used in the existing ballast pipe was prepared. The test samples are BRE(Basalt fiber reinforced epoxy), BRP(Basalt fiber reinforced unsaturated polyester), GRE(Glass fiber reinforced epoxy), and GRP(Glass fiber reinforced unsaturated polyester). And then it was immersed in NaOH for 720 hours. The friction test of each specimen was conducted. The Friction coefficient analysis according to material friction depth and interfacial adhesion behavior between resin and fiber were analyzed. As a result, the mechanism of interfacial separation between resin and fiber could be analyzed. In the case of the unsaturated polyester resin with low interfacial bonding strength the longer the immersion time in the alkaline solution, the faster the internal deterioration caused by the deterioration that started from the surface, resulting in a decrease in the friction coefficient. It is hoped that this study will help to understand the degradation behavior of composite materials immersed in various chemical solutions such as NaOH, acid, and sodium hypochlorite in the future.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.635-641
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• 2003

A recycling process for the waste FRP from boats was developed. The recycling process is composed of decomposition of waste FRP with propylene glycol and synthesis of recycled unsaturated polyester resin from the decomposed liquid material. Prior to the decomposition, waste FRP was cut into 2cm x 5cm segments and mechanical impact was applied by press roller to give gaps between cumulated laminates. Propylene glycol effectively decomposed the waste FRP segments and glass fibers were easily separated from decomposed liquid material. Recycled unsaturated polyester resin could be made from the decomposed liquid material by reaction with maleic anhydride and phthalic anhydride.

• Korean Journal of Agricultural Science
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• v.37 no.1
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• pp.87-96
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• 2010

This study was performed to evaluate the planting properties of herbaceous plant and cool-season grass in porous polymer blocks that were manufactured by using recycled coarse aggregates and unsaturated polyester resin to develop environmentally friendly planting blocks. Unsaturated polyester resin, natural and recycled coarse aggregates and $CaCO_3$ were used. The mix proportions were determined to satisfy the requirement for the workability and slump according to aggregate sizes(5-10 and 5-20mm). Tests for the void ratio and compressive strength of porous polymer concrete were performed at curing age 7 days. Also, porous polymer block using recycled coarse aggregates were applied to kinds of plants such as tall fescue, Perennial ryegrass, Lesedeza and Alfalfa. After seed, initial germination, germination ratio, cover view and growth length for planting blocks were estimated by various methods.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.429-432
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• 2003

MMA-modified fiberglass-reinforced plastic composite pipe was produced by using the binder of MMA-modified unsaturated polyester resin in which low viscosity MMA was added to unsaturated polyester resin. Sixteen specimens were made of polymer mortar and fiberglass-reinforced plastic by the centrifugal method. For these specimens the external strength tests were carried out by taking the core thickness consisting of polymer mortar and the fiberglass content per unit area as experimental variables to figure out the effect of variations of these variables influencing on flexural rigidity that is an important property for the composite pipe. Results of this study are believed to provide the basic data for more economical and practical design of MMA-modified fiberglass-reinforced plastic composite pipe.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.321-326
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• 2000

Many different polymer based concrete materials are known today, but the large setting or hardening shrinkage of polymer concrete is a problem to overcome in their practical applications. The setting shrinkage reaches about five to ren times he drying shrinkage ordinary cement concrete, i.e, 50 to $60\times10^{-4}$. This paper deals with a reduction in the hardening shrinkage of unsaturated polyester resin concrete which is treated with respect to shrinkage-reducing agent content, S/a ratio and catalyst content, and tested for length change during hardening, and flexural and compressive strength. It is show that the change of shrinkage-reducing agent content and S/a ratio affected the length change of the unsaturated polyester resin concrete during hardening.

• Transactions on Electrical and Electronic Materials
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• v.14 no.2
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• pp.53-58
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• 2013

Graphene-based polymer nanocomposites are very promising candidates for new high-performance materials that offer improved mechanical, barrier, thermal and electrical properties. Herein, an approach is presented to improve the mechanical, thermal and electrical properties of unsaturated polyester resin (UPR) by using graphene nano sheets (GNS). The extent of dispersion of GNS into the polymer matrix was also observed by using the scanning electron microscopy (SEM) which indicated homogeneous dispersion of GNS through the UPR matrix and strong interfacial adhesion between the GNS and UPR matrix were achieved in the UPR composite, which enhanced the mechanical properties. The tensile strength of the nanocomposites improved at a tune of 52% at a GNS concentration of 0.05%. Again the flexural strength also increased around 92% at a GNS concentration of 0.05%. Similarly the thermal properties and the electrical properties for the nanocomposites were also improved as evidenced from the differential scanning caloriemetry (DSC) and dielectric strength measurement.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.235-239
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• 1994

Polymer mortars are mainly used as protective coatings in concrete, reinforced concrete, and more rarely, steel, while polymer concretes represent a new type of structural material capable of withstanding highly corrosive environments. The mechanical properties, chemical stability, and some other useful properties are the reasons research, design, and production organizations. However polymer mortars and polymer concretes have been introduced only recently, and many of their properties are still imperfectly known. And, the main technique in producing polymer concrete is to minimize void volume in the aggregate mass so as to reduce the quantity of the relatively impressive polymer necessary for binding the aggregate. In this study, compressive strength and flexural strength of unsaturated polyester resin concrete are related to quantity of resin and solid volume of aggregate. It was founded that the more solid volume of aggregate increase, the less using quantity of resin decrease with out reducing mechnical properties. When solid volume ratio of aggregate is 70.6%, using quantity of resin is minimized to 10wt.%.