견피브로인/Poly(2-hydroxyethyl methacrylate) 브렌드 필름의 구조 및 열적 특성

엄인철,권해용,박영환 한국잠사학회 2000 한국잠사곤충학회지 Vol.42 No.1

Structural and termal characteristics of silk fibroin/poly(2-hydroxyethyl methacrylate)(PHEMA) blend films were investigated using FTIR, X-ray diffractometer, differential scanning calorimeter, thermogravimeter and scanning electron microscope. FTIR spectra showed that the conformation of silk fibroin prepared by dissolving in formic acid was β-sheet, which did not affected by blending with PHEMA, The X-ray diffraction patterns also showed that individual crystalline structure of silk fibroin and PHEMA was not affected by blending with PHEMA. The X-ray diffraction patterns also showed that individual crystalline structure of silk fibroin and PHEMA was not affected for the blend films. The initial thermal decomposition temperature of silk fibroin/PHEMA blend film tends to be higher than either of silk fibroin or PHEMA. Thermal stability of both polymers, more notably PHEMA, can be improved by blending two components. As a result of SEM observation, the phases separation for silk fibroin/PHEMA blend films occurred regardless of blend ratio; continuous and dispersed phase were silk fibroin and PHEMA component, respectively.

견피브로인/폴리우레탄 브랜드 필름의 구조 및 성질

엄인철,권해용,황창모,민병구,박영환 한국고분자학회 2001 한국고분자학회 학술대회 연구논문 초록집 Vol.2001 No.4

알칼리 처리에 따른 아마섬유의 헤미셀룰로스 제거와 결정구조 전이

엄인철,권해용,박영환,Um, In Chul,Kweon, Hae Yong,Park, Young Hwan 한국섬유공학회 2012 한국섬유공학회지 Vol.49 No.5

In this study, delignified flax fiber was treated with a NaOH aqueous solution. XRD diffractometry and FTIR spectroscopy were utilized to examine the structural transition of the alkali-treated flax fibers. Also, the effect of the hemicellulose removal on the structural change of flax fibers was discussed. XRD measurement revealed that the crystallinity of cellulose I increased at low NaOH concentration (3%) due to the elimination of amorphous hemicellulose. The structural transition from cellulose I to cellulose II occurred in a NaOH concentration range of 12~15%. Considering most hemicellulose in flax fiber is removed at 12% NaOH, it can be assumed that the presence of hemicellulose in flax fiber has a role in preventing the structural change of flax cellulose. IR absorbance ratios ($A_{1370cm}{^{-1}}/A_{2900cm}{^{-1}}$ and $A_{1430cm}{^{-1}}/A_{2900cm}{^{-1}}$) were utilized as a barometer of cellulose I crystalline exhibiting a similar result with the cellulose I crystallinity from XRD. Another absorbance ratio ($A_{895cm}{^{-1}}/A_{2900cm}{^{-1}}$) reflected the cellulose II crystalline showing almost the same trend as cellulose II crystallinity. On the whole, the total crystallinity of flax fiber was increased at low NaOH concentration (3%) and decreased at 12% due to the reduction of cellulose I content and increased again at 15% attributed to the formation of cellulose II content.

셀룰로오스 에테르를 첨가한 쌀면의 기계적 물성

엄인철,유영진,Um, In Chul,Yoo, Young Jin 경북대학교 농업과학기술연구소 2013 慶北大農學誌 Vol.31 No.3

본 연구에서는 셀룰로오스 에테르의 분자량, 치환도 및 치환체가 이들을 첨가한 쌀건면의 기계적 물성에 주는 영향에 대해 살펴보았다. HPMC의 분자량이 증가함에 따라, 쌀건면의 굽힘강도는 서서히 증가하였으나, 밀면의 강도보다는 낮은 수준을 나타냈다. 분자량이 증가함에 따라, 쌀건면의 굽힘신도는 서서히 감소하였으나, 밀면의 신도보다는 모두 높은 값을 나타내어 셀룰로오스 에테르 첨가가 쌀건면의 신도 향상에 기여했음을 확인하였다. 셀룰로오스의 치환도 및 치환체에 따라서는 굽힘강도 및 굽힘신도가 다소 차이가 있는 것으로 나타났다. This study examined the effect of the molecular weight, substitution degree, and substitution type of cellulose ether on the mechanical properties of dried rice noodles. When increasing the molecular weight of the hydroxypropyl methylcellulose (HPMC), the bending strength of the dried rice noodles also increased. However, the bending strength of the rice noodles with added HPMCs was still lower than that of the wheat noodles. Meanwhile, the bending elongation of the dried rice noodles was higher than that of the wheat noodles and was increased when decreasing the molecular weight of the HPMC. In conclusion, the bending strength and elongation of dried rice noodles is affected by the substitution degree and type of cellulose ether.

