Dynamic Mechanical and Thermal Properties of Red Algae Fiber Reinforced Poly(lactic acid) Biocomposites

심경자,한성옥,서영범 한국고분자학회 2010 Macromolecular Research Vol.18 No.5

This study compared the dynamic mechanical and thermal properties of biocomposites reinforced with algae fiber; polypropylene (PP) and poly(lactic acid) (PLA) biocomposites. The biocomposites are manufactured with a bleached red algae fiber (BRAF) loading ranging from 30 to 60 wt%. The thermal properties of BRAF, PLA and PP were determined by DSC and TGA. The dynamic mechanical and thermomechanical properties of the PLA matrix and biocomposites were analyzed by DMA and TMA. The dynamic mechanical and thermomechanical properties of both BRAF/PLA and BRAF/PP biocomposites show improvement with increasing BRAF loading. The fibers were well bonded with the PLA matrix, indicating strong adhesion, as observed by SEM observations of the fractured surface. In addition, greater improvement in the storage modulus was achieved with the BRAF/PLA biocomposites than with the BRAF/PP biocomposites. Therefore, BRAF/PLA biocomposites can be used as an alternative completely biodegradable biocomposite to BRAF/PP biocomposites.

Manufacture and Characterization of hemp-Acrodur Biocomposites: Variation of Process Parameters

Mohammad S Islam,Menghe Miao 한국섬유공학회 2022 Fibers and polymers Vol.23 No.8

In this study, hemp fibre reinforced Acrodur resin biocomposites were manufactured using nonwoven hemp fibremats by varying a range of processing parameters such as Acrodur solution to dispersion ratio, relative humidity, curing time,and temperature. Dry fibre mats using Acrodur solution to dispersion ratio of 3:1 at a temperature of 160 oC and processingtime of 20 minutes were found to be optimum condition for the manufacture of the biocomposites. These optimumparameters gave the best combination of specific tensile strength (26.4 MPa-cm3/g) and specific Young’s modulus (4.4 GPacm3/g) with a density of 0.94 g/cm3. Thermogravimetric analysis (TGA) of the optimised biocomposites showedsimilarthermal stability when compared with pristine fibres. Contact angle measurements of the optimised biocomposites showedincreased hydrophobicity of the biocomposites than those of the pristine fibres. From the water immersion test, the path ofwicking of water molecules into the biocomposites was believed to be rather straight than tortuous and A 4-week waterimmersion test of the optimised biocomposites conceded about 43.5 % loss of tensile strength and 57.1 % loss of Young’smodulus which was believed to be due to wicking of the water molecules into the fibre of the biocomposites in a straight pathrather than a tortuous path.

Effects of Ammonium Polyphosphate on the Flame Retarding, Tensile, Dynamic Mechanical, and Thermal Properties of Kenaf Fiber/Poly(lactic acid) Biocomposites Fabricated by Compression Molding

Yeonhae Woo,조동환 한국섬유공학회 2021 Fibers and polymers Vol.22 No.5

Chopped kenaf fibers, poly(lactic acid) (PLA), and ammonium polyphosphate (APP) were uniformly compoundedby twin-screw extrusion process, and then kenaf/PLA biocomposites with various APP loadings were fabricated bycompression molding. The effects of APP on the flame retardant, tensile, dynamic mechanical, and thermo-dimensionalproperties were investigated. The biocomposites exhibit highly increased flame resistance, showing the limiting oxygenindex increased with increasing the APP loading and the UL-94 V-0 level with 20 wt.% and higher APP loadings. Thethermal stability of the biocomposites was increased, whereas the thermal expansion behavior was decreased with increasingthe APP loading. The incorporation of APP into the PLA matrix contributed to simultaneously enhancing not only the flameretardancy, thermal stability, and thermo-dimensional stability, but also to enhancing the tensile and storage moduli of kenaffiber/PLA biocomposites.

