본 논문에서는 약용매에서 용해될 수 있는 지방산 변성 에폭시수지를 합성하였고, 합성한 수지 의 용해도 평가가 이루어졌다. 지방산 변성 에폭시수지를 합성하기 위하여 비스페놀A형, 페놀 노볼락형 및 오르소 크레졸 노볼락형의 3종류 에폭시수지를 사용하였고, 여기에 지방산, dodecyl phenol (DP), toluene diisocyanate (TDI)를 도입하였다. 합성조건은 당량기준으로 에폭시수지/지방산 = 1/0.5, 지방산/DP = 0.25/0.25, TDI 0.5이었고, 에폭시수지 종류에 따라 12종류의 지방산 변성 에폭시수지가 합성되었다. 합성 된 지방산 변성 에폭시수지에 대하여 점도 및 용매√가용성을 평가한 결과, 벤젠고리와 글리시딜기의 함량 및 알킬기의 탄소수가 증가할수록 약용매에 대한 용해성이 우수한 것으로 나타났다. 또한 약용매에 용해성 이 우수한 지방산 변성 에폭시수지를 사용하여 투명 도료를 제조하여 물성을 평가한 결과, 비스페놀A형 에 폭시수지/지방산/DP/TDI의 당량비가 1.0/0.25/0.25/0.5인 것과 페놀 노볼락형 에폭시수지/지방산/DP의 당량비가 1.0/0.25/0.25인 조성에서 건조시간, 접착력, 도막경도, 내충격성, 내알칼리성에서 양호한 물성을 나타내었다.

본 연구에서는 RO(Reverse osmosis) membrane과 이온교환수지를 이용하여 방사성 이온을 제거하였다. RO필터 2개회사, 3종(1종은 세정한 폐필터)으로 요오드와 세슘을 포함하는 공급수에 대해 2bar, 4bar의 압력, 10, 50, 100ppm의 공급수 농도로 실험을 하였다. 대체적으로 고압에서 높은 제거율을 얻을 수 있었으며, 고농도에서 높은 제거율을 얻을 수 있었다. 세정한 폐필터에 대한 결과 값으로 미루어 보았을 때, 세정효과가 큰 것을 확인할 수 있었다. 이온교환수지 도 3개회사의 제품을 사용하였으며, 같은 농도하에서 수지의 양을 달리하여 제거율을 비교하였다. 비교적으로 요오드보다 세슘에 대한 제거율이 높았으며, 혼합수지에 비해 단일수지의 제거율이 높은 것을 확인 할 수 있었다.

The characteristics of aqueous lithium recovery by ion exchange were studied using three commercial cation exchange resins: CMP28 (porous type strong acid exchange resin), SCR-B (gel type strong acid exchange resin) and WK60L (porous type weak acid exchange resin). CMP28 was the most effective material for aqueous lithium recovery; its performance was even enhanced by modifying the cation with K+. A comparison to Na+ and H+ form resins demonstrated that the performance enhancement is reciprocally related to the electronegativity of the cation form. Further kinetic and equilibrium isotherm studies with the K+ form CMP28 showed that aqueous lithium recovery by ion exchange was well fitted with the pseudo-second-order rate equation and the Langmuir isotherm. The maximum ion exchange capacity of aqueous lithium recovery was found to be 14.28 mg/g and the optimal pH was in the region of 4-10.

FRP Hybrid Bar, composite structures composed of synthetic resins, deformed bar and glass fiber, was invented in order to solve corrosion of rebar in reinforced concrete structures. In order to bond deformed bar and glass fiber to FRP Hybrid Bar, synthetic resins is used. Curing time of the synthetic resins greatly affect productivity. If curing time of synthetic resins is short, cost of facilities is reduced and productivity is increased. Also, If this curing time is shorter or omitted, FRP Hybrid Bar can be commercialized. So, it can cause mass-production and substantial economic effect. Therefore, in this paper, optimum mix proportion is observed in order to increase economic efficiency of FRP Hybrid Bar and reduce curing time of synthetic resins. Total 9 variables are set, adjusting ratio of hardener ratio, and 3 resin moulds on each variables are fabricated. Optimum mix proportion is suggested based on data measured by temperature sensor.

