• Elastomers and Composites
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• 제54권2호
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• pp.128-134
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• 2019

Many scientific approaches have been developed for the preparation of alternative crosslinker system of amino resins and isocyanate prepolymers. Herein, copolymerization of trimethoxy silane with N-butoxymethyl acrylamide was performed, and the product was reacted with hydroxyl groups in the alkyl main chain without the need for an additional crosslinker. For the crosslinker synthesized herein, the molecular weight, glass transition temperature, and viscosity increased with increasing content of N-butoxymethyl acrylamide.

• Advances in nano research
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• 제4권1호
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• pp.15-29
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• 2016

A low cost environmentally benign surface coating binder is highly desirable in the field of material science. In this report, castor oil based hyperbranched polyester/bitumen modified fly ash nanocomposites were fabricated to achieve the desired performance. The hyperbranched polyester resin was synthesized by a three-step one pot condensation reaction using monoglyceride of castor oil based carboxyl terminated pre-polymer and 2,2-bis (hydroxymethyl) propionic acid. Also, the bulk fly ash of paper industry waste was converted to hydrophilic nano fly ash by ultrasonication followed by transforming it to an organonano fly ash by the modification with bitumen. The synthesized polyester resin and its nanocomposites were characterized by different analytical and spectroscopic tools. The nanocomposite obtained in presence of 20 wt% styrene (with respect to polyester) was found to be more homogeneous and stable compared to nanocomposite without styrene. The performance in terms of tensile strength, impact resistance, scratch hardness, chemical resistance and thermal stability was found to be improved significantly after formation of nanocomposite compared to the pristine system after curing with bisphenol-A based epoxy and poly(amido amine). The overall results of transmission electron microscopic (TEM) analysis and performance showed good exfoliation of the nano fly ash in the polyester matrix. Thus the studied nanocomposites would open up a new avenue on development of low cost high performing surface coating materials.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.231-231
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• 2006

We fabricated a polymer sub-microstructure for optical device application by two-photon-induced laser lithography technique. Polymer pattern could be minimized as small as ${\sim}100\;nm$. The photopolymerization resin contains laser-dye, thus promising a high level of the optical gain. We utilized the lithography technique to the photonic crystal application, where the template of the two-dimensional photonic crystal was modified by polymer gain medium as defect-shape and line-shape orientations. Photonic band gap effect from polymer-doped photonic crystals is expected to exploit the application such as organic solid-state laser device.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.357-362
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• 1997

The purpose of this study is to evaluate the adhesion of concrete pipe lining using polymer mortar. The polymer mortars with various mix proportions are prepared, and tested for flexural and compressive strengths, adhesion in tension, and the aspects of lining surface and workability are evaluated. Form the test results, it is apparent that the appropriate polymer mortars of lining to concrete pipe can be produced. The flexural and compressive strengths of polymer mortar for lining are affected by type of resin, and aggregates content, and water content at the surface of concrete pipe is important factor for improvement in adhesion of polymer mortar. It is obvious that the economical polymer mortars having an excellent cost performance ration can be produced through this study.

• 폴리머
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• 제24권5호
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• pp.701-712
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• 2000

인발수지 함침장치를 사용하여 장섬유 강화 GF/PA 연속섬유를 제조한 후, 이에 PP 수지를 부가하는 새로운 방법으로 GF/PA/PP 삼성분계 복합재료를 제조하였다. 이들 복합재료의 기계적 특성을 비교한 결과, 제조 공정에 따라 물성이 다르게 나타났다. 예측한 대로 단일 사출 공정으로 제조한 GF/PA/PP(I) 복합재료 시편이 압출 후 사출 공정을 거친 GF/PA/PP(EI) 복합재료 시편보다 장섬유 함량이 높아 우수한 물성을 보여 주었다. 각 상 간의 계면 결합력을 개선시키기 위하여 상용화제로 PP-MAH를 첨가한 복합재료 제조 연구를 수행한 결과, 상용화제가 첨가되지 않은 복합재료보다 상용화제가 도입된 복합재료가 각 상 간의 계면 결합력이 향상되어 점도 및 기계적 특성이 크게 증가함을 볼 수 있었다. 특히, 이들 복합재료의 모폴로지를 관찰한 결과 상용화제가 첨가되지 않은 GF/PA/PP 복합재료의 경우는 가공 방법에 관계없이 유리섬유 주변에 PA 수지가 남아 있는 형태학적 구조를 나타내었으나, 상용화제로 PP-MAH가 도입된 경우는 PA 수지와 PP 수지 및 기지재와 유리섬유 사이에 계면 결합력이 증가됨으로 인해 유리섬유 계면에 인접한 수지가 PA 수지외에 PP 수지도 남아 있는 복잡한 구조를 보여 주었다.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4109-4116
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• 2012

An efficient solid-phase methodology has been developed for the synthesis of 2-amino and 2-amidobenzo[d]-oxazole derivatives. The key step in this procedure involves the preparation of polymer-bound 2-aminobenzo-[d]oxazole resins 4 by cyclization reaction of 2-hydroxy-phenylthiourea resin 3. The resin-bound 2-hydroxyphenylthiourea 3 is produced by the addition of 2-aminophenol to the isothiocyanate-terminated resin 2 and serve as a key intermediate for the linker resin. This core skeleton 2-aminobenzo[d]oxazole resin 4 undergoes functionalization reaction with various electrophiles, such as alkylhalides and acid chlorides to generate 2-amino and 2-amidobenzo[d]oxazole resins 5 and 6 respectively. Finally, 2-amino and 2-amidobenzo[d]oxazole derivatives 7 and 8 are then generated in good yields and purities by cleavage of the respective resins 5 and 6 under trifluoroacetic acid (TFA) in dichloromethane ($CH_2Cl_2$).