Effect of Natural Fiber Surface Treatments on the Interfacial and Mechanical Properties of Henequen/Polypropylene Biocomposites

조동환,이현석,한성옥 한국고분자학회 2008 Macromolecular Research Vol.16 No.5

The surfaces of henequen fibers, which can be obtained from the leaves of agave plants, were treated with two different media, tap water and sodium hydroxide, that underwent both soaking and ultrasonic methods for the fiber surface treatment. Various biocomposites were fabricated with untreated and treated, chopped henequen fibers and polypropylene using a compression molding method. The result is discussed in terms of interfacial shear strength, flexural properties, dynamic mechanical properties, and fracture surface observations of the biocomposites. The soaking (static method) and ultrasonic (dynamic method) treatments with tap water and sodium hydroxide at different concentrations and treatment times significantly influenced the interfacial, flexural and dynamic mechanical properties of henequen/polypropylene biocomposites. The alkali treatment was more effective than the water treatment in improving the interfacial and mechanical properties of randomly oriented, chopped henequen/PP biocomposites. In addition, the application of the ultrasonic method to each treatment was relatively more effective in increasing the properties than the soaking method, depending on the treatment medium and condition. The greatest improvement in the properties studied was achieved by ultrasonic alkalization of natural fibers, which was in agreement with the other results of interfacial shear strength, flexural strength and modulus, storage modulus, and fracture surfaces.

Dynamic Mechanical Properties of Natural Fiber/Polymer Biocomposites: The Effect of Fiber Treatment with Electron Beam

Han, Young-Hee,Han, Seong-Ok,Cho, Dong-Hwan,Kim, Hyung-Il The Polymer Society of Korea 2008 Macromolecular Research Vol.16 No.3

Environmentally friendly biocomposites were made using plant-based natural fibers, such as henequen and kenaf. The natural fiber reinforced polypropylene (PP) and unsaturated polyester (UP) biocomposites were examined in terms of the reinforcing effect of natural fibers on thermoplastic and thermosetting polymers. Kenaf (KE) and henequen (HQ) fibers were treated with an electron beam (EB) of 10 and 200 kGy doses, respectively, or with a 5 wt% NaOH solution. Four types of biocomposites (KE/PP, HQ/PP, KE/UP and HQ/UP) were fabricated by compression molding and each biocomposite was characterized by dynamic mechanical analysis and thermogravimetric analysis. The kenaf fiber had the larger reinforcing effect on the dynamic mechanical properties of both PP and UP biocomposites than the henequen fiber. The highest storage modulus was obtained from the biocomposite with the combination of UP matrix and 200 kGy EB treated kenaf fibers.

Effect of Natural Fiber Surface Treatments on the Interfacial and Mechanical Properties of Henequen/Polypropylene Biocomposites

Lee, Hyun-Seok,Cho, Dong-Hwan,Han, Seong-Ok The Polymer Society of Korea 2008 Macromolecular Research Vol.16 No.5

The surfaces of henequen fibers, which can be obtained from the leaves of agave plants, were treated with two different media, tap water and sodium hydroxide, that underwent both soaking and ultrasonic methods for the fiber surface treatment. Various biocomposites were fabricated with untreated and treated, chopped henequen fibers and polypropylene using a compression molding method. The result is discussed in terms of interfacial shear strength, flexural properties, dynamic mechanical properties, and fracture surface observations of the biocomposites. The soaking (static method) and ultrasonic (dynamic method) treatments with tap water and sodium hydroxide at different concentrations and treatment times significantly influenced the interfacial, flexural and dynamic mechanical properties of henequen/polypropylene biocomposites. The alkali treatment was more effective than the water treatment in improving the interfacial and mechanical properties of randomly oriented, chopped henequen/PP bio-composites. In addition, the application of the ultrasonic method to each treatment was relatively more effective in increasing the properties than the soaking method, depending on the treatment medium and condition. The greatest improvement in the properties studied was achieved by ultrasonic alkalization of natural fibers, which was in agreement with the other results of interfacial shear strength, flexural strength and modulus, storage modulus, and fracture surfaces.

Effect of Electron Beam Irradiation on the Interfacial and Thermal Properties of Henequen/Phenolic Biocomposites

Pang, Yansong,Yoon, Sung Bong,Seo, Jeong Min,Han, Seong Ok,Cho, Donghwan The Society of Adhesion and Interface 2005 접착 및 계면 Vol.6 No.4

Natural fiber/phenolic biocomposites with chopped henequen fibers treated at various levels of electron beam irradiation (EBI) were made by means of a matched-die compression molding method. The interfacial property was explored in terms of interfacial shear strength measured by a single fiber microbonding test. The thermal properties were studied in terms of storage modulus, tan ${\delta}$, thermal expansion and thermal stability measured by dynamic mechanical analysis, thermomechanical analysis and thermogravimetric analysis, respectively. The result showed that the interfacial and thermal properties depend on the treatment level of EBI done to the henequen fiber surfaces. The present result also demonstrates that 10 kGy EBI is most preferable to physically modify the henequen fiber surfaces and then to improve the interfacial property of the biocomposite, supporting earlier results studied with henequen/poly (butylene succinate) and henequen/unsaturated polyester biocomposites.

