• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 1999년도 Proceedings of Pre-symposium of the 10th ISWPC
• /
• pp.50-55
• /
• 1999

Sizing development of AKD-sized paper by beta-ketoester formation has been debated until recent years because of absence of its obvious and direct spectroscopic evidence. In this study, reaction between AKD and cellulose was investigated to disclose the possibility of beta-ketoester formation between two components under no catalyzed neutral condition. In absence of water, AKD reacted with cellulose to form beta-ketoester linkage under no catalyzed neutral condition, while, in presence of water, most of AKD was hydrolyzed to a dialkyl ketone or beta-ketoacid. Therefore, the main mechanism of AKD sizing would not be the formation of beta-ketoester between AKD and cellulose in the papermaking process. It could be suggested that the sizing development of AKD-sized paper is obtained by next two mechanisms: 1) formation of a thin-layer of AKD on the fiber surface through melting and spreading of AKD emulsion particles by heat, and 2) the formation of ketone by the hydrolysis of AKD during drying and storage of AKD-sized papers.

• Bulletin of the Korean Chemical Society
• /
• 제30권12호
• /
• pp.2969-2972
• /
• 2009

A mild and efficient method has been developed for condensation of substituted phenol with ${\beta}$-ketoester in the presence of catalytic amount of ammonium metavanadate (10 mol%) at ambient temperature to afford the corresponding substituted 4-methyl-2H-chromen-2-one in high yields under mild conditions. Utilization of commercially available inexpensive catalyst makes this manipulation very interesting from an economic perspective.

• Bulletin of the Korean Chemical Society
• /
• 제10권1호
• /
• pp.112-112
• /
• 1989

• 펄프종이기술
• /
• 제39권1호
• /
• pp.16-24
• /
• 2007

This study was performed to investigate the reaction between alkylketene dimer(AKD) and cellulose molecules in AKD-sized paper sheet. AKD was added to highly beaten($80{\pm}3^{\circ}SR$) SwBKP(ca. 0.8% on pulp) in order to have much AKD retention in the paper sheet. This AKD-sized paper sheet was aged at different temperatures, $60^{\circ}C,\;80^{\circ}C,\;105^{\circ}C\;and\;125^{\circ}C$. Changes in FT-IR spectra of AKD in paper sheet during the ageing were measured. In addition, sizing degrees of the AKD-sized paper sheet pretreated for 30 sec. at $105^{\circ}C$ were measured by HST size tester during the storage at different temperature. IR spectra of AKD-sized paper sheet preheated at $105^{\circ}C$ for 30 sec. showed unchanged spectra two absorption bands at $1849cm^{-1}\;and\;1722cm^{-1}$ which refer to the typical AKD IR bands. However, these typical AKD bands were gradually reduced with increasing ageing, completely disappeared after 6 hrs. and formed new absorption band at $1706cm^{-1}$, which refers to carbonyl stretching vibration of dialkylktone. Eventually the AKD molecule was hydrolyzed to diakylketone without formation of ${\beta}$-ketoester with cellulose in paper sheet. After 6 days ageing, a little amount of ${\beta}$-ketoester bands was identified in 6 or 7 days ageing, because of the absence of water due to long-term heating. The same tendency was observed at different ageing conditions. At the practical papermaking process, AKD reacts prevailing with water, and mostly seems to be hydrolyzed to dialkylketene. Concerned to the sizing development, AKD-sized paper sheet was shown no sizing development at the initial stage of ageing at $60^{\circ}C$ after heating treatment at $105^{\circ}C$ for 30 sec., and gradually increased the sizing degree with increasing ageing, such as Hercules Sizing Tester (HST) 130 see for 12 hr, HST 300 sec. for 3 days and HST 400 sec. for 5 days. It was concluded that hydrolyzed AKD could contributed to the sizing development of the paper sheet.

• Bulletin of the Korean Chemical Society
• /
• 제26권6호
• /
• pp.878-879
• /
• 2005

• 농약과학회지
• /
• 제5권2호
• /
• pp.26-32
• /
• 2001

새로운 농약살균제의 개발을 목적으로 trifluoromethyl기 dihydro-1,4-dithiin기 포함된 ${\alpha},{\beta}$-불포화 carboxamide 유도체 12를 합성하였다. trifluoromethylated ${\beta}$-ketoester 유도체 4를 염화한 다음 1,2-ethandithiol과 반응시켜 중간체 1,4-dithiane 유도체 9를 얻었다. 중간체 9의 정제없이 hydroxy기를 염소로 치환하여 생성된 중간체 8을 triethylamine 존재하에서 탈염화하여 trifluoromethyl기가 포함된 dihydro-1,4-dithiin ethyl ester 7을 합성하였다. Ester 7을 가수분해하여 생성된 carboxylic acid 10의 hydroxy를 염소로 치환하여 활성화한 다음 여러 가지 amine 유도체와 반응시켜 trifluoromethyl기가 포함된 dihydro-1,4-dithiin carboxamide 유도체 12를 합성하였다. 합성된 화합물을 대표적이 6종의 식물병원균, 벼 도열병원균, 벼 잎집무늬마름병원균, 오이 잿빛곰팡이병원균, 토마토 역병원균, 밀붉은녹병원균, 보리 흰가루병원균 등에 대한 항균력을 시험 (in vivo) 하였다. 그 결과, 대부분의 화합물이 미약한 항균을 나타냈다. 페닐기의 meta 위치에 isopropy기가 치환된 화합물 12h는 250 ppm에서 밀 붉은녹병원균에 대한 항균력 (99%)을 나타냈다.