• Proceedings of the Membrane Society of Korea Conference
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• 1997.10a
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• pp.131-132
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• 1997

1. 서론 : 이온 복합막은 투과증발을 통한 유기수용액의 탈수에 있어서 높은 수투과유량과 선택도를 나타내는 것으로 알려져 있다. 그러나 장시간 운전시에 이온 복합막은 막표면에 있는 금속 counterion이 feed에 씻겨버리기 때문에 분리능의 급격한 감소를 띠게 된다. counterion이 유기물일 경우에는 막속으로 확산되어 우기농축물에 포함될 문제가 있다. counterion이 고분자이면, 막 효능의 안정성이 증가되지만 막 제조과정이 다소 어려워진다. 아크릴산과 스티렐폰산을 포함하고 있는 개질 PAN막을 이용한 피리딘 수용액의 탈수에 관한 이전의 연구에서, 피드내의 피리딘과 막내의 산 기능기 사이에 형성된 in-situ complex가 막의 투과물사이에 특별한 반응이 없거나 막과 주요 투과 물간에 수소결합이 있는 막보다 더 좋은 탈수 효능을 나타냄이 확인되었다. 본 연구에서는 포스페이트를 함유하고 있는 폴리아크릴로니트릴 막의 제조와 피리딘 수용액의 탈수 효능에 대해 언급할 것이다.

• The Korean Journal of Rheology
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• v.5 no.2
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• pp.144-148
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• 1993

Nylon-6의 내충격성을 개선하기 위한 개질제로써 에틸렌-프로필렌 고무(EPR)와 에 틸렌-아크릴 에스터-무수말레산 공중합체(EAM)를 첨가한 nylon-6/EPR/EAM 블렌드 시스 템의 유변학적 특성을 24$0^{\circ}C$에서 조사하였다. 개질제중 EAM의 점도는 조성물 가운데 가장 낮음에도 불구하고 첨가량을 증가함에 따라 블렌드의 점도는 증가하였다. 또한 EPR(I)의 점 도가 EPR(II)의 점도보다 낮지만 EAM 함량이 증가함에 따라 nylon-6/EPR(I)/EAM의 점도 는 nylon-6/EPR(II)/EAM의 점도보다 높아지는 현상이 관찰되었다. 이러한 특성을 분산상의 morphology 변화와 전단력하에서 변형이 어려워지기 때문인 것으로 해석하였다.

• Polymer(Korea)
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• v.34 no.4
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• pp.306-312
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• 2010

Triphenylvinylsilane (TPVS) containing vinyl acetate (VAc), butyl acrylate (BA), and Nmethylolacrylamide (NMA) copolymers were prepared by emulsion polymerization. The polymerization was performed at $80^{\circ}C$ in the presence of auxiliary agents and ammonium peroxodisulfate (APS) as the initiator. Sodium dodecyl sulphate (SDS) and Arkupal N-300 were used as anionic and nonionic emulsifiers, respectively. The resulting copolymers were characterized by using Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), and dynamic light scattering (DLS). Thermal properties of the copolymers were studied by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphology of copolymers was also investigated by scanning electron microscopy (SEM) and then the effects of silicone concentrations on the properties of the TPVS-containing VAc-acrylic emulsion copolymers were discussed. The obtained copolymers have high solid content (50%) and can be used in weather resistant emulsion paints as a binder.

• Journal of the Korean Applied Science and Technology
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• v.38 no.2
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• pp.476-487
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• 2021

To prepare acrylic resin coatings containing 70% of solids, we used n-butyl methacrylate(BMA), methyl methacrylate(MMA), 2-hydroxyethyl methacrylate(2-HEMA), and acetoacetoxyethyl acrylate(AAEA), caprolactone acrylate(CLA) as raw materials, the glass transition temperature(T_g) of acrylic copolymer was adjusted around 50 ℃. The viscosity and molecular weight of the acrylic resins was increased with increasing OH values. Di-tert-amyl peroxide was found to be the suitable initiator to get high-solids acrylic resins. The optimum reaction conditions found in the study are 5 wt% of initiator, 4 wt% of chain transfer agent, 4 hrs of dropping time, and 140 ℃ of reaction temperature. The structure of the synthesized resins were characterized by FT-IR and ¹H-NMR spectroscopy. Number average molecular weight of 1900~2600 and molecular wight distribution of 1.4~2.1 were obtained. Crosslinked acrylic urethane clear coatings were obtained by curing reaction between the synthesized acrylic resins and hexamethylene diisocyanate trimer(Desmodur N-3300), the equivalent ratio of NCO/OH was 1.2/1.0. The physical properties from the following studies were carried out: viscosity(Zahn cup #2), adhesion, drying time, pot-life, pensil hardness, and 60° specular gloss. Various properties of the acrylic urethane clear coatings were also evaluated on the coating specimens. Adhesion property to a substrate, drying time, pot-life, pencil hardness, and 60° specular gloss of prepared paint showed quite good properties. Futhermore, prepared paint containing 10% of CLA showed quite good properties for adhesion, low viscosity and high hardness.