Dissolution, crystallilnity, and mechanical properties of silk sericin from Sericinjam silkworm cocoons

엄인철 한국잠사학회 2023 International Journal of Industrial Entomology Vol.46 No.1

Recently, a silkworm strain (tentatively named Sericinjam) producing 100% sericin cocoons has been studied in South Korea. In this preliminary study, the crystallinity, mechanical properties, and dissolution conditions of sericin from Sericinjam cocoons were examined. The Sericinjam cocoon could be dissolved in water at high temperature (120o C) and high pressure (HTHP method) in an autoclave and in a CaCl2/H2O/EtOH mixture (ternary solvent method), resulting in 82% and 97% dissolution after 30 min, respectively. The solution viscosity of the silk sericin formic acid (SSFA) solution obtained from sericin extracted using the ternary solvent method was higher than that obtained using the HTHP method; however, SSFA solutions obtained from sericin extracted from conventional Baekokjam cocoons yielded a higher solution viscosity. The crystallinity and breaking strength of the sericin film from Sericinjam cocoons were slightly lower, respectively, than those from Baekokjam cocoons. In contrast, the elongation at break of the Sericinjam sericin film obtained using the HTHP method was higher than that of the Baekokjam sericin film.

A Comparative Study on the Dielectric and Dynamic Mechanical Relaxation Behavior of the Regenerated Silk Fibroin Films

엄인철,권해용,기창석,박영환,김태희 한국고분자학회 2009 Macromolecular Research Vol.17 No.10

In this paper, the relaxation behavior of the regenerated silk fibroin (SF) films was investigated using dielectric thermal analysis (DETA), and compared with the dynamic mechanical behavior obtained from dynamic mechanical thermal analysis (DMTA), in order to gain a better understanding of the characteristics of dielectric behavior of SF film and identify the differences between the two analyses. Compared to DMTA, DETA exhibited a higher sensitivity on the molecular relaxation behaviors at low temperature ranges that showed a high γ-relaxation peak intensity without noise. However, it was not effective to examine the relaxation behaviors at high temperatures such as α- and αc-relaxations that showed a shoulder peak shape. On the contrary, DMTA provided more information regarding the relaxation behaviors at high temperatures, by exhibiting the changes in width, intensity and temperature shift of the α-relaxation peak according to various crystallinities. Conclusively, DETA and DMTA can be utilized in a complementary manner to study the relaxation behavior of SF over a wide temperature range, due to the different sensitivity of each technique at different temperatures.

The Effect of Coagulant on the Post Drawing and Morphology of Wet Spun Regenerated SF/Nylon 6 Blend Filaments

엄인철 한국잠사학회 2008 International Journal of Industrial Entomology Vol.16 No.2

In this paper, the regenerated silk fibroin (SF)/nylon 6 blend filaments were fabricated using wet spinning technique and the effect of coagulant on the post drawing and morphology of blend filaments was investigated. In the result of wet spinnability, methanol, acetone, DMF, and THF showed relatively good coagulation strength and fiber formation for the regenerated SF. On the contrary, they did not exhibit strong enough to produce a uniform nylon 6 filament due to the lack of coagulation strength. In the examination of post drawing performance, methanol showed the highest maximum draw ratio of the blend filament over all blend ratios. The maximum draw ratio of SF/nylon 6 blend filaments decreased with the reduction of SF content regardless of type of coagulant. SEM observation showed the consistent result with that of post-drawing performance. As SF content decreased, the uniform and regular structure was changed to irregular one. In particular, the severe macro-phase separation between SF and nylon 6 could be detected in the 50/50 SF/nylon 6 blend filaments coagulated in methanol and THF.

유변물성 측정기를 이용한 셀룰로오스 에테르가 첨가된 쌀 반죽의 압축 및 접착 특성

엄인철,유영진 경북대학교 농업생명과학대학 2014 Current Research on Agriculture and Life Sciences Vol.32 No.1

본 연구에서는 유변물성측정기를 이용하여 HPMC 첨가량, 물 양, HPMC 분자량, 셀룰로오스 에테르 치환체 및 치환도가 쌀 반죽의 압축 및 접착 특성에 미치는 영향에 대해 살펴보았다. HPMC 첨가량이 증가함에 따라 접착강도는 꾸준히 증가하였으나, 압축강도는 2% HPMC 첨가량에서 최대 강도를 보였다. HPMC의 분자량이 증가하거나, 물 양이 감소할수록 쌀 반죽의 압축강도 및 접착강도가 증가하는 결과를 보였다. 이들 인자 외에도, 셀룰로오스 에테르의 치환체 및 치환도도 쌀 반죽의 압축강도 및 접착 강도를 결정하는 중요한 인자임을 확인하였다. The present study examined the effect of cellulose ether on the compression and adhesion characteristics of rice dough using a rheometer. When increasing the amount of hydroxypropyl methylcellulose (HPMC), the adhesion strength consistently increased. However, the compression strength of the rice dough was the highest with 2% HPMC. When increasing the molecular weight and decreasing the water content, the compression and adhesion strength of the rice dough were both increased. Furthermore, the substitution type and degree of cellulose ether were also found to be key factors determining the compression and adhesion strength of the rice dough.

