• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.88-91
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• 2004

In this study, a number of natural fiber henequen reinforced polymer matrix composites were successfully fabricated by means of a compression molding technique using chopped henequen fibers surface-treated with different electron beam irradiation (EBI) dosages, thermoplastic poly(butylene succinate), thermosetting unsaturated polyester and phenolic resins. Their interfacial and thermal characteristics were studied in terms of interfacial shear strength, fracture surface, dynamic mechanical properties, dimensional stability, and thermal stability using single fiber microbonding test, SEM, DMA, TMA, and TGA. The results show that their interfacial and thermal properties significantly depend on the intensity of EBl treatment on the natural fiber surface.

• Korean Chemical Engineering Research
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• 제61권1호
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• pp.109-115
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• 2023

목질계 바이오매스 가수분해액에 존재하는 알코올 발효 저해물질인 페놀화합물 중 물리화학적 유사성이 높은 페놀케톤 3종에 대한 추출 및 흡착 특성을 조사하였다. 반응추출을 이용하여 페놀케톤 3종으로 부터 acetosyringone을 선택적으로 분리하는 데 가장 적합한 염기성 추출제가 trioctylphosphine oxide라는 것이 밝혀졌다. 또한, 고분자 중성수지 흡착제인 XAD16을 이용한 흡착 또는 hexane을 이용한 물리추출이 4'-hydroxyacetophenone (HAP)과 acetovanillone (AVO)의 분리에 적합한 분리 방법임을 알 수 있었다. 동등한 질량백분율로 존재하는 페놀케톤 3종을 분리 및 농축하기 위하여 위에서 언급한 추출 및 흡착을 포함한 5단계 분별화 공정이 처음으로 제안되었다. 분별화 공정의 단계 4와 5로서 hexane에 의한 물리추출 및 NaOH 용액에 의한 역추출이 각각 사용되었을 때, 페놀케톤 3종의 순도를 거의 70% 이상 얻는 것이 가능하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.251.2-251.2
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• 2010

Plant biomass has been proposed to be an alternative source for petroleum-based chemical compounds. Especially, phenolic chemical compounds can be obtained from lignin by chemical depolymerization processes because lignin consists of complex aromatic polymer such as trans-p-coumaryl, coniferyl and sinapyl alcohols, etc. Phenolic chemical compounds from lignin were usually produced in super critical water. However, we applied Near-critical water (NCW) system because NCW is known as a good solvent for lignin depolymerization. Organic matter like lignin can be solved in NCW system and the system has a unique acid-base property without conventional non-eco-friendly chemicals such as sulfuric acid and sodium hydroxide. In this work, we tried to optimize the NCW depolymerization system by adjusting the processing variables such as reaction time, temperature and pressure. Moreover, the amount of additional phenol was optimized by changing the molar ratio between water and phenol. Phenol was used as capping agent to prevent re-polymerization of active fragment such as formaldehyde. Alkali-lignin was used as a starting material and characterized by a Solid State 13C-NMR, FT-IR and EA (Elemental Analysis). GC-MS analysis confirmed that o-cresol, p-cresol, anisole and 4-hydroxyphathalic acid were the main product and they were quantitatively analyzed by HPLC.

• 한국세라믹학회지
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• 제40권7호
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• pp.625-631
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• 2003

Recent work at USC has focused on strategies to enhance the toughness and overall mechanical performance of polymer foams for use in lightweight sandwich structures. Both mechanical and chemical approaches have been employed with reasonable success. Fiber reinforcement, though difficult from a processing perspective, can lead to substantial enhancements in toughness and strength, while reducing friability. Chemical modifications are also challenging from a processing perspective, but can produce similar enhancements in performance. Efforts to enhance performance of phenolic foam and PVC foam through fiber reinforcement and chemical modification are described, along with the resulting enhancements in performance.

• Macromolecular Research
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• 제17권2호
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• pp.84-90
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• 2009

We prepared side-chain liquid crystalline polymers comprising two monomeric units, one having a mesogenic side group that could form a smectic mesophase and the other having a phenolic group attached to the polymer backbone via a thermally reversible urethane bond. The urethane linkage between the isocyanate and phenol groups was stable at room temperature, but it cleaved to generate an isocyanate group when the temperature was increased. When annealed, the copolymers in their smectic mesophases became insoluble in common organic solvents, suggesting the formation of network structures. XRD analysis showed that the annealed polymers maintained their smectic LC structures. The crosslinking process probably proceeded via the reaction of the dissociated isocyanate groups. Some of the isocyanate groups would have first reacted with moisture in the atmosphere to yield amino groups, which underwent further reaction with other isocyanate groups, resulting in the formation of urea bonds. We presume that only polymer chains in the same layer were crosslinked by the reaction of the isocyanate groups, resulting in the formation of a layered polymer network structure. Reactions between the layers did not occur because of the wide layer spacing.