Very recently, an efficient electrochemical desalination process employing bipolar membranes with large ion-exchange area is being developed (so-called ‘electro-adsorptive deionization’). In this process, ions dissolved in a feed solution can be removed through an ion-exchange mechanism under a strong electric field (a forward bias condition). The membranes can also be regenerated without the use of additional chemicals by the water-splitting reactions which occur at the bipolar junction of membranes (a reverse bias condition). In this work, we have developed novel bipolar membranes containing iron oxide/hydroxide catalysts. In addition, the ion-exchange capacities of the bipolar membranes have been largely enlarged by embedding finely powdered ion-exchange resins. (No. 10047796) (No. 2015H1C1A1034436)

Molding trouble in injection-molded parts is caused by change of complexed molding product and molding process condition, etc. Warpage, which is one of the molding trouble, acts as possible factor which results in defect in assembly. In this study, a mold was designed to produce specimens with rib parallel to flow direction, specimens with rib perpendicular to flow direction and specimens without rib. This work researched change of warpage according to injection molding condition such as packing pressure, packing time, resin temperature in crystalline polymers(PP). Flat shape with ribs showed higher warpage than flat shape without ribs. The Specimens with ribs that are located perpendicular to the flow direction.

This study used transmission electron microscopy (TEM) to investigate the micro-morphological features of two formaldehyde to urea (F/U) mole ratio liquid urea-formaldehyde (UF) resins with three hardener levels as a function of the curing time. The micro-morphological features of the liquid UF resins were characterized after different curing times. As a result, the TEM examination revealed the presence of globular/nodular structures in both liquid UF resins, while spherical particles were only visible in the low F/U mole ratio resins. The high F/U mole ratio liquid UF resins also showed extensive particle coalescence after adding the hardener, along with the appearance of complex filamentous networks. When the resins were cured with a higher amount of hardener and longer curing time, the spherical particles disappeared. For the low mole UF resins, the particles tended to coalesce with a higher amount of hardener and longer curing time, although discrete spherical particles were still observed in some regions. This is the first report on the distinct features of the crystal structures in low F/U mole ratio UF resins cured with 5% hardener and after 0.5 h of curing time. In conclusion, the present results indicate that the crystal structures of low F/U mole ratio UF resins are formed during the curing process.

In order to prove that perchlorate-laden resins could be bio-regenerated through direct contact with anaerobic microorganisms, two bio-regeneration systems, internal and external, were tested. Anaerobic digestion was demonstrated to be very efficient in degrading perchlorate that had been adsorbed onto A520E resin. The internal bio-regeneration test showed that the fully exhausted resins recovered about 80% of the perchlorate-exchange capacity after 4 weeks of bio-treatment in the anaerobic digester. The bio-regeneration efficiency of the external system increased with the amount of flow passed through the column. Comparison of two perchlorate breakthrough curves obtained from column test, one with virgin resin and the other with bio-regenerated resin, proved that the bio-regenerated resin could be used repeatedly to treat perchlorate in spent or waste brine. The A520E resin was very stable in the anaerobic digester and its perchlorate-exchange capacity was barely changed during 26 weeks of incubation. The most significant contribution of this research is to develop the concept of direct bio-regeneration of exhausted resins by combining physicochemical ion-exchange and biological reduction technology, especially for the removal of perchlorate.

본 연구에서는 수용성 아크릴을 합성한 다음 수성 카제인 수지를 합성하여 기합성 완성된 아크릴 수지에 카제인 수지의 적하량을 점차 증가시켜 변화하는 물성을 피혁(Lamb leather)에 표면 코팅하여 물성을 측정 분석하였다. 내용제성 측정 결과 높은 내용제성 물성을 지닌 아크릴 수지와 카제인 수지의 함량이 물성 변화에 끼치지 않았으며 모두 높은 물성치를 나타내었다. 인장 강도 측정치에서는 아크릴 단독 코팅의 측정치가 1.399kgf/mm2로 가장 낮은 수치를 나타내었으며, 카제인 수지의 합량이 제일 높은 WAC-3가 가장 높은 인장력 1.426kgf/mm2을 나타내었다. 또한 내마모도 측정에서는 WAC-3가 제일 높은 69.774 mg.loss로 우수한 물성변화를 나타내었고, 연실률의 경우 아크릴 단독 코팅인 WAR이 820 %로 가장 높은 수치를 나타내었다.

