• Title/Summary/Keyword: Acetic anhydride

Search Result 108, Processing Time 0.028 seconds

Synthesis of Highly Purified Rosin-Maleic Anhydride Adducts as Reactive Monomer (반응성 단량체로서의 고순도 로진-말레산 부가물의 합성)

  • Choi, Hyeong-Ki;Kim, Jum-Sik;Ahn, Sung-Tae
    • Applied Chemistry for Engineering
    • /
    • v.5 no.2
    • /
    • pp.313-320
    • /
    • 1994
  • Rosin-maleic anhydride adduct(RMA) was synthesized from rosin and maleic anhydride. Highly purified RMA for the application of polymerization monomer was synthesized by means of two methods; the melt reaction followed by further purification and the solution reaction. As a result of this study, the solution reaction was better than the melt reaction for obtaining higher yield of RMA. Maximum yield of RMA obtained by the melt reaction was only 40%. But the yield of RMA obtained by the reaction in carbon tetrachloride solution was 48%(theoretical yield 87.6%) and that obtained by the reaction in acetic acid solution was 51.5%(theoretical yield 94%) respectively.

  • PDF

Changes of Functional Properties of Acylated Fish Protein (Acyl화에 의한 어류 단백질의 이화학적 성질의 변화)

  • Bang, Chan-Sik;Kim, Ze-Uook
    • Applied Biological Chemistry
    • /
    • v.33 no.1
    • /
    • pp.52-61
    • /
    • 1990
  • Fish protein was acylated with acetic anhydride(AA), succinic anhydride(SA) and maleic anhydride(MA) in order to improve the functional properties of the protein. The surface hydrophobicity and functional properties of protein were measured to study the relationship between them. It was found that the extented acylation of nucleophilic groups such as amino and sulfhydryl groups of the amino acid residues of fish protein was higher than other groups when acylated with AA, and the degree of acylation was 89.5 % for amino groups and 72.2 % for sulfhydryl groups. The surface hydrophobicity of fish protein was decreased by succinylation and maleylation, whereas acetylation caused tittle change. The acylated fish protein concentrate(FPC) showed higher surface hydrophobicity than the acylated fish myofibrilla protein(FMP). Acylation with AA, SA and MA of fish protein resulted in a significant increase in protein solubility, emulsifier properties, foaming properties, water adsorption capacity and oil adsorption capacity. These properties of acylated FMP were more improved than those of acylated FPC. Decrease in protein hydrophobicity was highly correlated with increase in protein solubility, and emulsifier properties and foaming properties were largely dependent on the solubility as well as surface hydrophobicity. The water adsorption capacity of the protein was significantly affected by solubility. Surface hydrophobicity had greater influence on oil adsorption capacity, whereas it had tittle effect on water adsorption capacity.

  • PDF

Studies on the Functional Properties of Modified Soy Protein Isolate (변형대두 단백질의 기능 특성에 관한 연구)

  • Kim, Young-Sug;Hwang, Jae-Kwan;Cho, Eun-Kyung;Lee, Shin-Young;Pyun, Yu-Ryang
    • Korean Journal of Food Science and Technology
    • /
    • v.17 no.5
    • /
    • pp.383-388
    • /
    • 1985
  • Soy protein isolate was acylated with succinic anhydride and acetic anhydride. The functional properties are markedly improved by acylation of the $\varepsilon$-amino groups. Acylation of the available amino groups shifted the isoelectric point from 4.5 to 4.0 and enhanced the solubility between pH 4.0-6.0. In the 0.03M-$CaCl_2$ solution the solubility of the modified soy protein is much larger than that of the unmodified protein above the isoelectric point. The emulsion properties and foaming properties also improved by the modification and the effects of pH on the properties paralleled its effect on protein solubility. The changes of reduced viscosity with concentration followed Huggin's equation and by modification the intrinsic viscosity of the soy protein increased and the interaction coefficient decreased.

  • PDF

Application Study of Skin Beauty Culture, Green Laver Culture and Synthesis of ${\alpha}$-Chloro Substituted Chitosan Succinic Acid Derivatives (${\alpha}$-Chloro 치환기를 갖는 Chitosan Succinic Acid 유도체 합성 및 피부미용과 해태 김 양식 응용 연구)

  • Ryu, Soung-Ryual
    • Journal of Integrative Natural Science
    • /
    • v.4 no.4
    • /
    • pp.323-331
    • /
    • 2011
  • In this study, ${\alpha}$-chlorosuccinic acid was synthesized through the reaction of maleic anhydride with HCl(g), (UV)250 nm~300 nm wavelength in presence of $CCl_4$. For the second reaction of N-(monochloro)succinic acid contained glucosamine derivatives(I) was accomplished by a modification of the general acylation using excess ${\alpha}$-chlorosuccinic anhydride in the presence of 2% acetic acid with methanol condition as a solvent at elevated temperature($70^{\circ}C$). We considered organic acid derivatives were useful especially for treatment for the cultivating porphyra.

