• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.35 no.1
• /
• pp.21-28
• /
• 2019

This study investigates the applicability of composite polyurea to contain fiber reinforcement like fiber glass, steel fiber and carbon nanotube. Polyurea as elastomer is an excellent water-proofing material with many mechanical characteristics such as high tensile strength, ductility, high rate of expansion and contraction, and so on. The reinforcing fibers can be utilized for improving the load-carrying capacity of concrete structures. The polyurea plays a role to improve the ductility and toughness. Composite polyurea takes the mechanical advantages of the fibers and the polyurea. The test variables include the type of reinforcing fiber, its spraying thickness, and its weight ratio contained in the composite polyurea. It is observed that the load-carrying capacity, and the ductility and toughness are improved with the increase in the spraying thickness and the weight ratio contained in the composite polyurea. It is expected that the composite polyurea can be widely utilized in enhancing the structural and seismic performance.

• Journal of the Korea Concrete Institute
• /
• v.23 no.4
• /
• pp.511-520
• /
• 2011

Recent studies to improve reinforcement of structures have developed stiff type Polyurea by using highly polymized compound Polyurea, but the reinforcing effect of it appears to be merely good. To find the proper usage of Polyurea as structural reinforcement, stiff type Polyurea has developed by manipulating the ratio of the components that consist flexural type Polyurea and the developed stiff type Polyurea shows higher hardness and tensile capacity. The reinforcement effect evaluation of has been performed by the polyurea applied RC slab specimens, and the reinforcement effect of the combination of fiber sheet and polyurea has been tested. The results shows that the Polyurea applied specimens have significant improvement on hardness and ductility compare to those of unreinforced. Also, the specimens that stiff type Polyurea is sprayed on fiber sheet reinforcement has higher reinforcing effect than only sheet reinforced specimens. However, the specimens that and fiber sheet attached after polyurea applied on showed that the high toughness of fiber sheet restrains the ductile behavior of Polyurea due to the high ductility, thereby the specimen suffers the concentration of load, which leads the brittle fracture behavior.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.41-42
• /
• 2012

High temperature / high pressure spray equipment using a conventional method, unlike spray polyurea adjustable pot life and yellowing caused by UV light and chemicals do not occur, or discoloration of Self-Leveling Type of rugged hand-polyurea resin for technology development is underway. This new concept of polyurea resin roller, brush, airless spray, and they installed easily using the unfamiliar labor, and curing time of approximately four hours to gain control of the glass because it is Pot. Construction, but does not like the spray polyurea resin, compared to the existing degradation of the adhesion strength is concerned. In this study, Self-Leveling Type Manual of polyurea resin adhesion strength of target deterioration Let's minimize problems by reviewing existing domestic and infrastructure long-term durability for long life of the facility is to obtain.

• Journal of Adhesion and Interface
• /
• v.22 no.4
• /
• pp.136-143
• /
• 2021

Polyurea has been investigated as a polymer matrix for composite materials because of its high mechanical strength. Although polyurea has a similar chemical structure to polyurethane, it has much higher strength and durability. In this study, the fabrication of polyurea composites reinforced with carbon nanotube (CNT) and graphene oxide (GO) is demonstrated to enhance the tensile strength of the glass fibers composite. Using FTIR and Raman spectroscopies, the chemical structures of polyurea, CNT, and GO are investigated. As a result, spectroscopy analysis reveals that the chemical structure of CNT, GO, and polyurea is maintained during the fabrication of the composite structure. Scanning electron microscopy reveals the uniform distribution of CNT and GO across the polyurea matrix. The reinforcement of 1 wt% CNT in polyurea enhances the tensile strength of CNT/polyurea composites. In contrast, the reinforcement of GO in polyurea induces the degradation of the tensile strength of GO/polyurea composites.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2003.11a
• /
• pp.149-151
• /
• 2003

