• 펄프종이기술
• /
• 제36권4호
• /
• pp.49-59
• /
• 2004

This study was carried out to obtain the basic data for producing higher functional coating agents for pulp mold by evaluating various kinds of starch derivatives. At that time, four kinds of starch derivatives were manufactured for making coating agents respectively. Physical properties of coated paperboards were tested. Conclusions obtained from this results were as follows. The water and oil resistance of hydroxypropylated, cyanoethylated and carboxymethy­lated starch were high when degree of molar substitution(DS) of propylene oxide, acrylonitrile and sodium monochloroacetate were 0.18, 0.07 and 0.009, respectively. Also, the those of crosslinked starch were high when degree of crosslinking of epichlorohydrin was 0.02. Consequently, $8\%$ solution of carboxymethylated starch made with DS 0.009 of monochloroacetate was the best among coating agents from starch derivatives men­tioned above.

• 한국환경보건학회지
• /
• 제24권3호
• /
• pp.11-17
• /
• 1998

Chitin is known as biodegradable natural polymer. In spite of various application of chitin derivatives from waste marine sources, commercial use of chitin has been limited due to high resistance to chemicals and the absense of proper solvents. We chitin prepared through the decalcification, bleaching and deproteination from Protunus trituberculatus shells by change of Hackman's method. Also, Microcrystalline chitin made by hydrolysis that was reduce made of resistance solvents used by dilute hydrochloric acid, ultrasonic and hydrogen peroxide. Crosslinked chitin derivatives were preparaed from chitin with crosslink agents(epichlorohydrin, 1,3-dichloropropanol) follwed by crosslinkage at 6C position. The effects of these parameters on chitin dervatives were invastigated by IR, DSC, XRD, BET, PSA and SEM. SEM analysis showed that both chitin and crosslinked chitin had a particle shaped morphology.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제9권1호
• /
• pp.62-64
• /
• 2004

The use of enantioselective hydrolysis for preparing chiral epichlorohydrins was investigated using recombinant Pichia pastoris with the enantioselective epoxide hydrolase of Rhodotorula glutinis. The rate of the recombinant epoxide hydrolase-catalyzed enantioselective hydrolysis of racemic epichlorohydrins was enhanced by the addition of 5%(v/v) Tween 20. Enantiopure (R)-epichlorohydrins with an enantiopurity of 100% ee and a yield of 26% were obtained within 5min from 50mM racemates.

• 한국염색가공학회지
• /
• 제14권3호
• /
• pp.26-33
• /
• 2002

Dyeing properties and crosslinking effect of bifunctional reactive dyes on chitosan fiber were investigated to improve the stability of chitosan fiber against the mild acidic solution and the wet processing. Chitosan fibers were crosslinked with epichlorohydrin for comparing purpose, and dyed with C. I. Reactive Red 194, C. I. Reactive Blue 50, and the reactive dye having two $\alpha$-bromoacrylamide groups at various concentrations. The initial dyeing rates of reactive dyes are rapid and chitosan fibers absorb the relatively large amount of dyes. The chitosan fibers dyed with these dyes show the low degree of swelling and the low solubility in 1 % acetic acid solution and also represent the higher thermal stability The reactive dye with two $\alpha$-bromoacrylamide groups shows higher crosslinking effect than other dyes.

• 한국염색가공학회지
• /
• 제6권4호
• /
• pp.46-53
• /
• 1994

Polymer cationic agent was prepared by the initial polymerisation of epichlorohydrin followed by amination with diethylamine. Cotton fibre treated with the polymer (6~8% o.w.f.) is highly cationic and exhibit increased substantivity for reactive dyes under neutral to weakly acid conditions. The modified substrate could be dyed with reactive dyes without salt or a little salt from dye bath. The increased concentration of cationic agents resulted in an increase the colour yield. Futhermore, treated cotton has an electropositive surface charge. Adsorption of Reactive dye can be attributed to both van der waals force and electrostatic attraction.

• Bulletin of the Korean Chemical Society
• /
• 제27권8호
• /
• pp.1171-1174
• /
• 2006

Various off-the-shelf Lewis acids in conjunction with various onium salts are screened for coupling reaction of $CO_2$ with epoxides. Among the tested ones, $VCl_3/n-Bu_4NOAc$, $VCl_3/(n-Bu_4NCl$ or PPNCl), $FeCl_3/ n-Bu_4NOAc$, and $FeCl_3/ n-Bu_4NOAc$are proved to be highly active. Propylene oxide, epichlorohydrin, styrene oxide, and cyclohexene oxide can be converted over 90% yields to the corresponding cyclic carbonates without the use of organic solvents under mild conditions by 0.1-1.0 mol% catalyst charge.

• 한국환경과학회지
• /
• 제14권3호
• /
• pp.359-366
• /
• 2005

Starch was crosslinked with epichlorohydrin. Crosslinked starch-filled waterborne acrylate (CSWAC) films were prepared by blending this crosslinked starch with waterborne acrylate. The thermal and mechanical properties of these films were investigated by thermogravimetric analysis (TGA), tensile strength and elongation test. The biodegradability was also studied by determination of reduced sugar products after enzymatic hydrolysis and the surface morphology was investigated by scanning electron microscopy (SEM). The CSW AC film showed significantly higher tensile strength and elongation than those of starch-filled waterbonre acrylate (SWAC). The biodegradability of this film was higher than that of native starch-filled acrylate film, and was increased by the addition of crosslinked starch to the acrylate film.

• 한국염색가공학회지
• /
• 제7권2호
• /
• pp.1-8
• /
• 1995

Polymer cationic agent was prepared by the initial polymerization of epichlorohydrin followed by amination with diethyl-amine. Cotton fibre treated with the polymer (6∼8% o.w.f.) is highly cationic and exhibit increased substantivity for anionic dyes. The modified substrate could be dyed with direct dyes without salt or a little salt from dye bath. The increased concentration of cationic agents resulted in an increase the colour yield. Futhermore, treated cotton has an electropositive surface charge. Adsorption of direct dye can be attributed to both van der waals force and electrostatic attraction.

• 펄프종이기술
• /
• 제29권1호
• /
• pp.13-25
• /
• 1997

To establish the weed control method without herbicide and weeding work, mulch paper was developed from domestic old corrugate container. Basis weight of mulch paper should be above 120 g/$m^2$ to guarantee the mechanical properties. It was concluded that polyamide polyamine epichlorohydrin was desirable to improve the wet strength of mulch paper and the optimum addition level was about 1.5% on the basis of oven dry pulp. The mulch paper was found to be effective in controlling paddy weeds. For the complete weed control the mulch paper should be sustained without decomposition over 45 days. As the paper mulching reduced the soil temperature, the mulch paper was required to improve the penetration of radiant heat.

• 한국표면공학회지
• /
• 제12권3호
• /
• pp.174-179
• /
• 1979

The effects of brightness, electrochemical behaviour on the organic additives, such as aldehydes, polymers, amines and condensed product obtained from epichlorohydrin and nicotinamide, in cyanide zinc electrolplating bath have been studied by controlled potential electrolyser. The results were summerized as follows: (1) It was found that the addition of only one compound of these organic compounds in the bath was unsuitable but mixture of anisaldehyde or monoethanolamine and condensed product as suitable as brightener. (2) The cathodic polarization curve of polymers or aldehydes in cyanide zinc electroplating bath was almost the same but the cathodic polarization curve of condensed product remarkable shifted to noble potential more than non-additive curve.