• 펄프종이기술
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• 제37권3호
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• pp.50-58
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• 2005

It is generally known that paper industry is the second largest industry in the use of process water, and also have the highest environmental impact load in the contaminant sources. Paper is produced from the mixtures composed of 1% fibrous raw materials and 99% water. The optimum use of process water effects on the quality properties of paper and the environmental impact load of waste water treatment. In this research, the kinds of fibrous raw material & additives used in the paperboard production line were investigated, and the quantification of environmental loads and the environmental effects of process water on COD potential were evaluated. The NBDCODs were also analyzed from process water by the method of waste water treatment in paper mill and applied for the optimum use of recycling water, and zero effluent process. In the fibrous raw materials, KOCC caused the highest COD potentials, and sack paper & UKP was comparatively low. The NBDCOD of KOCC largely reduced after biological treatment because of easily biodegradable properties, but AOCC contained non-biodegradable materials. In chemical additives, COD was high in turns of rosin>starch>deaeration agent>dye, NBDCOD greatly reduced in starch and deaeration agent. In the case of 2 kinds of paperboard product, the COD potentials was mainly high in starch, AOCC and KOCC.

• Advanced Composite Materials
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• 제16권4호
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• pp.335-347
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• 2007

Green composites composed of long maize fibers and poly $\varepsilon$-caprolactone (PCL) biodegradable polyester matrix were manufactured by the thermo-mechanical processing termed as 'Sequential Molding and Forming Process' that was developed previously by the authors' research group. A variety of processing parameters such as fiber area fraction, molding temperature and forming pressure were systematically controlled and their influence on the tensile properties was investigated. It was revealed that both tensile strength and elastic modulus of the composites increase steadily depending on the increase in fiber area fraction, suggesting a general conformity to the rule of mixtures (ROM), particularly up to 55% fiber area fraction. The improvement in tensile properties was found to be closely related to the good interfacial adhesion between the fiber and polymer matrix, and was observed to be more pronounced under the optimum processing condition of $130^{\circ}C$ molding temperature and 10 MPa forming pressure. However, processing out of the optimum condition results in a deterioration in properties, mostly fiber and/or matrix degradation together with their interfacial defect as a consequence of the thermal or mechanical damages. On the basis of microstructural observation, the cause of strength degradation and its countermeasure to provide a feasible composite design are discussed in relation to the optimized process conditions.

• 한국산학기술학회논문지
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• 제21권2호
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• pp.280-286
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• 2020

일반적으로 사용되고 있는 합성수지인 PVC, PET 소재로 이루어진 카드는 쉽게 산화되거나 분해되지 않아서 사용 후에 폐기물로써 소각 또는 매립 처리되어지고 있으며, 소각 과정에서 환경호르몬과 연소가스등의 공해 문제를 일으킨다. 또한 매립 시에는 분해되지 않고 반영구적으로 쓰레기로 남아있어 환경오염을 일으키는 문제점 있다. 본 연구에서는 현재 사용하고 있는 카드의 문제점을 해결할 수 있는 대체 재료로써 대표적인 생분해성 소재인 폴리락트산(PLA : Polylacticacid)을 사용하여 이러한 문제점을 해결하고자 하였다. 그러나 PLA 소재로만 얇은 시트형태의 카드 기재가 만들어질 경우 재료 본래의 물성이 제한되어 저온 충격강도, 고온 안정성, 휨(Bending) 특성 등이 불충분하여 카드로써의 사용범위도 제한될 수밖에 없는 문제점을 가지고 있다. 이를 해결하기 위하여 PLA와 물성보강을 위한 원료의 적절한 배합 조성비를 검토하고, 결정화 핵제 및 첨가제 등의 조성물 검토와 나노컴파운드 기술을 통한 최적의 생분해성 컴파운드 조성물을 제조, 평가 하였다. 또한, 어닐링 (Annealing) 기술을 적용한 라미네이팅 공정을 통해 생분해성 범용 카드로써의 고기능화를 검증하였다.

• 한국약용작물학회지
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• 제24권3호
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• pp.183-190
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• 2016

Background: This study determined the effects of mulching, an environment friendly organic cultivation method, on antioxidant compound contents and growth in Codonopsis lanceolata, commonly known as Deodeok. Methods and Results: C. lanceolata was treated by mulching with several different methods (a non-woven fabric, biodegradable film, or rice husks) and also treated with hand weeding. A non-treatment plot was used as a control. The growth and levels of weed control in C. lanceolata were better in plants cultivated under mulching treatments (non-woven fabric, biodegradable film, and rice husks) than in those under non-mulching treatments (hand weeding and non-treatment). The contents of antioxidant compounds, such as total flavonoids, phenolics, and anthocyanins, were highest under the biodegradable film treatment, followed by the non-woven fabric treatment, rice husks treatment hand weeding, and non-treatment. There were identifiable differences in DPPH and ABTS activity in comparison to antioxidant compound content by solvent fractions. Mulching treatments resulted in higher DPPH scavenging activity in water and ethyl ether fractions and ABTS scavenging activity in n-butanol fractions than in other fractions, as opposed to hand weeding and non-treatment groups, although total activity of DPPH and ABTS did not increase with mulching treatments. Conclusions: Mulching C. lanceolata with biodegradable film and non-woven fabric is an effective method for improving plant growth and inhibiting the occurrence of weeds as well as for increasing antioxidant compound content and altering antioxidant activity.

