Journal of the University of Chemical Technology and Metallurgy, XXXVIII, 2003, Book 2
CHEMICAL TECHNOLOGIES
QUO VADIS GLOBAL SUSTAINABLE DEVELOPMENT? THE JOHANNESBURG SUMMIT AND BEYOND
B. NathSYNTHESIS, STRUCTURE AND ANTIHELMINTIC ACTIVITY OF SOME NOVEL DERIVATIVES OF THIAZOLO[3,2-a]-BENZIMIDAZOLE-3(2H)-ONE
A. Mavrova, K. Anichina, D. VuchevSYNTHESIS AND PRELIMINARY SCREENING OF NEW N-PYRROLYLCARBOXYLIC HYDRAZIDES AS PROSPECTIVE ANTITUBERCULOSIS AGENTS
A. Bijev, D. Yaneva, A. NankovNEW PYRROLECARBOXYLIC HYDRAZONES AS POTENTIAL ANTITUBERCULOSIS AGENTS
A. Bijev, S. Vladimirova, A. NankovON THE SYNTHESIS AND APPLICATION OF SOME NEW BIFUNCTIONAL REACTIVE DYES
T. Konstantinova, P. PetrovaON THE PROPERTIES OF SOME NAPHTHALIMIDE DYES AN THEIR COPOLYMERS WITH METHYLMETHACRYLATE
Temenoushka Konstantinova, Radoslava LazarovaBIOELECTROCATALYTICAL SYNTHESIS OF GLUCONIC ACID
M. StoytchevaOXIDATIVE STABILITY OF LOW-SULFUR DIESEL FUELS IN PRESENCE OF ORGANOMETALLIC COMLEXES
T. Hadjyiski, K. StanulovIMPROVEMENT OF OXIDATION STABILITY OF BASE TRANSFORMER OIL
L.Topalova1, K.Nakov1, C. .Jossifov2ENERGY SAVING DURING SEPARATION OF AZEOTROPIC MIXTURE CONTAINING ACETONE
N. Popov, K. PopovCHOICE OF A METHOD FOR INVESTIGATION OF CONSTANT MAGNETIC FIELDS INFLUENCE ON SUPERMOLECULAR STRUCTURE OF CRYSTALLIZING ELASTOMER FILMS
I. Petrova, N. Dishovsky, N. TipovaVULCANIZATION OF UNFILLED NATURAL RUBBER BASED COMPOUNDS IN CONSTANT MAGNETIC FIELD
L. Miladinov1, K. Ruskova1, N. Dishovsky1, S. Borros2, N. Shoylev1TEMPERATURE-RESPONSIVE POLYMER MATERIALS CONTAINING POLY(VINYL METHYL ETHER) SEGMENTS
D. Markova, D. Christova, R. VelichkovaON THE ACTIVITY OF CATALYSTS FOR RING OPENING AND CONDENSATION REACTIONS
I.Glavchev1, D.Pavlov2, N.Gospodinova2, K.Petrova3, I.Devedjiev3INFLUENCE OF MALEATED POLYPROPYLENES ON THE MECHANICAL PROPERTIES AND DEFORMATION MECHANISMS OF RUBBER-TOUGHENED AND WOOD-FILLED POLYPROPYLENE COMPOSITES
V. Hristov, S. VasilevaUSE OF POLYMERS IN THE PROCESSING OF CERAMIC SUPERCONDUCTOR/ POLYMER COMPOSITES
G. Kotzev, S. Djoumaliisky, N. Touleshkov, L. Lakov, K. TonchevaWIDE-ANGLE X-RAY STUDIES ON FOAMED POLYOLEFIN BLENDS INJECTION-MOLDED BY GAS-COUNTERPRESSURE PROCESS
S. Djoumaliisky1, P. Zipper2THERMOSTIMULATED REVERSIBLE SWELLING OF POLYZWITTERIONIC HYDROGELS
I. Kamenova, A. Tzoneva, V. Georgieva, G. GeorgievPRODUCTION OF ACRYLIC COPOLYMER SOLUTIONS USABLE FOR A PREPARATION OF THE NAIL LACQUER COMPOSITIONS
E. Kamenska, G. GeorgievTHERMOPHYSICAL PROPERTIES OF COTTON FABRICS FINISHED WITH DIFFERENT CELLULASES
R. Betcheva, M. StamenovaINVESTIGATION ON GRUS MINERAL SORBENT WITH IMPROVED ADSORPTION PROPERTIES TOWARDS DYE SOLUTIONS
S. Veleva, A. Georgieva, D. PishevOPTIMIZATION OF THE COTTON FABRIC IMPREGNATION PROCESS
V. Vassileva, D. Damgaliev, D. BudurovaCOMPARISON OF SOME UNHAIRING METHODS OF SHEEP SKINS
M. Koleva, D. Ivanova, N. Pepeldjiska, L. Vezenkov, D. DanalevKINETICS OF THE PROCESSES IN CHEMICAL TRANSFORMATIONS OF HOLOCELLULOSE UNDER THE CONDITIONS OF SULPHATE COOKING OF WOOD
G. Antova1, E. Valcheva2ANAEROBIC COMPOSTING OF THE BIODEGRADABLE FRACTION OF MUNICIPAL SOLID WASTE
J. RobinsonLANDFILL BIOGAS GENERATION DEPENDING ON THE SOLID WASTE COMPOSITION – CASE STUDIES
V. Mihajlovich, B. Koumanova, S. StoyanovSEA WATER MICROFILTRATION CHARACTERISTICS
R. StoichevaCALCULATION OF THE TEMPERATURE FLAMMABILITY LIMITS OF INDIVIDUAL HYDROCARBONS AND DISTILLATE OIL FRACTIONS
III. REFORMATION OF THE MAXWELL EQUATION
Z. Zdravchev, J. Balgaranova, M. Christova, E. Tcholakova
QUO VADIS GLOBAL SUSTAINABLE DEVELOPMENT? THE JOHANNESBURG SUMMIT AND BEYOND
B. Nath
European Center for Pollution Research
Unit 1A, 289 Cricklewood Broadway, London NW2 6NX, UK
E-mail: BhaskarNath@aol.com
