prof. Ing. Josef PELIKÁN, CSc.
1973 - 1990 děkan Fakulty technologie paliv a vody
Narozen v Praze v roce 1930.
Po absolvování reálného gymnasia v Karlíně se stal posluchačem VŠCHT Praha, kterou absolvoval v roce 1953. Po krátké době zaměstnání na tehdejší Katedře koksárenství a plynárenství na Fakultě technologie paliv a vody se stal odborným asistentem na Katedře tepelné techniky. Kandidátskou disertační práci obhájil v roce 1962 a habilitační řízení absolvoval v roce 1966 úspěšnou obhajobou práce „Měření vodíku v páře“. V roce 1980 byl jmenován profesorem pro obor „Tepelná technika“.
V roce 1980 mu byla udělena medaile prof. Ferdinanda Schulze.
Smrz, M.,; Vosta, J., Macak, J., Pelikan, J., Kudlicka, J. Corrosion passivation of steel (1991), patent CS 272104 B1 19910115.
Steels in a carbonate-contg. medium are passivated by enrichment of the medium by adding 150-1500 mg Fe3+/L. Optionally, the enrichment is done by electrochem. generation of ions for 0.5-10 min at a c.d. of 0.5-10 A/m2. Thus, C steel exposed to an aq. soln. contg. 20 K2CO3 and 10% KHCO3 was passivated by adding 500 mgFe3+/L soln. in the form of an EDTA complex at 65°. The passivation was more efficient than that attained with conventional K2CrO4.
Pelikan, J., Macak, J., Vosta, J. Corrosion and corrosion inhibition of aluminum alloys for central heating radiators Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1990), D58, 175-90.
The corrosion resistance of Al alloys, used for central heating radiators, was studied by using an electrochem. technique and by using circuits in which actual operation conditions were simulated. Both types of expts. were also used for estn. of effectiveness of a corrosion inhibitor mixt. of benzotriazole, Na silicate, and phenylacetic acid. Electrochem. characteristics were obtained from anodic polarization data and polarization resistance measurements. Parameters of the elec. macroelements Al alloy/brass and Al alloy/steel, and time dependence of the gas vol. were detd.
Macak, J., Vosta, J., Smrz, M., Pelikan, J.,; Hluchan, V., Vymetal, J., Vavrin, J. Corrosion inhibitor for fuel gas production (1991), patent CS 270917 B1 19900814.
The corrosion inhibitor consists of abietic acid (I) 5-45, dibenzylsulfoxide (II) 0.5-7, heterocyclic N bases 10-30, condensation products of C2-8 alkenylamines and C8-22 fatty acids 5-50, aliph. C8-22 amines 0.5-7, and morpholine (III) 0.5-15 wt.%. The corrosion inhibitor is sol. in org. solvents down to -15°, and condensation products of alkenylamine and fatty acids hydrolyzed at elevated temps. function also as corrosion inhibitors. Thus, the corrosion inhibitor was prepd. by mixing a 5% II soln. in quinoline bases d. 243-253° 17, III 15, I 36, a condensation product of diethylenetriamine with fatty acids 25, and octadecylamine (as 10% soln. in EtOH) 7 wt.%. The corrosion inhibitor was added to a model aq. soln. of AcOH, NaCl, and Na2S. Efficiency of corrosion inhibition for C steel specimens was 97.1%.
Macak, J., Vosta, J., Smrz, M., Pelikan, J., Hluchan, V., Vymetal, J., Vavrin, J. Corrosion inhibitor for petroleum atmospheric distillation equipment (1991), patent CS 270916 B1 19900814.
The corrosion inhibitor consists of dibenzylsulfoxide (I) 0.5-10, heterocyclic N bases 10-40, C2-8 amines as an alkalization component 20-60, and optionally surfactants 0.5-35 wt.%. The amines neutralize HCl(g), formed by hydrolysis of chlorides in petroleum during distn., to form noncorrosive alkylammonium chlorides which also have a synergistic effect on the adsorption components of the inhibitor (i.e., T + heterocyclic N bases). The surfactants have also a synergistic effect. Thus, 10 ppm corrosion inhibitor consisting of a 7% I soln. in quinoline bases b. 245-275° 30, diethylamine 50, and a condensation product of diethylenetriamine and oleic acid (as surfactant) 20 wt.% was added to a model soln. simulating a water condensate during atm. distn. of petroleum. Efficiency of corrosion inhibition for C steel specimens was 96.4%.
Smrz, M.,Vosta, J., Macak, J., Pelikan, J., Vavrin, J., Lohnisky, J.,Novotny, M., Horak, Z., Vana, O. et al. Corrosion inhibitor for energetic gases' exploitation,transportation and storage equipment (1991), patent CS 274680 B2 19910915.
Vosta, J., Smrz, M., Oliva, L., Horak, Z.,Pelikan, J., Macak, J.,Viden, I., Kratochvil, J., Vavrin, J. Directional corrosion inhibitor (1990),patent CS 268318 B1 19900314.
Tulackova, D., Pelikan, J., Hluchan, V., Surface modification of metals by laser radiation Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1990), D58, 123-37.
In a review with 8 refs., Nd:YAG lasers, CO2 lasers, and excimer lasers and their application for welding aree discussed. Cutting, drilling, and surface treatment of metals is discussed.
Cimicka, H., Pelikan, J., Hluchan, V. Corrosion of steam turbine blades Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1990), D58, 21-45.
In a review with 35 refs., the state of knowledge of corrosion of steam turbine blades in the transition region between dry and wet steam is discussed. Environment (i.e., impurities in steam, their concn. distribution, and their deposition), corrosion fatigue, pitting corrosion resistance, microstructure, protective coatings on the turbine blades, and dynamic loading of the blades are discussed.
Jiricek, I., Hluchan, V., Pelikan, J. Corrosion of austenitic steels in the environment of a coolant of pressurized light-water reactors Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1990), D58, 91-122.
In a review with 50 refs., types and mechanisms of corrosion attack of austenitic steels in cooling cycles of light-water pressure nuclear reactors are discussed. Corrosion resistance and its relation to microstructure and its changes due to aging are considered. Their resistance to fatigue crack propagation is discussed. Two basic mechanisms of crack propagation in a coolant medium are corrosion due to anodic dissoln. and H embrittlement. The mechanisms permit quant. calcn. of crack growth rate.
Pesinova, V., Cimicka, H., Pelikan, J., Dusek, J., Comparison of the pitting-corrosion resistance of steels for manufacture of steam turbine blades Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1990), D58, 233-9.
The resistance of Poldi AK1 steel, conventionally used for steam turbine blades, and martensitic pptn. hardenable steel 03Cr10Ni10Mo2 subjected to hardening and quenching, to pitting corrosion was examd. by using cyclic voltammetry. The measurements were completed by metallog. evaluation of the corroded surfaces. There was no substantial difference between corrosion resistance of either steel.
Vosta, J., Pelikan, J., Macak, J. Thiocyanato and mercapto compounds as inhibitors for iron corrosion in hydrochloric acid Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1989), D57, 271-80.
Use of thiocyanato and mercapto compds. as corrosion inhibitors for 99.999% Fe in 5% HCl was evaluated by using polarization potentiodynamic curves. The 4-thiocyanatoaniline, 6-aminothiophenol, and 4-thiocyanotolbenzoic acid had suitable inhibition properties. According to quantum chem. data, the compds. in a nonprotonized state acted as electron donors during sorption on Fe. The protonized forms of substituted anilines were considered in the quantum calcns.
Pelikan, J., Vosta, J., Vanek, F. Inhibition of class 15 steel corrosion in hydrofluoric and hydrochloric acids on RDE [rotating disk electrode],Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1989), D57, 237-53.
