• Journal of the Korean Wood Science and Technology
• /
• 제51권6호
• /
• pp.481-492
• /
• 2023

The ecofriendly lifestyle has attracted considerable support for sustainable development. Natural dyes, as sustainable products, have become a research focus and development area for many scientists. Ecofriendly processing also supports circular sustainable development. This study effectively obtained tannins as a natural dye from merbau (Intsia bijuga) sawdust using water as an ecofriendly solvent. Merbau sawdust is an underutilized industrial waste. Temperature and solid-solvent ratio variations were performed to extract tannins from merbau sawdust. Temperature and solid-solvent ratio positively affected solution yield and tannin concentration. The optimal condition was identified using response surface methodology and experimental observations. A yield of 0.2217 g tannins/g merbau was obtained under the conditions of 333.15 K and 0.125 solid-solvent ratio. Extraction was controlled by convective mass transfer at the interface of solid particles.

• Bulletin of the Korean Chemical Society
• /
• 제31권4호
• /
• pp.981-983
• /
• 2010

The condensation of several aromatic/heteroaromatic aldehydes with 2-aminothiophenol catalyzed by silica sulfuric acid under microwave irradiation afforded 2-arylbenzothiazoles in high yields and short reaction times under solvent-free conditions. The major advantages of the present method are good yields, ecofriendly, reusable catalyst, mild and solvent-free reaction conditions.

• Bulletin of the Korean Chemical Society
• /
• 제34권11호
• /
• pp.3410-3414
• /
• 2013

Atom-economical esterification is of great importance in green chemistry. In this work, we demonstrated the catalyst and additive free esterification of alcohols by their reaction with 2-acyl-4,5-dichloropyridazin-3(2H)-ones without solvent at $100^{\circ}C$. Aliphatic and aromatic alcohols were converted into the corresponding esters in good to excellent yields. It is noteworthy that the reaction is solvent-free, atom-economic, easy-workup, and rapid and that the process is inexpensive.

• 대한화학회지
• /
• 제51권2호
• /
• pp.115-124
• /
• 2007

α, β-불포화 케톤 유도체를 실리카-황산 촉매 하에서 비용매 교차 알돌 응축 반응법을 이용하여 합성하였다. 합성 수율은 90% 이상이었으며, 사용된 촉매는 회수 가능하였다. 합성돤 화합물들의 물리화학적인 특성은 IR, NMR, Mass 등의 분광학적 분석 방법을 이용하여 결정하였다. 케톤 생성물에 미치는 치환기 효과는 측정된 분광 데이터와 Hammet 치환기 상수간의 상관관계로 표현되는 다중 상관계수 방정식에 의하여 잘 설명될 수 있었다.

• Bulletin of the Korean Chemical Society
• /
• 제33권5호
• /
• pp.1457-1464
• /
• 2012

An ecofriendly catalytic route for selective synthesis of $N$-substituted azacyclopentanes, nitrogen-containing heterocyclic intermediates for many bioactive compounds, was established by carrying out $N$-heterocyclization (di $N$-alkylation) of primary amines with 1,4-dichloro butane (as dialkylating agent) using catalytic amount of hydrotalcite as solid base catalyst. The hydrotalcite was found to be efficient solid base catalyst for di $N$-alkylation of different primary amines (aniline, benzyl amine, cyclohexyl amine and n-butyl amine) giving 82 to 96% conversion (at optimized reaction condition) of 1,4-dichloro butane and > 99% selectivity of respective $N$-substituted azacyclopentanes within 30 min. under solvent free condition. The reaction parameters significantly influence the conversion of 1,4-dichloro butane to $N$-substituted azacyclopentanes. The nature of substituent present on amino group affects the reactivity of amine substrates for di $N$-alkylation reaction with 1,4-dichloro butane. The 1,4-dichloro butane was found to be highly reactive alkylating agent for di $N$-alkylation of amines as compared to 1,4-dihydroxy butane. The reusability of the catalyst and its chemical stability in the reaction was demonstrated.

• 한국염색가공학회지
• /
• 제32권1호
• /
• pp.38-43
• /
• 2020

To overcome the harmful effects caused by conventional oxidative hair dyes, natural colorants becomes more popular in the hair dyeing. By extracting Sagassum fusiforme powders with aqueous alkaline solution as a solvent at 130℃ for 60 minutes, a fucoxanthin concentration of up to 216㎍/ml can be obtained. UV/Vis analysis was used to prove the presence of fucoxanthin in the extract powder. A K/S value of 23.8 can be obtained when wool fabrics were dyed with the extract at 120℃ for 60 minutes under pH 2. The color fastness properties of the dyed wool fabrics were very good as indicated by rating 4 for laundering(color change), rating 3 or higher for rubbing, and rating 5 for light irradiation. The dyed wool fabric was found to have antimicrobial activity against Staphylococcus aureus. The antioxidant and antimicrobial activity of the Sagassum fusiforme extract can be an effective functional hair colorant. Hair dyeing with the extract formulation at 45℃ for 40 minutes under pH 5 accomplished a K/S value of 8.9. The color fastness of the dyed hair showed rating 3 against light irradiation, which increased to rating 5 with after-mordanting of tannin acid.

• 분석과학
• /
• 제25권5호
• /
• pp.292-299
• /
• 2012

GC/MS (gas chromatography/mass spectrometry)는 훌륭한 분리능과 재현성으로 인해 널리 활용되고 있으며, 정립된 데이터베이스의 활용을 통한 성분 분석에서 활용도가 높다. 또한 HS-SPME (headspacesolid phase micro extraction)법은 용매로 추출을 하지 않은 휘발성 물질의 추출을 하는데 널리 사용되었다. 이 두 방법의 연계는 다양한 시료에서 발생하는 휘발성 성분의 분석에 널리 활용되었다. 위 특징을 이용하여 살아있는 Camponotus japonicus가 분비하는 미량의 페로몬 구성 성분의 분석 방법을 확립하였다. n-Decane, n-undecane, n-tridecane 등의 물질이 미량 페로몬에서 검출되었으며, 이 탄화수소들을 분석하는데 적합한 SPME fiber, 추출 온도, 추출 시간을 최적화하였다. 살아있는 시료를 분석할 수 있기 때문에 특정 현상이 발생하는 그 순간을 분석하는 장점이 있는 한편, 살아있는 시료를 분석하기 때문에 추출 시간 등이 제한된다는 한계점이 있었으나 살아있는 HS-SPME GC/MS 분석방법이 정립된다면 살아있는 시료를 죽일 필요 없다는 점에서 친환경적인 연구의 발전에 해결책이 될 수 있을 것으로 전망한다.