• Journal of the Korean Wood Science and Technology
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• 제40권4호
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• pp.229-236
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• 2012

본 연구는 감마선 조사가 소나무(Pinus densiflrora), 느티나무(Zelkovas serrenata), 오동나무(Paulownia tomentosa)의 세포벽 열화, 셀룰로오스 결정화도, 휨 강도에 미치는 영향을 구명하기 위해 수행되었다. 각 목재 시편들을 100 kGy 선량의 감마선 조사 후 주사전자현미경(scanning electron microscope; SEM) 관찰 결과, 목재 세포벽 열화는 관찰되지 않았으며 휨 강도 역시 현저한 변화가 나타나지 않았다. 감마선 조사에 의한 셀룰로오스 결정화도 역시 유의한 변화가 관찰되지 않았다. 이러한 감마선에 대한 목재의 높은 안전성은 감마선 조사 기술을 재질손상 없이 목재를 가해 중인 균류와 충류 구제를 위해 적용할 수 있음을 의미한다.

• 펄프종이기술
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• 제47권3호
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• pp.3-10
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• 2015

In this study, we evaluated properties of pulp treated with swelling agent and swelling concentration. We used swelling agent, such as NaOH, DMSO, urea. One of them, pulps treated with NaOH from 0 to 5% measured WRV, beating efficiency, crystallinity and aspect ratio. We identified that NaOH when freeness reaches 100mL CSF was the shortest, on the other hand, WRV didn't change. Because NaOH is good beating efficiency, when pulp treated with various concentration of NaOH from 0 to 5%, pulp treated 1% NaOH was best beating efficiency. However, WRV, crystalline structure and crystallinity didn't change. The more NaOH concentration increased, the more aspect ratio increased, but when NaOH concentration exceeds 3%, aspect ratio decreased. As a result, pulp treated with 1% NaOH was the greatest beating efficiency and WRV, chemical structure didn't change.

• 한국결정성장학회지
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• 제34권3호
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• pp.79-85
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• 2024

고압 균질기를 이용하여 면 셀룰로오스 원료로부터 직접 셀룰로오스 나노결정을 추출하고 이에 대한 결정 구조 및 화학적 결합 상태에 대한 연구를 수행하였다. 형성된 셀룰로오스 나노결정은 나노와이어 형태의 구조적 특성을 가지며, 조밀한 구조의 메쉬 형태로 분포하였다. X-ray diffraction (XRD) 분석을 통해 관찰된 Bragg 결정면의 면간거리 계산을 통해 고압 균질기로부터 추출된 셀룰로오스 나노결정이 셀룰로오스 Iβ 하부 다형체인 monoclinc 결정구조를 갖음을 확인하였다. 셀룰로오스 나노결정에 포함된 비정질 영역을 정량적으로 평가하기 위한 Solid-state nuclear magnetic resonance(NMR) 분석 결과 셀룰로오스 나노결정의 결정화도 지수는 5 3.06 %로 계산되었다. 형성된 셀룰로오스 나노결정 표면의 O/C ratio는 0.82로 계산되었으며, C-C 결합 혹은 C-H 결합, C-O 결합, O-C-O 결합 혹은 C=O 결합, O-C=O 결합의 화학적 결합이 셀룰로오스 나노결정 표면의 주요 화학적 상태임을 알 수 있었다.

• Fibers and Polymers
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• 제6권2호
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• pp.95-102
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• 2005

Sodium cellulose carbonate (CC-Na) dissolved in $8.5\;wt\%$ NaOH/ZnO (100/2-3, w/w) aqueous solution was spun into some acidic coagulant systems. Diameter of regenerated cellulose fibers obtained was in the range of $15-50\;{\mu}m$. Serrated or circular cross sectional views were obtained by controlling salt concentration or acidity in the acid/salt/water coagulant systems. Velocity ratio of take-up to spinning was controlled up to 4/1 with increasing spinning velocity from 5 to 40 m/min. Skin structure of was developed at lower acidity or higher concentration of coagulants. Fineness, tenacity and elongation of the regenerated cellulose fibers were in the range of 1.5-27 denier, 1.2-2.2 g/d, and $8-11.3\;\%$, respectively. All of CC-Na and cellulose fibers spun from CC-Na exhibited cellulose II crystalline structure. Crystallinity index was increased with increasing take-up speed.

• 한국응용과학기술학회지
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• 제26권4호
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• pp.428-433
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• 2009

Cellulose triacetate (CTA) was prepared from cotton linter and pulps which contain various contents of $\alpha$-cellulose. CTA which contains 2.8 of degree of substitution (DS) and 222 of degree of polymerization (DP) was obtained from V-81 pulp under the heterogeneous system. The DS was measured by the titration method, and the DP was obtained by measurement of viscosity. FT-IR spectometer (FT-IR 6300, JASCO) was used to analyze the chemical structure of raw materials and cellulose triacetate, and X-ray diffractometer (X-pert MPD PW3040, Philips) was used to confirm the crystal structure and to calculate the relative crystallinity index (RCI). As $\alpha$-cellulose content in pulp increased, the acetylation yield increased. Besides with a kind of pulp, it contains insoluble residue which was mainly formed due to the formation of glucomannan triacetate and xylan diacetate during the esterification.

• 펄프종이기술
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• 제48권2호
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• pp.68-74
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• 2016

Nanofibrillated cellulose (NFC) was prepared from cotton linter after electron beam irradiation to investigate its effects on the manufacturing efficiency of the NFC preparation and the property changes by the treatment. Mechanical device (Super Masscolloider) was used to prepare the NFC and its passing frequency for each NFC preparation was recorded. More electron beam irradiation resulted in less passing frequency. Alpha cellulose content, molecular weight, crystallinity index, and thermal decomposition behavior of each treatment were lowered by electron beam treatment (10 and 100 kGy) and grinding process. NFC films were prepared to investigate their mechanical properties. There were little changes in tensile properties of the NFC films.