As a part of abating formaldehyde emission of urea-formaldehyde resin, this study was conducted to investigate the rmalcure kinetics of both neat and modified urea-formaldehyde resins using differential scanning calorimetry. Neat urea-formaldehyde resins with three different formaldehyde/urea mol ratios (1.4, 1.2 and 1.0) were modified by adding three different additives (sodium bisulfite, sodium hydrosulfite and acrylamide) at two different levels (1 and 3wt%). An isoconversional method at four different heating rates was employed to characterize thermal cure kinetics of these urea-formaldehyde resins to obtain activation energy () dependent on the degree of conversion (). The values of neat urea-formaldehyde resins (formaldehyde/urea = 1.4 and 1.2) consistently changed as the increased. Neat and modified urea-formaldehyde resins of these two F/U mol ratios did show a decrease of the at the final stage of the conversion while the of neat urea-formaldehyde resin (formaldehyde/urea = 1.0) increased as the increased, indicating the presence of incomplete cure. However, the change of the values of all urea-formaldehyde resins was consistent to that of the Ea values. The isoconversional method indicated that thermal cure kinetics of neat and modified urea-formaldehyde resins showed a strong dependence on the resin viscosity as well as diffusion control reaction at the final stage of the conversion.

본 연구에서는 밀크 카제인과 WPU를 이용한 하이브리드 수지를 합성하였다. 합성한 하이브리드 수지를 피혁(Full-Grain) 표면에 코팅을 하여 카제인이 하이브리드수지에 어떤 영향을 주는지에 대해 분석 하였다. 내용제성 테스트 데이터에 의하면 WPU 와 하이브리드 수지 양쪽 모두 높은 물성치를 나타내었다. 인장 강도 측정치에서는 WPU 단독 결과(2.130 kgf/mm2)가 가장 낮은 수치를 나타내었으며, WPC-3(WPU 91: casein resin 9)의 경우가 가장 높은 인장력(2.191 kgf/mm2)을 나타내었다. 또한 내마모도 측정에서는 WPC-3(50.090 mg.loss)가 좋은 물성값을 나타내었다. 연실률의 경우 WPU(637 %) 단독 코팅물의 분석값이 가장 높은 637%로 알 수 있었다.

Most of the plastics products have been manufactured by injection molding. Molding trouble in injection-molded parts is caused by changing a molding product and molding process condition, etc. In this study, warpage in the injection molded part have been studied. specimens are rectangular flat shape with and without ribs. Non-crystalline resins (PC) and crystalline resins (PA66) were used for material and 30% glass fiber reinforced-resins(PC, PA66). Flat shape ribs showed higher warpage than flat shape without rib by 10 to 41%. the specimens with ribs that are located parallel to flow direction has higher warpage than the specimens with rib that are located perpendicular to flow direction by 11 to 50%. crystalline resins have higher warpage than non-crystalline resins by 22 to 78%.

The surface treatment effects of reinforcement filler were investigated based on the dynamic mechanical properties of mutiwalled carbon nanotubes (MWCNTs)/epoxy composites. The as-received MWCNTs(R-MWCNTs) were chemically modified by direct oxyfluorination method to improve the dispersibility and adhesiveness with epoxy resins in composite system. In order to investigate the induced functional groups on MWCNTs during oxyfluorination, X-ray photoelectron spectroscopy was used. The thermo-mechanical property of MWCNTs/epoxy composite was also measured based on effects of oxyfluorination treatment of MWCNTs. The storage modulus of MWCNTs/epoxy composite was enhanced about 1.27 times through oxyfluorination of MWCNTs fillers at 25℃. The storage modulus of oxyfluorinated MWCNTs (OF73-MWCNTs) reinforced epoxy composite was much higher than that of R-MWCNTs/epoxy composite. It revealed that oxygen content led to the efficient carbon-fluorine covalent bonding during oxyfluorination. These functional groups on surface modified MWCNTs induced by oxyfluorination strikingly made an important role for the reinforced epoxy composite.

