Journal of the University of Chemical Technology and Metallurgy, XXXVIII, 2003, Book 1
ON THE APPLICATION AND ASSESSMENT OF SOME SPECIFIC TREATMENTS OF POLYESTER TEXTILE MATERIALS
A.Georgieva, B.Alexandrov, Chr.IvanovaADSORPTION OF HEAVY METAL IONS FROM SOIL IN THE PRESENCE OF NATURAL POLYMER PRODUCTS
S. Nenkova, E. TzolovaFIBROUS-WOOD SORBENT FOR ELIMINATION OF OIL POLLUTION
S. NenkovaSYNTHESIS OF AZOMETHINES OF N-ALKYL-2-AMINOBENZIMIDAZOLES AS POTENTIAL ANTIMICROBIAL PRODUCTS
K. Anichina, A. MavrovaSURFACE MODIFICATION OF NATURAL RUBBER LATEX FILMS BY PEG HYDROGEL COATING
T. Vladkova, E.-S. Jonsson, C.-G. GolanderKINETIC STUDY OF BLOCK COPOLYMERS BASED ON NYLON-6 AND FUNCTIONALIZED POLYISOPRENE
R. Filyanova, N. Toncheva, R. Mateva, R. VelichkovaHARDWOOD KRAFT PULP BLEACHING BY PERACETIC ACID
G. Simeonova, I. Valchev, S. NenkovaCALCULATION OF THE TEMPERATURE FLAMMABILITY LIMITS OF INDIVIDUAL HYDROCARBONS AND DESTILATED OIL FRACTIONS
II. TRANSFORMATION OF KALLINGERT-DAVIS EQUATION
Z.Zdravchev, J.Balgaranova, M.Christova, Ek.TcholakovaEFFECT OF MODIFIERS ON THE THERMAL STABILITY OF ALUMINA SUPPORT
D. Vladov, N. Kassabova, D. Stoyanova
ON THE APPLICATION AND ASSESSMENT OF SOME SPECIFIC TREATMENTS OF POLYESTER TEXTILE MATERIALS
A.Georgieva, B.Alexandrov, Chr.Ivanova
University of Chemical Technology and Metallurgy, 8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: angi@mail.bg
Received 27 December 2002
Accepted 7 January 2003
The aim of this work is to find a suitable substance imparting a prolonged effect, which can combine well with the newly synthesized anti-microbial agent "Flavinok" aiming to treat polyester textile materials, which can find application in medicine. The method of treatment is presented in brief. On the basis of the original conditions of the experiment a comparative assessment of the anti-microbial effect of the treated samples in dynamics has been made.
Keywords: anti-microbial substances, special treatment of textile materials, prolonged effect.
ADSORPTION OF HEAVY METAL IONS FROM SOIL IN THE PRESENCE OF NATURAL POLYMER PRODUCTS
S. Nenkova, E. Tzolova
University of Chemical Technology and Metallurgy, 8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: nenkova@uctm.edu
Received 19 December 2002
Accepted 5 February 2003
The adsorption ability of the soil towards the ions of heavy metals in the presence of technical hydrolysis lignin (THL) and the compost from THL and avian dung is examined.
The spreading of THL or the compost from THL and avian dung in cinnamon wood soil increases adsorption ability of this mixture towards Pb2+, Cu2+ and Cd2+.
The results may find practical realization in the agriculture.
Keywords: lignin, avian dung, cinnamon wood soil, heavy metals, adsorption ability.
FIBROUS-WOOD SORBENT FOR ELIMINATION OF OIL POLLUTION
S. Nenkova
University of Chemical Technology and Metallurgy, 8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: nenkova@uctm.edu
Received 19 December 2002
Accepted 2 February 2003
The possibility for elimination of oil pollution is examined by using fibrous-wood sorbents on the basis of short wool fibers, technical hydrolysis lignin, wood saw-dust and barks.
The sorption ability of waste fibrous-wood materials has been investigated by determination of Chemical Oxygen Demand (COD).
Keywords: oil sorbents, oil floods, waste fibers, saw-dusts, barks, lignin.