Pickling of CSN 15121 boiler steel by 2% HF or 5% HCl was investigated under laminar flow conditions. To inhibit corrosion, several inhibitors were investigated. In the case of HF, pitting corrosion was obsd. Efficiency of the most inhibitors was 95-98%. Corrosion in HCl was evaluated according to the corrosion elec. current and slope of the linear portion of the polarization curves.
Vosta, J., Pelikan, J.,Smrz, M. Pyridine derivatives as inhibitors of iron corrosion in hydrochloric acid Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1989), D57, 255-70.
The corrosion inhibitor action of pyridine and its derivs. for 99.99% Fe in 5% HCl was investigated by using polarization potentiodynamic curves. Isonicotinic acid nitrile and 4-acetyl pyridine were the best inhibitors. To support the inhibiting action, the Hammett consts. were used and correlated with the Tafel slope in the cathodic and anodic parts. The quantum chem. evaluation confirmed the accepting effect in the sorption of compds.
Pelikan, J., Vosta, J., Hluchan, V., Corrosion inhibitor for aluminum alloys in aqueous medium (1989), patent CS 258861 B1 19880916.
The corrosion in a closed heating system contg. a circulating aq. medium is prevented by adding Na phenylacetate (I) 30-80, Na2SiO3 40-100, and 1,2,3-benzotriazole (II) 5-15 mg/L. The circulating water in an Al alloy radiator is mixed with I 60,Na2SiO3 60, nd II 10 mg/L, and no corrosion was obsd. after long-term service.
Bartos, M., Macak, J., Vosta, J., Pelikan, J. Study of an inhibited corrosion reaction. IV. Evaluation of the behavior of p-halo-substituted anilines using an a.c. impedance technique Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1988), D56, 291-321.
Sorption reaction of p-halogen substituted anilines on the surface of an Fe rotating disk electrode in 5% HCl was investigated by means of the faradaic impedance method. Values of corrosion currents were detd., from polarization measurements. Impedance spectra were measured at open circuit potential and at anodic and cathodic polarizations /at c.d. ± 1,2 mA.cm2/. It was shown, that inhibition efficiency increases in this homol. series from aniline to p-iodoaniline. This result was confirmed by the correlation of exptl. data with the values of Hammet-substituent consts.
Jiricek, I., Hluchan, V., Pelikan, J. Corrosion cracking of steel in aqueous media. II Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1988), D56, 251-89.
Stress corrosion cracking of 08Cr18Ni10Ti stainless steel was studied in high temp. (255°) pure H2O environment according to the service condition of pressure water reactors. Environment sensitive fracture was obsd. in slow-strain rate tests at strain rates of the order -6 to -7/s mainly in O-present water environment. Deleterious effects were detected even with Na phosphate and hydrazine presence. Effects of NaCl soln. on high cycle corrosion fatigue of notched steam generator pipes were studied at the room temp. Pit-forming mechanism was supposed for redn. in fatigue limit compared to the air test observation.
Vosta, J., Pelikan, J., Varga, L., Smrz, M., Holinka, M., Hluchan, V., Peca, M. Passivation of brass tubes for heat exchangers (1987), patent CS 234628 B1 19850416.
After cleaning with pressurized water, brass heat exchange tubes (esp. condenser tubes in elec. power plants) are passivated by treatment with 0.5-5% H2SO4, HCl, and/or citric acid in the presence of corrosion inhibitors selected from 1,2,3-benzotriazole (I) 0.1, dibenzylsulfoxide (II) or quinoline 0.1, and/or benzimidazole (III) 0.1 g/L. The passivated heat-exchanger tubes are flushed with purified water and passivated again for 1-6 h in aq. soln. contg. I 0.1, tannin 0.1, and coco fatty acid alkanolamides 0.5 g/h. The passivation mixt. is suitable for protection during long shutdown periods, startup periods of new elec. power plant equipment involving frequent interruption of service, or as a const. addn. in the cooling circuit during service. Thus, 0.6% H2SO4 soln. contg. I 0.1, II 0.1, and III 0.1 g/L was used for final cleaning of brass condenser tubes. After draining the soln., the condenser was flushed with purified water until the effluent was neutral. The tubes were then passivated by circulating aq. soln. contg. I 0.1, tannin 0.1, and coco fatty acid alkanolamides 0.5 g/L for 5 h.
Varga, L., Vosta, J., Holinka, M., Pelikan, J., Smrz, M., Panacek, F. Decreasing the corrosion aggressivity of cooling media in power system condensers (1987), patent CS 234627 B1 19850416.
The corrosion rate was decreased by up to 70% by feeding benzothiazole inhibitors and other additives into the circulating water of power system condensers during interrupted performance. EDs, based on 1 ton water, are: (a) 30 g Na salt of mercaptobenzothiazole; (b) 25 g 1,2,3-benzotriazole (I); (c) 2 g I, 2 g tannin, and 6 g coco fatty acid alkanolamides; (d) 50 g Na hexametaphosphate and 5 g I; or (e) 20 g N-contg. condensates.
Vosta, J., Smrz, M., Pelikan, J., Kapounova, H., Kleprlik, Z., Hluchan, V., Eliasek, J. Removal of copper deposits from boiler surfaces in power plants (1986), patent CS 236422 B1 19850515.
Aq. cleaning bath for Cu removal is composed of 0.05-0.5% diperoxyacetic acid (I), 0.05-10% NH4OH, 0.05-5% ethylenediaminetetracetic acid salts or nitriletriacetic acid (II), and optionally 0.05-5% H2O2. Thus, boiler tubes were treated with aq. bath composed of 0.2% I, 0.2% NH4Cl, and 0.4% II before etching with 2.5% HF to remove Cu completely from the surface.
Hluchan, V., Vosta, J., Pelikan, J.,Smrz, M., Nemcova, J. Stress-corrosion cracking inhibitor (1986), patent CS 228745 B1 19840514.
Stress cracking of steel in acid and chloride-contg. media is inhibited in the presence of alkanolamines, thiazoles, quinoline derivs., amines, and (poly)amides. Thus, inhibitor mixt. contained triethanolamine 28.5, mercaptobenzothiazole 15, coco fatty acid alkanolamide 2, crude quinoline fraction 18, octadecylamine 28.5, and polyacrylamide 8 parts. At 0.1% concn. the mixt. gave 91% corrosion inhibition, and prevented for 29 days the crack formation in tensile-stressed specimens of austenitic stainless steel in an aq. soln. contg. 2.5 M H2SO4 and 0.5 M NaCl.
Cervinka, J., Pelikan, J., Hluchan, V., Vosta, J. Corrosion of ferritic steels in products of the sodium-water reaction Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1985), D51, 215-34.
The corrosion resistance was studied of the ferritic steels Type 1Ch2M, Type W.St. Nr. 1.6770, and Type 15418. These steels are used in fast reactor steam generators. The changes of mech. properties were detd. from material loss. All steels exhibited at 340-480° similar corrosion resistance. The corrosion was dependent exponentially on temp, and the steels exhibited good resistance against stress corrosion cracking at ≤400° and a load of 80% of the limit σ0.2. The corrosion resistance of steels is sufficient for the case of a steam generator accident.
Vosta, J., Pelikan, J., Smrz, M., Nemcova, J., Varga, L. Passivating and corrosion inhibiting agent for heat exchangers of brass (1986), patent CS 223221 B1 19830915.
A 1:1:2 mixt. of benzotriazole, tannin, and coconut fatty acid alkanolamides is added at 20 ppm. to cooling water. Corrosion protection is comparable with results from alkali chromates that show ecol. problems.
Hluchan, V., Pelikan, J., Vosta, J. Mechanism of stress corrosion cracking Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1985), D51, 199-214.
Austenitic stainless steels e.g. 18-8 are sensitive to stress corrosion cracking (SCC) in environments contg. Cl-, SO42-, OH-, etc., and therefore this study was made in 2.5M H2SO4 + 0.5M NaCl. The exptl. work was concerned with the several known methods of detn. of SCC and results supported the view that SCC occurs in the Cl-/SO42- environments by destroying the protection layer and by anodic local dissolving. The crack propagation rates (CPR) were calcd. in the active and passive regions and the effect of 10-2M K2CrO4 on the redn. of CPR is also discussed.
