목질제품의 포름알데히드방출량 측정방법과 개선방안

박병대,박종영,Park Byung-Dae,Park Jong Young 한국가구학회 2004 한국가구학회지 Vol.15 No.2

This paper attempted to review measuring methods of formaldehyde emission from wood-based panel products. Methods included for the discussion were desiccator methods, extraction method, and various chamber methods. First, the procedures and testing conditions of 24-hour desiccator method was critically reviewed, and an improvement of this method was proposed to meet international standards. Two different small chamber methods ($20\ell$ and $1m^3$ chamber methods) were also compared in terms of their advantages and disadvantages. In addition, the regulation levels of formaldehyde emission of wood-based composite panels were compared for different countries. The selection of a reference method of measuring formaldehyde emission of wood panel products should consider the ease of conducting test and cost required. Results should be exchangeable for different methods.

남매에서 발생한 결절성 경화증 Tuberous Sclerosis in Sibling )

박병대(Byung Dae Park),이형래(Hyung Lae Lee),장성구(Sung Goo Chang),채수응(Soo Eung Chai) 경희대학교 경희의료원 1992 慶熙醫學 Vol.8 No.2

Transforming Crystalline Thermosetting Urea-Formaldehyde Resins to Amorphous Resins

Byung-Dae Park(박병대) 한국고분자학회 2022 한국고분자학회 학술대회 연구논문 초록집 Vol.47 No.1

나노피브릴화 셀룰로오스와 마이크로피브릴화 셀룰로오스의 무용매 아세틸화

박성수 ( Seongsu Park ),박병대 ( Byung-dae Park ) 한국목재공학회 2020 한국목재공학회 학술발표논문집 Vol.2020 No.1

Nanocellulose has advantages such as hydrophilicity, low density, high strength property and surface area. But, its hydrophilicity become a problem when it contact with polymer matrix in nanocomposites. So, it is necessary to modify hydrophilicity to hydrophobicity through chemical modification. This work focused on the impact of solvent-free acetylation using iodine and sulfuric acids as a catalyst and compared the properties of acetylated cellulose nanofibrils (CNFs) and cellulose microfibrils (CMFs). Various techniques such as attenuated total reflectance infrared (ATR-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and contact angle (CA) measurement were conducted to obtain degree of substitution (DS), crystallinity, thermal stability, and wettability.

밀성박씨 경주 손곡문중 목판의 수종식별

엄유정 ( Yu-jeong Eom ),박병대 ( Byung-dae Park ) 한국목재공학회 2018 목재공학 Vol.46 No.3

본 연구에서는 기록으로 남아있는 밀성박씨 경주 손곡문중의 박씨문헌록(朴氏文獻錄)과 지당실기(智堂實紀)의 인쇄에 사용된 목판의 수종을 식별하고자 수행되었다. 전체 282장의 목판 중 88장을 무작위로 선정하여 광학현미경으로 목재해부학적 특징을 비교분석한 결과, 7개의 목재수종이 식별되었다. 즉 가장 많이 사용된 수종은 서어나무로 39.8%를 차지하였고, 그 다음으로 돌배나무가 25.0%, 고로쇠나무가 15.9%, 산벚나무가 10.2%, 피나무가 3.4%, 감나무가 3.4%, 그리고 거제수나무가 2.3%가 사용된 것으로 조사되었다. 이 같은 결과는 일반적으로 목판인쇄에 사용된 목재수종의 범주에 속하는 것이다. 또 식별된 모든 수종들은 활엽수 산공재로 복잡한 한자를 새기기 쉽고 여러 번 인쇄를 하더라도 글자가 쉽게 닳지 않고 용이하게 구할 수 있는 목재수종이 사용된 것으로 판단된다. This study was conducted to identify wood species of two printing woodblocks either from the Park clan’s documentary or Ji-dang documentary of Songok clan of the Milseong Park, Songok, Gyeongju, Korea. Eighty-eight woodblocks out of the total 282 woodblocks were randomly selected to compare anatomical features for the identification of wood species, using a light microscope. As a result, seven wood species were identified, and all of them were diffuse-porous hardwood species. The most significant portion, i.e., 39.8% of wood species was Carpinus laxiflora Blume. Then, Pyrus pyrifolia Nakai, Acer mono Maxim, Prunus sargentii Rehder, Tilia amurensis Rupr, Diospyros kaki Thunb, and Betula costata Trautv was 25.0%, 15.9%, 10.2%, 3.4%, 3.4% and 2.3%, respectively, indicating that all diffuse-porous hardwood species had been used for the woodblocks. It was believed that diffuse-porous hardwoods had been used because they provided an easy of engraving complex Chinese letters, of acquiring these wood species in Gyeongju areas, and a high resistance to repeated printing.

