• Journal of Forest and Environmental Science
• /
• v.32 no.4
• /
• pp.323-328
• /
• 2016

Thermal stability and rheological behaviors of Ricinodendron heudelotii wood were investigated. Thermogravimetric analysis conducted at a heating rate of $10^{\circ}C/min$ from 20 to $600^{\circ}C$ in a nitrogen atmosphere indicated that there was no variation in the decomposition of the onset and final temperature for all the polymers. The thermal behaviours were investigated at a temperature range from 130 to $0^{\circ}C$ at $3^{\circ}C/min$, multi-frequencies of 0.1-10 Hz using dynamic mechanical analysis. N-methyl-2-pyrolidone saturated specimens were tested while submerged under the same solvent. Polymers decomposition pattern during thermogravimetric analysis are similar in the radial position of the wood. The glass transition temperature (Tg) of R. heudelotii is $45{\pm}1^{\circ}C$ at 0.1 Hz. The Tg differs from the innerwood to outerwood. The Tg showed that N-methyl-2-pyrolidone saturated R. heudelotii would require low energy consumption during chemi-thermomechanical pulping.

• Journal of the Korean Wood Science and Technology
• /
• v.25 no.1
• /
• pp.1-7
• /
• 1997

Kraft oak lignin and ricestraw lignin from acetosolve pulping were dissolved in 50/50 mixture of tetralin/m-cresol solvent. The dissolved lignin was reacted in the pressurized autoclave which was operating at $350{\sim}500^{\circ}C$ of reaction temperature and 10~20 atms of reaction pressure respectively_Hydrogen pressure of 60~80kg/$cm^2$ was exercising into the pressurized autoclave reactor to create thermochemical hydrogenolysis reaction. It was identified by GLC, GC-MS and HPLC that the alkyl-aryl-${\beta}$-O-4 ether bond of lignin was cleaved and degraded into various smaller molecules of aromatic compound such as phenols and cresols under the reaction conditions around $300^{\circ}C$ and 10 atms of reaction temoerature and pressure. Hydrogenolysis reaction of lignin compound which was done above $500^{\circ}C$ of reaction temperature and 20 atms of reaction pressure showed that the amount of aromatic compound such as phenols and cresols degraded from reactant lignin was decreasing with newly present and increasing water out of product mixtures. It was supposed that new aliphatic compound of high molecular weight hydrocarbon is composed due to higher reaction temperature and pressure of hydrogenolysis reaction such as $500^{\circ}C$ and 20 atms, even though it was almost impossible, to identify what kind of degraded products it was by HPLC.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 1999.11b
• /
• pp.115-119
• /
• 1999

During mechanical pulp production and blcaching wood components, such as extractives, carbohydrates and lignin are dissolved and dispersed into the process waters. These components are called dissolved and colloidal substances(DCS). DCS can accumulate during water circulation and can in turn affect paper machine runnability and also the strength and optical properties of the paper. In this work DCS fraction origination from TMP process were treated with enzymes acting on triglycerides. glucomannans, and lignin and the effect of enzymatic treatments on the water composition as well as sheet properies were evaluated. Lipases were found to modify the chemical structure of the extractives resulting in more hydrophilic fibre surface and subsequent improvement in the sheet strength properties. Mannanase treatment, on the other hand, destabilized pitch. As a result, aggregation of pitch to the fibres was observed which in turn resulted in impaired strength properties. Laccase could effectively polymerize lignans and the reaction products seemed to be sorbed onto the fibres.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.4
• /
• pp.475-481
• /
• 1999

The study of lignin, a major component of secondary cell wall, has been partly focused on its removal from the woody part in the kraft pulping industry. Cinnamyl alcohol dehydrogenase (CAD; EC 1.1.l95) catalyzes the synthesis of cinnamyl alcohols from corresponding cinnamaldehydes. A cDNA clone, MdCADl, encoding putative CAD from apples (Malus domestica Borkh. cv Fuji) was characterized in this study. The clone contains an open reading frame of 325 amino acid residues, which shows a greater than 80％ identity with Eucalyptus CADl. MdCADl mRNA was detectable in vegetative tissues and was strongly expressed in the fruit. The expression pattern of MdCADl mRNA in the fruit peel after light exposure was also examined. The mRNA was rapidly increased until 1 day after light exposure and remained stable thereafter, suggesting that MdCADl is light inducible. The inducibility of the MdCADl gene was examined using several environmental stresses. Mechanical wounding of leaves increased the MdCADl mRNA level and the induction was further increased by salicylic acid. Southern blot hybridization showed that there is either one or a few copies of CAD genes in apples. To our knowledge, it is believed that MdCADl is the first CAD clone expressed predominantly in fruit.