Mostecky, J., Nemcova, J., Vosta, J., Pelikan, J., Lohnisky, J., Novotny, M., Hluchan, V., Strnadova, V. Deicing salt with a mixed corrosion inhibitor (1985), patent CS 219449 B1 19830325.
Road salt compns. with anticorrosion efficiency ≥93% toward steel, Zn, Cu, Al, and the pavement surface consist of alkali or alk. earth chlorides 98.2-99.1, alkali phosphates 0.5-0.8, inorg. Zn salts 0.3-0.6, alkali sulfites 0.05-0.3, and a base (alk. earth hydroxides, C2-8 alkanolamines) 0.05-0.1%. Thus, an aerated 3% aq. soln. of a compn. contg. NaCl 92, MgCl2 6.7, Na6P6O18 [10124-56-8] 0.7, ZnSO4 0.4, Na2SO3 0.15, and triethanolamine [102-71-6] 0.05% exhibited a ≥95% anticorrosion effect on steel, Cu, Zn, and Al.
Nemcova, J., Bartonicek, R., Holinka, M.,Sverepa, O., Mostecky, J., Pelikan, J., Vosta, J., Panacek, F., Eliasek, J.,; et al. Corrosion inhibitor for brass with a biocidal effect (1985), patent CS 222108 B1 19830429.
Corrosion inhibitors contg. alkanolamines, C12-18 alkylamines, mercaptobenzothiazoles, and surfactants prevent dezincification of brass ducts and condensers as well as their fouling with biol. deposits. Thus, triethanolamine [102-71-6] 54 was mixed at 60° with C18H37NH2 [124-30-1] 3 and 2-mercaptobenzothiazole [149-30-4] 43. The mixt. was stirred at 60° for 2 h, cooled, and mixed with monoethanolamides of coconut acids 43 parts at 40°. Using this mixt. in a brass cooler at 20 ppm in water gave 98% corrosion inhibition and 70% suppression of microbial growth.
Mostecky, J., Humhej, J., Lohnicky, J., Vosta, J., Pelikan, J., Nemcova, J., Smrz, M. Deicing agents for asphalt compositions (1985), patent CS 218692 B1 19830225.
Deicing agents for pavement consist of a core of CaCl2 or NaCl and NaOH coated with Zn stearate [557-05-1] 0.4-5, ZnSO4 0.1-3, octadecylamine [124-30-1] 0.01-0.1, and inorg. or org. peroxide 0.1-2% (per particle). Thus, asphalt compns. used for roads with long-term icing resistance and anti-corrosive effects were composed of the usual bituminous mixt. and 5% deicing granules composed of CaCl2 89.9, NaOH 5, and ZnSO4 0.7% coated with Zn stearate 4, cumene hydroperoxide [80-15-9] 0.3, and octadecylamine 0.1%.
Hluchan, V.; Pelikan, J.; Vosta, J. Corrosion and SCC of steel in hydrogen sulfide environment Proc. - Int. Congr. Met. Corros. (1984), 3, 538-42.
Corrosion inhibitors for H2S were evaluated in connection with natural gas prodn. in Czechoslovakia. The corrosion study was carried out by measuring the potentiodynamic polarization, and by the const. strain rate deformation method. The inhibitors Sever 1, Garesin, and I-21-D were the most effective.
Kozak, P., Stejskal, M., Kubelka, V., Barszcz, M., Richtar, A., Mostecky, J., Pelikan, J. Lubricating oils for cold drawing and rolling of metals (1983), patent CS 208584 B1 19810915.
A mixt. of chlorinated paraffins (contg. 40% Cl) 650, Ca(OH)2 200, Ca oleate [142-17-6] 30, and polyol Me ether 20 parts reduces wear of the mandrels and increases luster of the lining of drawn tubes. It may contain 10 parts Zn dialkyl dithiophosphate, Ca petroleum sulfonate, and a mixt. of imidazole derivs., to increase resistance to seizure and corrosion.
Hluchan, V., Pelikan, J., Vosta, J. Corrosion and corrosion cracking in hydrogen sulfide environment Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1984), D50, 57-70.
The elec. polarization curves and the rates of sample elongation at const. load were used to det. the effect of com. corrosion additives on the elec. and mech. properties of steel pipes in a medium simulating a petroleum well environment (H2S satd. 5% NaCl-0.5% AcOH soln. at 25°). Of the 8 com. inhibitors tested, the best were Sever 1 [54692-93-2], Garesin [84136-89-0], and I 21-D [73989-41-0]
Vanek, F., Pelikan, J., Vosta, J. Study of point corrosion of aluminum in aqueous sodium chloride medium by measuring chemical impedance Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1984), D50, 39-55.
Chem. impedance (effect of chem. inhibitors on the elec. impedance) on an Al sample (99.99%) in a 1% NaCl medium and in the presence or in the absence of inhibitors K2CrO4 and NaNO3 in 5 × 10-2M concn. was measured. The sample was applied as a rotating disk electrode. Better knowledge of the broad dependence of impedance frequency parameters was made possible by using the method of Lissajous figures. The course of frequency impedance spectra in the presence of inhibitors corresponded to the course of a slow electrode action or to an irreversible electrode reaction. In the medium without inhibitors the course was different, giving evidence of a reaction controlled by diffusion or of a quasi-reversible electrode action.
Pelikan, J., Vanek, F., Vosta, J. Study of pitting corrosion of aluminum in aqueous sodium chloride medium by means of RDE Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1984), D50, 19-37.
The measurements of corrosion under convection by means of the rotating disk electrode (RDE) disclosed the possibility of using this electrochem. method for distinguishing the effect of corrosion inhibitors on the metal-medium interface for pitting corrosion. The combination of potentiodynamic polarization measurements and the measurement of c.d. under const. potential proved to be good for the detn. of relatively more suitable inhibitors under given conditions. The effect of inhibitors can be explained mainly by the oxidn. and chemisorption effects with simultaneous coverage of a large part of the area, and/or of the active corrosion sites, of the rotating disk Al samples. When using the inhibitors, NaNO3 proved to be more effective against pitting corrosion than K2CrO4 in the concn. of 5 × 10-2M.
Vosta, J., Pelikan, J., Macak, J., Hluchan, V., Smrz, M. Study of an inhibited corrosion reaction. III Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1984), D50, 71-82.
Corrosion inhibitors were evaluated by electrode impedance. Electrochem. measurements were performed with CSN 17246 [50947-31-4] stainless steel electrode in active and passive states in a soln. contg. 2.5M H2SO4 and 0.5M NaCl, and also with 99.9% Fe electrode in 10% HCl with the addn. of Nitrone [4745-47-5], dibenzyl sulfoxide [621-08-9], pyridine [110-86-1], and pyrrole [109-97-7] as corrosion inhibitors. Impedance dependence in the initial passive state and during transpassivation was examd.
Vosta, J.; Trabanelli, G.; Pelikan, J.; Zucchi, F.; Hluchan, V. Contribution for evaluation of some benzonitriles as corrosion inhibitors. Proc. - Int. Congr. Met. Corros. (1984), 1, 378-9.
The efficiency of benzonitriles as corrosion inhibitors for Fe in 5 N H2SO4 was studied. The HOMO orbital, which is a theor. analog to the ionization potential of a substance, was used for evaluation of exptl. results. The electron donor and acceptor action of inhibitors, and electron transfer and forming of the bond between metal and inhibitor are considered.
Mostecky, J., Pelikan, J., Vosta, J., Lohnisky, J., Nemcova, J., Smrz, M., Novotny, M. Antifreeze composition from sodium chloride and corrosion inhibitors (1984), patent CS 216579 B1 19821126.