Nanocellulose를 이용한 나노복합재의 최근 연구 동향

조미정 ( Mi Jung Cho ),박병대 ( Byung Dae Park ) 한국목재공학회 2010 목재공학 Vol.38 No.6

본 총설은 나노셀룰로오스의 원효의 종류, 단리방법과 나노셀룰로오스의 특성 그리고 이를 바탕으로 한 나노복합재의 최근 연구동향을 검토하였다. 나노셀룰로오스를 얻는 원료는 목질자윈 및 미생물셀룰로오스 등을 포함하여 다양한 자원이 이용되고 있다. 또 나노셀룰로오스의 단리방법은 물리적, 기계적 및 화화적 방법등이 사용되고 있으며 이들 단리방법에 따라 나노셀룰오스의 특성은 달랐다. 나노셀룰로오스의 길이와 폭은 사용된 원료종류와 단리방법에 따라 크게 영향을 받지만 길이는 약 100~300 nm이며 폭은 5~50 nm로 다양하였다. 나노복합재의 제조에는 대부분 수용성 고분자들이 기질로 사용되었으며 2~10%의 나노셀룰로오스로 강화된 나노복합재의 인장강도와 저장탄성계수(E`)는 크게 향상되는 경향을 보였다. 소수성 고분자에 사용될 경우 나노셀룰로오스의 표면을 변화(modification) 시치는 다양한 방법딜이 소개되었다. 나노셀룰로오스를 바탕으로 한 나노복합재의 응용은 다양하게 보고되었으나 적합한 응용분야에 대한 연구가 필요하다. 특히 나노셀룰로오스의 이용확대를 위해서는 목질자원으로부터 나노셀룰로오스를 상업적으로 대량으로 제조할 수 있는 연구와 기술개발아 향후에 필요하다. This review attempted to overview characteristics of nanocellulose from various sources, its isolation methods, and properties of nanocellulose-based nanocomposites. Currently, nanocelluloses could be obtained from a variety of cellulose sources, including wood pulp, tunicate, bacterial cellulose etc., and are isolated by various ways such as chemical, physical, or biological methods. The length and width of nanocellulose is in th range of 100~300 nm long and 5~50 nm wide although characteristics of nanocellulose shows a wide variability, depending on sources and isolation method. Nanocellulose is also being used as a reinforcement in the nanocomposites via various methods. Many water soluble polymers were reinforced by the incorporation of nanocellulose, which significantly improves tensile and storage moduli of the nanocomposites. In order to be used for hydrophobic polymers, the surface of nanocellulose was modified. Even though there is a significant progress in the utilization of nanocellulose as a reinforcement of polymers, further research is required to find a niche market of nanocellulose-reinforced nanocomposites. In addition, isolation methods of producing the nanocellulose in a large quantity for commercial applications should be developed to extend the application of nanocellulose-based bio-nanocomposites in future.

탈메틸화 개질처리의 활엽수 크라프트 리그닌을 이용한 리그닌-페놀-폼알데하이드 수지의 접착력

김민정 ( Minjeong Kim ),박병대 ( Byung-dae Park ) 한국목재공학회 2022 한국목재공학회 학술발표논문집 Vol.2022 No.2

Lignin is abundant biopolymer that has the potential to efficiently replace phenol since it is a natural aromatic polymer which has a comparable structure of phenol. Especially, hardwood lignin, mainly comprised with syringyl and guaiacyl units, has much more methoxyl groups than softwood lignin. Thus, In this study, hardwood kraft lignin entirely dissolved in acetone are demethylated with Na₂SO₃ to increase those reactivity for finished wood-composite resins. Because the fractionation approach, which mostly employs organic solvents, is successful in simplifying the non-uniform molecular structure of lignin and is one of the methods predicted to boost reactivity more stably, thus an acetone-soluble lignin is demethylated to convert methoxyl groups into phenolic hydroxyl groups. Demethylated lignin was characterized using GPC, and ATR-IR measurements to offer a fresh suggestion for a bio-based wood adheisves. Additionally, the wettability measurement and the tensile shear strength of plywood were used to suppose the adheison of the demethylated acetone soluble hardwood kraft lignin-phenol-formaldehyde (DAS-HKL-PF) resins.