• 펄프종이기술
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• 제43권3호
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• pp.59-65
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• 2011

The saw dust of tropical hardwood, Nyatoh(Palaquium Spp.), was used as a raw material for the preparation of the high valued microcrystalline cellulose(MCC). Three pulping methods, soda pulping, Kraft pulping, and acid-sulfite pulping were applied to obtain cellulose from the saw dust. The residual impurities were removed with the additional bleaching processes: (A) $ClO_2{\rightarrow}H_2O_2$; (B) $ClO_2{\rightarrow}O_3$; (C) $O_3$. For the acid treatment for MCC preparation, the $H_2SO_4$, with three concentration, 20%, 40%, 60% were applied and the effects of $H_2SO_4$ concentration on the properties of MCC were evaluated. The results indicated that the MCC obtained by acid-sulfite pulping followed with $O_3$ treatment and 40% $H_2SO_4$ treatment showed less residual lignin, higher brightness and crystallinity than that of Avicel MCC.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권1호
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• pp.26-31
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• 2006

The saccharogenic liquid (SFW) obtained by the enzymatic saccharification of food wastes was used as a medium for production of bacterial cellulose (BC). The enzymatic saccharification of food wastes was carried out by the cultivation supernatant of Trichoderma harziaum FJ1 culture. Acetobacter xylinum KJ1 was employed for the BC production culture. The physical properties, such as polymerization, crystallinity, Young's modulus, and tensile strength, of BCs produced by three culture methods: the static cultures using HS (Hestrin-Schramm) as a reference medium (A) or the SFW medium (B), the shaking culture (C) or the air circulation culture (D) using the SFW medium, were investigated. The degrees of polymerization of BCs produced under the different culture conditions (A-D) showed 11000, 9500, 8500, and 9200, respectively. Young's modulus was 4.15, 5.0, 4.0, and 4.6 GPa, respectively. Tensile strength was 124, 200, 80, and 184 MPa, respectively. All of the BC had a form of cellulose I representing pure cellulose. In the case of the shaking culture, the degree of crystallinity was 51.2%, the lowest degree. Under the other culturing conditions, the trend should remain in the range of 89.7-84%. Overall, the physical properties of BC produced from SFW were similar to those of BC from HS medium, a commercial complex medium, and BC production by the air circulation culture mode brought more favorable results in terms of the physical properties and its ease of scale-up. Therefore, it is expected that a new BC production method, like air circulation culture using SFW, would contribute greatly to BC-related manufacturing.

• Journal of the Korean Wood Science and Technology
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• 제49권4호
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• pp.287-298
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• 2021

Torch ginger (Etlingera elatior Jack) is a potential source of lignocellulose material for various derivative products. This study aims to determine the chemical components, ratio of syringyl to guaiacyl units (S/G) in lignin, and crystallinity of the biomass of torch ginger. The effects of soda pulping on the chemical characteristics of torch ginger pulp were also studied. Pulping of the chips was conducted with active alkali of 15%, 20%, and 25% and a Liquor-to-Wood (L/W) ratio of 4:1, 5:1, and 6:1. The impregnation and pulping times at maximum temperature (170℃) were 120 and 90 min, respectively. To assess the effect of treatments on the properties of pulping, a two-factorial experimental design was applied. Results showed that the content of α-cellulose and hemicellulose in the torch ginger was 48.48% and 31.50%, respectively, with an S/G ratio of 0.70 in lignin. Soda pulping changed the crystalline structure of the biomass from triclinic to monoclinic. Active alkali, L/W ratio, and interactions considerably influenced the observed responses. The degree of delignification increased with an increase in the loading of active alkali, which lead to a decrease in the kappa number of the pulp. An active alkali content of 25% and an L/W ratio of 6:1 resulted in the highest delignification selectivity with a kappa number of 2.78 and a yield of 24%. Given its cellulose content and ease of pulping, torch ginger can be a potential raw material for derivative products that require delignification as pretreatment. However, the increase in cellulose crystallinity should be considered when converting torch ginger to bioethanol.

• 한국미생물·생명공학회지
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• 제8권1호
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• pp.41-46
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• 1980

저분자량의 효소인 셀루라아제가 Sephadex G-100 gel chromatography를 사용하여 정제되었다. 정제된 성분의 생화학적 성질들이 조사되었는데 최적 PH와 온도가 각각 6.0과 5$0^{\circ}C$이었다. 서로 다른 결정도(crystallinity)를 갖고 있는 4가지 섬유소 기질의, 효소에 의한 가수분해가 측정되었다. 무정형(amorphous) 부분의 가수분해가 일어난 후에 결정화되어 있는 부분의 가수분해가 뒤따라온다는 것을 알 수 있었다. 효소가 섬유소 기질에 흡착되는 정도가 가수분해 반응에 미치는 영향을 보기 위해 흡착에 대한 연구가 수행되었다. 시간에 따라서 소분자량의 endo-glucanase가 여러가지섬유소 기질에 흡착되는 정도의 변화가 25분간 측정되었다. 무정형의 섬유소에 흡착되는 속도와 정도가 결정형 섬유소에 대한 그것들 보다 더욱 크게 나타났다. 이러한 결과는 endo-glucanase가 섬유소의 결정화 부분의 가수분해보다는 무정형부분의 가수분해에 대해서 더욱 중요한 역할을 한다는 것을 시사해 준다.