Antifreeze compns. for road surfaces with suppressed corrosive action towards metals and concrete contain CaCl2 or MgCl2 6-8, alk. phosphates 0.3-0.6, ZnSO4 0.2-0.4, caprolactam [105-60-2] 0.1-0.7, arom. thiazoles and/or their salts 0.001-0.2, Zn stearate (I) [557-05-1] 0.01-0.05, hydroxyalkylamides of coconut oil acids, Na dodecylbenzenesulfonate [25155-30-0], and/or alkyl polyethyleneglycol ether phosphate (II) 0.01-0.15, Na2SiF6 0.0005-0.1, and NaCl up to 100%. A typical compn. comprised NaCl 92, CaCl2 6.1, (NaPO3)6 0.01, I 0.02, II 0.03, and mercaptobenzothiazole [149-30-4] 0.02% and had an anticorrosion efficiency of 93% compared to NaCl.
Vosta, J., Pelikan, J., Smrz, M., Zehle, I. Corrosion protection of metal-plated contacts in electronics (1984), patent CS 213533 B1 19820409.
The corrosion protection agent is a liq. mixt. of 0.4-0.6 g stearic acid [57-11-4], 0.6-1.0 g paraffin, and 3-5 mL bis-(2-ethylhexyl)sebacate [122-62-3] in 100 mL xylene contg. 0.04 octadecylamine [124-30-1], 0.02 lanolin, and 0.04% mixed imidazoline [28299-33-4] derivs. The agent optionally also contains 0.08% Zn stearate [557-05-1].
Vosta, J., Pelikan, J., Smrz, M., Hluchan, V., Smetana, J., Wagner, M. Anticorrosion treatment of equipment (1984), patent CS 213223 B1 19820326.
Equipment put on standby is flushed out with steam contg. film-forming C12-20 aliph. amines 50-500 and optionally an alkalizing agent (e.g., cyclohexylamine) 0.5-5 and a nontoxic, volatile, corrosion inhibitor (e.g., BzONH24) 0.5-5 g/kg steam. The treatment is esp. suitable for power and metallurgical plants. Thus, a nuclear-power-plant unit was put on standby and the system, consisting of austenitic stainless-steel components, was preserved by flushing with steam contg. 15 g octadecylamine/kg steam. Corrosion did not occur. The protective film was removed by superheated steam before returning the unit to operation.
Pelikan, J.,Vosta, J., Mostecky, J., Inhibited anticorrosive lacquer (1983), patent CS 202460 B1 19810130.
An inhibited, anticorrosive varnish, suitable for rusty, wet, or greasy metal surfaces, consists of C18H37NH2 (I) [124-30-1] or (C18H37)2NH [112-99-2] 2-20; C12-18 fatty acid or alc. ethoxylated with 15-35 mols. oxirane 0.1-0.5; the reaction products (II) of oleic acid with 1-(2-aminoethyl)-2-heptadecenyl-2-imidazoline 0.1-1; MgO 0.1-1; powd. Al, Zn, Cd, or Pb 0.02-0.5; NaNO2 0.1-2; and H2O 75-97%. Thus, a varnish comprised I 2, ethoxylated fatty acid 0.2, II 0.1, powd. Al 0.05, NaNO2 2, and H2O 95.65%.
Macak, J., Vosta, J., Pelikan, J. Smrz, M., Hluchan, V., Havlas, Z. Study of the inhibited corrosion reaction. II Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1982), D45, 99-134.
Inhibition effects and the kinetics of surface sorption corrosion reactions of tetracyanoethylene, nitron, and argenton 0.001 mol/L 5% HCl at Fe and Ni electrodes were studied by the faradaic impedance method and by measuring the elec. double layer capacitance by the single current pulse method. Only nitron showed significant inhibition effects. The results were interpreted by chemisorption of nitron (as supported by HOMO energy data).
Nemcova, J., Holinka, M., Mostecky, J., Pelikan, J., Vosta, J., Eliasek, J., Smrz, M., Lohnisky, J., Novotny, M., Mencl, F., Corrosion inhibitor for aqueous heat exchange media in brass (1983), patent CS 211962 B1 19820226.
The corrosion inhibitor contains aliph. amines, arom. azoles, surfactant, polymer, and quinoline or derivs. Thus, 1000 m3 of cooling water was treated with octadecylamine [124-30-1] 0.9, diethanolamine [111-42-2] 0.5, 2-mercaptobenzothiazole [149-30-4], 0.2, 1,2,3-benzotriazole [95-14-7] 0.2, coconut acid diethanolamide 0.05, polyacrylamide [9003-05-8] 0.05, and quinoline [91-22-5] 0.1 kg. The treatment had a 97% corrosion-inhibiting effect and did not remove Zn from the brass surface.
Havrland, B., Jara, J., Smrz, M., Vosta, J., Pelikan, J., Mostecky, J. Anticorrosion protection of metal articles (1983), patent CS 211982 B1 19820226.
The agent contains a novel mixt. of tannin and unsatd. fatty acids alkanolamides with synergetic effect. It converts Fe oxides to tannates, stabilizes rust by sorption of inhibitors, and abolishes the adverse effect of the rust layer on base paint. A typical compn. is tannin 15, coconut fatty acids alkanolamides 3, and 1,2,3-benzotriazole [95-14-7] 0.5 parts dissolved in a 40:20:21.5 mixt. of iso-PrOH [67-63-0], BuOH [71-36-3], and water.
Vosta, J., Pelikan, J., Smrz, M., Sedlacek, M. Inhibition of corrosion reactions. I Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1982), D45, 5-25.
Inhibition of corrosion was studied. Influence of structure on the inhibitor efficiency during sorption at the liq./solid interface was investigated. The internal structure was detd. by using a quantum chem. calcn. method, boundary orbitals, and mol. diagrams. Efficiency of the inhibitors was evaluated from polarization potentiodynamic curves and by measurement of the Faraday impedance. Expts. were done with 4-aminobenzonitrile [873-74-5] and 4-aminothiophenol [1193-02-8] inhibitors and Fe wire. Irreversibility of the reaction between the inhibitor and metal was explained by chemisorption.
Vosta, J., Kadija, I. V., Pelikan, J., Hackermann, N., Hluchan, V. Inhibition corrosion of iron by means of RDRE Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1982), D45, 75-97.
The rotating double ring electrode (RDRE) was used to investigate some corrosion processes in 6N HCl. The inhibitor mols. are considered from the quantum-chem. point of view. The electrochem. and quantum-chem. data were correlated to give a more general picture of the nature of corrosion inhibition. Much more exact measurements and evaluations of different inhibitors can be done by using the RDRE. Both HOMO and LUMO are of great influence on chemisorption and inhibition activity of compds. Therefore, strong electron donors and acceptors can act as good inhibitors by forming chem. bonds with the surface. The results obtained from this type of investigation can be correlated directly with the evaluation of catalytic phenomena, esp. in flowing systems.
Hluchan, V., Pelikan, J., Vosta, J. Stress corrosion cracking of steels in aqueous environments Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1982), D45, 51-74.
Nemcova, J., Sverepa, O., Mostecky, J., Pelikan, J., Vosta, J., Smrz, M., Volf, J., Safar, M., Fousek, V., et al. Bactericidal agent inhibiting corrosion of metals (1983), patent CS 202494 B1 19810130.
Corrosion-preventing agents contain an alkalizing agent, a corrosion inhibitor, a film-forming amine, and surfactant. They are esp. useful for equipment used in the drilling, storage, and transport of natural and city gas. Thus, a mixt. of cyclohexylamine [108-91-8] 30, octadecylamine [124-30-1] 20, imidazoline [504-75-6] 25, coconut acid monoethanolamide 5, and ethoxylated octadecylamine 20 parts had in 10% alc. soln. 98% protection and entirely suppressed Desulfovibrio bacteria.
