• 접착 및 계면
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• 제6권2호
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• pp.13-20
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• 2005

환경 친화적인 자연섬유 강화 고분자 복합재료의 계면 전단강도는 총체적인 기계적 물성을 조절하는데 매우 중요한 역할을 수행한다. Ramie와 Kenaf 섬유 강화 에폭시 복합재료의 계면 전단강도는 최종 물성을 위한 최적 조건을 찾아내기 위해 미세역학시험법과 비파괴 음향방출시험을 이용하여 평가했다. Ramie와 Kenaf 섬유의 동적 접촉각을 측정했고, 계면 접착에서 젖음성과 상호 관련시켜서 해석하였다. Ramie와 Kenaf 섬유의 기계적 물성은 단섬유 인장시험을 통해 조사했고, 통계학적으로 uni-와 bimodal Weibull 분포를 통해서 분석하였다. Ramie와 Kenaf 섬유에 대한 실제 신장율의 clamping 효과의 영향도 평가할 수 있었다. 두 가지의 다른 미세파괴 형상은 섬유다발과 단섬유 복합재료로부터 오는 축방향의 debonding과 섬유상의 fracture는 인장과 압축하중하에서 관찰할 수 있었다.

• 폴리머
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• 제37권5호
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• pp.613-617
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• 2013

나노입자크기의 케냐프섬유를 폴리프로필렌에 첨가하였을 시, 복합소재의 물성변화를 관찰하였다. 천연크기의 케냐프섬유를 나노입자크기의 케냐프섬유로 대체하였을 시, 그 복합소재의 인장강도, 휨강도, 충격강도, 열변형온도가 증가한 반면에, 용융지수, 연신율(%), 충격강도 등이 감소하였다. 이는 나노입자크기의 케냐프섬유가 폴리프로필렌과 접촉하는 표면적의 증가와 섬유표면에 존재하는 휘발성 추출물질 등의 불순물의 감소에 따른 것으로 판단된다.

• Macromolecular Research
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• 제16권3호
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• pp.253-260
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• 2008

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.

• 한국의류학회지
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• 제28권9_10호
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• pp.1282-1291
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• 2004

Kenaf was cultivated and harvested in large quantity in Cheju Island and Chinju, Kyungsangnamdo. It was chemically rotted with 3% NaOH for 60 minutes at 100$^{\circ}C$, neutralized using 1% acetic acid, washed and dried, and obtained 40kg of dry kenaf fiber. Kenaf 15/rayon 85, flax 15/rayon 85, and rayon 100% yam was spun and the physical characteristics were measured. Plain weave and twill weave fabrics were made using each of the above yarns as the filling yam. Cotton 100% yam was used as the warp yam in all fabrics. Kenaf/rayon blend yarns were higher in tenacity and elongation, lower in yam uniformity, higher in the number of nep than the flax/rayon blended yams. Kenaf/rayon blend fabric had higher tenacity and elongation compared to the flax/rayon blend fabric Kenaf/rayon blend fabric was most stiff in both plain weave and twill weave fabrics whereas drape characteristics was dependent upon the fabric structure of the kenaf/rayon blend and flax/rayon blend. There were little differences between the kenaf/rayon blend fabric and the flax/rayon blend fabric in the Kawabata physical measurements and the PHVs. The only drawback of kenaf fiber was it's surface roughness and it is expected that it can be improved by enzyme retting and mechanical bundle separation.

• 방사선산업학회지
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• 제8권1호
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• pp.49-52
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• 2014

Kenaf fibers have excellent properties and possess the potential to be outstanding reinforcing fillers in cement. The grafting of poly(ethylene glycol) methacrylate (PEGMA) to the kenaf fibers is important in improving the compatibility between the fibers and the cement. PEGMA was grafted onto kenaf fibers using gamma-ray radiation. The radiation dose ranged from 20 to 60 kGy, and the dose rate was $10kGy\;h^{-1}$. The degree of grafting increased with increased radiation doses. FT-IR analysis revealed an increase in PEGMA content after gamma-ray radiation induced grafting, further evincing the attachment of PEGMA to the kenaf fibers. The mechanical properties of the gamma-ray grafted kenaf fiber/cement composites were superior to those of the ungrafted kenaf fiber/cement specimens.

• 한국건설순환자원학회논문집
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• 제2권1호
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• pp.19-25
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• 2014

본 연구에서는 천연섬유인 양마를 섬유보강 콘크리트에 사용하기 위한 방안으로, 양마의 혼입량에 따른 콘크리트의 역학적 특성을 실험적으로 확인하였다. 양마는 표면이 거칠고 섬유의 인장력 및 부식저항성이 우수하기 때문에, 섬유보강재로 적용할 경우에 콘크리트의 인장강도 및 부착력 증대에 의한 균열저감 효과, 그리고 이산화탄소를 저감하는 친환경 재료로 기대된다. 이러한 연구를 위하여 기본배합 조건에 양마의 혼입량 4종류(0, 0.3, 0.6 및 $0.9kg/m^3$)를 대상으로 슬럼프, 공기량, 소성수축 균열 및 압축강도, 할열인장강도, 휨강도, 그리고 건조수축량 등에 대한 성능시험을 실시하였다. 실험결과, 양마의 혼입량이 증가할수록 슬럼프 저하 및 공기량 증대현상이 나타났지만, 차이는 크지 않았다. 특히, 할열인장강도 및 휨강도 증진에 매우 효과적이며, 소성수축균열 및 건조수축량 저감에도 큰 효과가 있는 것으로 나타났다. 따라서 콘크리트의 역학적 성능, 경제성 등을 고려하여 양마의 혼입량은 $0.6kg/m^3$로 사용하는 것이 가장 적합한 것으로 나타났으며, 향후 사용성 및 비교시험을 통한 현장적용성의 검토가 필요할 것으로 사료된다.