• KCI Concrete Journal
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• 제11권3호
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• pp.89-97
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• 1999

The purpose of this research is to investigate the utilization of recycled fine aggregates as a material to apply to a building finished walls or as a decorating material in combination with a polymer. The strengths of two resin mortars using recycled fine aggregates and natural fine aggregates was made. In order to improve the workability and the strength of the resin mortar with recycled fine aggregates, partial replacement of recycled fine aggregates with natural ones was made with the application of various type of fillers. The results, it show that the compressive strength and flexural strength of resin mortar using the recycled fine aggregates were about 70% to 100% of those of resin mortar using natural fine aggregates. It was enough to assure the utilization of the recycled fine aggregates as a material for the production of resin mortar. From the result of partial replacement of recycled fine aggregates with natural ones, the compressive strength was Increased from 5% to 15% and the flexural strength was much as 5% to 20% as a result of 70% substitution It was also found that the use of garnet powder shows a similar tendency in the compressive strength and slag powder does in the flexural strength and tensile strength.

• Structural Engineering and Mechanics
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• 제87권4호
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• pp.375-389
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• 2023

In many fiber concrete beams with Carbon Fiber Reinforced Polymer (CFRP), debonding occurs between the carbon sheets and the concrete due to the low strength of the bonding resin. A total of 42 fiber concrete beams with a cross-section of 10×10 cm with a span length of 50 cm are fabricated and retrofitted with CFRP and subjected to a 4-point bending test. Graphene Oxide (GO) at 1, 2, and 3 wt% of the resin is used to improve the mechanical properties of the bonding resins, and the effect of length, width, and the number of layers of CFRP and resin material are investigated. The crack pattern, failure mode, and stress-strain curve are analyzed and compared in each case. The results showed that adding GO to polyamine resin could improve the bonding between the resin and the fiber concrete beam. Furthermore, the optimum amount of nanomaterials is equal to 2% by the weight of the resin. Using 2% nanomaterials showed that by increasing the length, width, and number of layers, the bearing and stiffness of fiber concrete beams increased significantly.

• Composites Research
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• 제35권6호
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• pp.394-401
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• 2022

Polyvinylidene chloride-resin(PVDC-resin)와 polyvinylidene fluoride(PVDF)의 두 폴리머 전구체는 열분해 과정을 통해 마이크로 다공성 탄소로 변환되어 되므로 이온 흡/탈착으로 전하를 저장하는 슈퍼커패시터용 전극재료로 유리하다. 더욱이, 두 전구체를 구성하는 여러가지 이종원소들은 탄화 후 작용기를 형성하여 추가적인 전하저장에 기여할 수 있으므로, 탄화 시 생성되는 작용기에 대한 분석은 에너지 저장용 탄소소재를 개발하는데 중요하다. 본 연구에서는 두 폴리머 전구체를 탄화시킨 후 생성된 작용기를 X-선 광전자 분광법(X-ray photoelectron spectroscopy)과 다양한 pH의 전해질에서 탄소 전극의 전기화학 거동 관찰을 통하여 확인하였다. 산성(1 M H₂SO₄) 전해질에서 측정된 두 탄소 전극의 비전기용량은 생성된 quinone 작용기의 패러데익 충/방전 반응 덕분에 중성 전해질(0.5 M Na₂SO₄)에서보다 증가하였다. 특히, PVDC-resin으로부터 합성된 탄소는 매우 작은 마이크로 기공이 표면에 형성되어 있어 전해질 이온의 흡착을 어렵게 하므로, PVDF로부터 합성된 탄소 전극에 비해 낮은 용량을 보인다. 염기성 전해질(6 M KOH)에서 두 탄소 전극 모두 3가지 전해질 중 가장 높은 비전기용량이 측정되었는데, 이는 구성하는 전해질 이온들(K⁺, OH^-)이 두 탄소에 형성된 마이크로 기공으로 흡/탈착이 용이하게 일어나는 동시에 패러데익 충/방전 반응으로 추가적인 전하가 저장되었기 때문이다.

• 폴리머
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• 제30권4호
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• pp.350-356
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• 2006

실리콘/아크릴수지를 기반으로 한 내후성 도료의 조성이 물성에 미치는 영향을 연구하기 위하여 안료분산 용 및 희석용 실리콘/아크릴수지의 배합비를 중량비율 2 : 8, 3 : 7, 4 : 6 의 3종으로 변화시키면서 내후성 도료를 제조하였다. 제조된 도료의 도막물성 및 내후성이 판단할 수 있는 각종 도막실험을 실시한 결과, 실리콘 성분함량이 증가할수록 열적안정성, 염수분무 및 내후성 등이 향상되었으며, 적정배합비는 2 : 8임을 알 수 있었다. 또한 실리콘 성분을 30 wt% 함유한 도료는 고내후성을 보유함을 확인하였다.