Received: 4 June 2003
Accepted 23 September 2003
It was at the Rio Earth Summit of 1992 that sustainable development was pushed to the top of the global environmental agenda as the only developmental model that could ensure both intergenerational and intragenerational equity in terms of global environmental capital. However, despite Rio’s Agenda 21, which set out in considerable detail a blueprint of how global sustainable development could be achieved through local action, in the ten years between Rio and the World Summit on Sustainable Development (WSSD), held in Johannesburg in 2002, negative progress towards sustainable development has in fact been made in many areas of global environmental concern. Indeed, this was acknowledged at the WSSD which identified poverty eradication and greater provision of educational opportunities, especially in developing countries, as key to achieving global sustainable development.
However, it is argued in this paper that neither poverty eradication nor greater provision of educational opportunities could deliver global sustainable development, and neither could science or technology. It is argued, furthermore, that the main obstacle to global sustainable development is the prevailing freemarket economic system itself, which works only when there is uninterrupted growth in production and consumption of goods and services. Finally, it is argued that if the international community is at all serious about achieving even a modest degree of global sustainability, then current patterns of unsustainable development, created by increasingly consumptive and polluting life-styles that degrade the environment, must be reversed; and that this could only be accomplished by teaching the young genuinely environment-respecting moral values.
Keywords: sustainable development, Johannesburg earth summit, education, moral values.
SYNTHESIS, STRUCTURE AND ANTIHELMINTIC ACTIVITY OF SOME NOVEL DERIVATIVES OF THIAZOLO[3,2-a]-BENZIMIDAZOLE-3(2H)-ONE
A. Mavrova, K. Anichina, D. Vuchev
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: anichina@ abv.bg
Received:20 September 2003
Accepted 1 October 2003
The preparation of 2-arylidene-thiazolo[3,2-a] benzimidazole-3(2H)-ones involves three steps starting from (un)substituted in benzene ring 2-mercapto-1H-benzimidazoles. The IR- and 1H-NMR spectral data confirm the chemical structures of the new compounds.
The synthesized thiazolobenzimidazoles derivatives were subjected to testing anti-parasitic activity on the helminth Trichinella spiralis in vitro as well as in vivo on experi-mentally infected white mice.
Keywords: 2-substituted-thiazolo[3,2-a]benzimidazole-3(2H)-ones, 2-mercapto-1H-benzimidazoles, antihelmintic activity.
SYNTHESIS AND PRELIMINARY SCREENING OF NEW N-PYRROLYLCARBOXYLIC HYDRAZIDES AS PROSPECTIVE ANTITUBERCULOSIS AGENTS
A. Bijev, D. Yaneva, A. Nankov
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail:a.bijev@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
New hydrazides of N-pyrrolylcarboxylic acids and their hydrazones with 5-nitrofurfural were synthesized as structural analogs of known bioagents and tuberculostatics. The preliminary results of the antituberculosis screening showed that the hydrazides of N-pyrrolylcarboxylic acids displayed antitubercul-osis activity unlike the acids themselves and compound 3 1-hydrazinocar-bonylmethyl-2-methyl-5-(4-nitro-phenyl)-1H-pyrrole-3-carboxylic acid ethyl ester possessed the highest inhibiting potency (34 % at concentration 6.25 ?g/ml) against M. tuberculosis. The results obtained encouraged the extension of the selected approach as a strategy in the global engagement against the striking back tuberculosis.
