• Title, Summary, Keyword: Microfibrillated cellulose

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The effect of chemical surface treatment on the fracture toughness of microfibrillated cellulose reinforced epoxy composites

  • Yeo, Jun-Seok;Kim, Oh Young;Hwang, Seok-Ho
    • Journal of Industrial and Engineering Chemistry
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    • v.45
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    • pp.301-306
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    • 2017
  • We conducted the surface modification of a microfibrillated cellulose (MFC) as a reinforcing filler of epoxy resin with triethoxy(3-glycidylpropyl)silane (GPS) to increase the mechanical properties of epoxy composite. The chemical modification for the surface of pristine MFCs was confirmed by FT-IR and SEM/EDX. Two different epoxy composite series were prepared using the pristine MFCs and GPS-modified MFCs (GPS-MFCs) to investigate the mechanical properties and fracture toughness of the epoxy composites according to the cellulosic filler contents. The tensile and impact properties of the epoxy composites showed the better performance of GPS-MFC/epoxy composites than of the pristine MFC/epoxy composites. The results of the critical stress intensity factor ($K_{IC}$) and the critical strain energy release rate ($G_{IC}$) show the improved interfacial adhesion between epoxy matrix and cellulosic filler in the GPS-MFC/epoxy composites, and their enhanced fracture toughness.

Paper Properties Improvement by adding Microfibrillated Cellulose-Mineral Composites (Microfibrillated Cellulose (MFC)와 중질탄산칼슘 (GCC)로 구성된 복합충전제를 이용한 종이 물성 향상)

  • Lee, Jung Myoung
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.48 no.2
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    • pp.83-90
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    • 2016
  • Increasing the amount of filler in paper is of high interest for paper industry while maintaining its key sheet quality properties. In this study, a MFC-GCC composite, made through a co-grinding NBSK (Northern bleached softwood kraft) pulp with a ground calcium carbonate (Intracarb 60), was used as a strength aid in paper in order to evaluate a potential cost reduction through filler increase without sacrificing paper quality. Hand-sheets were made of NBSK and/or eucalyptus pulp by using white water recirculation in a Tappi sheet former and was compared its properties without or with MFC additions at different filler levels. It was found that the MFC-GCC composite has a large surface area compared to the fiber, allowing the formation of more hydrogen bonds in the web, thus giving natural strength to the paper. Overall results are encouraging that the MFC-GCC composite allows papermaker to reduce basis weight and maintain critical sheet properties.

Effects of Pulp Pre-treatment and Grinder Clearance on the Manufacturing Characteristics of Microfibrillated Cellulose (펄프의 전처리 및 그라인더 간격이 MFC 제조 특성에 미치는 영향)

  • Yong, Seong Moon;Kwak, Gun Ho;Cho, Byoung-Uk;Lee, Yong Kyu;Won, Jong Myoung
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.2
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    • pp.61-69
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    • 2015
  • A number of researches have been carried out regarding the utilization of nanocellulose(crystalline nanocellulose, microfibrillated cellulose, nanofibrillated cellulose) for the manufacture of various kinds of composites and functional products. However, only few research works on the manufacturing characteristics of nanocellulose could be found, although some companies started already the production of nanocellulose in commercial scale. However, the most important thing in commercializing of production and utilization of nanocellulose is to develop the economical and efficient process. Thus, this study was carried out in order to investigate the effects of refining, alkaline pre-treatment and grinder clearance on the characteristics of microfibrillated cellulose and energy consumption. There was no significant differences in crystalline index with the degree of microfibrillation. The initial fibrillation could be improved by refining pre-treatment, but its effect was not observed anymore since the fibrillation was done up to certain level by grinding. Refining pre-treatment did not improved the energy efficiency. Alkaline pre-treatment can be helpful because the swelling of pulp fiber will facilitate fibrillation. It was found that the decrease in grinder clearance was helpful to improve the energy efficiency.