플라즈마 표면처리에 의한 Silk/PLA 바이오복합재료의 계면접착

추보영,권미연,이승구,조동환,박원호,한성옥,Chu, Bo Young,Kwon, Mi Yeon,Lee, Seung Goo,Cho, Donghwan,Park, Won Ho,Han, Seong Ok 한국접착및계면학회 2004 접착 및 계면 Vol.5 No.4

견섬유와 폴리라틱산(PLA) 사이의 계면접착 특성을 향상시키기 위하여 천연섬유 표면을 아르곤과 에틸렌 플라즈마로 각각 처리하였다. 플라즈마 표면처리 후, 견섬유의 표면 모폴로지와 접착이 크게 변화하였다. 다음의 여러 플라즈마 처리조건이 본 연구에 사용되었다: 10, 25, 50 그리고 150 W의 전력, 1, 3, 5, 7 그리고 10분의 처리시간 및 10과 50 sccm의 가스흐름속도, 플라즈마 처리된 Silk/PLA 바이오복합재료의 계면전단강도는 단섬유 micro-droplet debonding 시험방법으로 측정하였다. 결과는 Silk/PLA 바이오복합재료의 계면접착을 향상시키기 위한 최적의 플라즈마 처리 조건을 제공하여 주었다. Silk fibers were subjected to argon and ethylene plasma treatments in order to improve the interfacial adhesion with polylactic acid (PLA). After the plasma surface treatment, the surface morphology and surface adhesion of silk fibers to the PLA resin were largely changed. Various plasma treatment conditions were used in this work: 10, 25, 50, 100 and 150 W of electric power, 1, 3, 5, 7 and 10 minutes of treatment time, and 10 and 50 sccm of a gas flow rate. The interfacial shear strength of plasma-treated Silk/PLA biocomposites was measured by a single fiber micro-droplet debonding test method. The result provided an optimal plasma treatment condition to obtain the improved interfacial adhesion in the Silk/PLA biocomposites.

Electron beam irradiation effect on the mechanical and thermal properties of 2-D silk fibroin fabric/poly(lactic acid) biocomposites

이지혜,Nicolas Le Boulicaut,권오형,박원호,조동환 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.71 No.-

Silkfibroin fabrics (SFF) were irradiated at various electron beam absorption doses. The irradiation effecton the breaking properties of SFF, thefiber topography, and the tensile,flexural and dynamic mechanicalproperties of 2-directional SFF/poly(lactic acid) (PLA) biocomposites were explored. The irradiation at10 kGy was most effective not only to increase the SFF breaking properties, but also to enhance themechanical and thermal properties of SFF/PLA biocomposites. The microscopic analysis of fracturedsurfaces supported the irradiation dependence of the mechanical and thermal data, showing theincreased interfacial bonding between the silkfiber and the PLA, particularly at 10 kGy.

The effect of dense polymer brush on the microfibrillated cellulose for the mechanical properties of poly(ε-caprolactone) biocomposites

Yeo, J.S.,Hwang, S.H. Butterworth-Heinemann Ltd. 2017 International journal of adhesion & adhesives Vol.78 No.-

<P>Two different cellulosic fibers [pristine microfibrillated celluloses (MFCs) and 2,2-bis(hydroxymethyl)propionic acid-modified MFCs (bis-MPA-modified MFCs)] were grafted by poly(e-caprolactone) (PCL) molecules through the ring-opening polymerization (ROP) method. The PCL-grafted MFCs were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and elemental analysis. The results showed that the grafting of PCL on the bis-MPA-modified MFCs was more efficient than that of the pristine MFCs due to the higher density of the activated hydroxyl groups on the bis-MPA-modified MFCs. Furthermore, the numerous PCL chains bound to the bis-MPA-modified MFCs (PCL-g-mMFC) demonstrated the stronger interfacial adhesion between the modified MFC fibers and the PCL matrix, as well as the greatly improved dispersion of the modified MFCs in the PCL matrix of the PCL/cellulose biocomposites.</P>