Keywords: antituberculosis agents, pyrrole, hydrazides, hydrazones, synthesis.
NEW PYRROLECARBOXYLIC HYDRAZONES AS POTENTIAL ANTITUBERCULOSIS AGENTS
A. Bijev, S. Vladimirova, A. Nankov
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: a.bijev@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
Six new pyrrole hydrazones are synthesized as structural analogs of known tuberculostatics through condensation of three various pyrrolecarboxylic hydrazides. Isatin, salycilic and indole aldehydes were used as carbonyl reaction partners. The series of new compounds displayed inhibiting activity against M. tuberculosis and the compound 2,4- dimethyl-1H- pyrrole-3-carboxylic acid (2-oxo-1,2-dihydro-indol-3-ylidene) hydrazide possessed the highest potency (59 %).
Keywords: antituberculosis agents, hydrazones, pyrrole, synthesis.
ON THE SYNTHESIS AND APPLICATION OF SOME NEW BIFUNCTIONAL REACTIVE DYES
T. Konstantinova, P. Petrova
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: ppolya@abv.bg
Received:30 September 2003
Accepted 15 October 2003
The synthesis of eight bifunctional reactive monochloro-triazine dyes and their intermediates was investigated. Three monochlorotriazine reactive dyes, a red, an orange and a blue one, applied in the practice as basic chromophores were chosen. The quantitative thin layer chromatography (TLC) to monitor the synthesis was applied. Cotton fabrics were dyed and their colourimetric characteristics were measured. The copolymerization of the dyes with acrylamide (ACA) was studied. The copolymers with an intense colour that is stable to solvents extraction were obtained thus presenting a possibility for an environmental more tolerant application of the dyes.
Keywords: bifunctional reactive triazine dyes, polymerisable dyes, inherently colored polymers of acrylamide.
ON THE PROPERTIES OF SOME NAPHTHALIMIDE DYES AN THEIR COPOLYMERS WITH METHYLMETHACRYLATE
Temenoushka Konstantinova, Radoslava Lazarova
Organic Synthesis Department, University of Chemical Technology & Metallurgy,
8 Ohridsky str., Sofia 1756, Bulgaria, E-mail: konst@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
Nine polymerizable dyes, derivatives of N-allylnaphthalimide were investigated. On the basis of the spectrophotometric investigations of the dyes in different solvents it can be concluded that the charge transfer transition is ?? ?*. Textile samples of polyamide were dyed in bright fluorescent yellow-greenish colours. At radical copolymerization of the dyes with MMA, intensively coloured, highly fluorescent copolymers were obtained. The chemical bond dye-polymer was proved. It was determined that over 50 % of the initially put dye was incorporated in the polymer chain. Photostability of the dyes in solution and in the copolymer was investigated during irradiation with UV ligth and the connection between this property and the dye structure was discussed.
Keywords: polymerizable dyes, naphthalimide derivatives, photostability
BIOELECTROCATALYTICAL SYNTHESIS OF GLUCONIC ACID
M. Stoytcheva
University of Mining and Geology “St. Ivan Rilski”, 1700 Sofia, Bulgaria
E-mail: margarita@mgu.bg
Received:30 September 2003
Accepted 15 October 2003
A bioelectrocatalytical method for gluconic acid and respectively for calcium gluconate production, representing an interest for the pharmaceutical industry, has been proposed. For this purpose, an electrode with immobilized by covalent bonds on its surface glucoseoxidase, catalyzing the oxidation of the glucose in gluconic acid in presence of the mediator p-benzoquinone, has been used. The effect of the variation of the concentration of the enzyme, the substrate and the mediator, as well as of the electrode rotation speed, pH and the temperature has been studied in order to optimize conditions of gluconic acid obtaining with a high yield.
Keywords: bioelectrocatalytical synthesis, glucoseoxidase electrode, gluconic acid.