• 한국의류학회지
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• 제35권8호
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• pp.982-990
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• 2011

Kenaf fiber can be obtained by decortications of the kenaf plant stem. The properties of the kenaf fiber treated by alkali (NaOH) were investigated by spectrocolorimeter, SEM, X-ray diffractometer, FT-IR and TGA. The kenaf fibers treated by alkali became darker and their Munsell color values changed from Y (yellow) to YR (yellowred) according to an increased NaOH concentration. SEM observation of the kenaf fibers showed that their crimps were developed and their surfaces were cleaned by the removal of protruding ends and impurities after alkali treatments. In the x-ray diffraction analysis, the structures of the fibers were found in the form of cellulose I when treated with a 0-16% alkali concentration and cellulose II when treated with over 20%. It was also confirmed that the crystallinity was lowered according to an increased NaOH concentration. The change of fiber compositions was investigated in FT-IR analysis. Strong band of $1,738cm^{-1}$ and asymmetrical stretching strong bands of $1,630-1,600cm^{-1}$ in spectrum (which represent pectin) were not found in the samples because the pectin was removed by the alkali treatment. Weak bands of $1,728-1,730cm^{-1}$ and peaks of $1,245-1,259cm^{-1}$ (which represent hemicellulose) and peaks of $1,592cm^{-1}$, $1,504cm^{-1}$, $1,462cm^{-1}$ and $1,429cm^{-1}$ (which are related to lignin) were not found or reduced in the samples treated with a concentration over 20%. TGA indicated that the kenaf fiber had the better hydrophilic properties by alkali treatment. The higher Tmax in TGA and the higher thermal stability when treated by alkali with the higher concentration. The fibers treated with an alkali concentration over 30% did not show any changes in Tmax.

• 펄프종이기술
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• 제41권2호
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• pp.47-54
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• 2009

Anatomical characteristics of kenaf were investigated in transverse, radial and tangential direction by optical and scanning electron micrograph. Kenaf was made up of bast fibers, wood fibers, vessels and parenchyma cells. Bast fibers were long slender cells with different types of pits. The shape of wood fibers were in various ways and pointed at the ends. The pits were observed on the surface of bast fibers. Kenafs were diffuse and radial porous. and composed of solitary pores and two or three radial pore multiples. Various types of vessels were observed. The pits showed alternate pitting and larger diameter than other cells. Parenchyma cells were rectangular or square with different shapes of pith parenchyma cells compared to conventional types of parenchyma cells in wood. The number of pith on the surfaces were small.

• 한국의류학회지
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• 제29권7호
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• pp.938-947
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• 2005

Kenaf basts were double retted by using water and enzyme. The best conditions were enzyme concentration $0.125\%$ and 1 day treatment at $50^{\circ}C$, 4 days treatment at $20^{\circ}C$. It was showed that the double rotting could be more economical and eco-friendly than just water rotting or enzyme rotting. Kenaf fibers have been cottonized by removing lignin and hemicellulose partially. In order to cottonize kenaf fiber, lignin of kenaf fibers were removed by sodium chlorite and then hemicellulose of kenaf fibers were removed by sodium hydroxide. The cottonizing phenomenon of kenaf fibers were was confirmed in transversal and longitudinal photograph of SEM. The tensile strength and crystallinity of cottonized fiber were investigated. The tensile strength and crystallinity were lower as the lignin and hemicellulose of kenaf fibers were less.

• 한국의류학회지
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• 제31권8호
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• pp.1286-1296
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• 2007

Hanji, the korean traditional papers were mostly made from mulberry paper. But the production and demand of hanji have decreased rapidly because mulberry paper yields were insufficient and handworked hanji procedures were complicated. Recently, the researches on hanji were carried out to improve the properties of hanji. Kenaf fibers have been interested as a substitute resource of mulberry paper for hanji production. In this research, Kenai pulps were manufactured with removal methods of lignin or hemicellulose from kenaf fibers and paper mulberry pulps with traditional alkali methods. Kenaf papers, paper mulberry, and kenaf/paper mulberry mixed papers were manufactured with their pulps. The crystallinity, fiber length, color of the pulps and tensile strength, tear strength, water absorption of the papers were investigated. The results were as follow: The removal rates of lignin of chemical retted kenaf fibers with sodium chlorite reaction for 40 minutes were 70% and were higher than 40% of double retted fibers. Paper mulberry pulps has less lignin and hemicellulose than kenaf differently. The crystallinity of paper mulberry pulps were very low with 60%, but kenaf pulps were 90%. The chemical retted CR-40-1 pulps were similar with paper mulberry pulps on fiber length & fibrilation of fibers. Tensile strength of paper mulberry were higher than kenaf papers because of fibrilation of paper mulberry, but tear strength were lower. Tensile strength and tear strength were improved on kenaf/paper mulberry 30/70 mixed papers.