Mostecky, J., Pelikan, J., Vosta, J., Smrz, M., Nemcova, J., Sverepa, O., Safar, M., Fousek, V., Demcik, Z., Slanina, F. Mixed corrosion inhibitor (1982), patent CS 207959 B1 19810831.
Corrosion inhibition of 93-95% for metals used in the transport and storage of natural gas is obtained by using a mixt. of 20-60 parts higher film-forming amines, such as cyclohexylamine and octadecylamine, 20-40 parts unsatd. fatty acid alkanolamides, and optionally 20-25 parts imidazole or imidazoline derivs. and/or 25 parts ester of fatty acids with higher alcs. as a 5% soln. in a MeOH-hydrocarbon soln. A typical corrosion inhibitor consists of cyclohexylamine [108-91-8] 30, octadecylamine [124-30-1] 30, and alkanol amide of unsatd. fatty acids in a 10% alc. solns. 40%.
Vosta, J., Pelikan, J., Mostecky, J., Nemcova, J., Smrz, M., Holinka, M. Corrosion inhibiting and bactericidal treatment of heat exchange medium (1983), patent CS 200933 B1 19801031.
Cooling and heating water systems are treated with 0.02-0.1% polyethylene oxide [25322-68-3], polyacrylamide [9003-05-8], or polyacrylonitrile [25014-41-9]. The additives markedly decrease the friction coeff. between circulating liq. and the heat-exchange surface, enhance transport of the present corrosion inhibitors and biocidal agents, and thus increased the efficiency and service life of the equipment.
Sedlacek, M. Pelikan, J.; Vosta, J. Measurement of the frequency dependence of chemical cell impedance Elektrotechnicky Casopis (1983), 34(2), 118-28.
Two methods are described for measuring the impedance of electrochem. cells consisting of a tested metal sample, a cylindrical Pt mesh ref. electrode, and corrosive electrolyte contg. corrosion inhibitors. Regulated d.c. bias voltage was applied and a small low frequency voltage superimposed. In the 0.01-500 Hz frequency range impedances were calcd. from phase relations between voltage and current. In the 100-10,000 Hz range impedances were measured with a modified de Sauty's bridge. These measurements serve for evaluation of protection efficiency of corrosion inhibitors used in boiler feed waters for power stations. These measurements are important to metallic corrosion inhibition
Pelikan, J., Smrz, M., Nemcova, J., Vosta, J., Holinka, M. Treatment of a heat-transfer medium for cooling circuits (1982), patent CS 199200 B1 19800731.
Exposing a cooling circuit to UV radiation of 150-200 W extented the protective effect of biocidal agents, such as dimethyllaurylbenzylammonium phosphate [85213-06-5] or O,O'-dimethylthiophosphate [1112-38-5]. This effect is ascribed to labilization of the lyosomal membrane of algae and bacteria by irradn. which activates lyosomal enzymes and delays adaptation of corrosion-producing organisms to the biocides.
Vosta, J.,Pelikan, J., Smrz, M., Mostecky, J. Passivating agent for metal protection (1982), patent CS 200099 B1 19800829.
Mixts. of octadecylamine (I) [124-30-1] and powd. Zn, Al, or Cd have a synergic anticorrosion effect which is ascribed to the interaction of a free electron pair of the NH2 group with the active surface of the protected metal and to electrochem. protection with the dispersed metal or its oxide. Thus, structural steel is sprayed at 60° with I melt contg. 10% powd. Zn or painted with a soln. of I 10-30, powd. Al 5, and imidazoline deriv. 0.5% in CHCl:CCl2 or EtOH. Difficultly accessible spots are sprayed with an aq. emulsion contg. I 20, powd. Cd 10, Zn stearate 1, higher fatty alc.-acid esters 5, and polyethylene glycol 0.1%.
Nemcova, J., Vosta, J., Pelikan, J., Holinka, M., Rabl, V.,; Smrz, M. Anticorrosive and biocidal agent for a heat-exchanging medium (1981), patent CS 202864 B1 19810227.
Corrosion and biofouling inhibitors were formulated from allylthiourea (I) [109-57-9], coconut acid ethanolamides, PhNCO [103-71-9], and Zn dialkyl dithiophosphate. Thus, an agent contg. I 10, coconut acid ethanolamides 53, PhNCO 10, and Zn O,O-dibutyl dithiophosphate [6990-43-8] 27 parts inhibited cooling water corrosion by 90% and suppressed biofouling by 70%.
Pelikan, J., Vosta, J., Mostecky, J., Janecek, J. Removable anticorrosive coatings (1982), patent CS 196177 B1 19800331.
Removable coatings for temporary mech., anticorrosive, and antisoil protection of metal surfaces during storage and transportation contain poly(vinyl butyral) (I) 30-78, plasticizer 20-50, fillers (carbon black, bentonite) 1-20, pigments 0.01-2, dyes 0.01-2, corrosion inhibitors 0.1-3, hydrophobic agents 0.05-2, bactericides 0.1-3, and an adhesion agent 0.1-3%, and are applied as a melt or a 10-30% soln. The corrosion resistance time of metals coated with this coating increased by a factor of 21-50, compared to samples coated with common removable coatings. A typical compn. applicable as a melt comprises I 59.5, triethylene glycol di(2-ethylbutyrate) [95-08-9] 40, C18H37NH2 [124-30-1] 0.1, silicone oil 0.15, and 1-(β-aminoethy)-2-heptadecenyl-2-imidazoline oleate [84748-81-2] 0.25%.
Vosta, J., Pelikan, J., Smrz, M., Mostecky, J., Talasek, V. Bactericidal agent having an anticorrosive affect for cooling circuits (1981), patent CS 192290 B1 19790831.
An ED for 1 ton cooling water consists of an aq. emulsion contg. 2-5 g octadcylamine [124-30-1] and 0.05-0.1 g emulsifier, such as ethoxylate fatty acids or polyethylene glycol [25322-68-3]. It is combined with 5 g methylethyllaurylbenzylammonium hydroxide [81336-03-0] or 3 g dimethyllaurylbenzylammonium hydroxide [500-33-4] and 2 g cetylguanidine [48073-73-0]. It may optionally contain 0.3 g p-H2NC6H4SO2NH2 [63-74-1] and 0.2 g alkyl isothiocyanate.
Safar, M. Fousek, V.,; Slanina, F.,; Mostecky, J., Pelikan, J., Vosta, J., Smrz, M., Nemcova, J., Sverepa, O. A mixed corrosion inhibitor (1981), patent GB 2064985 A 19810624.
Corrosion-inhibiting solns. for equipment in contact with coal or natural gas comprise 5-50 parts solvent/part compn. contg. ≥1 alkalizer 5-30, ≥1 C10-25 film-forming amine 5-50, and ≥1 unsatd. fatty acid alkanolamide 10-40, and optionally imidazoline derivs. 5-25 and an ester of a fatty acid with a higher alc. 5-25%. Thus, a compn. contg. cyclohexylamine [108-91-8] 30, octadecylamine [124-30-1] 30, and unsatd. fatty acid alkanolamides 40% applied as a 10% alc. soln. showed 93% inhibition efficiency in lab. tests simulating real corrosion conditions. Two other compns. are also given.
Vosta, J., Pelikan, J., Smrz, M., Horejs, J. Cooling mixture (1981), patent CS 187766 B1 19790228.
Noncorrosive cooling liq. of low eutectic temp. for cooling circuits consists of urea 10-70, corrosion inhibitors based on cyclic oligomers of H3PO4 and Zn2+ 0.1-10, and benzothiazole (I), mercaptobenzothiazole, or their derivs. 0.1-1% in 5-80% aq. EtOH or MeOH. Thus, area 50, EtOH 20, ZnSO4 0.5, Na hexametaphosphate 1, I 0.3, and water up to 100% gave the cooling mixt. applicable to -20° for corrosion-stressed systems.