OXIDATIVE STABILITY OF LOW-SULFUR DIESEL FUELS IN PRESENCE OF ORGANOMETALLIC COMLEXES
T. Hadjyiski, K. Stanulov
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: ceco@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
The organometallic complexes are compounds of coordinately linked metal or mixture of two metals (Cu, Co, Fe, Pb, Mn, etc.) with hydrocarbone chain containing at least two functional groups (-OH, -NH2 ,etc.). In the medium of hydrotreated and practically without natural inhibitors of oxidation diesel fuels, the catalytic effect of these complexes on the stability of the fuels during their storage, handling and exploiting is essential.
The aim of this paper was to investigate the oxidative stability of low-sulfur diesel fuel in the presence of laboratory synthesized organometallic complex containing copper.
The additive was prepared on the base of nonylphenol, ethylenediamine and paraformaldehyde. Complexing agent was copper carbonate.
The investigations were carried out using gasometric installation at 1000C and additive’s concentration in the fuel in the range of 40 – 645 ppm. The induction period, the quantity of consumed oxygen, the rate of oxidation and the content of hydroperoxides in the mixture were the parameters determined. “Ionol” (2,6-di-tert-butyl, 4-methylphenol) with concentration 35 ppm was used as an inhibitor of oxidation.
It was established that the fuel’s oxidation was catalyzed by the additive concentration up to 200 ppm and was inhibited at higher concentration. The antioxidative effect of the organocopper complex at the presence of 35 ppm “Ionol” is increasing.
These investigation give an opportunity for determination of optimal concentrations of organometallic complexes in the composition of low-sulfur fuels and their stabilization using antioxidative additives.
Keywords: diesel fuels, organometallic complexes, oxidative stability, additives.
IMPROVEMENT OF OXIDATION STABILITY OF BASE TRANSFORMER OIL
L.Topalova1, K.Nakov1, C. .Jossifov2
1University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
2Institute of Polymers, Bulgarian Academy of Sciences,
Acad. G. Bonchev Str. Bl. 103-A, 1113 Sofia
E-mail: knakov@abv.bg
Received:30 September 2003
Accepted 15 October 2003
The paper reports on the possibility to use some inhibitors of radical processes as antioxidation additives to transformer oils. The additives used are poly(9,10-dihydroanthracene-9,10-diylidene) and 2,2,6,6-tetramethyl-4-piperidone. They are known to act as inhibitors of thermodestruction of polymers. The investigations have shown that the antioxidation properties of these products are close to the ones of the wide-spread additives ionol and Hitec 566.
Keywords: Transformer oil, antioxidant additives, oxidation stability.
ENERGY SAVING DURING SEPARATION OF AZEOTROPIC MIXTURE CONTAINING ACETONE
N. Popov, K. Popov
Refining and Petrochemistry Institute,
LUKOIL-NEFTOCHIM, Bourgas, Bulgaria
E-mail: npopov@neftochim.bg
Received:30 September 2003
Accepted 15 October 2003
The main method for commercial production of phenol and acetone is the cumene oxidation to cumene hydroperoxide and cleavage of the latter to phenol and acetone. In this technology the basic compounds are clarified a lot of azeotropic mixtures. The process consumes a great deal of energy and this was the reason for investigation of the feasibility to optimize the separation. A new technological scheme for clarifying of acetone that is commercialized in the “Phenol and acetone” plan in LNB is presented. Besides the significant energy and chemicals savings the quality of the resultant acetone has been improved too.
Keywords: production, acetone, energy saving technological scheme.
CHOICE OF A METHOD FOR INVESTIGATION OF CONSTANT MAGNETIC FIELDS INFLUENCE ON SUPERMOLECULAR STRUCTURE OF CRYSTALLIZING ELASTOMER FILMS
I. Petrova, N. Dishovsky, N. Tipova
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: irena_parvanova@yahoo.com
Received:30 September 2003
Accepted 15 October 2003
During magnetic modification the elastomers are being treated with magnetic fields to obtain a desired supermolecular structure. This treatment provides preconditions needed for purposeful change and control of all their structure sensitive properties. The aim of this study is to choose a method – sufficiently precise, sensitive and accessible for evaluation of the modifying effect of different in characteristics magnetic fields on crystallizing chloroprene rubber. Two methods - specific volume resistivity measurement and photocurrent intensity measurement - were compared by Fischer-criterion. It was found by analysis and comparison of variances that the photocurrent intensity measurement gives better results in respect to their reproducibility. This method is more suitable for the evaluation of the modifying effect of magnetic fields on crystallizing elastomer films.
Keywords: magnetic modification, elastomers, supermolecu-lar structures.
