Journal
of the University of Chemical Technology and Metallurgy, XXXV, 2000
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CHEMICAL TECHNOLOGIES
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PREPARATION OF GLYCIDYLMETHACRYLATE
I. Glavchev, Kr. Petrova
INVESTIGATION ON THE EXTRACTION OF ENCAPSULATED FUNGICIDES
AND INSECTICIDES
Iv.
Glavchev, Chr. Ivanova, Sl. Slavov
CHARACTERIZATION OF A NEW ANTIMICROBIAL SUBSTANCE “FLAVINOK”
A.Georgieva, P. Pavlov, B. Alexandrov, Chr. Ivanova,
M. Pankova
DEGREE OF WHITENESS – COLOR OF DYED POLYACRYLONITRILE
YARNS
A.Georgieva, D.Pishev, S.Veleva
PEAK-LIKE DEPENDENCE OF THE COEFFICIENT OF THERMAL EXPANSION - TEMPERATURE
I.
Glavchev, Kr. Petrova, M. Ivanova
MATHEMATICAL MODELLING OF THE PROCESS OF THE ELECTROCHEMICAL PRODUCTION OF
SODIUM HYPOCHLORITE
L. Petkov, Sv. Kamenova, K. Bochnakov
CORROSION RESISTANCE OF SOME METALS AND ALLOYS USED
IN MOLECULAR ELECTRONICS
L.Fachikov, H.Atanassov, L.Petkov
PREPARATION OF GLYCIDYLMETHACRYLATE
I. Glavchev, Kr. Petrova
|
University of
Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: ivgl@uctm.edu
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|
The raw material
for obtaining of glycidylmethacrylate (GMC) usually is methacrylic acid. Methylmethacrylate
is more suitable because it is less toxic. The potassium salt was obtained from
methylmethacrylate and KOH in the presence of copper pieces and after washing
with ether reacted with epichlorohydrine in the presence of catalysts quaternary
ammonium salts. The reaction lasted for 3 hours at 90-95oC. The optimal
conditions for obtaining of glycidylmethacrylate were determined.
Keywords:
glycidylmethacrylate, rate of substitution, order according catalysts
INVESTIGATION ON THE EXTRACTION OF ENCAPSULATED FUNGICIDES
AND INSECTICIDES
Iv. Glavchevx, Chr. Ivanovax, Sl. Slavovxx
|
xUniversity of
Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
xxCivil Defence – Varna
e-mail: ivgl@uctm.edu
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|
The kinetic of extraction by water of the fungicides
Cuprozin and Fundazol and insecticides Agria 1050 and B-58-EK, which are encapsulated
with epoxy resin Diepox 600 is studied. UV spectrophotometry is used in the
investigation. The rates of extraction and the quantity of the extracted toxic
compounds are determined. From the obtained data it is possible to determine
the danger for environment pollution from encapsulated toxic compounds.
Keywords:
fungicides, insecticides, epoxy resins, extraction, UV spectroscopy
CHARACTERIZATION OF A NEW ANTIMICROBIAL SUBSTANCE “FLAVINOK”
A.Georgieva,
P. Pavlov, B. Alexandrov, Chr. Ivanova, M. Pankova
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University
of Chemical Technology and Metallurgy,
8 Kl.
Ohridski, 1756 Sofia, Bulgaria
e-mail: bor.dad@mail.bg
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|
The
structure of a new antimicrobial agent named “Flavinok” is proved by means of
element
organic analysis, ultraviolet and infrared spectroscopy. Its molecular mass
and melting point are determined. The probable mechanism of the interaction
between the initial components, resulting in the obtaining of the new compound
is proposed.
Keywords: technology of chemical-pharmaceutical
remedies, antimicrobial agents, spectral methods of characterization
DEGREE OF WHITENESS – COLOR OF DYED POLYACRYLONITRILE YARNS
A.Georgieva, D.Pishev, S.Veleva
|
University
of Chemical Technology and Metallurgy
8,
Kl. Ohridski Blvd., 1756 Sofia, Bulgaria
E-mail:
pishev@uctm.edu
|
Received
18 October 2000
Accepted
20 November 2000
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The purpose of the
present study is establishing the influence of differences in the degrees of
whiteness of yarns of polyacrylonitrile fibers on the color properties of fabrics,
dyed with cationic dyes.
The
dyeing was done with Maxilon (Ci-Gy) dyes, independently and in thrichromie.
The color properties were determined using the Datacolor system.
It
was established that the varying degrees of whiteness influence the color properties
to different extent, depending on the type of dye used. The differences in the
degree of whiteness of PAN yarns influence their color properties after dyeing
to different degrees, according to the type of dye used. Through the use of
the instrumental method it has been established that lower degrees of whiteness
cause yellow cast and darker shading of the color.
Differences
in the degree of whiteness around 4% lead to a visually perceptive color difference,
objectively set at 2. The influence of differing degrees of whiteness of PAN
yarns on their color properties if they are to be used in the manufacturing
of fabrics, can be sufficiently reduced by the proper selection of color to
be obtained through dyeing.
Keywords: Degree of whiteness,
PAN-yarns, Cationic dyes.
PEAK-LIKE DEPENDENCE OF THE
COEFFICIENT OF THERMAL EXPANSION
- TEMPERATURE
I. Glavchev, Kr. Petrova, M. Ivanova
|
University of
Chemical Technology and Metallurgy
8 Kl. Ohridski, 1756 Sofia, Bulgaria
e-mail: ivgl@uctm.edu
|
|
Epoxy composites
with determined values of the coefficient of thermal expansion (CTE) were obtained
using a bisphenol A based epoxy resin with molecular weight 600 and 20% dibuthylphtalat,
different fillers and hardeners. The peak in the dependence CTE/temperature
was evaluate by the value D=((amax-amin)/amax).100, where amax and amin are 3xCTE. The results
from measurement of CTE for epoxy resins and composites were compared with values
for polymers, steels and alloys.
Keywords: coefficient of thermal expansion,
epoxy resins and composites, steels, alloys
MATHEMATICAL MODELLING OF
THE PROCESS OF THE ELECTROCHEMICAL PRODUCTION OF SODIUM HYPOCHLORITE
L. Petkov, Sv. Kamenova, K. Bochnakov
|
University of
Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: petkovv@uctm.edu
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|
Results of the investigation of the process of
electrochemical production of sodium hypochlorite with the purpose to determine
the mathematical relationship between some parameters of the process - current
density, temperature, current efficiency and mass of hypochlorite are reported.
For developing the mathematical models an optimum composite a plan
for two (m=2) independent factors was made.
The calculated values of the multiple relation
coefficient (R = 0.99)
and comparison of FT - criteria with F- number leads to the conclusion
that the models are significant.
Keywords:
optimum composite plan, multiple relation coefficient, dependent function.
CORROSION RESISTANCE OF
SOME METALS AND ALLOYS USED IN MOLECULAR ELECTRONICS
L.Fachikov, H.Atanassov, L.Petkov
|
University of
Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
e-mail: fachikov@uctm.edu
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|
The
corrosion behaviour of some metals and alloys employed in the molecular electronics
has been studied in mercury-rhodanate and sulphuric acid solutions by gravimetric
measurements. The tests have been performed upon conditions allowing both
contacts and no contacts with metallic mercury.
The results obtained
demonstrate high corrosion resistances of Mo in a mercury-rhodanate solution
as well as of Mo and alloys (12X18H9T
and 79HM)) in sulphuric acid solutions. The
data concerning the polarization of the metal surfaces upon the resistance
of the metals tested are reported.
Keywords: molecular electronics, corrosion, corrosion
resistance