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Isao Hasegawa - One of the best experts on this subject based on the ideXlab platform.

  • Production of depolymerized lignin Resin Material from lignocellulosic biomass using acetone–water binary solution
    Chemical Engineering Journal, 2015
    Co-Authors: Yosuke Muranaka, Ryuichi Murata, Isao Hasegawa, Kazuhiro Mae
    Abstract:

    Abstract The use of lignin, one of the main components of biomass, has only been for the recovery of energy through the combustion due to its complex structure. However, it needs to be used as more valuable Material to make biorefinery feasible. In this study, the development of the lignin conversion method into Resin Materials was examined. Lignin was extracted from biomass with acetone/water binary solution at 220 °C. The extracted lignin solution was treated under the severer condition for the depolymerization using flow reaction system. Through these two-step treatment, the extracted lignin was depolymerized to Mw

  • production of depolymerized lignin Resin Material from lignocellulosic biomass using acetone water binary solution
    Chemical Engineering Journal, 2015
    Co-Authors: Yosuke Muranaka, Ryuichi Murata, Isao Hasegawa
    Abstract:

    Abstract The use of lignin, one of the main components of biomass, has only been for the recovery of energy through the combustion due to its complex structure. However, it needs to be used as more valuable Material to make biorefinery feasible. In this study, the development of the lignin conversion method into Resin Materials was examined. Lignin was extracted from biomass with acetone/water binary solution at 220 °C. The extracted lignin solution was treated under the severer condition for the depolymerization using flow reaction system. Through these two-step treatment, the extracted lignin was depolymerized to Mw

  • Production of lignin Resin Material from lignocellulosic biomass combining acidic saccharification and acetone treatment
    2015
    Co-Authors: Yosuke Muranaka, Junji Hosokawa, Ikuta Junya, Ryuichi Murata, Isao Hasegawa, Kazuhiro Mae
    Abstract:

    The structure of lignin, which is one of the main components of lignocellulosic biomass, is basically formed by the cross-linking of phenolic compounds. Taking the advantage of this structural property, the conversion method of lignin to Resin Material was developed in this study. Because lignin is complex and huge molecular compounds, depolymerization is one of the important factors for the utilization of basic frameworks. Lignin is extractable from lignocellulosic biomass using acetone/water binary solution, therefore, the simultaneous extraction and depolymerization of lignin under high temperature and high pressure from Japanese cedar (Cryptomeria japonica) was examined. Prior to the extraction process, cedar was treated with 50 wt% formic acid at 175 C for the saccharification of some other components of biomass such as hemicellulose or weak part of cellulose. Without this acidic saccharification, they might be extracted via the treatment using acetone lowering the purity of lignin, and might be the inhibitors for the Resinification. Thus pretreated lignocellulosic biomass whose inhibitors were removed via acidic saccharification was subsequently treated with 30 wt% acetone at the higher temperature of 295 C for the simultaneous extraction and depolymerization of lignin. Next, the curing properties of obtained samples were evaluated by differential thermal analysis. Lastly, this treatment method was applied to eucalyptus ('Eucalyptus globulus'), and the validity of this method to another type of lignocellulosic biomass was confirmed.

Ji-man Park - One of the best experts on this subject based on the ideXlab platform.

  • 3D Printing of Resin Material for Denture Artificial Teeth: Chipping and Indirect Tensile Fracture Resistance
    Materials, 2018
    Co-Authors: Yoojin Chung, Ji-man Park, Jin-soo Ahn, Hyun-suk Cha, Tae-hyung Kim, Joo-hee Lee
    Abstract:

    3D printing of denture artificial teeth with Resin Materials is worthy of study in a novel way. This study evaluated chipping and indirect tensile fracture resistance of 3D printing Resin Material (Dentca 3D printing denture teeth Resin) compared with conventionally prefabricated Resin denture teeth (Premium-8, Surpass, SR-Orthosit-PE, and Preference). One hundred tooth specimens were prepared for testing. The 3D printed tooth specimens were printed at a 50 µm layer thickness with methacrylate-based photopolymerized Resin by stereolithography 3D printing. Chipping and indirect tensile fracture tests were conducted at a speed of 1 mm/min until fracture. The indirect tensile fracture loads of the 3D printed Resin teeth were higher than those of Premium-8, Surpass, and SR-Orthosit-PE, and lower than those of Preference teeth. Regarding chipping resistance, the 3D printed Resin teeth were not different from Surpass and SR-Orthosit-PE, and were lower than Premium-8 and Preference teeth. The 3D printed Resin teeth exhibited vertical fracture of the loaded cusp without deformation in chipping. The 3D printed Resin teeth showed simultaneous fracture of two cusps in indirect tensile fracture, unlike other teeth. The results of this study suggest that 3D printing technology using Resin Materials provides adequate fracture resistance for denture artificial tooth use.