VULCANIZATION OF UNFILLED NATURAL RUBBER BASED COMPOUNDS IN CONSTANT MAGNETIC FIELD
L. Miladinov1, K. Ruskova1, N. Dishovsky1, S. Borros2, N. Shoylev1
1University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
2Institut Quimic de Sarria-Universitat Ramon Llul, 08017 Barcelona, Spain
E-mail: lmiladinov@yahoo.com
Received:30 September 2003
Accepted 15 October 2003
The influence of a constant magnetic field with an induction of 0,20 T on the vulcanization process of unfilled natural rubber based compounds was investigated by specially designed laboratory equipment. The influence was monitored by measuring volume resistivity, mechanical properties and degree of swelling of obtained vulcanizates.
It was found that the application of a constant magnetic field leads to increasing of the volume resistivity and tensile strength and decreasing of the degree of swelling. The magnetic field shows a well-expressed accelerating action on the process of vulcanization, as well as an influence on the vulcanization net characteristics.
Keywords: magnetic field, natural rubber, vulcanization.
TEMPERATURE-RESPONSIVE POLYMER MATERIALS CONTAINING POLY(VINYL METHYL ETHER) SEGMENTS
D. Markova, D. Christova, R. Velichkova
Institute of Polymers, BAS,
Acad. G. Bonchev St. 103A 1113 Sofia, Bulgaria
e-mail: rumivel@polymer.bas.bg
Received:30 September 2003
Accepted 15 October 2003
Temperature-responsive interpenetrating polymer networks (IPN’s) have been obtained via crosslinking of poly(vinyl alcohol) (PVA) in the presence of the temperature-sensitive linear polymer poly(vinyl methyl ether) (PVME). As a second component commercial PVME was used as well as PVME-co-PVA copolymer, synthesized by Williamson etherification reaction of poly(vinyl acetate) with methyl iodide. The thermo-responsive properties of the corresponding hydrogels have been evaluated by measuring the equilibrium swelling degree as a function of temperature. It has been shown that considerable and reversible shrinkage of the hydrogels obtained occurs when increasing the temperature from 25 to 80 ºC.
Keywords: temperature-responsive polymers and hydrogels; LCST; swelling, PVA, PVME.
ON THE ACTIVITY OF CATALYSTS FOR RING OPENING AND CONDENSATION REACTIONS
I.Glavchev1, D.Pavlov2, N.Gospodinova2, K.Petrova3, I.Devedjiev3
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
2University of Rousse “Angel Kanchev”(Rousse),
8 Studentska Str.,Rousse,Bulgaria
3Bulgarian Academi of Science, Sofia, Bulgaria
E-mail: ivgl@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
The activity of several catalysts was investigated in ring opening and condensation reactions. The rates of ring opening reactions of trioxane and of phtalic, maleic anhydrides and bisphenol A based epoxy resin were obtained from the dependences yield of polyoxymethylene/time of polymerization or degree of curing/time of heating. The catalysts for polymerization of trioxane were Ziegler-Natta systems. For the ring opening reactions of anhydrides and epoxy resin the catalysts were metal salts or phosphorus containing compounds, some of which had not been described before. The catalysts for condensation of phthalic anhydride and i-octanol and for polycondensation of dicarboxylic acids, polyols and i-octanol were metal salts and titanium alcoholates. The rate of the reactions were calculated from the dependences acid number/time. In all cases have dependence between the activity of the catalysts and the ionity of their molecules.
Keywords: catalysts, ring opening reaction, condensation, ionity.
INFLUENCE OF MALEATED POLYPROPYLENES ON THE MECHANICAL PROPERTIES AND DEFORMATION MECHANISMS OF RUBBER-TOUGHENED AND WOOD-FILLED POLYPROPYLENE COMPOSITES
V. Hristov, S. Vasileva
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: velichko_hristov@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
Mechanical properties and deformation mechanisms of polypropylene (PP)/wood fiber (WFb) and rubber-toughened PP composites modified with maleated polypropylene as compatibilizer have been studied. The poorer mechanical properties of unmodified composites are due to poor adhesion and worse stress transfer through the interface. The E-modulus, yield stress as well as impact strength can be improved by adding maleated PP’s in the composites. Scanning electron microscopy (SEM) and High voltage electron microscopy (HVEM) were performed to study the morphology and microdeformation behavior of the investigated composites.
Keywords: polypropylene composites, maleated polypropylene, mechanical properties, deformation mechanisms.