• 융복합기술연구소 논문집
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• 제3권1호
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• pp.45-49
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• 2013

Spherical active carbon materials have been used for the removal of pollutants in the area of food processing, water treatment, air purification, oral administration. Moreover, they are now expected to make an epoch in the areas of electronics, life science, environmental technology, and so on due to their superior physical properties. Carbon particles should be requested for the edgeless spherical shapes in order to minimize the loss due to the abrasion during the process and/or practical use, but the carbon particles manufactured from petroleum-based pitch do not meet these needs. Nowadays, thus, the spherical active carbon particles carbonized from various spherical polymer beads are studied with thermoplastic and/or thermosetting polymers. In this paper, the synthesis of spherical phenolic beads and furan beads, which are thermosetting polymers, and their carbonization techniques are examined.

• 대한화학회지
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• 제16권5호
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• pp.320-327
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• 1972

韓國産 土炭의 흄酸의 性狀(分子量, 分子式 및 示性式)과 基應用(田沓用 土壤改良制 및 溶性燐質 肥料製造)에 關해서 이미 硏究報韓 바가 있으나, 흄酸의 構造를 推定하는데 있어서, 未及한 鮎이 있어서, 이의 補完策으로서 aromatic diazonium salt를 coupling 시켜, phenolic-OH group 의 結合狀態를 살펴보고 各種 aromatic diazonium salt와 흄酸 및 니트로흄酸에 依해서 얻어진 生成物들을 Azo 染料로 利用함으로서 應用策의 一環을 講究했다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1988년도 추계학술대회 논문집
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• pp.21-26
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• 1988

Composition with O-3 connectivity were fabricated from PZT and phenolic resin powders. These composites were investigated for dielectric and pizoelectric properties with PZT-polymer interface porosity variation. The interface porosity dependence of dielectric and piezoelectric properties was especially discussed by porosity factors. The interface porosity dependence of piezoelectric constant was larger than that of dielectric constant. It was considered that the interface pore plays the role of a stress buffer. Thus the local stress applied on PZT particles in the composite was remarkably diminish.

• Carbon letters
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• 제4권2호
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• pp.57-63
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• 2003

In polymer precursor based activated carbon, the structure of starting material is likely to have profound effect on the surface properties of end product. To investigate this aspect phenolic resins of different types were prepared using phenol, mcresol and formaldehyde as reactants and $Et_3N$ and $NH_4OH$ as catalyst. Out of these resins two resol resins PFR1 and CFR1 (prepared in excess of formaldehyde using $Et_3N$ as catalyst in the basic pH range) were used as raw materials for the preparation of activated carbons by both chemical and physical activation methods. In chemical activation process both the resins gave activated carbons with high surface areas i.e. 2384 and 2895 $m^2/g$, but pore size distribution in PFR1 resin calculated from Horvath-Kawazoe method, contributes mainly in micropore range i.e. 84.1~88.7 volume percent of pores was covered by micropores. Whereas CFR1 resin when activated with KOH for 2h time, a considerable amount (32.8%) of mesopores was introduced in activated carbon prepared. Physical activation with $CO_2$ leads to the formation of activated carbon with a wide range of surface area (503~1119 $m^2/g$) with both of these resins. The maximum pore volume percentage was obtained in 3-20 ${\AA}$ region by physical activation method.

• 폴리머
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• 제24권1호
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• pp.97-104
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• 2000

산화처리 된 평직형태의 탄소섬유와 resole 형태의 페놀수지를 7:3 중량비로 혼합하여 성형공정에 따라 탄소섬유/페놀수지 복합재료를 제조하였으며, 이를 다시 불활성 분위기에서의 탄화(100$0^{\circ}C$) 및 $CO_2$ 분위기에서 활성화(700, 800,, 900 및 100$0^{\circ}C$)시켜 PAN계 활성탄소섬유/페놀수지 복합재료를 제조하였다. 본 연구에서는, 이렇게 제조된 복합재료에 활성화 온도가 미치는 영향을 중화 적정법에 따른 pH, 표면 산도 및 표면 염기도 등의 표면성질과 BET 방법에 따른 비표면적, 기공구조 등의 흡착특성을 측정하여 고찰하였다. 또한, ASTM에 따라 시편에 걸리는 압력 손실을 측정하였다. 결과적으로, 활성화 온도는 그 표면 성질의 변화에 영향을 주어, 90$0^{\circ}C$ 이상의 온도에서 시료의 표면은 점차 염기성이 커지는 것을 확인할 수 있었다. 또한, 비표면적, 총 기공 부피 및 기공 크기 분포도 등의 발달은 활성화 온도의 증가에 따라 점차 증가함을 쉽게 확인할 수 있으며, 그 중 활성화 온도가 90$0^{\circ}C$인 경우 가장 발달한 것으로 나타났다. 마찬가지로, 활성화 온도의 증가에 따라 시편 양 단면에 걸리는 압력손실은 점차 감소하였으며, 이것은 열처리 온도에 의한 활성탄소섬유 복합재료의 질량손실에 의한 것으로 사료된다.