A Study on Chemical Cyclodehydration of Aromatic Poly(ether-amide-amic acid)s (방향족 폴리(에테르-아미드-아미드산) 중합체의 화학적 탈수 고리화 반응)

  • Ahn, Young Moo
    • Textile Coloration and Finishing
    • /
    • v.7 no.4
    • /
    • pp.39-44
    • /
    • 1995
  • A study has been made about some correlations in the chemical cyclization of precursors, poly(ether-amide-amic acid)s by treating in solution a mixture of acetic anhydride and pyridine in the presence of 4,4-dimethyl formamide, with the poly(ether-amic acid)s being respectively reacted between trimellitic anhydride chloride and 3 kinds of diamines, i.e., 4,4'-bis(m-aminophenoxy) benzophenone, 2,2'-bis[4-(m-aminophenoxy) phenyl] propane and 4,4'-bis(m-aminophenoxy) diphenyl sulfone. The cyclization of imide ring in the poly(ether-amide-amic acid)s may be regarded as an intramolecular acylation of amide group by o-carboxyl group. As a result of this reseach, the effects on the conversion to poly(ether-amide-imide)s have been found by changing the ratio of cosolvents in the cyclization mixture.

  • PDF

Comparison of Physicochemical Properties of Starch Acetates Prepared by Conventional, Preheat Treatment and Extrusion Process (습식법과 예열처리법 및 Extrusion 공정에 의해 제조한 초산전분의 이화학적 성질비교)

  • Kim, Chong-Tai;Ryu, Gi-Hyung;Kim, Dong-Chul;Kim, Chul-Jin
    • Korean Journal of Food Science and Technology
    • /
    • v.22 no.6
    • /
    • pp.659-667
    • /
    • 1990
  • Starch acetates were prepared by conventional method, preheat treatment, and extrusion process through acetylation of corn starch with acetic anhydride and their physicochemical properties were investigated. The optimal conditions of the acetylation of starch by conventional method(CSA) was found that starch concentration was 30%, reaction temperature $35^{\circ}C$ and pH 8.5. With increasing the molar ratio of acetic anhydride to anhydrous glucose unit from 0.03 to 0.20, DS(Degree of substitution) value of corn starch acetate prepared at the optimum condition was increased from 0.019 to 0.080, while the acetylation efficiency was decreased from 31.6% to 20.5%. In the case of the preheated (gelatinized), then acetylated starch(PSA), DS value was increased from 0.027 to 0.04 at the fixed molar ratio of the acetic anhydride with increasing preheating temperature from $60^{\circ}C\;to\;90^{\circ}C$. The DS was low as 0.02 in the case of starch acetate prepared by extrusion process(WESA). The CSA and PSA showed lowering gelatinization temperature and enthalpy than raw corn starch with increasing DS. All of starch acetates showed the increased degree of transparency, the decreased lightness and the increased yellowness as compared to the raw corn starch. WESA showed lower apparent viscosity and more close to the characteristic of the Newtonian fluid than CSA and PSA. Intrinsic viscosity was reduced in CSA and WESA, although PSA has a slightly higher one than raw corn starch. The rate of retrogradation of the gels was retarded in all starch acetates.

  • PDF

Solvent-Free Synthesis of Some1-Acetyl Pyrazoles

  • Thirunarayanan, Ganesamoorthy;Sekar, Krishnamoorthy Guna
    • Journal of the Korean Chemical Society
    • /
    • v.57 no.5
    • /
    • pp.599-605
    • /
    • 2013
  • Some N-acetyl pyrazoles including 1-(3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-$^1H$-pyrazole- 1-yl) ethanones have been synthesised by solvent free cyclization cum acetylation of chalcones like substituted styryl 3,4- dichlorophenyl ketones using hydrazine hydrate and acetic anhydride in presence of catalytic amount of fly-ash: $H_2SO_4$ catalyst. The yield of these N-acetyl pyrazole derivatives are more than 75%. The synthesised N-acetyl pyrazoline derivatives were characterized by their physical constants and spectral data.

NMR study on secondary metabolites isolated from an identified tunicate

  • Rho, Jung-Rae
    • Journal of the Korean Magnetic Resonance Society
    • /
    • v.8 no.2
    • /
    • pp.115-126
    • /
    • 2004
  • Four secondary metabolites from an unidentified tunicate were isolated by treatment with trichloroethyl chloroformate(TECF) or acetic anhydride in pyridine. Their structures were determined by an extensive NMR analysis and the configuration of diacetyl derivatives(3a, 4a) was assigned by comparing with NMR data of a similar compound. Three new naturally occurring compounds (1, 3, 4) showed potent brine shrimp lethality and antifungal effect against Candia albicans.

  • PDF