USE OF POLYMERS IN THE PROCESSING OF CERAMIC SUPERCONDUCTOR/ POLYMER COMPOSITES
G. Kotzev, S. Djoumaliisky, N. Touleshkov, L. Lakov, K. Toncheva
Institute of Metal Science – BAS,
67 Shipchenski Prohod St., 1574 Sofia, Bulgaria
E-mail: kotzev@ims.bas.bg
Received:30 September 2003
Accepted 15 October 2003
The use of polymers in the processing of ceramic superconductor/ polymer composites (CS/PC) aims at an increase of the productivity of forming and on the other hand - at preparing of articles with complex shape, stable to mechanical and chemical treatments. A review of different techniques used for the production of ceramic superconductor/ polymer composites and assemblies is present: impregnation of porous ceramic samples with polymerizing monomers or thermoset resins cured by the action of temperature or chemical agents; compression molding of polymer-ceramic mixtures in powder form; preparation of conductive polymer/ ceramic superconductor structures. The advantages and the limitations of the different techniques and materials used are discussed.
Keywords: polymer-ceramic composites, superconductivity.
WIDE-ANGLE X-RAY STUDIES ON FOAMED POLYOLEFIN BLENDS INJECTION-MOLDED BY GAS-COUNTERPRESSURE PROCESS
S. Djoumaliisky1, P. Zipper2
1 Institute of Metal Science, BAS,
1574 Sofia, Bulgaria,E-mail: str.djum@ims.bas.bg
2 Institute of Chemistry, University of Graz, 8010 Graz, Austria
Received:30 September 2003
Accepted 15 October 2003
Blends from i-PP and LDPE were prepared using a twin-screw extruder Brabender DSE 35/17D at composition ratios of 0/100, 25/75, 50/50, 75/25 and 100/0, into which 0.5 wt. % blowing agent was added. Specimens composed of three co-axial cylinders differing in diameter and length, were injection molded by gas-counterpressure process. Cross-sections cut from the middle of each cylinder were investigated by wide-angle X-ray scattering (WAXS) in a two-circle goniometer. The raw data were presented in 2D intensity maps. The comparison of the results derived from the maps for different PP/PE blends shows differences in the orientation behavior of monoclinic a-PP and orthorhombic PE, distribution of ß -PP, and crystallinity depending on blend composition, sample configuration and macrostructure of the moldings
Keywords: foamed polyolefin blends, WAXS, orientation, distribution of ß-PP, crystallinity.
THERMOSTIMULATED REVERSIBLE SWELLING OF POLYZWITTERIONIC HYDROGELS
I. Kamenova, A. Tzoneva, V. Georgieva, G. Georgiev
University of Sofia,
1, J. Bourchier, 1164 Sofia, Bulgaria;
E-mail: irena_kamenova@yahoo.com
Received:30 September 2003
Accepted 15 October 2003
The thermostimulated hysteresis of poly(N,N-dimethylamino propylacryloyl amidopropylsulfonat) (PDMAPS) hydrogel was determined. The hysteresis dependencies on the time the dry network was swollen at the initial temperature and the time the network has been kept at each temperature where the swelling ratio Q is measured were estimated. The hysteresis loop area decreases as the network approaches its equilibrium swelling ratio Qeq. This is explained in terms of the different content of “zip” - clusters, varying in size, structural perfection and strength, in the initial network. These “zip”-clusters, acting as physical junctions of a physical network formed additionally to the chemical one, could be destructed either by elevated temperature and/or by the solvent molecules solvatation action.
Keywords: polyzwitterionic hydrogels, hysteresis loop, thermostimulated reversible swelling.
PRODUCTION OF ACRYLIC COPOLYMER SOLUTIONS USABLE FOR A PREPARATION OF THE NAIL LACQUER COMPOSITIONS
E. Kamenska, G. Georgiev
University of Sofia,
1, J. Bourchier, 1164 Sofia, Bulgaria;
E-mail: kamenska@chem.uni-sofia.bg
Received:30 September 2003
Accepted 15 October 2003
The copolymers of methyl methacrylate (MMA) with butyl methacrylate (BMA) and of MMA with 2-ethylhexylacrylate (EHA) are synthesized in a butyl acetate (BA)- xylene (X) mixed solvent by radical copolymerizations, reaching conversions 98.96 % and 99.39 %, respectively. These values permit directly use of the copolymer solutions of the nail polish compositions. The MMA and EHA relative reactivities in a BA/X mixed solvent (volume ratio 3/2) are determined for the first time.
Keywords: comonomer relative reactivities, a lacure resin.