유변물성 측정기를 이용한 셀룰로오스 에테르가 첨가된 쌀 반죽의 압축 및 접착 특성

엄인철,유영진,Um, In Chul,Yoo, Young Jin 경북대학교 농업과학기술연구소 2014 慶北大農學誌 Vol.32 No.1

The present study examined the effect of cellulose ether on the compression and adhesion characteristics of rice dough using a rheometer. When increasing the amount of hydroxypropyl methylcellulose (HPMC), the adhesion strength consistently increased. However, the compression strength of the rice dough was the highest with 2% HPMC. When increasing the molecular weight and decreasing the water content, the compression and adhesion strength of the rice dough were both increased. Furthermore, the substitution type and degree of cellulose ether were also found to be key factors determining the compression and adhesion strength of the rice dough. 본 연구에서는 유변물성측정기를 이용하여 HPMC 첨가량, 물 양, HPMC 분자량, 셀룰로오스 에테르 치환제 및 치환도가 쌀 반죽의 압축 및 집착 특성에 미치는 영향에 대해 살펴보았다. HPMC 첨가량이 증가함에 띠라 접착강도는 꾸준히 증가하였으나, 압축강도는 2% HPMC 첨가량에서 최대 강도를 보였다. HPMC의 분자량이 증가하거나, 물 양이 감소할수록 쌀 반죽의 압축강도 및 접착강도가 증가하는 결과를 보였다. 이들 인자 외에도, 셀룰로오스 에테르의 치환제 및 치환도도 쌀 반죽의 압축강도 및 접착강도를 결정하는 중요한 인자임을 확인하였다.

셀룰로오스 에테르 첨가 쌀 면의 조리 특성

엄인철,유영진 경북대학교 농업생명과학대학 2014 Current Research on Agriculture and Life Sciences Vol.32 No.2

셀룰로오스 에테르의 분자량, 첨가량, 치환도 및 치환체 종류, 물 양이 쌀면의 조리특성에 주는 영향을 살펴보기 위해 자외선 가시광선 분광분석기를 이용하여 조리 후 쌀면 국물 탁도 를 측정하고 유변물성 측정기를 이용하여 쌀면의 압축강도를 측정하였다. HPMC의 분자량 및 물 양이 증가할수록 국물의 탁도가 감소하여 조리 시 쌀면의 형태안정성이 향상되었고, 셀룰로오스 에테르 첨가량, 치환체 종류, 치환도에 따라 탁도 값이 변화하여, 이들 인자 모두가 쌀면의 형태안정성에 영향을 준다는 것을 확인하였다. 또한, 이들 인자를 효과적으로 조절할 경우, 밀면을 조리한 국물의 탁도보다 낮은 탁도값이 얻어져 셀룰로오스 에테르의 첨가에 따라 조리 시 쌀면의 형태안정성이 크게 향상됨을 확인하였다. 유변물성 측정기를 이용한 쌀면의 압축특성 측정은 조리시간에 따른 쌀면의 호화정도 및 변화하는 조직감을 살펴보는 데 효과적이였으며, 물 양 및 셀룰로오스 에테르의 분자량이 다른 인자들에 비하여 조리시간 별 쌀면의 호화특성 및 조직감에 큰 영향을 주는 것으로 나타났다. This study uses turbidity and rheological measurements to examine the effects of the molecular weight (MW), substitution type and substitution degree of cellulose ether and water content on the cooking characteristics of rice noodles, the turbidity of the cooking solution, and the compression strength of the cooked noodles. When increasing the MW of cellulose ether and water content, the turbidity decreased, thereby improving the morphological stability of the rice noodles during cooking. Thus, when controlling the above factors effectively, the rice noodle cooking solution had a lower turbidity than with wheat noodles. Measuring the compression strength of the rice noodles using a rheometer was also effective for examining the pasting characteristics of the rice noodles and texture changes during cooking. As a result, the water content and MW of cellulose ether were found to affect the pasting characteristics and texture of the rice noodles more than the other factors examined.