• 자원리싸이클링
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• 제18권6호
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• pp.10-17
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• 2009

과열 증기를 이용하여 생활 폐기물내 유기성 성분의 분해를 수행하고 폐기물의 특성 및 반응 시간이 폐기물의 분해율에 미치는 영향을 살펴보았다. 과열 증기를 이용한 분해 후 음식 및 폐지와 같은 생분해성 유기 성분은 쉽게 분해되었고 생분해성 유기 성분중 나무와 석유계 유기성 성분인 플라스틱, 금속과 같은 무기성 성분이 분해되지 않은 상태로 남아 쉽게 분리가 가능한 상태를 형성하였다. 입자의 크기 변화를 살펴본 결과 폐기물 내 생분해성 유기 성분이 적을수록 짧은 반응 시간에도 높은 입자 크기 감소를 보였으며 반응 시간이 60분 이상에서 최대 90% 이상의 입도 감소를 나타내었다.

• Korean Chemical Engineering Research
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• 제59권3호
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• pp.443-449
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• 2021

전분과 구연산의 에스테르화 반응을 통한 가교화로 내수성 및 도포성이 우수한 생분해성 비산 방지용 박막소재를 제조하고 특성을 분석하였다. 이들 소재의 박막 형성 및 물성을 향상하기 위하여 PVA과 글리세린 등을 첨가하여 도포된 박막의 유연성을 확보하였다. 또한 원재료 및 첨가재의 농도, 온도 및 반응 시간에 따른 물에 대한 팽윤도 및 용해도와 같이 재료 기능성을 최적화하는 조건을 분석하였다. FT-IR 분석으로 전분과 구연산의 가교 반응을 확인하였으며, 이들 반응과정에서 단일 및 다중 에스테르화 반응이 동시에 일어남을 알 수 있었다. 가교된 전분-구연산 박막재료는 토양매립 후 12주가 지났을 때 95%가량 분해되었어 생분해성이 우수함을 알 수 있다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.97-97
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• 2003

Recently, attention has been paid to biodegradable polymers in relation to the global environment. Poly-lactide (PLA) is one of such polymers and has studied by some investigators. In this study, the changes of crystal structure, crystal orientation and supermolecular structure of Poly(L-lactide) (PLLA) during drawing or annealing have been investigated.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2007년도 학술발표회 논문집
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• pp.489-490
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• 2007

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• 펄프종이기술
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• 제43권2호
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• pp.66-71
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• 2011

Biocomposites were fabricated with biodegradable polymers and natural fibers. Biocomposites have benefits of low cost, low density, and biodegradability over inorganic fiber composite, and give comparable strength properties. Hydrophobic polymer used for sizing in paper industry, AKD (Akenyl Keten Dimer), was applied to natural fibers, red algae fibers (RAF) in this study, to make fiber surfaces more compatible to hydrophobic nature of matrix polymers. Composites with RAF, kenaf, glass fibers, and carbon fibers have been fabricated by a compression molding method and their thermo-mechanical properties have been studied. Also, the thermal dimensional stability test was done from at 30 to $100^{\circ}C$. The storage moduli and the thermo-mechanical stabilities of polypropylene and poly lactic acid based biocomposites were improved by reinforcing with the RAF and much more with AKD treated fibers. Dimensional stability of biocomposite was also markedly improved by AKD pretrement on RAF.

• Macromolecular Research
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• 제16권5호
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• pp.446-456
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• 2008

A recent theoretical approach based on the coupling of both the Flory-Huggins (FH) and the Association Equilibria thermodynamic (AET) theories was modified and adapted to study the miscibility properties of a multi-component system formed by two polymers (a proton-donor and a proton-acceptor) and a proton-acceptor solvent, named copolymer(A)/solvent(B)/polymer(C). Compatibility between polymers was mainly attained by hydrogen-bonding between the hydroxyl group on the phenol unit of the poly(styrene-co-vinyl phenol) (PSVPh) and the carbonyl group of the biodegradable and environmentally friendly poly(3-hydroxybutyrate) (PHB). However, the self-association of PSVPh and specific interactions between the PSVPh and the H-acceptor group (an ether oxygen atom) of the epichlorohydrin (ECH) solvent were also established in a lower extension, which competed with the polymer-polymer association. All the binary specific interactions and their dependence with the system composition as well as with the copolymer content were evaluated and quantified by means of two excess functions of the Gibbs tree energy, ${\Delta}g_{AB}$ and ${\Delta}g_{AC}$. Experimental results from fluorescence spectroscopy were consistent with the theoretical simulations derived with the model, which could also be applied and extended to predict the miscibility in solution of any polymer blend with specific interactions.