• 접착 및 계면
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• 제12권1호
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• pp.34-42
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• 2011

자동차용 도장시스템으로 새롭게 대두되고 있는 roll coating process는 비친환경적이면서도 생산성이 떨어지는 기존의 습식도장공정을 완전 대체할 수 있는 기술로 알려져 있다. Pre-painted 강판 시스템에서 도막 유연성 및 강도 등의 구현을 위하여 경화거동뿐만 아니라 내식성 및 성형가공성, 유변학적 거동 등의 평가가 매우 중요하다. 본 연구에서는 pre-painted system에 적용하기 위하여 polyester 수지를 수산화기 및 분자량 변성을 통하여 합성한 후, 경화거동 및 딥드로잉, 인장력, 유변특성 등을 평가하였다. 40 (mg KOH-/mol)정도의 수산화기를 갖는 N-0375-40 system이 유연성 및 도막강도, 경화거동 등의 가장 우수한 물성을 나타내었다.

• Macromolecular Research
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• 제14권2호
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• pp.179-186
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• 2006

In the present work, low density polyethylene (LDPE)/aliphatic polyester (APES)/organoclay ternary nanocomposites were prepared. In particular, the effect of a compatibilizer, polyethylene-graft-maleic anhydride (PE-g-MAH), on the morphology and properties of the ternary nanocomposites was investigated. LDPE/APES/organoclay nanocomposites were prepared through melt intercalation method using two different kinds of organoclay. The dispersibility of silicate clays in the nanocomposites was investigated by X-ray diffraction and atomic force microscopy. The ternary nanocomposites showed higher tensile properties than the LDPE/APES blend did. The dispersibility and properties of nanocomposites containing Cloisite 30B were better than those of the nanocomposites containing Cloisite 20A. Unlike Cloisite 20A, hydroxyl groups in the intercalants in Cloisite 30B interlayer underwent a certain polar interaction with the carboxyl group of APES, favoring the intercalation of APES chains and the formation of LDPE/APES/Closite 30B nanocomposites. However, the introduction of the polar hydroxyl groups also enhanced the interaction with the silicate surface at the same time, thereby rendering somewhat difficult the replacement of the surface contacts by LDPE chains, and impeding the extensive intercalation and further exfoliation of Cloisite 30B in the LDPE/APES matrix. The compatibilizer enhanced the intercalation of the polymer chain inside the clay gallery and thus improved the mechanical properties of the ternary nanocomposites. Rheological measurements of the nanocomposites via frequency sweep experiment indicated a certain interaction between the clay platelet and the polymer molecules in the melted state.

• 한국염색가공학회지
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• 제35권1호
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• pp.20-28
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• 2023

In this study, TPU resin for coating was prepared by varying the mixing ratio of antistatic TPU and recycled TPU to manufacture permanent antistatic materials. The coated yarn was prepared by coating on the nylon yarn, and then the thermal, rheological, mechanical properties and antistatic properties were analyzed. In addition, antistatic properties and durability were confirmed after manufacturing UD fabrics using coated yarns. The mixing ratio of antistatic TPU and recycled TPU was most appropriate at 4:6, and the antistatic property had a surface resistance of 2.20 × 10⁹ Ω and a static charge of 398 V. In the coating process, the coating speed was most appropriate at 0.21 m/s, and the surface resistance of the UD fabric manufactured with the coated yarn manufactured under this condition was 6.80 × 10⁹ Ω and the static charge was 484 V. The UD fabric had a surface resistance of 7.21 × 10⁹ Ω and a static charge of 517 V after washing 10 times, and it was confirmed that the permanent antistatic property was excellent.

• 공업화학
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• 제5권6호
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• pp.935-942
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• 1994

두 가지 종류의 고무로부터 ABS를 제조한 후, 각 ABS를 PMMA와 블렌딩하여 블렌드의 몰폴로지, 기계적 성질 및 용융물성을 검토하였다. 또한 블렌드에 카본블랙을 첨가하여 카본블랙의 분산형태 및 블렌드 물성에 미치는 영향을 조사하였다. PMMA함량에 따라 블렌드의 굴곡탄성률, 인장항복강도 및 표면광택은 증가하였으며, 파단신율 및 충격강도는 감소하였다. 카본블랙을 첨가 하였을 경우, 블렌드 물성은 전반적으로 감소하는 경향을 보였다. 아울러 사용한 ABS형태 및 카본블랙 첨가에 따른 용융거동을 조사하였다.

• 한국축산식품학회지
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• 제39권4호
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• pp.576-584
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• 2019

This study was performed to evaluate the physicochemical properties of myofibrillar protein (MP) gels containing pork skin gelatin at different salt concentrations. MP gels were prepared to the different salt levels (0.15, 0.30, and 0.45 M) with or without 1.0% of pork skin gelatin. Cooking yield (CY), gel strength, shear stress were measured to determine the physical properties, and SDS-polyacrylamide gel electrophoresis, scanning electron microscopy, fourier transform infrared spectroscopy, sulfhydryl group and protein surface hydrophobicity was performed to figure out the structural changes among the proteins. The addition of gelatin into MP increased CYs and shear stress. MP at 0.45 M salt level had the highest CY and shear stress, as compared to MPs at lower salt concentrations. As the salt concentration of MP gels increased, the microstructure became the compact and wet structures, and decreased the amount of ${\alpha}-helix$/unordered structures and ${\beta}-sheet$. MP with gelatin showed a decreased amount of ${\alpha}-helix$/unordered structures and ${\beta}-sheet$ compared to MP without gelatin. The addition of gelatin to MP did not affect the sulfhydryl group, but the sulfhydryl group decreased as increased salt levels. MP mixtures containing gelatin showed a higher hydrophobicity value than those without gelatin, regardless of salt concentration. Based on these results, the addition of gelatin increased viscosity of raw meat batter and CY of MP gels for the application to low salt meat products.