  • 3d printing of Resin Material for denture artificial teeth chipping and indirect tensile fracture resistance
    Materials, 2018
    Co-Authors: Yoojin Chung, Ji-man Park
    Abstract:

    3D printing of denture artificial teeth with Resin Materials is worthy of study in a novel way. This study evaluated chipping and indirect tensile fracture resistance of 3D printing Resin Material (Dentca 3D printing denture teeth Resin) compared with conventionally prefabricated Resin denture teeth (Premium-8, Surpass, SR-Orthosit-PE, and Preference). One hundred tooth specimens were prepared for testing. The 3D printed tooth specimens were printed at a 50 µm layer thickness with methacrylate-based photopolymerized Resin by stereolithography 3D printing. Chipping and indirect tensile fracture tests were conducted at a speed of 1 mm/min until fracture. The indirect tensile fracture loads of the 3D printed Resin teeth were higher than those of Premium-8, Surpass, and SR-Orthosit-PE, and lower than those of Preference teeth. Regarding chipping resistance, the 3D printed Resin teeth were not different from Surpass and SR-Orthosit-PE, and were lower than Premium-8 and Preference teeth. The 3D printed Resin teeth exhibited vertical fracture of the loaded cusp without deformation in chipping. The 3D printed Resin teeth showed simultaneous fracture of two cusps in indirect tensile fracture, unlike other teeth. The results of this study suggest that 3D printing technology using Resin Materials provides adequate fracture resistance for denture artificial tooth use.

  • Wear Resistance of 3D Printing Resin Material Opposing Zirconia and Metal Antagonists.
    Materials, 2018
    Co-Authors: Ji-man Park, Jin-soo Ahn, Hyun-suk Cha, Joo-hee Lee
    Abstract:

    3D printing offers many advantages in dental prosthesis manufacturing. This study evaluated the wear resistance of 3D printing Resin Material compared with milling and conventional Resin Materials. Sixty substrate specimens were prepared with three types of Resin Materials: 3D printed Resin, milled Resin, and self-cured Resin. The 3D printed specimens were printed at a build angle of 0° and 100 μm layer thickness by digital light processing 3D printing. Two kinds of abraders were made of zirconia and CoCr alloy. The specimens were loaded at 5 kg for 30,000 chewing cycles with vertical and horizontal movements under thermocycling condition. The 3D printed Resin did not show significant difference in the maximal depth loss or the volume loss of wear compared to the milled and the self-cured Resins. No significant difference was revealed depending on the abraders in the maximal depth loss or the volume loss of wear. In SEM views, the 3D printed Resin showed cracks and separation of inter-layer bonds when opposing the metal abrader. The results suggest that the 3D printing using Resin Materials provides adequate wear resistance for dental use.

Yosuke Muranaka - One of the best experts on this subject based on the ideXlab platform.

  • Production of depolymerized lignin Resin Material from lignocellulosic biomass using acetone–water binary solution
    Chemical Engineering Journal, 2015
    Co-Authors: Yosuke Muranaka, Ryuichi Murata, Isao Hasegawa, Kazuhiro Mae
    Abstract:

    Abstract The use of lignin, one of the main components of biomass, has only been for the recovery of energy through the combustion due to its complex structure. However, it needs to be used as more valuable Material to make biorefinery feasible. In this study, the development of the lignin conversion method into Resin Materials was examined. Lignin was extracted from biomass with acetone/water binary solution at 220 °C. The extracted lignin solution was treated under the severer condition for the depolymerization using flow reaction system. Through these two-step treatment, the extracted lignin was depolymerized to Mw

  • production of depolymerized lignin Resin Material from lignocellulosic biomass using acetone water binary solution
    Chemical Engineering Journal, 2015
    Co-Authors: Yosuke Muranaka, Ryuichi Murata, Isao Hasegawa
    Abstract:

    Abstract The use of lignin, one of the main components of biomass, has only been for the recovery of energy through the combustion due to its complex structure. However, it needs to be used as more valuable Material to make biorefinery feasible. In this study, the development of the lignin conversion method into Resin Materials was examined. Lignin was extracted from biomass with acetone/water binary solution at 220 °C. The extracted lignin solution was treated under the severer condition for the depolymerization using flow reaction system. Through these two-step treatment, the extracted lignin was depolymerized to Mw

  • Production of lignin Resin Material from lignocellulosic biomass combining acidic saccharification and acetone treatment
    2015
    Co-Authors: Yosuke Muranaka, Junji Hosokawa, Ikuta Junya, Ryuichi Murata, Isao Hasegawa, Kazuhiro Mae
    Abstract:

    The structure of lignin, which is one of the main components of lignocellulosic biomass, is basically formed by the cross-linking of phenolic compounds. Taking the advantage of this structural property, the conversion method of lignin to Resin Material was developed in this study. Because lignin is complex and huge molecular compounds, depolymerization is one of the important factors for the utilization of basic frameworks. Lignin is extractable from lignocellulosic biomass using acetone/water binary solution, therefore, the simultaneous extraction and depolymerization of lignin under high temperature and high pressure from Japanese cedar (Cryptomeria japonica) was examined. Prior to the extraction process, cedar was treated with 50 wt% formic acid at 175 C for the saccharification of some other components of biomass such as hemicellulose or weak part of cellulose. Without this acidic saccharification, they might be extracted via the treatment using acetone lowering the purity of lignin, and might be the inhibitors for the Resinification. Thus pretreated lignocellulosic biomass whose inhibitors were removed via acidic saccharification was subsequently treated with 30 wt% acetone at the higher temperature of 295 C for the simultaneous extraction and depolymerization of lignin. Next, the curing properties of obtained samples were evaluated by differential thermal analysis. Lastly, this treatment method was applied to eucalyptus ('Eucalyptus globulus'), and the validity of this method to another type of lignocellulosic biomass was confirmed.