SYNTHESIS OF AZOMETHINES OF N-ALKYL-2-AMINOBENZIMIDAZOLES AS POTENTIAL ANTIMICROBIAL PRODUCTS
K. Anichina, A. Mavrova
University of Chemical Technology and Metallurgy, 8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: anichina@ abv.bg
Received 27 January 2003
Accepted 25 February 2003
A series of (1-alkylbenzimidazol-2-yl)-N-(piperonalydene-)
amines and (1-alkylbenzimidazol-2-yl)-N-(5-nitrothenylidene-2-)
amines have been synthesized by a reactions of N-alkyl-2-aminoben-zimidazoles with piperonal and 5-nitro-2- thiophenecarboxaldehyde. A literature study supports the pharmaceutical interest in this class of compounds as potential antimicrobial agents .
IR, 1H-NMR- spectra as well as analytical thin layer chromatography confirm the chemical structures and the purity of the new compounds.
Keywords: azomethines, benzimidazoles, heterocycles, synthetic methods.
SURFACE MODIFICATION OF NATURAL RUBBER LATEX FILMS BY PEG HYDROGEL COATING
T. Vladkova, E.-S. Jonsson, C.-G. Golander
University of Chemical Technology and Metallurgy, 8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: TGV@uctm.edu
Institute for Surface Chemistry, Stockholm
Received 21 March 2003
Accepted 9 June 2003
Hydrogel coatings of monoacrylated PEG methylethers with different molecular weights were attached to natural rubber latex films and cross-linked with haxandioldiacrylate (HDDA) by UV-polymerization. The solvent choise was critical for the coating adhesion. Good wetting by water was found for all coatings. The wetting, evaluated with the water contact angles, correlated with the surface oxyethylene chains density, evaluated with the ESCA =C-O-/ -CH2-ratio obtained from the C(1s) peak. As measured by the ESCA N(1s) peak, bovin serum albumin (BSA) formed thick adsorbates on the natural rubber latex films. However, very thin protein adsorbates were found on the PEG coated surfaces. A strong correlation was demonstrated between a low protein adsorption and a high substrate =C-O-/-CH2-ratio. The PEG coated natural rubber latex films demonstrated also a very low cell and plattelet adhesion.
Keywards: natural rubber, PEG hydrogels coating, UV curing, wettability, protein adsorption, cell adhesion, plattelet adhesion
KINETIC STUDY OF BLOCK COPOLYMERS BASED ON NYLON-6 AND FUNCTIONALIZED POLYISOPRENE
R. Filyanova, N. Toncheva, R. Mateva, R. Velichkova
University of Chemical Technology and Metallurgy, 8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: rpm@uctm.edu
BAS, Institute of Polymers, "Acad. Georgi Bontchev" St.Bl. 103-A, 1113 Sofia, Bulgaria
Received 21 March 2003
Accepted 9 June 2003
Block copolymers of Nylon-6 (N-6) and polyethyelene oxide-polyisoprene-polyethylene oxide copolymers (PI/PEO) have been synthesized via activated anionic polymerization. PI/PEO terminated with isophorone diisocyanate (5-isocyanate1-isocyanatomethyl-1,3,3- trimethylcyclohexane) and blocked with hexanelaktam (HL) have been used as macroactivators (PACs). The polymerization proceeded in the presence of the sodium salt of hexanelactam (Na-HL) as an initiator and PACs which act as elastificators for Nylon-6. The effects of the soft PAC blocks (concentration and molecular weight) on the polymerization kinetics at different temperatures and on the molecular weights of the block copolymers obtained were studied. The copolymers were isolated and characterized using IR and 1H NMR spectroscopies.
Keywords: block copolymers, kinetics, anionic polymerization, synthesis.