• Journal of the Korean Wood Science and Technology
• /
• v.22 no.2
• /
• pp.19-24
• /
• 1994

This study was performed to study utilization of separated carbohydrates as well as separation, following analysis of the major components and separation of the carbohydrates in waste liquors of SP, KP, ASAM and AS. The result can be summerized as follows; Inorganic contents in waste liquors increase in this order AS

• Journal of the Korean Wood Science and Technology
• /
• v.10 no.4
• /
• pp.67-75
• /
• 1982

모텔리그닌의 펄프화(化) 처리(處理) 및 폐액(廢液)리그닌의 반응생성물(反應生成物)로부터 알칼리 및 설페이트 펄프화중(化中)에 일어나는 반응양식(反應樣式)을 조사(調査)한 것이다. 알칼리의 처리결과(處理結果)는 친핵시약(親核試藥)에 의해 페놀레이트 이온이 생성(生成), 퀴논메타이드 중간체(中間體)를 걸쳐 $C_6-C_3$ 단위(單位)의 ${\alpha}$위(位) aryl은 탈리(脫離)하여, 리그닌은 저분자화(低分子化)가 시작되고, 저분자생성물(低分子生成物)은 축합반응(縮合反應)에 의해 극(極)히 일부(一部)는 고분자화(高分子化)된다. 저분자화(低分子化)된 리그닌은 산화(酸化)에 의해 퀴노이드 착색구조(着色構造)를 형성(形成)한다. 페놀성의 일부(一部) 및 비(非)페놀성리그닌은 oxirane와 thiirane의 중간체(中間體)를 거쳐 $C_6-C_3$ 단위(單位)의 ${\beta}$위(位)의 arylether가 탈리(脫離)된다. 그러나, hydrosulfide 이온은 hydroxide 이용 보다 강(强한)한 친핵종(親核種)이므로 thiirane의 중간체(中間體) 생성(生成)이 용량(容量)하여 개열(開裂)이 더욱 촉진(促進)된다. 저분자(低分子)리그닌의 고분자축합(高分子縮合)은 벤젠핵(核)의 2.6 위(位)보다 5위(位)에 축합(縮合)이 많이 일어 난다.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2006.06b
• /
• pp.475-478
• /
• 2006

Environment-friendly shock-absorbing materials were made using a vacuum forming method from waste wood collected from local mountains in Korea. The waste wood was pulped by thermomechanical pulping. The TMP cushions showed superior shock-absorbing properties with lower elastic moduli compared to EPS and pulp mold. Even though the TMP cushions made using different suction times had many free voids in their inner fiber structure, their apparent densities were a little higher than EPS and much lower than pulp mold. The addition of cationic starch improved the elastic modulus of the TMP cushions without increasing the apparent density, which was different from surface sizing with starch. The porosity of the TMP cushions was a little greater than EPS and much less than pulp mold. Finally, the TMP cushions have great potential to endure external impacts occurring during goods distribution.

• Journal of Radiation Industry
• /
• v.5 no.3
• /
• pp.227-230
• /
• 2011

Pulps were separated from wood chips using an Electron beam irradiation (EBI) treatment without a NaOH-AQ (anthraquinone) treatment for cooking. The methods were based on a hot water treatment after EBI and two-step bleaching processes. Chemical compositions and FT-IR spectroscopy demonstrated that the content of lignin and hemicellulose in the bleached wood pulps treated with various EBI dose decreased with an increase of EBI doses. Specifically, the lignin in the bleached with pulps treated at 600 kGy of EBI dose was almost completely removed. Moreover, TGA analysis showed that a thermal stability increased with increasing the content of cellulose but the lignin decomposed slowly over the wide region.

• Elastomers and Composites
• /
• v.56 no.3
• /
• pp.136-151
• /
• 2021

Biomass lignin, a waste produced during the paper and bio-ethanol production process, is a cheap material that is available in large quantities. Thus, the interest in the valorization of biomass lignin has been increasing in industrial and academic areas. Over the years, lignin has been predominantly burnt as fuel to run pulping plants. However, less than 2% of the available lignin has been utilized for producing specialty chemicals, such as dispersants, adhesives, surfactants, and other value-added products. The development of value-added lignin-derived co-products should help make second generation biorefineries and the paper industry more profitable by valorizing lignin. Another possible approach towards value-added applications is using lignin as a component in plastics. However, blending lignin with polymers is not simple because the polarity of lignin molecules results in strong self-interactions. Therefore, achieving in-depth insights on lignin characteristics and structure will help in accelerating the development of lignin-based products. Considering the multipurpose characteristics of lignin for producing value-added products, this review will shed light on the potential applications of lignin and lignin-based derivatives on polymeric composite production. Moreover, the challenges in lignin valorization will be addressed.

• Korean Journal of Materials Research
• /
• v.29 no.11
• /
• pp.664-669
• /
• 2019

In this paper, a water-based green polymer mud is synthesized by simple compounding method. Effects of different kinds of tackifiers, their molecular weight on the viscosity of polymer mud and the effects of different fluid loss additives on mud fluid loss are studied. The results show that when polystyrene and anionic polyacrylamide with molecular weight of 8 ~ 10 million are used as the main thickening ingredient, polymer mud with high viscosity and high stability can be obtained. When the prepared polymer mud is formulated as NPAM: PEO: Hydroxypropyl cellulose(HPC) : Water = 42:10:10:100000 (unit: kg), the viscosity can reach 20.6 s, the filtration loss in 7.5 min is 24 mL, and the sand content is only 0.1 %. Compared with traditional bentonite mud, the green environment-friendly polymer mud has the advantages of small amount of waste, low environmental pollution, and low pulping cost, and can meet the construction needs for most topography and geomorphology drilling engineering.