Micro-Fibrillated Cellulose Preparation with Enzyme Beating Pretreatment and Effect on Paper Strength Improvement (Enzyme beating 전처리를 통한 Micro-Fibrillated Cellulose 제조 및 지력증강 효과)

  • Ahn, Eun-Byeol;Hong, Sung-Bum;Kim, Kang-Jae;Eom, Tae-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.6
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    • pp.57-65
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    • 2015
  • Microfibrillated cellulose (MFC) or Nanofibrillated cellulose (NFC) has been used to reduce the use of raw pulp and to improve paper strength. The problem of MFC preparation is high manufacturing cost. In this study, it was carried out to prepare MFC after enzyme beating and estimated properties of MFC. Endo-D was the best beating efficiency among three type of endo-glucanase. As the grinder pass number increased, the viscosity and the fines of MFC suspension increased while the crystallinity and the porosity of MFC sheet decreased. Also enzyme beating MFC was higher value in the crystallinity and lower value in the viscosity than non-enzyme MFC. In addition, the aspect ratio of MFC was the highest at 5 pass. MFC addition improved the handsheet strength and the air permeability but worsened the drainage.

Trends and Prospects of Microfibrillated Cellulose in Bio-industries (마이크로피브릴화 셀룰로오스를 이용한 바이오산업의 동향)

  • Jung, Young Hoon
    • Microbiology and Biotechnology Letters
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    • v.45 no.1
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    • pp.1-11
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    • 2017
  • In this review, we focus on one of the most attractive biomaterials, microfibrillated cellulose (MFC). MFC, a type of nanocellulose, mainly originates from cellulose in lignocellulosic biomass. MFC represents one of incredible important natural resources due to its abundancy, renewability, and sustainability. MFC is produced through mechanical pretreatment, and it is composed of various sizes of microfibers, ranging from a few nanometers to a few micrometers. Because of the heterogenetic compositions of MFC, it possesses superior properties as a material, such as high surface area, high aspect ratio, and peculiar insolubility as a biomaterial. These properties allow MFC to be used in various bio-industries, from the traditional pulp industry to the high-tech food/bio/chemical/medical industries. However, it is difficult to use MFC on a commercial scale owing to the high energy input required during its production and the challenge of controlling its reactivity. Therefore, future studies should be focused on accurately characterizing MFC's surface morphologies, regulating its characteristics in a desirable direction, and standardizing proper guidelines for the analysis of surface morphologies its analysis.

Effect of pMDI as Coupling Agent on The Properties of Microfibrillated Cellulose-reinforced PBS Nanocomposite (pMDI 커플링제가 마이크로피브릴 셀룰로오스 강화 PBS 나노복합재료의 성질에 미치는 영향)

  • Jang, Jae-Hyuk;Lee, Seung-Hwan;Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.4
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    • pp.483-490
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    • 2014
  • The effect of microfibrillated cellulose (MFC) content and coupling agent (polymeric methylene diphenyl diisocyanate, pMDI) on the properties of MFC-reinforced polybutylene succinate (PBS) nanocomposite. With increasing MFC content, tensile strength and elastic modulus were increased. More than 1.5 times in tensile strength of PBS/MFC(70/30) nanocomposite was improved by the addition of pMDI (1 phr), compared to the nanocomposite without pMDI. This trend was being significant in nanocomposite with higher MFC content. Thermal stability of the nanocomposite was increased by the addition of pMDI. These improvements is considered to be due to the improvement of MFC dispersion and interfacial adhesion between MFC and PBS matrix.

Electron Microscopy for the Morphological Characterization of Nanocellulose Materials (전자현미경을 이용한 나노셀룰로오스 물질의 형태학적 특성 분석 연구)

  • Kwon, Ohkyung;Shin, Soo-Jeong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.48 no.1
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    • pp.5-18
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    • 2016
  • Electron microscopy is an important investigation and analytical method for the morphological characterization of various cellulosic materials, such as micro-crystalline cellulose (MCC), microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC), and cellulose nanocrystals (CNC). However, more accurate morphological analysis requires high-quality micrographs acquired from the proper use of an electron microscope and associated sample preparation methods. Understanding the interaction of electron and matter as well as the importance of sample preparation methods, including drying and staining methods, enables the production of high quality images with adequate information on the nanocellulosic materials. This paper provides a brief overview of the micro and nano structural analysis of cellulose, as investigated using transmission and scanning electron microscopy.

