• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.357-363
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• 1997

The effect of replacement of cotton seed meal (CSM), with various levels and sources of non-protein nitrogenous (NPN), substances on in vitro ruminal fermentation were studied. Cotton seed meal, in control ration provided nitrogen equivalent to 12.5 percent crude protein while in experimental ration was replaced at 30, 50 & 70 percent levels with urea, diammonium phosphate (DAP) and biuret, respectively. The results of incubation upto 48 hours indicated an improvement in digestibility by replacement of CSM with urea and biuret upto 50 percent protein equivalent, but not with DAP. Bacterial count from cultures containing 50% nitrogen from biuret was significantly higher than DAP, urea and CSM. Various sources of nitrogen produced $NH_3-N$ in increasing order of CSM, biuret, DAP and urea. Increasing levels of NPN resulted in progressive increase in the levels of $NH_3-N$. The levels of various NPN sources had no effect on pH. However, the pH values determined for urea and CSM were higher than biuret and DAP.

• Bulletin of the Korean Chemical Society
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• v.20 no.8
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• pp.943-947
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• 1999

Ligand field analyses for tris(biuret)chromium(III) chloride and hexaureachromium(III) bromide were performed and compared to understand the ligand field properties of both ligands. The optimized eσO and eπO values indicate that coordinated oxygen atom in biuret ligand is a moderate s- and strong p-donor, while that in urea ligand is a weak σ- and moderate π-donor. The electronic structures of those two complexes are quite different and they were well accounted by inclusion of an anisotropic p bonding.

• YAKHAK HOEJI
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• v.7 no.2_3
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• pp.67-71
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• 1963

Studies the reaction mechanism and optimal reaction condition of the process of preparing sodium isocyanate, by means of heating of sodium carbonate and urea. Proposing, at the sametime, the quantitative analyzing method of sodium isocyanate in the presence of impurities of $Na_{2}CO_{3}$, urea and biuret. 1. Sodium isocyanate could be prepared by means of heating reaction of sodium carbonate and urea. 2. Adding urea into the heated sodium carbonate is reasonable. 3. Quantitative analysis of sodium isocyanate in the presence of impurities, $Na_{2}CO_{3}$, urea and biuret could be done by the following method:-adding nitrobarite solution into sample solution in order to remove $CO_{3}"$ and neutralize the solution, filtering off $BaCO_{3}$, and then precipitating isocyanate as a silver salt, filtering off AgNCO, and then, titrating remaining $AgNO_{3}$ with $NH_{4}SCN$, (indicator $FeNH_{4}(SO_{4})_{2})$/TEX>

• Journal of the Korean Applied Science and Technology
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• v.20 no.2
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• pp.110-117
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• 2003

Pyrophosphoric modified polyesters (TATBs) were synthesized by polycondensation of adipic acid, trimethylolpropane, 1,4-butanediol, and tetramethylene bis(orthophosphate). Two-component PU flame-retardant coatings (TATBCs) were prepared by blending TATBs with HDI-Biuret. Most of the physical properties of the flame-retardant coatings were comparable to those of non-flame-retardant coatings. Coatings containing 10 and 15wt% 1,4-butanediol, TATBC-10C and TATBC-15C were not flammable in the vertical flame-retardancy test.

• Korean Journal of Crystallography
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• v.9 no.2
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• pp.143-148
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• 1998

Tris(biuret)chromium(III) Perchlorate Monohydrate (Cr(C2H5N3O2)3·(ClO4)3·H2O)의 결정 및 분자구조를 X-선 회절법으로 연구하였다. 결정의 공간군은 P, a=10.486(3) , b=11.371(5) , c=11.485(4) , α=88.70(3)o β=66.85(3)0, γ=67.11(3)o, V=1146.2(7) 3가 Z=2이다. 회절반점들의 세기는 Enraf-Noninus CAD-4 Diffractometer로 얻었으며, MoKα radiation X-선을 사용하였다. 분자구조는 직접법으로 풀었으며 최소자승법으로 정밀화하였다. 최종 신뢰도 R값은 1528개의 회절반점에 대하여 0.114이었다. Tris(biuret)chromium(III) cation은 octahedral 배열을 하고 있으며, 평균 Cr-O 결합길이는 1.94 이다. 모든 perchlorate anion은 각각 두가지 위치로 disorder되어 있다. 양이온과 음이온들은 물분자들을 포함한 수소결합들로 결합되어 결정을 이루고 있다. 양이온내의 모든 N-H가 모두 수소결합에 참여하고 있다.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.41-49
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• 1991