• Elastomers and Composites
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• v.44 no.4
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• pp.429-435
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• 2009

The pressure sensitive adhesives (PSA) were synthesized by soap-free emulsion polymerization of acrylic monomers such as butyl acrylate, 2-ethyl hexyl acrylate, and acrylic acid in the presence of starch as a protective colloid and copolymer. The peel strength and holding power of PSA were increased with starch contents due to the enhancement of gel content, But the initial tackiness of PSA was decreased with starch contents. The contact angle analysis of PSA indicated that the wettability was increased with starch contents owing to the increase of polarity by hydroxy group in starch. In the pH measurement of emulsion with time for biodegradability, the starch in the PSA accelerated the lowering of pH due to the formation of organic acids followed by decomposition of starch.

• Elastomers and Composites
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• v.49 no.3
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• pp.199-203
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• 2014

Terpolymer syrups were photopolymerized from 2-ethylhexyl acrylate, 2-hydroxylethyl acrylate and isobornyl acrylate to prepare acrylic pressure sensitive adhesives (PSAs). After polymerization, various crosslinkers as 1,6-hexanediol diacrylate (HDDA), poly (ethylene glycol) diacrylate (PEGDA, Mn = 250, 575, and 700) were added and then UV-irradiated to prepare the semi-IPN type PSAs. Their adhesion performance and storage modulus (G') were strongly dependent on their chemical structure and molecular weight of the crosslinkers. Optical properties such as transmittance (> 92.5 %), haze (< 1.0 %) and color-difference (< 0.3) of PSAs samples were not affected by crosslinker types used in this study.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.386-390
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• 2009

In this study, sulfadiazine acrylamide monomer was synthesized by the reaction of sulfadiazine, known as an antibiotic substance, with acryloyl chloride. The monomer was characterized by $^1H-NMR$, and $^{13}C-NMR$. Using the synthesized sulfadiazine acrylamide monomer and styrene monomer, a copolymer, poly(styrene-co-sulfadiazine), was obtained by the free radical copolymerization and characterized by $^1H-NMR$, GPC, DSC and TGA. The copolymer nanofibers web has been successfully prepared by electrospinning technique under DMF solution. The diameter of the nanofibers was in the range between 500 and 800 nm. Antibacterial activity of the nanofiber web was evaluated utilizing the colony counting method against Staphylococcus aureus and Escherichia coli.

• Journal of Adhesion and Interface
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• v.11 no.4
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• pp.155-161
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• 2010

A series of ethylene vinyl acetate (EVA) based hot melt adhesives containing different types and compositions of tackifier resins were prepared to investigate their rheological behavior and T-peel adhesion strength on polyurethane (PU) elastomeric sheets. C5 aliphatic hydrocarbon resin (C5 resin), C9 aromatic hydrocarbon resin (C9 resin), hydrogenated dicyclopentadiene resin ($H_2$-DCPD resin), and dicyclopentadiene and acrylic monomer copolymer resin (DCPD-acrylic resin) were used as the tackifiers for the hot melt adhesives. To determine the polarity of the tackifiers, their oxygen contents were analyzed, and the DCPDacrylic resin was found to contain an oxygen content higher than the other tackifiers. Only the DCPD-acrylic resin showed complete miscibility with EVA and the homogeneous phase of the hot melt adhesive blends at all compositions. The T-peel adhesion strength between the hot melt adhesives and polyurethane elastomeric sheets was mainly affected by the polarity of the tackifier resins in the hot melt adhesives, rather than by the storage moduli, G', of the hot melt adhesives themselves.

• Polymer(Korea)
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• v.27 no.5
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• pp.443-448
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• 2003

2-Biphenylyl acrylate (BPA) was synthesized by the reaction of 2-phenylphenol as a microbicide with acryloyl chloride, and copolymers with the moiety of 2-phenylphenol were prepared by the radical terpolymerization of BPA-methylmethacrylate-acrylic acid. The contents of BPA unit in the poly mers were found to be 4.2 mol% and 9.1 mol% from their nuclear magnetic resonance spectra. The number average molecular weights of the polymers were in the range of 15000 to 16000. 2-Phenylphenol was released through the hydrolysis of the polymers. The release rate of the microbicide increased with increasing pH of the release medium. The released solution showed higher microbicidal activity for E. coli as a negative microbe than S. aureus as a positive microbe.

• Applied Chemistry for Engineering
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• v.34 no.5
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• pp.522-528
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• 2023

In this work, adhesive tapes were prepared for the dicing process in semiconductor manufacturing. Compounds with different numbers of photoreactive groups (f = 1 to 3) were synthesized and incorporated into acrylic copolymers to formulate UV-curable acrylic adhesives. Structural confirmation of the synthesized photoreactive compounds (f = 2 or 3) was performed using nuclear magnetic resonance (NMR) spectroscopy. The introduction of the photoreactive compounds into the acrylic adhesive was accomplished by urethane reactions, and the successful synthesis of the UV-curable acrylic adhesive was verified by Fourier transform infrared (FT-IR) measurements. To evaluate the performance of the adhesive, the peel strength was evaluated before and after UV irradiation using a silicon wafer as a substrate. The adhesive exhibited high peel strength (~2000 gf/25 mm) before UV exposure, which was significantly reduced (~5 gf/25 mm) after UV exposure. Interestingly, the adhesive containing multifunctional photoreactive compounds showed the most significant reduction in peel strength. In addition, surface residue measurements by field emission scanning electron microscopy (FE-SEM) showed minimal surface residue (~0.2%) after UV exposure. Overall, these results contribute to the understanding of the behavior of UV-curable acrylic adhesives and pave the way for potential applications in semiconductor manufacturing processes.