THERMOPHYSICAL PROPERTIES OF COTTON FABRICS FINISHED WITH DIFFERENT CELLULASES
R. Betcheva, M. Stamenova
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: betcheva@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
The aim of this work is to study the influence of cellulase finishing on the physicothermal parameters of white and reactive dyed cotton fabrics in order to reveal the effect of different cellulases. Enzymatic hydrolysis was carried out with different cellulases e.g. total crude (TC) and cellulases enriched of endogluganase (EG) and cellobiohydrolase (CBH). Five basic static and dynamic physicothermal characteristics were determined through computer controlled instrument Alambeta. Heat conductivity, thermal absorption, thermal resistance, heat flow and sample thickness of white and pre-dyed specimens were measured before and after cellulase treatment. It has been found out that the investigated properties of sample studied changed considerably after the enzymatic treatment. They are influenced additionally by the presence of reactive dyes. The observed changes are discussed in terms of decreasing of the enzyme activity caused by the blocking effect of reactive dyes covalently bounded to the cellulose macromolecule hydroxyl groups.
Keywords: thermal properties, cellulase, reactive dyes.
INVESTIGATION ON GRUS MINERAL SORBENT WITH IMPROVED ADSORPTION PROPERTIES TOWARDS DYE SOLUTIONS
S. Veleva, A. Georgieva, D. Pishev
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: pishev@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
In the present work the grus material used was subjected to a preliminary processing in order to eliminate ineffective compounds and to decrease its dispersion heterogeneity. The enfluence of that treatment on the adsorption properties of the material was studied. Experiments with water solutions of 20 acid and 13 direct dyes were carried out, in which the adsorption dye was determined by spectrophotometric method. The adsorption isotherms obtained were described by the equation of BET for polymolecular adsorption. Based on the results obtained it was considered that this material could be successfully used for discolouring of the effluent from the dyeing of textile with acid and direct dyes.
Keywords: grus material, acid dyes, direct dyes, adsorption.
OPTIMIZATION OF THE COTTON FABRIC IMPREGNATION PROCESS
V. Vassileva, D. Damgaliev, D. Budurova
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: violet@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
Textile materials become water- and oil repellant and pollutant-resistant after impregnation treatment with fluorocarbon polymers. This treatment is characterized by a good permanence. The fluorocarbon polymer is laid on from an aqueous medium followed by drying and condensation processes. The derived mathematical model is based on the experiment and permits the determination of the optimal treatment conditions, to ensure the intended values of the investigated properties.
Keywords: cotton fabric, water-and oil-repellency, fluorocarbon products, mathematical modeling.
COMPARISON OF SOME UNHAIRING METHODS OF SHEEP SKINS
M. Koleva, D. Ivanova, N. Pepeldjiska, L. Vezenkov, D. Danalev
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: mkoleva@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
Two methods of unhairing sheep skins: enzymatic and with alkaline pretreatment of the wool are compared. The total nitrogen, Ca(OH)2 and Na2S content in wastewaters are determined. The received wool is characterized by some analyzes – yield, fat content, alkaline solubility, acid solubility and carbamid – disulfite solubility. Some results of the amino acid composition of the wool, treated by these two methods are discussed too.
Keywords: unhairing, enzymes, wool, ecology, skins.
KINETICS OF THE PROCESSES IN CHEMICAL TRANSFORMATIONS OF HOLOCELLULOSE UNDER THE CONDITIONS OF SULPHATE COOKING OF WOOD
G. Antova1, E. Valcheva2
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: ceco@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
University of Plovdiv,
24 Tzar Assent, 4000 Plovdiv,
e-mail: ginant@pu.acad.bg
2University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
Received:30 September 2003
Accepted 15 October 2003
ABSTRACT
The kinetics of the transformation of the holocellulose part of wood under the conditions of the sulphate cooking obtaining is studied. The experiments are carried out on holocellulose samples isolated from spruce wood. It is found that the destruction of holocellulose and the dissolution of its pentosans are described by a topochemical kinetic equation analogical to that obtained for the wood cooking process. The results obtained show the determining effect of the carbohydrate complex on the kinetic behaviour of wood as a whole under the conditions of sulphate cooking process.
Keywords: holocellulose, sulphate cooking, topochemical kinetics.
ANAEROBIC COMPOSTING OF THE BIODEGRADABLE FRACTION OF MUNICIPAL SOLID WASTE
J. Robinson
Department of Environmental Health and Safety,
Queen Mary, University of London, London E1 4NS, UK
E-mail: j.p.robinson@qmol.ac.uk
Received: 4 June 2003
Accepted 23 September 2003
The concept of the waste hierarchy, first developed by the EU, Strategy for Waste Management, was reaffirmed and further refined in chapter 5.7 of the Fifth Environmental Action Programme. According to this "waste management hierarchy", prevention of waste is the most desirable option followed by recycling and reuse of material and finally safe disposal either by combustion of waste as fuel, incineration without energy recovery and, least preferred, landfilling.