The reaction of molten urea with paraformaldehyde in sealed tubes has been examined, and the concentrations of the products obtained from this reaction have been contrasted to previous results from the identical reaction carried out in open beakers. In these studies, high performance liquid chromatography(HPLC) and nuclear magnetic resonance(NMR) spectroscopy were used to analyze the products formed in the reactions. These products were biuret, triuret, dimethylenetriurea, methylenediurea, and biuretmethyleneurea. The results from the HPLC analyses showed that the concentrations of dimethylenetriurea and methylenediurea in the reaction products increased as the amount of the paraformaldehyde starting material increased. However, the amount of biuret formed in the products decreased as the paraformaldehyde concentration was increased in the urea melt. The results from the NMR analyses showed that the $NH_2$ resonance frequencies for urea, methylenediurea, and dimethylenetriurea all occurred at approximately 5.6 ppm, while the $NH_2$ frequencies for biuret and triuret occurred at approximately 6.9ppm. In the case of biuret and triuret, NH protons absorb between 8.5 and 9.5 ppm, whereas the NH protons in methylenediurea and dimethylenetriurea absorb in the 6.5-6.6ppm region. The melt reaction seems to hold promise as a different technique for ureaform preparation in general.

• Polymer(Korea)
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• v.24 no.1
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• pp.72-81
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• 2000

Benzoic acid polyester/lactone polyol were synthesized by polycaprolactone 0201 as diol, trimethylolpropane as triol, adipic acid as dibasic acid, and benzoic acid as monobasic acid. Polyisocyanate prepolymer Desmodur N-100 of HDI-biuret type was used in this study. Two-component polyurethane coatings were prepared by blending benzoic acid polyester/polycaprolactone, polyisocyanate, wetting/dispersing agent, white pigment, and flowing agent. Various properties were examined on the film coated with the prepared polyurethane. They showed excellent physical properties such as abrasion resistance, accelerated weathering resistance, and yellowness index. They also showed good physical properties such as flexibility, impact resistance, 60$^{\circ}$ specular gloss, cross hatch adhesion, hydrocarbon resistance, and lightness index difference. Hardness of coating showed a little poor character. The introduction of polycaprolactone 0201 as diol in the polyurethane coatings improved the hydrocarbon resistance, impact resistance, and flexibility of coatings. According to the drying and curing behavior with the contents of benzoic acid, they seem to have reasonable coating properties such as drying time of 2 to 4 hours and pot-life time of 20 to 37 hours.

• Journal of the Korean Applied Science and Technology
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• v.15 no.2
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• pp.59-66
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• 1998

Two-packaged polyurethane coatings were prepared by blending benzoic acid lactone modified polyester polyol(BLMPs) and HDI-biuret. BLMPs were synthesized by polycondensation of benzoic acid, viscosity depression component, with 1,4-butanediol, adipic acid, and polycaprolactone polyol. Kinematic viscosity of BLMP was gradually decreased with increasing benzoic acid content in BLMP. The low viscosity of modified polyester has an advantage of making a high-solid content coatings. After the film was coated with the prepared polyurethane coatings and cured at room temperature, the various physical properties were measured. They showed good physical properties such as flexibility, impact resistance, cross hatch adhesion, yellowness index, and rust resistance. These advantages are the results of introducing polycaprolactone polyol.

• Polymer(Korea)
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• v.28 no.3
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• pp.273-280
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• 2004

Acrylic resins (ethyl methacrylate-2-hydroxypropyl methacrylate-n-butyl acrylate-acrylic acid EHBCs) containing 80％ of solid were synthesized. Then, high-solid coatings (ethyl methacrylate-2-hydroxypropyl methacrylate-n-butyl acrylate-acrylic acid/hexamethylene diisocyanate-biuret : EHBCNs) were prepared by curing of the acrylic resin with curing agent hexamethylene diisocyanate-biuret at room temperature. The cure time of prepared coatings EHBCN-4 (EHBC-4 : $T_{g}$ = $0^{\circ}C$) and EHBCN-7 (EHBC-7 : $T_{g}$ = 3$0^{\circ}C$), measured by rigid-body pendulum method, was recorded 6.2 hours and 4.5 hours, respectively. Dynamic viscoelastic experiment revealed the glass transition temperature of EHBCN-4 and EHBCN-7 to be $14^{\circ}C$ and $39^{\circ}C$, respectively. It was found that the adhesion and flexural properties among various properties of coatings were enhanced by the incorporation of caprolactone acrylate monomer into the acrylic resins.

• Korean Journal of Food Science and Technology
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• v.4 no.4
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• pp.235-238
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• 1972

A biuret method by Johnson and Craney (1971) was slightly modified and applied to the multiple analysis of nitrogen in brown rice. The results were compared with those by the dye-binding method to see if the former be applicable to the determination of higher nitrogen content in rice. The nitrogen content of rice samples ranged from $1.2{\sim}2.0%$. The correlation between biuret absorbance and nitrogen content was highly significant; its correlation coefficient being 0.841. The biuret method, however, showed rather lower correlation coefficient in case of high nitrogen samples.