최근 문화유산에 대한 관심이 고조 되면서 노후화된 건조물문화재의 보존에 대한 중요성이 대두되고 있다. 건조물문화재의 대부분이 목재를 주재료로 사용하였으며, 이들 건조물문화재의 노후화에 따른 부식 및 손상에 대한 보존수리는 부재자체의 문화재적 가치를 고려하여 원형유지를 기본원칙으로 한다. 이에 따라, 합성수지를 이용한 보존처리방법이 부각되고 있다. 이에 본 논문은 합성수지로 보강한 원형단면 목재의 압축보강 성능에 관한 실험적 연구로서 합성수지의 보강단면적비율, 단면의 보강방향, 보강길이, 합성수지강도를 변수로 하여 총 14개의 시험체를 제작하여 실험하였다. 실험결과 합성수지를 이용하여 적절하게 보강할 경우 신재이상의 보강효과가 있는 것으로 나타났으며 문화재의 보수 및 보강에서 가장 중요한 오센티시티(authenticity)를 확보할 수 있을 것이다.

In order to synthesize high-solid coatings, acrylic resins (HSAs) containing 90% solid content were first synthesized, then the synthesized HSAs were cured with a curing agent, isocyanate, at room temperature to obtain high-solid coatings. In the HSAs synthesis, conversion was in a range of 82~87%, and viscosities and number-averaged molecular weight (Mn) of the HSAs were in a range of 4380~8010 cP and 1540~1660, respectively. From the correlation between Tg value, viscosity and Mn, it was found that, with increasing Tg value, viscosity increases rapidly and molecular weight increases slowly. From the visco-elasity measured by the pendulum method, it was found that the curing time decreased with increasing Tg values. From the tests of physical properties of the coatings' film, 60˚ specular gloss, impact resistance and heat resistance were proved to be good and pencil hardness, drying time and pot-life were proved to be poor.

To prepare weather-resistant modified silane acrylic resin coatings for an architectural purpose, tetrapolymers were synthesized by radical polymerization. 3-Methacryloxypropyltrimethoxysilane (MPTS) as a silicone monomer and n-butyl acrylate, methyl methacrylate, and n-butyl methacrylate as acrylic monomers were used. The composition of monomers was adjusted to fix the glass transition temperature of acrylic polymer for 20℃. The composition of MPTS in the synthesized polymer were varied from 10 wt% to 30 wt%. On the basis of synthesized resin amber paints were prepared and their physical properties and effects on weatherability were examined. The presence of MPTS in modified silane acrylic resins generally resulted in low molecular weight and broad molecular weight distribution, and also lowered the viscosity of the copolymers. The coated films prepared from these resins showed good and balanced properties in general. Adhesion to the substrate was outstanding in particular. Weatherability tests were carried out in three different types such as outdoor exposure, QUV, and SWO. The test results showed that the modified silane acrylic resins containing 30 wt% of MPTS had superior weathering properties.

Characteristics of polyaniline anti-corrosive coatings with various primer coating resins(epoxy resin, urethane resin, and others) and top coating resins(epoxy and acrylic urethane resins) were investigated through adhesion, acid resistance, alkaline resistance, water resistance, and anti-corrosion tests. As a result, the anti-corrosive properties of the prepared coatings using polyaniline varied with the types of primer and top coating resins. In this condition, the properties of adhesion, chemical resistance, and water resistance were found to be very satisfactory when using emeraldine base (EB) of polyaniline blended with single-packaged urethane and acrylic urethane resins as the primer coatings, and using acrylic urethane resin as the top coatings. Also, the anti-corrosive function of these anti-corrosive coatings was well preserved for 1000 hr in the salt spray experiment.

The influence of adding urea to phenol-formaldehyde (PF) resins as a co-polymer component were investigated aiming at synthesizing useful phenol-urea-formaldehyde resins. Urea was added at 10% by total resin weight. Several methods for the addition of urea to the PF resins during synthesizing resins to see the co-polymerization occurs between urea and PF resins. The urea was added at the beginning, at three different middle stages, and at the end of PF resin synthesis. The copolymerized methylene bridges between phenol and urea molecules were not observed by 13C-NMR; no signal around 50ppm. The curing of urea-modified PF resins, evaluated by dynamic mechanical analysis(DMA), showed some differences among the resins. DMA gel times ranged from 2.75 min to 3.25 min and the resins made with earlier urea additions showed slightly shorter gel times. The longest cure time and gelation time was observed for the resin PFU. Catalyst effects on the DMA cure time values of resins were not significant with different amounts of catalyst or different types of catalyst for all resins tested. Gel times of urea-modified PF resins shortened the most by triacetin catalyst