HARDWOOD KRAFT PULP BLEACHING BY PERACETIC ACID
G. Simeonova, I. Valchev, S. Nenkova
University of Chemical Technology and Metallurgy, 8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: ivoval@uctm.eduReceived 27 May 2003
Accepted 30 May 2003
The process of kraft pulp bleaching has undergone considerable changes in recent years. These changes are primarily an effort on the part of the mill to reduce the impact on the environment because of strict requirements introducing. Environment pollution by chlorine containing organic substances is unfavourable. As a result the bleaching technologies have been developed very fast and new bleaching agents are introduced. One of the possibilities for chlorine free bleaching is organic and inorganic peroxyacids using.
The aim of the present investigations is to study the depen-dences of hardwood kraft pulp peracetic acid bleaching.
Industrial alkali extracted under oxygen pressure (EO) bleached pulp from Svilosa Company is used. The optimal pH range and the charge of bleaching agent are found. The temperature-time regime of the peracetic bleaching process is studied at the optimal conditions. The influence of the bleaching conditions on the pulp brightness and strength properties is examined.
The obtained results indicate that the use of peracetic acid as a bleaching agent for hardwood kraf pulp is expedient at the found optimal conditions.
Keywords: bleaching, peracetic acid, hardwood kraft pulp
CALCULATION OF THE TEMPERATURE FLAMMABILITY LIMITS OF INDIVIDUAL HYDROCARBONS AND DESTILATED OIL FRACTIONS
II. TRANSFORMATION OF KALLINGERT-DAVIS EQUATION
Z.Zdravchev, J.Balgaranova, M.Christova, Ek.Tcholakova
University of Chemical Technology and Metallurgy, 8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: zdravchev@uctm.eduReceived 18 May 2003
Accepted 20 May 2003
The assessment of the fire hazard of chemical raw materials, products and processes in the chemical industry is based on a variety of parameters. The elements of essential significance here are the temperature flammability limits (TFL). The experimental determination of these parameters is a labor consuming and in certain conditions even an impossible operation.
Following our previous investigation, analytical relationships are derived for the calculation of the temperature flammability limits of individual hydrocarbons present in the distillate oil fractions. Aimed at this the Kalingert-Davis equation, which expresses the analytical dependence of the saturated vapor pressure on the temperature is transformed. Using the derived analytical relationship, the upper and lower flammability limits with sufficient practical accuracy are determined.
Keywords: Temperature flammability limits, calculation, hydrocarbons, distillate oil fractions
EFFECT OF MODIFIERS ON THE THERMAL STABILITY OF ALUMINA SUPPORT
D. Vladov, N. Kassabova, D. Stoyanova
University of Chemical Technology and Metallurgy, 8 Kl. Ohridski, 1756 Sofia, Bulgaria
Institute of General and Inorganic Chemistry, BAS
Acad. G.Bonchev str., block 11, Sofia 1113, Bulgaria
E-mail: grancharov@uctm.eduReceived 24 March 2003
Accepted 30 April 2003
The influence of modifying additives (CaO, Cr2O3) on -Al2O3 in the process of formation and thermal treatment is studied with the aim of obtaining an appropriate structure of carriers having a wide range of industrial application. The method of mechanically mixing the ingredients in synthesizing the carriers is applied. The initial mass of aluminum hydroxide is precipitated on a medium of an aqueous suspension of precipitate (CaCO3). The ratio Al2O3/CaO is 90/10. The chromium containing compound in the carrier mass is Cr2O3, introduced as an aqueous solution of chromium anhydride. The Cr2O3 content in the carrier varied from 1.5 to 15 %mass. Carrier forming is carried out by means of a tabletting press machine at a pressure of 1.5 MPa.cm-2. The carrier thus obtained is calcinated at two different temperatures of 873 K and 1073 K. The carried out X-ray analysis established that the precipitated pseudoboehmit phase is highly dispersed. With the increase of the Cr2O3 content in the carrier, the degree of crystallinity of the phases tends to increase. The presence of 1.5 %mass of Cr2O3 in the alumina mass leads to a sharp increase of the carrier mechanical strength up to 700x105 N.m-2, while the specific surface area remains sufficiently high - 90 m2.g-1.These characteristics ensure the suitability of the carriers for the supported type of catalysts.
Keywords: carrier, catalyst, dispersity, phase composition.
