• Structural Engineering and Mechanics
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• v.63 no.3
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• pp.317-327
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• 2017

The addition of different types of polymers such as SBR, VAE, Acrylic, etc. in concrete and mortar leads to an increase in compressive, tensile and bond strength and decrease in permeability of polymer modified mortar (PMM) and concrete (PMC). The improvement in properties such as bond strength and impermeability makes PMM/PMC suitable for use as repair/retrofitting and water proofing material. In the present study effect of addition of fluoropolymer on the strength and permeability properties of mortar has been studied. In the cement mortar different percentages viz. 10, 20 and 30 percent of fluoropolymer by weight of cement was added. It has been observed that on addition of fluoropolymer in mortar the workability of mortar increases. In the present study all specimens were cast keeping the workability constant, i.e., flow value $105{\pm}5mm$, by changing the amount of water content in the mortar suitably. The specimens were cured for two different curing conditions. Firstly, these were cured wet for one day and then cured dry for 27 days. Secondly, specimens were cured wet for 7 days and then cured dry for 21 days. It has been observed that compressive strength and split tensile strength of specimens cured wet for 7 days and then cured dry for 21 days is 7-13 percent and 12-15 percent, respectively, higher than specimens cured one day dry and 27 days wet. The sorptivity of fluoropolymer modified mortar decreases by 88.56% and 91% for curing condtion one and two, respectively. However, It has been observed that on addition of 10 percent fluoropolymer both compressive and tensile strength decreases, but with the increase in percentage addition from 10 to 20 and 30 percent both the strengths starts increasing and becomes equal to that of the control specimen at 30 percent for both the curing conditions. It is further observed that percentage decrease in strength for second curing condition is relatively less as compared to the first curing condition. However, for both the curing conditions chloride ion permeability of polymer modified mortar becomes very low.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2127-2128
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• 2012

• Journal of the Korean Home Economics Association
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• v.35 no.3
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• pp.275-286
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• 1997

The effects of water-and oil-repellent finishes on the surface characteristics of polyester fabrics were investigated in this study. Three kinds of fluoropolyment were selected as water=and oil-repellent finishing agents. The effects of water-and oil-repellent finishes were determined by the water repellency and oil repellency. The surface properties of untreated and treated polyester fabrics were evaluated with respects to crease resistance, contact angle and wicking time. The results of this study were as follows: 1. The polyester fabrics treated with fluoropolymers showed much higher water repellency and oil repellency than those of untreated polyester fabrics. Water-and oil-repellency of fabrics were increased with the crystallinity and the hydrophobic-hydrophillic components of fluoropolymers. 2. Water repellency of fabrics treated with fluoropolymer with hydrophobic components was the highest. Oil repellency of fabrics treated with fluoropolymer with high crystallinity was the highest. Water-and oil-repellency of fabrics treated with fluoropolymer with hydrophyllic components was low comparatively. 3. The crease resistance of polyester fabrics treated with fluoropolymer nearly approached to that of untreated polyester fabric. 4. The water-and oil-repellent finishes improved contact angle markedly. Especially the contact angle of ployester fabric treated with fluropolymer with hydrophobic component was the biggest. 5. The wicking time of polyester fabric treated with fluropolymer with hydrophobic component was the longest.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2408-2413
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• 2012

Effects of stanous catalyst on the cross-linking reaction characteristics of multi-functional fluoropolymer with blocked-hexamethylene diisocyanate(HMDI) were studied by dynamic DSC and non-isothermal thermogravimetric analysis (TGA). Results showed that cross-linking reaction occurred around $230-250^{\circ}C$ aftr the solvent and phenol, blocking agent, were removed upto the $150^{\circ}C$. It was considered that the reaction mechanism of the multi-functional fluoropolymer with HMDI might not be changed by the catalyst, however, the reaction rate became extremely faster upto to 100 times, showing the change of activation energy 81.8 kJ/mol for non-catalytic system to 61.7 kJ/mol for 1 phr catalytic system.