Pelikan, J., Smrz, M.; Vosta, J. Corrosion of concrete in the presence of deicing agents Razrab. Mer Zashch. Met. Korroz., Mezhdunar. Nauchno-Tekh. Konf. Probl. SEV, 3rd (1980), 5, 270-3.
The corrosion resistance of concrete in NaCl, CaCl2, NH4NO3, EtOH [64-17-5], urea [57-13-6], urea + EtOH (AM-75), and Na2SO4solns. with f.p. -8° used as deicing agents was evaluated from detns. of pH, concrete wt. changes, and CaO and SiO2 content in solns. Min. wt. loss occurred in concrete specimens immersed in CaCl2, max. in loss NH4NO3, and intermediate losses in urea + EtOH solns. Taking into account the low aggressiveness to metals, the urea + EtOH soln. is recommended as an agent for deicing roads.
Pelikan, J., Vosta, J. Study of the inhibition of corrosion of aluminum in an aqueous chloride medium Razrab. Mer Zashch. Met. Korroz., Mezhdunar. Nauchno-Tekh. Konf. Probl. SEV, 3rd (1980), 5, 66-8.
Electrochem. methods were used to study the pitting corrosion of Al in 1% NaCl soln. The breakdown potential and the repassivation potential were established as a function of the inhibitor concns. (K chromate and NaNO3). Potentiodynamic polarization curves were also plotted.
Vosta, J., Pelikan, J. Study of corrosion inhibition using faradaic impedance Razrab. Mer Zashch. Met. Korroz., Mezhdunar. Nauchno-Tekh. Konf. Probl. SEV, 3rd (1980), 5, 30-3.
Faradaic impedance measurements yield reliable information on the nature of the bond between inhibitor and metal. Therefore, the characteristics are given of the behavior of inhibitors on the metal surfaces, i.e. the extent of soly. was detd. and the chemisorption and phys.-adsorption natures of the inhibiting reactions were established. The corrosion inhibitor di-Bu sulfoxide [2168-93-6] was selected for study because it is a good inhibitor of corrosion of Fe and steel in acid (HCl) soln.
Mostecky, J., Pelikan, J., Vosta, J., Smrz, M., Nemcova, J., Sverepa, O., Safar, M., Fousek, V., Slanina, F. Mixed corrosion inhibitor for metals, (1981), patent DE 2949394 A1 19810611.
The corrosion inhibitor contains an alk. agent 5-30, film-forming C10-25 amine 5-50, and alkanolamide of unsatd. fatty acids 10-40 or imidazoline and its derivs. 5-25, or ester of fatty acids with alcs. 5-25 wt.%. The inhibitor is dild. in a solvent in a 1:(5-50) ratio. The inhibitor is suitable for protection of metal equipment used for recovery, storage, and transportation of natural gas. Typically, 0.2 L inhibitor/1000 m3 gas is injected. Thus, corrosion inhibitor contg. cyclohexylamine 30, octadecylamine [124-30-1], and alkanolamide of unsatd. fatty acids 40% was used as 10% soln. in lab. tests. The corrosion inhibitor efficiency was 93%.
Pelikan, J., Smrz, M., Vosta, J. Surface treatment of an aluminum electrode prior to electrochemical measurements Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1980), D 41, 25-33.
Treatment of the electrode in a bath composed of 80 mL concd. H3PO4, 10 mL concd. HNO3 and of 10 g citric acid for 30 s at 85° followed by pickling in a 5% aq. NaOH for 60 s was found to be the best with respect to constancy of rest potential with time.
Vosta, J., Pelikan, J., Laznicka, P. Study of corrosion inhibition by faradaic impedance Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1980), D 41, 35-41.
At the corrosion potential for Fe in 5% HCl, the sorption of dibenzyl sulfoxide is irreversible, the inhibiting reaction being proceeded by chemisorption. The inhibiting action becomes a reversible reaction at more pos. potentials. Capacitance and resistance becomes higher with decreasing frequency (10 kHz to 300 Hz) in the cathodic part of the polarization curve.
Pelikan, J., Vosta, J., Antos, M. A study of corrosion inhibition of aluminum in an aqueous chloride medium Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1980), D 41, 17-24.
Both chromates and nitrates exhibit inhibition effects only when their concn. is higher than 10-3M. Chromates at these concns. enhance the induction time but they do not affect the potential of repassivation. Nitrates do not affect the induction time. The c.d. on current-time curves did not reach 0.25 mA.cm-2 within 120 min when chromate concn. was >5 × 10-3M, in the case of nitrates concn. >10-2 M being necessary for reaching the 0.25 mA.cm-2 c.d. limit but the time course of c.d. is then decreasing. Breakdown potentials detd. by the potentiodynamic method are with increasing concn. of inhibitor shifted to pos. values more than when they are detd. by stationary methods.
Vosta, J. Pelikan, J. Eliasek, J. Corrosion inhibition Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1980), D 41, 83-103.
A review with 119 refs. on the mechanism of corrosion and classification of corrosion inhibitors is given.
Pelikan, J., Vosta, J., Mostecky, J., Smrz, M., Lohnisky, J. Liquid deicer (1980), patent CS 184118 B1 19800715.
Deicing mixts. contain an aq. urea [57-13-6] soln., EtOH [64-17-5], and a selective corrosion inhibitor. Thus, a soln. contg. urea 25, EtOH 25, ZnF2 0.04, Na hexametaphosphate 0.1%, and the balance water inhibits corrosion of hard Mg-Al alloys and is used on airfields. A soln. contg. urea 45, EtOH 5-10, ZnSO4 0.04, Na hexametaphosphate 0.08%, and the balance water inhibits corrosion of steel and is used for road
Pelikan, J., Horejs, J.,; Smrz, M., Vosta, J. Corrosion inhibitor for a neutral aqueous medium (1980), patent CS 183599 B1 19800615.
Mixts. of Na6(PO3)6 (I), benzotriazole (II) [95-14-7], and Na2MoO4 (III) have a synergistic effect manifested by decreased corrosion and deposits. The recommended ratios of I:II:III are 5:0.5:1 for a closed heating system, 5:1:1 for an open cooling charged with distd. water used for heating homes.
Pelikan, J., Vosta, J., Mostecky, J., Smrz, M., Lohnisky, J. Deicing agent for roads (1980), patent CS 183475 B1 19800515.
The agent contains urea 10-99.9, corrosion inhibitor consisting of phosphate or polyphosphate and Zn2+ compds. (e.g. F-, naphthenates, salts of fatty acids, polyphosphates) 0.1-10, and optionally nitrates 12-88% and/or org. compds. having a chemisorption or electrostatic effect (e.g. imidazole derivs). The agent is in the form of granules or aq.-alc. solns. The agent attacks the roads and bridges less than the conventional salt mixts. and is less harmful to the environment. Typically, the granulated mixt. suitable for application at low temps. consists of urea 70, Na hexametaphosphate 0.1, ZnF2 0.05, (NH4)2HPO4 0.05-0.1%, and balance NaNO3.
Pelikan, J., Vosta, J., Smrz, M. Inhibitor of pitting and intercrystal corrosion (1980),patent CS 182094 B1 19800315.
Treating cooling waters contg. Cl- with 10-4-10-2 mol/L of Na hexametaphosphate and with an alkali sulfate to obtain the SO42-/Cl- ratio of 1-3 prevented incrustation by Ca compds. and decreased corrosion. The above combination exhibited a synergistic effect.
Vosta, J., Pelikan, J., Hackerman, N. Study of the character of the inhibition reaction Annali dell'Universita di Ferrara, Sezione 5: Chimica Pura ed Applicata, Supplemento (1980), 7(Vol. 1, Eur. Symp. Corros. Inhibitors, 5th), 255-66.