The 1999 Landfill Directive requires both strict control of landfill management practices and a phased reduction in the proportion of biodegradable waste disposed to landfill.
There is growing pressure for separation of the biodegradable waste from general household waste to be carried out at source. Such source-separated biodegradable waste has properties that make it an attractive feedstock for anaerobic composting to produce biogas and soil conditioner. The process can be operated sustainably to provide cost effective de-localised biogas for renewable energy as well as a saleable soil conditioner, both by-products of waste management.
The controlled anaerobic composting bioreactor can be seen as a flexible, cost effective, and sustainable waste management option that represents a large-scale waste processing system rather than a waste deposit. This paper reviews biological and technical aspects of the anaerobic composting bioreactor.
Keywords: sustainable bioreactor, microbiology, anaerobic composting.
LANDFILL BIOGAS GENERATION DEPENDING ON THE SOLID WASTE COMPOSITION – CASE STUDIES
V. Mihajlovich, B. Koumanova, S. Stoyanov
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: bogdana@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
Quantity and quality of biogas produced by anaerobic digestion of solid wastes in landfill depends on several parameters such as waste management and processing (baling, shredding, material separation, etc.), waste composition, biological factors (moisture, nutrients, bacteria, pH, temperature), design of the landfill and landfilling operation. Predicting landfill gas production and composition is very useful for sizing landfill gas collection systems, evaluating the benefits of gas recovery and estimating gaseous emissions to the environment.
The aim of this study is to collect information about the composition of solid wastes from three different places (2 in Bulgaria and 1 in Macedonia) according to the source of their generation and type as well as organic and inorganic matter content. The main characteristics of the landfills were also described. The quantities of the two main components (CH4 and CO2) of landfill biogas generated in these sites have been calculated using EPA computer programme. The period of total gas production as well as the period of maximal production has been determined for the studied sites. The results are compared depending on the solid waste composition.
Keywords: solid wastes, anaerobic biodegradation, landfill biogas.
SEA WATER MICROFILTRATION CHARACTERISTICS
R. Stoicheva
University “Prof. Dr As. Zlatarov”,
1, Prof. Yakimov 8010 Bourgas, Bulgaria
Received:30 September 2003
Accepted 15 October 2003
The organic contamination is a parameter for the purity of sea water. Total content of organic substances is determined by the methods of KMnO4 oxidation [I], chemical oxygen demand (COD)[II] and biochemical oxygen demand (BOD).
The results from microfiltration analysis of sea water taken from three points in the Bourgas bay are discussed in the present work. The investigation involves a period of 9 months, (during autumn – summer, 1997-1998).
A correlation has been established between the permeability of PVC microfiltration membranes with 0,2 µm pore size and the content of organic substances estimated by methods I and II. It has been proved that a permeability of PVC microfilters up to 2.10-5 m3/m2.s, gives the sea water standard content of organic chemical substances.
Analysis of organic substances is necessary when the value goes below the number stated above.
Keywords: microfiltration, sea water, PVC membranes.
CALCULATION OF THE TEMPERATURE FLAMMABILITY LIMITS OF INDIVIDUAL HYDROCARBONS AND DISTILLATE OIL FRACTIONS
III. REFORMATION OF THE MAXWELL EQUATION
Z. Zdravchev, J. Balgaranova, M. Christova, E. Tcholakova
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: zdravchev@uctm.edu
Received:30 September 2003
Accepted 15 October 2003
Basic fire and explosion hazards parameters for the liquid materials and chemical substances are the Temperature Flammability Limits. There is no such data in the literature about the chemical mixtures. Their experimental determination is a labour consuming and in certain conditions even an impossible operation. Thus, the need arises for creating numerical methods for their determination. The Maxwell’s equation expressing the analytical relationship between the saturated vapour pressure and the temperature, is reformed into dependences determining the Temperature Flammability Limits of the individual hydrocarbons and distillate oil fractions on the basis of their boiling temperatures and Concentration Flammability Limits.
A comparative analysis is carried out for the accuracy of the obtained relationship and our previously determined analytical dependences, derived by reforming the Wilson’s and Challenger-Davis equations. The most accurate results from calculation of the Temperature Flammable Limits are these, obtained by using the reformed Challenger-Davis equation. The reformed Wilson equation is applicable for calculation of the Upper Temperature Flammability Limits. With the suggested analytical dependencies could be calculated the Temperature Flammability Limits with sufficient for practical purposes accuracy.
Keywords: calculation of Temperature Flammability Limits, hydrocarbons and distillate oil fractions.