Joo-hee Lee - One of the best experts on this subject based on the ideXlab platform.

  • 3D Printing of Resin Material for Denture Artificial Teeth: Chipping and Indirect Tensile Fracture Resistance
    Materials, 2018
    Co-Authors: Yoojin Chung, Ji-man Park, Jin-soo Ahn, Hyun-suk Cha, Tae-hyung Kim, Joo-hee Lee
    Abstract:

    3D printing of denture artificial teeth with Resin Materials is worthy of study in a novel way. This study evaluated chipping and indirect tensile fracture resistance of 3D printing Resin Material (Dentca 3D printing denture teeth Resin) compared with conventionally prefabricated Resin denture teeth (Premium-8, Surpass, SR-Orthosit-PE, and Preference). One hundred tooth specimens were prepared for testing. The 3D printed tooth specimens were printed at a 50 µm layer thickness with methacrylate-based photopolymerized Resin by stereolithography 3D printing. Chipping and indirect tensile fracture tests were conducted at a speed of 1 mm/min until fracture. The indirect tensile fracture loads of the 3D printed Resin teeth were higher than those of Premium-8, Surpass, and SR-Orthosit-PE, and lower than those of Preference teeth. Regarding chipping resistance, the 3D printed Resin teeth were not different from Surpass and SR-Orthosit-PE, and were lower than Premium-8 and Preference teeth. The 3D printed Resin teeth exhibited vertical fracture of the loaded cusp without deformation in chipping. The 3D printed Resin teeth showed simultaneous fracture of two cusps in indirect tensile fracture, unlike other teeth. The results of this study suggest that 3D printing technology using Resin Materials provides adequate fracture resistance for denture artificial tooth use.

  • Wear Resistance of 3D Printing Resin Material Opposing Zirconia and Metal Antagonists.
    Materials, 2018
    Co-Authors: Ji-man Park, Jin-soo Ahn, Hyun-suk Cha, Joo-hee Lee
    Abstract:

    3D printing offers many advantages in dental prosthesis manufacturing. This study evaluated the wear resistance of 3D printing Resin Material compared with milling and conventional Resin Materials. Sixty substrate specimens were prepared with three types of Resin Materials: 3D printed Resin, milled Resin, and self-cured Resin. The 3D printed specimens were printed at a build angle of 0° and 100 μm layer thickness by digital light processing 3D printing. Two kinds of abraders were made of zirconia and CoCr alloy. The specimens were loaded at 5 kg for 30,000 chewing cycles with vertical and horizontal movements under thermocycling condition. The 3D printed Resin did not show significant difference in the maximal depth loss or the volume loss of wear compared to the milled and the self-cured Resins. No significant difference was revealed depending on the abraders in the maximal depth loss or the volume loss of wear. In SEM views, the 3D printed Resin showed cracks and separation of inter-layer bonds when opposing the metal abrader. The results suggest that the 3D printing using Resin Materials provides adequate wear resistance for dental use.

E. Kazazoglu - One of the best experts on this subject based on the ideXlab platform.

  • A 3D finite element analysis of stress distribution on different thicknesses of mineral trioxide aggregate applied on various sizes of pulp perforation
    Clinical Oral Investigations, 2020
    Co-Authors: Zeynep Ozkurt-kayahan, B. Turgut, H. Akin, M.b. Kayahan, E. Kazazoglu
    Abstract:

    Objectives The aim of this study was to evaluate the stress distribution on different thicknesses of mineral trioxide aggregate (MTA) placed on various widths of pulp perforations during the condensation of the composite Resin Material. Materials and methods The mandibular molar tooth was modeled by COSMOSWorks program (SolidWorks, Waltham, MA). Three finite elemental analysis models representing 3 different dimensions of pulp perforations, 1, 2, and 3 mm in diameter, were created. The perforation area was assumed as filled with MTA with different thicknesses, 1, 2, and 3 mm for each pulp perforation width, creating a total of 9 different models. Then, a composite Resin Material was layered on MTA for each model. A 66.7 N load was applied and an engineering simulation program (ANSYS, Canonsburg, US) was used for the analysis. Results were presented considering von Mises stress criteria. Results As MTA thickness increased, the stress values recorded within the area between pulp and MTA decreased. Strain was decreased when the thickness of MTA increased. Conclusions Stresses at MTA-pulp interface and strain on MTA decreased with the increase in MTA thickness. Clinical relevance In clinical practice, when MTA is required for pulp capping, using a thick layer of the Material seems to be a better option in order to reduce the stress under forces of hand condensation of overlying restorative Materials.