In this investigation quantum chem. was applied to the study of the character of inhibition of the dissoln. reaction of Fe in aq. acid soln. by using impedance measurements. Results of HMO-LCAO calcns. were correlated with data from the electrochem. investigations of inhibition of this reaction rate by org. compds. Results of this study may also be used in the general evaluation of inhibition corrosion was catalytic processes where the interaction of the compd. with the metal or catalytic bed is involved.
Slepicka, J.; Pelikan, J.; Nekvasil, F. Use of ion exchangers for purification of chrome plating wastes Razrab. Mer Zashch. Met. Korroz., Mezhdunar. Nauchno-Tekh. Konf. Probl. SEV, 3rd (1980), 4, 119-22.
Pelikan, J.,Smrz, M., Vosta, J. Agent inhibiting corrosion of magnesium and its alloys (1980), patent CS 182093 B1 19800315.
Mg alloy systems in at. reactors were protected by treating with solns. contg. 0.02 K2SiF6 and optionally 0.005% ZnSiF6.
Pelikan, J., Smrz, M., Vosta, J. Concrete corrosion caused by deicing agents Stavivo (1979), 57(3), 84-6.
To simulate the action of deicing agents, concrete specimens were cyclically immersed 12 h in water and solns. of NaCl, CaCl2, NH4NO3, EtOH [64-17-5], urea [57-13-6], Na2SO4, and chloride-free(EtOH + urea)-contg. deicing agent AM-75 [57894-57-2]. After ≤50 cycles, concrete wt. losses, pH changes of the deicing solns., and amt. of dissolved Ca, Si, and Al were detd. The best results were obtained with AM-75.
Pelikan, J., Vosta, J., Cozl, V. Corrosion of steel in cooling water treated with peracetic acid Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1977), D 35, 87-98.
The corrosion rate of steel [12790-81-7] was detd. by immersion tests in model cooling water contg. 0.1-2% peracetic acid [79-21-0]. The corrosion rate was 5.2, 13.4, 116.0, and 278.3 g/m2-day in 0, 0.1, 1, and 2% AcOOH, resp. For concns. of 0.1 and 1%, the inhibiting effects of some inorg. compds. were detd. Best results were obtained with K2Cr2O7 and K2CrO4-(NaPO3)6-ZnSO4; the corrosion rate decreased to 3.5-1.2 and 81.7-45.4 g/m2-day in 0.1 and 1% AcOOH, resp. Of the org. inhibitors, fair results were obtained with CS(NH2)2 [62-56-6] (corrosion rate 51.5 g/m/day in 1% acid) and with Resistin K [(lauramidoethyl)pyridinium isooctyl xanthate] [54578-20-0]) which decreased the corrosion rate to 4.5 and 65.4 g/m2-day in 0.1 and 1% AcOOH, resp. Inhibitors were used in concns. of 10-3-10-2M.
Vosta, J., Pelikan, J., Vanek, F. Study of the behavior of iron in amidosulfonic acid using polarization resistance and polarization curves, Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1977), D 35, 99-112.
Polarization resistance in the dissoln. of Fe in 5% NH2SO3H strongly increases by addn. of dibenzyl sulfoxide and Resistin N (benzylpyridinium isooctyl xanthate). These inhibitors in concn. 10-3M have a good performance at 75°. The inhibitors substantially influenced the cathodic reaction.
Pelikan, J.,Vosta, J., Cozl, V. Pitting corrosion of steel in cooling water Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1977), D 35, 77-85.
Potentiokinetics polarization was used to det. the pitting potential Ep for steel in cooling water at 22 ± 2° and study the effect of inhibitors which produce a shift of Ep toward more pos. values. The lowest concns. used for the individual inhibitors were as follows: Na6P26O18 2 × 10-5, K2CrO4 5 × 10-5, ZnSO4 10-4, Na2MoO4 2 × 10-4, ZnCl2 5 × 10-4, and NaNO2 10-3M and the initial Ep value for the cooling water (-180 mV vs. SCE) was increased by 20 up to 80 mV. At higher concns. Ep continued to increase, the most pronounced effect being that of NaNO2 at concns. 2 × 10-2 and 5 × 10-2 M giving Ep values of 68 and 123 mV, resp. At low concns. of the inhibitor corrosion does not increase but pitting may take place. The concn. level is detd. by the salinity of the cooling water, esp. the content of Cl-, SO4-, NO3-, and HCO3 and the presence of org. compds. and microorganisms is also a factor.
Pelikan, J., Vosta, J.,Macura, J. A study on the corrosion of aluminum and duralumin in an inhibited sodium chloride solution Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1977), D 35, 61-75.
Potentiodynamic polarization curves were used to study the effects of inhibitors on the pitting corrosion of Al and Duralumin in satd. and dil. aq. NaCl (0.01, 0.1, 1, 3, and 5%). The possible inhibitors were: K2CrO4, K2Cr2O7, (NaPO3)6, NaH2PO4, Na2HPO4, and hexamethylenetetramine and were used in a 0.01M concn. The measurements were carried out using std. app. and the voltage change was 4.8 V/h. Low concns. of the inhibitors actually increased the pitting corrosion.
Skrdleta, V., Sykora, J.,Pelikan, J. Effect of varieties and inoculation on the content of bound amino acids in soybean seeds Rostlinna Vyroba (1975), 21(6), 597-605.
Inoculation of soybean with 3 differently effective strains of Rhizobium japonicum and symbiosis of these strains with different varieties of host soybean plants were shown to influence significantly the content of bound amino acids with respect to total N content in the seeds, as well as the content of individual bound amino acids. The inoculation affected significantly the content of total bound amino acids and the contents of arginine, phenylalanine, glutamic acid, histidine, lysine, and methionine. The most pos. effect was found for strain D 334. Also important was the effect of interactions between the host variety and inoculation. The neg. effect on the content of bound amino acids was found in the case of the variety Chippewa x strain D 216. The effective symbiosis with respect to protein synthesis was found in the case of the variety Adepta x strain D 344 and the variety Adepta x strain 331 B.
Vosta, J.; Pelikan, J.; Smrz, M. Investigation of corrosion inhibitors for iron in hydrofluoric acid Werkstoffe und Korrosion (1974), 25(10), 750-3.
Studies on the inhibition of the corrosion of Fe in 0.5-9.5% HF by gravimetry and measurements of the polarization resistance and potentiodynamic polarization revealed that dibenzyl sulfoxide and laurylpyridinium isooctylxanthate with thiourea are efficient corrosion inhibitors. Thiourea, pyridinium xanthate (Resistin K), urotropine, diphenylthiourea, diphenylthiocarbazide, and diphenylguanidine also have good inhibiting properties. The effect was interpreted generally in terms of the availability of free electron pairs.
Nekvasil, F.; Pelikan, J.; Slepicka, J. Stability of cation exchangers for regeneration of chromium and chromate electrolytes Povrchove Upravy (1974), 14(6), 29-31.
A comparative study of the stability of cation exchangers Ostion (Czechoslovakia) and Lewatit SP 120 (West Germany) was performed and the effect of porosity on the ion-exchange characteristics and their stability were investigated. A specially designed app. was used in the expts. Under exptl. conditions, all products investigated were highly resistant to the corrosive medium, Cr electrolyte. Effective capacity is ∼40% of the total capacity; this ratio proved practically independent of the no. of working cycles. In chromate electrolytes contg. 200, 300, and 400 g CrO3/l., the rate of total capacity drop depends on the concn.
Eliasek, J., Kocica, J., Panacek, F., Pelikan, J., Vcelak, L. Evaluating oxide layers in boiler tubes of steam generators Acta Hydrochimica et Hydrobiologica (1974), 2(3), 249-59.