This report describes the adhesibility of the polyurea greases. Generally, Polyurea greases were divided into three classes, aliphatic, alicyclic, and aromatic, according to the differences of the terminal alkyl group. The adhesion properties of polyurea greases were tested with Adhesion Tester by In-house method.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.264.2-264.2
• /
• 2013

Molecular layer deposition (MLD) is sequential, self-limiting surface reaction to form conformal and ultrathin polymer film. This technique generally uses bifunctional precursors for stepwise sequential surface reaction and entirely organic polymer films. Also, in comparison with solution-based technique, because MLD is vapor-phase deposition based on ALD, it allows epitaxial growth of molecular layer on substrate and is especially good for surface reaction or coating of nanostructure such as nanopore, nanochannel, nanwire array and so on. In this study, polyurea film that consisted of phenylenediisocyanate and phenylenediamine was formed by MLD technique. In situ Fourier Transform Infrared (FTIR) measurement on high surface area SiO2 substrate was used to monitor the growth of polyurethane and polyurea film. Also, to investigate orientation of chemical bonding formed polymer film, plan-polarized grazing angle FTIR spectroscopy was used and it showed epitaxial growth and uniform orientation of chemical bones of polyurea films.

• Textile Coloration and Finishing
• /
• v.19 no.5
• /
• pp.30-36
• /
• 2007

Cypermethrin-containing polyurea microcapsules were prepared by interfacial polymerization using aromatic 2,4-toluene diisocyanate(TDI) and Ethylene diamine(EDA) as wall forming materials. The effects of the protective colloids of polyvinylalcohol(PVA) and gelatin were investigated through experimentation. The mean size of the polyurea microcapsules was smaller and the surface morphology of the PVA was much smoother than gelatin. In addition the release behavior was much more controlled and better sustained. As the concentration of protective colloid increased, the wall membrane of the polyurea microcapsules became more stable, the thermal stability of the wall membrane increased, the mean particle size became smaller, and the particle distribution was more uniform. The release behavior of the core material changed according to the concentration. As the gelatin concentration was increased, a more controlled and sustained release behavior was observed. However, in the case of PVA, the increase of PVA concentration lead to a more rapid release rate.

• Proceedings of the Korean Fiber Society Conference
• /
• 2001.04a
• /
• pp.35-38
• /
• 2001

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2003.11a
• /
• pp.91-95
• /
• 2003

There is a problem to be solved for improvement of durability and safety supervision. When you do the waterproofing and anticorrosive work of main concrete from the design stage, the material and method of construction need to be correctly applied to appropriate circumstance conditions. Epoxy have mostly been used for concrete water tank structure. Lately, lots of subjects on adaption of polyurea resin waterproofing and anticorrosive are under discussion. Then, we attempt to approach by evaluating and comparing every capabilities with another waterproofs in this study. Performance evaluation items include the adherence performance, the imprint of seal performance, temperature dependence performance, promotion weatherizing ability, inner chemical performance, drinking water eruptive performance. Through the experiment analysis, we found that the polyurea resin waterproofing membrane is dominantly superior to other waterproofs. According to this study, we suggest the polyurea resin waterproofing membrane as a new waterproofing material for concrete structure.

• Journal of the Korea Institute of Building Construction
• /
• v.2 no.1
• /
• pp.131-138
• /
• 2002

There is a problem to be solved for improvement of durability and safety supervision. When you do the waterproofing work of main concrete from the design stage, the material and method of construction need to be correctly applied to appropriate circumstance conditions. Epoxy have mostly been used for concrete water tank structure. Lately, lots of subjects on adaption of polyurea resin waterproofing and anticorrosive are under discussion. Then, we attempt to approach by evaluating and comparing every capabilities with another waterproofs in this study. Performance evaluation items include the adherence performance, the imprint of seal performance, temperature dependence performance, promotion weatherizing ability, Inner chemical performance. drinking water eruptive performance. Through the experiment analysis, we found that the polyurea resin waterproofing membrane is dominantly superior to other waterproofs. According to this study, we suggest the polyurea resin waterproofing membrane as a new waterproofing material for concrete structure.