• 동아시아식생활학회지
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• 제16권2호
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• pp.174-179
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• 2006

This study was carried out to investigate the possible for utilization of garbage in pig feed by investigating the functional characteristics of pork from pigs fed tangerine-peels. The samples consisted of the pork loin from pigs not fed with tangerine-peel (control), the pork loin fed with 3% and 5% tangerine-peel during growing and finishing period (TP-1), and fed with 6% and 10% tangerine-peel during growing and finishing period (TP-2) there is no respective comparison here. The pH, VBN content TBARS value, bacterial counts, surface color, water holding capacity, loss degree and rheological properties of the samples were determined by physicochemical properties, and the sensory scores were evaluated. The pH, TBARS value, surface color, water holding capacity and loss degree were not different among the samples, but the VBN content and bacterial counts of TP-1 and TP-2 were significantly lower than those of the control (p<0.05). The hardness, springiness, cohesiveness, gumminess and chewiness, taste, aroma, tenderness and juiciness were not different among the samples, but the shear force value and palatability of TP-1 were the highest among the samples (p<0.05).

• 한국식품영양과학회지
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• 제40권5호
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• pp.738-746
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• 2011

Microbial transglutaminase(MTGase)를 이용하여 쌀 가수분해물과 초미세 생대두 분말을 혼합하여 전두부를 제조한 후 조직감, 동적점탄성, 단백질 결합패턴 및 미세구조를 평가하였다. 40%(w/v) 쌀 용액을 Termamyl 효소처리($85^{\circ}C$, 20분) 하였을 때 점조도 값 및 환원당 함량이 각각 $1.27\;Pa{\cdot}s^n$, 9.0%로 나타났다. MWSP 18~22% 농도에서 MTGase 효소로 응고시킨 전두부의 물성을 측정한 결과 MWSP 22% 첨가구에서 전형적인 두부의 조직감을 얻었으며, 쌀 가수분해물 7.5% 첨가구의 경우 경도 639.6 dyne/$cm^2$, 탄성 0.96으로 나타났다. MTGase 5%의 첨가 조건에서 MWSP 18~22% 농도에 따라 동적점탄성을 측정한 결과 MWSP 22% 첨가 경우 반응 6분 이내 G'(5.1 Pa) 및 G''(9.0 Pa)값으로 높게 나타났다. MWSP 22% 첨가구에서 시간에 따른 SDS-PAGE 상에서 대부분의 콩 단백질은 30분 이내에 중합되어 고분자중합체를 형성하였으며, 쌀 가수분해물이 첨가된 경우에도 대부분의 콩 단백질들이 중합되는 유사한 경향을 보였다. 쌀이 첨가된 전두부의 미세구조는 균일한 입자로 채워진 네트워크 구조를 보였으나 냉장저장 2일 후에는 쌀을 첨가하지 않은 대조구에 비해 더욱 거칠어진 표면을 확인할 수 있었다.

• 한국정밀공학회지
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• 제20권6호
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• pp.27-36
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• 2003

The Electro-Rheological (ER) fluid has been used to the ultraprecision polishing of single crystal silicon as new polishing slurry whose properties such as yield stress and particle structure changed with the application of an electric field. In this work, it is aimed to find the effective parameters in the ER fluid on material removal in the polishing system whose structure is similar to that of the simple hydrodynamic bearing. The generated pressure in the gap between a moving wall and a workpiece, as well as the electric field-induced stress of the mixture of ER fluid-abrasives, is evaluated experimentally, and their influence on the polishing of single crystal silicon is analyzed. Moreover, the behavior of abrasive and ER particles is described.

• 한국세라믹학회지
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• 제25권6호
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• pp.615-622
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• 1988

To develope good slip and microstructure of Si3N4 the knowledge of the interaction of particles in liquid systems is required. In this work polyethyleneimines was tested as a stabilizer for Si3N4-water system. The stability of slip dispersed with polyethyleneimines was good over a wide range of pH and concentrated slips with low viscosity could be cast. This work comprises a systematic investigation including determination of electrical mobility in order to estimate the particle surface charge, determination of sedimentation rate, as well as measurements of the viscosity as a function of dispersants, pH and shear rates. The influence of deflocculation on the microstructure of slip cast Si3N4 was discussed.

• 한국축산식품학회지
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• 제34권4호
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• pp.552-557
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• 2014

This study investigated the effects of ${\gamma}$-aminobutylic acid (GABA) on the quality and sensorial properties of both the GABA/NaCl complex and model meat products. GABA/NaCl complex was prepared by spray-drying, and the surface dimensions, morphology, rheology, and saltiness were characterized. For model meat products, pork patties were prepared by replacing NaCl with GABA. For characteristics of the complex, increasing GABA concentration increased the surface dimensions of the complex. However, GABA did not affect the rheological properties of solutions containing the complex. The addition of 2% GABA exhibited significantly higher saltiness than the control (no GABA treatment). In the case of pork patties, sensory testing indicated that the addition of GABA decreased the saltiness intensity. Both the intensity of juiciness and tenderness of patties containing GABA also scored lower than the control, based on the NaCl reduction. These results were consistent with the quality characteristics (cooking loss and texture profile analysis). Nevertheless, overall acceptability of the pork patties showed that up to 1.5%, patties containing GABA did not significantly differ from the control. Consequently, the results indicated that GABA has a potential application in meat products, but also manifested a deterioration of quality by the NaCl reduction, which warrants further exploration.