Exptl. results show a consolidation of the protective coating with increasing temp., heat loading, steam dryness, and time of exposure. Disturbances in water circulation have a neg. effect on oxide-coating formation by leading to an increased thickness and porosity as well as to a lowering of the corrosion resistance. The presence of primary corrosion products in the water phase result (in the absence of added corrosion products) in the formation of thick, porous coatings on the surface of the metal. A comparison between equil. corrosion current, layer thickness, and corrosion resistance values show the first to be most useful as a measure of porosity of the protective layer. X-ray studies of the oxide layers show the protective layer to be composed preferentially of magnetite. Under industrial working conditions a thick, amorphous, Cu contg. coating is found, whose pores are nonhomogeneous and whose evaluation is more complex, magnetite being the preponderant constituent. It is difficult to bring equil. corrosion current values into agreement with apparent thickness and corrosion resistance under these conditions.
Pelikan, J., Voshta, J., Panaczek, F., Kiefmann, J., Eliashek, J., Mostecky, J., Tauber, J., Shvejda, V. Antifreeze salts with corrosion inhibitor (1972), patent DE 2161522 B2 19731025.
Corrosion-inhibiting antifreeze salts for roads contain 80-99.9 parts chloride, 5-15 parts spent pickling lye (from a foundry) contg. alkali metal silicate with an alkali metal oxide-SiO2 ratio 0.5-1.0:1 and transition metals, and 1-10 parts Zn and (or) alkali metal phosphates, permanganates, nitrites, chlorates, or chromates. Thus, an antifreeze salt contains NaCl 1000, lye 100, NaH2PO4·H2O 38, and KMnO4 17.6 kg.
Panacek, F., Pelikan, J., Petrova, M. Steel corrosion in inhibited organic acids Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1972), D25, 27-35.
Steel corrosion in 2% citric, uvic, and oxalic acids at flow rates of 0.2 m-sec-1 was studied in dependence on temp. and time. Urotropine, dibenzyl sulfoxide (DBSO), and Resistine N were used as inhibitors. The highest inhibitory effect for citric acid was found with Resistine N, its effect increasing with temp., at 90° being as high as 95%. The effect of DBSO was ∼10% lower. With urotropine a 95% inhibitory effect was found at 60°, while at lower and higher temps. its effect was considerably lower. Very good results of inhibition in uvic acid were obtained at 60 and 90° with DBSO. A higher inhibitory effect of Resistine N was found only at 90°. In oxalic acid the inhibitory effect of none of the inhibitors used proved to be satisfactory. The values of the inhibitory effect were mostly <40%
Ocenasek, M., Pelikan, J., Eliasek, J. Neutralization of acid waste waters from direct cooling of combustion products (1971), patent CS 139660 19710115.
H2SO3 and H2SO4 contained in flue gas wash water are removed, without salt formation, by the use of an anion exchange bed which is regenerated alternately by an alk. desulfurization soln. contg. NH4OH, (NH4)2SO4, (NH4)2SO3, and (NH4)2CO3. The effluent from resin regeneration is recycled to water used to absorb S oxides. Useful ion exchange resins are Dowex 3 and Wofatit L 150.
Markovec, L., Landa, S., Kupec, F., Pelikan, J. Isomerization of 2-ethyl-1-hexene during the displacement chromatography on various grades of silica gel Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1969), 16, 135-47.
The effect of different methods of silica gel prepn. and activation was investigated with respect to the ability to cause the isomerization of 2-ethyl-1-hexene to 3-methylheptenes during displacement chromatog.
Pelikan, J. Formation of a protective layer in boiler tubes studied by measuring hydrogen in steam Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1969), 18, 29-38.
The formation of a protective layer in boiler tubes was studied by measuring the H2 content in the steam formed by the reaction: 3Fe + 4H2O → Fe3O4 + 4H2. The protective layer was prepd. in chem. cleaned boiler tubes. Neutral, distd. and de-aerated water was used. The expts. were carried out at different pressures from 6 to 90 atm for 24, 60, and 120 hr. At 6 and 20 atm the heat flux was changed from 9.04 × 104 to 2.37 × 105 kcal/m2 hr. During all expts. the outside temp. of the boiler tubes, the circulation rate, and H content in the steam were measured and the H2 no. ω = N k' w/Fi, where N = feed rate steam (tons/hr), k'w = concn. of H2 in the steam (std. cm3/ton), and Fi = oxidn. surface (m2), was calcd. The increasing heat flux had a pos. effect on the formation of the protective layer. At a heat flux of 2.37 × 105 kcal/m2 hr, the H2 content in the steam decreased after 8 hr to 4 μg/kg and the H2 no. to 42 std. cm3/m2 hr.
Pelikan, J., Ocenasek, M., Eliasek, J. Apparatus for the determination of capacity of ion exchangers for the removal of dissolved oxygen from water (1969), patent CS 131203 19690215.
Water is satd. with O produced electrolytically with a known quantity of elec. current. Satd. water is passed through a column of ion exchanger and the decrease in the O content, removed by the ion exchanger, detd. by means of a thermally conductive cell which has the measuring filaments connected in a Whe atstone bridge. The app. excludes the influence of atm. O, does not require involved batching of O, and laborious anal. methods.
Pelikan, J. Determination of hydrogen in steam Sbornik Vysoke Skoly Chemicko-Technologicke v Praze, D: Technologie Paliv (1967), 15, 71-86.
An app. was constructed for detn. of H in steam, based on desorption of gases from the steam condensate and detn. of the content of H in these gases from measurements of thermal cond. The advantage of this app. is that it is possible to work with smaller samples and therefore it could be used also in the pilot plants where the amt. of steam/hr. was 2O with a known content of H in solns. The dependence between the temp. and H2O flow rate and the temp. of air, which was used as a carrier gas, was studied.
Pelikan, J. Apparatus to determine the content of hydrogen dissolved in water (1966), patent CS 118372 19660515.
During passage through a plate column, H is desorbed from the analyzed sample with air. A thermally conducting sensing element is provided with heated measuring wires which form a Wheatstone bridge, connected with a registration millivoltmeter. The heat makes the gases stream upwards owing to lower sp. wt. and provides the intake of air by suction.
Pelikan, J.; Nekvasil, F.; Kuncir, J.; Valal, J. Investigation of the technological isolation of I from mineralized waters Sbornik Geologickych Ved, Technologie, Geochemie (1964), 4, 161-89.
A review of methods used for the sepn. of I from mineralized waters is given. The results of expts. with the waters from Darkov (Czechoslovakia) on a model app. are described. A procedure for I production from the Darkov waters is proposed.
Pelikan, J. Production of refractory mixed oxide ceramic masses resistant at high temperature Sklar a Keramik (1961), 11, 221-2.
On the basis of chem. structure, refractory materials are classified into 4 groups: (1) basic, e.g. MgO, (2) neutral, e.g. Al2O3, (3) amphoteric, e.g. Zr oxide, and (4) acid, e.g. Zr silicates. Further the selection of raw materials, dressing of mixts., the actual prepn. of melting crucibles made of these mixts., and their firing is dealt with.
Karas, F. Pelikán, J. Preparing a silicic acid sol by means of ion exchangers (1959), patent CS 89818 19590415.
Passing 2500 ml. soln. contg. SiO2 2.63, Na2O plus K2O 0.78, NH3 0.50, CaO plus MgO 0.01, Fe2O3 plus Al2O3 0.16, SO4 ion 0.001, and chloride ion 0.001% over 1000 ml. of the acid exchanger Katex FN at a rate 50 ml./min., washing the column with 10 l. H2O, and eluting with 900 ml. of 5% HCl gives 2100 ml. soln. contg. approx. 2.6% SiO2 with a ratio of SiO2:(Na2O plus K2O) equal to 5000:1.
Karas, F. Pelikán, J. Preparation of very pure silica gel (1958) Chemický Průmysl 8 (33)2, 59-61.
Ion exchangers "Katex FN" and "Anex MFD" are suitable for prepg. a silicic acid sol from dild. water-glass; the SiO2 gel prepd. from this sol. is very pure.