Changes of Micro- and Nanoscopic Morphology of Various Bioresources by Different Milling Systems

  • Jang, Jae-Hyuk;Lee, Seung-Hwan;Lee, Min;Lee, Sang-Min;Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.6
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    • pp.737-745
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    • 2017
  • This study was carried out to investigate the changes in micro- and nanoscopic morphology of cellulose nanofibrils (CNFs) from various bioresources by investigating various mechanical milling systems. Mechanical milling in herbaceous bioresources was more effective than in woody bioresources, demonstrating lower energy consumption and finer morphology. The milling time to reach nanoscopic size was longer in woody bioresources than in herbaceous bioresources. Furthermore, at the same level of wet disk milling time, CNFs from herbaceous bioresources showed more slender morphology than those from woody bioresources. Tensile properties of nanopaper prepared from CNFs of herbaceous bioresources were higher than those of woody bioresources. The highest tensile strength was found to be 77.4 MPa in the nanopaper from Evening prim rose.

Synthesis and Characterization of Composite Paper Using Polyamide Fiber and Surface Modified Microfibrillated Cellulose (표면 개질된 마이크로피브릴화 셀룰로오스를 이용한 폴리아마이드 섬유와의 복합페이퍼 제조 및 특성평가)

  • Lee, Jong-Hee;Lim, Jung-Hyurk;Kim, Ki-Young;Kim, Kyung-Min
    • Polymer(Korea)
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    • v.38 no.1
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    • pp.74-79
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    • 2014
  • Microfibrillated cellulose (MFC) was chemically modified with two different silane coupling agents (3-aminopropyltriethoxysilane and 3-mercaptopropyltriethoxysilane) and lauroyl chloride. The surface modification of MFC was confirmed by infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), and contact angle measurements. Composite paper was successfully prepared with surface modified MFC and polyamide (PA) fiber. The surface modification of MFC not only prevented aggregation of MFC but also improved adhesive property between PA fiber and surface modified MFC. It was impossible to prepare papers of only PA fiber because there is no binder to connect PA fibers. That is, surface modified MFC as a binder in PA fiber played a crucial role in making composite paper. Composite paper with silane modified MFC showed higher tensile strength and modulus than composite paper with lauroyl moiety modified MFC. The structure, morphology, and mechanical properties of composite paper were analyzed by scanning electron microscope (SEM) and universal testing machine (UTM).

Advanced 'green' composites

  • Netravali, Anil N.;Huang, Xiaosong;Mizuta, Kazuhiro
    • Advanced Composite Materials
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    • v.16 no.4
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    • pp.269-282
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    • 2007
  • Fully biodegradable high strength composites or 'advanced green composites' were fabricated using yearly renewable soy protein based resins and high strength liquid crystalline cellulose fibers. For comparison, E-glass and aramid ($Kevlar^{(R)}$) fiber reinforced composites were also prepared using the same modified soy protein resins. The modification of soy protein included forming an interpenetrating network-like (IPN-like) resin with mechanical properties comparable to commonly used epoxy resins. The IPN-like soy protein based resin was further reinforced using nano-clay and microfibrillated cellulose. Fiber/resin interfacial shear strength was characterized using microbond method. Tensile and flexural properties of the composites were characterized as per ASTM standards. A comparison of the tensile and flexural properties of the high strength composites made using the three fibers is presented. The results suggest that these green composites have excellent mechanical properties and can be considered for use in primary structural applications. Although significant additional research is needed in this area, it is clear that advanced green composites will some day replace today's advanced composites made using petroleum based fibers and resins. At the end of their life, the fully sustainable 'advanced green composites' can be easily disposed of or composted without harming the environment, in fact, helping it.