가수량을 달리하여 제조한 탁주의 품질특성

손홍석(Hong-Seok Son),박병대(Byung-Dae Park),고봉국(Bong-Kuk Ko),이철호(Cherl-Ho Lee) 한국식품과학회 2011 한국식품과학회지 Vol.43 No.4

본 연구에서는 용수 사용량에 따른 탁주의 특성을 비교 분석하였다. 원료 쌀의 중량을 기준으로 용수의 사용량을 2배(A), 4배(B), 5배(C), 6배(D)로 달리하여 탁주를 담금하였다. 초기 용수의 양에 비례하여 완성된 탁주의 양은 증가하였지만, 최종 알코올 농도를 6%(v/v)로 조정하면 얻어지는 탁주의 양이 대조구에 비하여 실험구에서 1.17-1.18배의 수율을 나타내었으며, 총산도는 1.34배(B), 1.40배(C), 1.46(D)배 높았다. 이는 기존의 방법대로 용수를 적게 사용하여 발효하고 후에 가수를 하는 것보다, 초기에 용수를 대량 사용하는 것이 더 많은 알코올과 유기산을 생성할 수 있다는 것을 보여준다. 또한 관능평가에서도 용수를 많이 사용한 실험구가 전체적인 기호도에서 대조구보다 우수하였으며, 이는 대조구가 단맛, 신맛, 쓴맛, 바디감 등이 약하기 때문으로 추정된다. 본 연구를 통해 탁주 발효 시 용수의 사용량만 가지고도 다른 종류의 탁주를 제조할 수 있음이 확인되었다. 목적하는 탁주의 성질에 따라 용수 첨가량을 달리할 필요가 있으며, 이를 이용하여 감미료를 첨가하지 않고도 높은 품질의 탁주를 제조할 수 있는 가능성을 제시하였다. The effect of the amount of water added during fermentation on the quality of takju (rice beer) was investigated. Takju was made by adding water 2-fold (A), 4-fold (B), 5-fold (C), and 6-fold (D), respectively, of the rice weight (w/w). Although the amount of takju increased in proportion to the amount of water added before fermentation, the amounts of B, C, and D were 1.17-1.19 times larger than the amount in A, and the total acidities of B, C, and D were 1.34, 1.40 and 1.46 times higher than those in A after adjusting alcohol content to 6%(v/v). Moreover, the sensory preferences for B, C, and D were higher overall than those for A, which was suggested to be due to the amount of sweet, sour, and bitter tastes as well as body in A. Different types of takju could be made by changing the amount of water added before fermentation.

Resin Impregnation of High-Density Hardwoods for Enhancing Their Dimensional Stability

이건희 ( Geonhui Lee ),박병대 ( Byung-dae Park ) 한국목재공학회 2024 한국목재공학회 학술발표논문집 Vol.2024 No.1

집성재 제조를 위한 상온경화형 요소 멜라민 수지 접착제의 성능 및 경화제의 조성

김민석 ( Minseok Kim ),박병대 ( Byung-dae Park ) 한국목재공학회 2020 한국목재공학회 학술발표논문집 Vol.2020 No.1

The synthesis method of cold-setting melamine-urea-formaldehyde (MUF) resin adhesives and composition of the hardener for glue laminated timber (Glulam) were investigated. Cold-setting MUF resins is synthesized in a sequential reaction process in which melamine contents (30, 40 %) and formaldehyde are first reacted, and then urea is reacted. In addition, the hardener for curing the MUF resins at room temperature was formulated using carboxymethyl cellulose (CMC) and formic acid. And, these MUF resins and the curing agent were mixed at a weight ratio of 100 : 15, respectively, and then used to manufacture of Glulam. Block shear strength, wood failure, and delamination tests were done to evaluate the adhesion performance of MUF resins. As a result, MUF resins were satisfied with the requirement of KS standard in block shear strength and wood failure, but only the MUF resins with 40% melamine content was satisfied with the requirement of KS standard in delamination test. Therefore, the cold-setting MUF resins with 40% melamine content could be used in the manufacture of Glulam.