• Journal of Information Display
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• v.12 no.4
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• pp.223-227
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• 2011

Electrophosphorescent devices with ionomer-type hole transport layers were investigated. On top of the 3,4-ethylenedioxy thiophene:poly(4-styrene sulfonate) [PEDOT:PSS] structures, fluoropolymer interfacial layers (FPIs) with different side chain lengths were introduced. Both for the PEDOT:PSS/FPI (layered) and PEDOT:PSS (mixed) structures with soluble phosphorescent emitters, the short-side-chain FPIs showed higher efficiency. The difference in the electrical properties of the two FPIs for bipolar (light-emitting) devices was not clear, but the hole-only device clearly showed the favored hole injection at the PEDOT:PSS/FPI structure with a shorter side chain, a copolymer of tetrafluoroethylene and sulfonyl fluoride vinyl ether.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.126-132
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• 2005

UV disinfection system allows the disinfection of municipal and industrial water and wastewater without the use of expensive chlorination and dechlorination techniques, labor intensive equipments In traditional ultraviolet systems the UV lamps are seperated from water by quartz sleeves. quartz is one of. the few materials that is virtually transparent to UV light, the UV lamp is placed inside the Quartz sleeve. UV light from the lamp is passed through the quartz and into the water, thereby providing disinfection. In fluoropolymer tube-used non-contact UV systems, the water flows through fluoropolymer plastic tubes. banks of UV lamps surround these tubes such that each tube gets exposed to ultra violet light from all sides. in non-contact design the lamps operates at almost constant temperature. this design is extremly efficient in the utilization of UV energy and superior to conventional contact- systems.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.584-587
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• 2006

An energy generating greenhouse based on fluoropolymer envelope and fresnel lens is proposed. The outstanding properties of the fluoropolymer films make them very suitable for large scale solar applications. Extremely high optical transmission over the whole solar spectrum, combined with mechanical strength, and durability allows us to design a highly optimized greenhouses for both plant growing and energy generation. Systems such as photovoltaic triple junction cells are especially attractive since they have up to 35% efficiency with much less cell material when the sun beam is focused with concentrators such as fresnel lenses. Cooling such devices will enhance the efficiency and provide useful thermal energy that could be further utilized for various applications depending on the local demands. This article introduces the basic ideas and principles of the energy generating greenhouses as a first step towards the actual deployment of such systems under Korean environment.

• Polymer(Korea)
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• v.38 no.4
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• pp.457-463
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• 2014

In this study, the changes in the chemical structure and the physical property of fluoropolymer films (PTFE, FEP, PFA, PVDF, and ETFE) induced by $Co^{60}$ gamma ray in air, $N_2$, and vacuum environments were investigated. FTIR spectra of the irradiated fluoropolymers indicate that the oxidation proceeded by the reaction of radicals generated by irradiation with oxygen in air. The changes in the heat of fusion and the degree of crystallinity of the irradiated fluoropolymers were investigated using DSC and the results indicate that the scission and crosslinking reactions of the irradiated fluoropolymers were largely influenced by the chemical structure. It was also found that the mechanical property of the irradiated fluoropolymer films under an air atmosphere was significantly decreased.

• Corrosion Science and Technology
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• v.2 no.5
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• pp.207-211
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• 2003

The weather resistance of five coatings systems based on alkyd, chlorinated rubber, epoxy, polyurethane and fluoropolymer were studied by natural exposure test and accelerated test. The coatings were exposed at Hanoi station with urban industry atmosphere and at Baichay station with marine atmosphere. The degradation of coatings was evaluated by gloss measurement and surface analysis by scanning electronic microscopy. The results obtained show that among coatings tested the gloss of polyurethane and fluoropolymer coatings remained highly and those of alkyd, chlorinated rubber and epoxy coatings were very low after two years of atmospheric exposure. Under accelerating conditions the gloss of fluoropolymer coatings remained highly after 80 cycles of testing. By comparison with accelerating test in UV-condensation chamber the conditions at atmospheric stations are more aggressive.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.33-33
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• 2010

Electrical properties of organic light-emitting diodes (OLEDs) were simulated by S.co's program. The OLEDs have stable operating parameters, high luminance, and high efficiency in simulation. The AF stands for amorphous fluoropolymer in simulation, and it was used as a hole-injection layer. In the five structure of OLEDs, an AF layer is sandwiched between the hole-transport layer and the ITO layer to increase the external quantum efficiency. By considering organic light-emitting diodes using an optimal energy gap of AF, it could contribute to the improvement of the efficiency of the device in the simulation.