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1

Mechanical and thermal properties of PP/PBT blends compatibilized with triblock thermoplastic elastomer

Ignaczak W., Wiśniewska K., Janik J., El Fray M.

Polish Journal of Chemical Technology

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2015

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Vol. 17, nr 3

78--83

EN

A linear triblock copolymer, poly(styrene-b-etylene/butylene-b-styrene)(SEBS) thermoplastic elastomer (TPE) grafted with maleic anhydride was used for compatibilization of PP/PBT blends. PP/PBT blends of different mass ratios 60/40, 50/50, 40/60 were mixed with 2.5, 5.0 and 7.5 wt.% of SEBS copolymer in a twin screw extruder. Differential scanning calorimetry and dynamic mechanical analysis were performed to define the phase structure of PP/PBT blends. TPE with a rubbery mid-block shifted the glass transition of PP/PBT blend towards lower temperatures, and significant decrease the crystallization temperature of a crystalline phase of PP component was observed. The influence of the amount of compatibilizer and the blend composition on the mechanical properties (tensile and flexural strengths, toughness and moduli) was determined. Addition of 5 wt.% of a triblock TPE led to a three-fold increase of PP/PBT toughness. A significant increase of impact properties was observed for all materials compatibilized with the highest amount of SEBS copolymer.

2

Influence of Au/Fe2O3 and Au/TiO2 Catalysts Preparation on Their Activity in CO Oxidation by Oxygen and Water Gas Shift Reactions

Jóźwiak W. K., Kaczmarek E., Ignaczak W.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 1-2

213-222

EN

Supported Au/Fe2O3 and Au/TiO2 catalysts appear very active in both carbon monoxide oxidation by oxygen or water. The aim of this work was to find correlation between gold catalysts activity andmethods of their preparation (impregnation and deposition-precipitation), the influence of alkali ions additives and temperature of calcination. The physico-chemical properties of Au/Fe2O3 and Au/TiO2 catalysts were investigated by TPR, ToF-SIMS and catalytic activity methods. Carbon monoxide conversion degree in oxidation by oxygen is higher for Au/Fe2O3 than for Au/TiO2 catalyst, but the activity of gold catalysts in carbon monoxide oxidation by water is opposite. The most active catalyst was Au/Fe2O3 prepared by deposition-precipitation method with an addition of urea and those catalysts prepared by impregnation method with an addition of KOH. The analogically prepared Au/TiO2 catalyst exhibited comparable activity. The gold catalysts appear the most active after drying at 60 graduate C – the role of disordered catalyst structure and hydroxyl groups. The carbon monoxide conversion degree depends on the applied precipitate agent in the following order: KOH > Na2CO3 > NH3. The gold catalysts do not lose catalytic activity during long lasting tests (170 h) and do not suffer on the presence of moisture and chlorine in catalyst system. The impregnated Au(K)/Fe2O3 catalysts with a ratio Cl/Au = 4/1 – 8/1 show considerable activity.

3

Porównanie aktywności nośnikowych katalizatorów złotowych Au/Fe2O3, Au/TiO2, Au/Al2O3 w reakcji utleniania CO tlenem

Kaczmarek E., Ignaczak W., Jóźwiak W. K.

Przemysł Chemiczny

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2006

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T. 85, nr 8-9

734-736

PL

Zbadano i porównano aktywność katalizatorów złotowych naniesionych na Fe2O3, TiO2 i Al2O3 o zawartości fazy metalicznej 0,5–10%. Katalizatory otrzymano metodami impregnacji nośnika wodnym roztworem HAuCl4, strącania poprzez osadzanie (prec–dep) oraz współstrącania. Aktywność katalizatorów określono w reakcji utleniania CO tlenem w reaktorze przepływowym. W celu zbadania składu fazowego układów katalitycznych przeprowadzono badania XRD. Konwersję CO na katalizatorach Au/nośnik uszeregowano wg malejącej aktywności: Fe2O3 > TiO2 > Al2O3. Odnotowano również znaczący wpływ alkaliów (Na, K), powodujących obniżenie temperatury reakcji nawet o 200°C.

EN

Activity of 0.5–10% Au/Fe2O3 or /TiO2 or /Al2O3 catalysts prepd. by impregnation (with aq. HAuCl4), co-pptn., or deposition–pptn., was studied in oxidn. of 3% CO with 6% O2 in He in a flow reactor at –80 to 500°C. The conversion/ catalyst activity fell in the descending support order: Fe2O3 > TiO2 > Al2O3. Alkalis (10% KOH) activated low-activity catalysts and also reduced the reaction temp. by as much as 200oC. The copptd. and the deposited (with urea as additive) catalysts were superior (Au crystallites < 5 nm) to the impregnated catalysts. Pptn. agents affected the conversion deg. in the descending order: KOH > Na2CO3 (NaBH4) > Na2CO3 > NH3.

4

Synthesis and investigation of textural properties of silica gels

Ignaczak W., Jóźwiak K. W., Kaźmierczak A., Dominiak D., Rynkowski J., Szynkowska M. I.

Polish Journal of Chemical Technology

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2003

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Vol. 5, nr 3

35-38

EN

Texture properties and structure of silica gels prepared by so-gel processing using different types of solvents and doped with Fions have been investigated by evaluating the specific surface area and pore specific volume. Solids were characterized by nitrogen adsorption at 77 K. XRD measurements were used to determine structure and scanning electron micrographs studies (SEM) were applied to observe an image of silica.

5

Characterization of Chromium Oxide Supported on Silica

Jóźwiak W., Ignaczak W., Kincel D., Góralski J., Paryjczak T.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 6

857-873

EN

Thermal stability and redox behavior of the surface Cr-oxo structures supported upon silica were investigated by: TPR, TPO, XRD, IR and XPS techniques. During reduction in hydrogen, the surface Cr(VI) oxide phase is completely transformed into the Cr(III) oxidation state. For low loaded Cr/SiO2 samples almost fully reversible interconversion Cr(VI)Cr(III) was found during TPR - TPO cycling up to 900_C. For higher loaded samples, temperature depended oxygen - hydrogen cycling strongly influences the relative composition of chromium oxide phase supported on silica. The coexistence of three major forms of chromium oxide phase in supported CrO3/SiO2 system has been confirmed: monomolecularly dispersed chromates strongly bonded to silica surface, relatively inactive stable crystallites of _-chromia and intermediate metastable amorphous aggregates of CrO3. The relative contribution of each form strongly depends on the chromium content, method of preparation, treatment conditions (temperature, atmosphere and water traces). The anchoring of chromate-like species requires suitable support adsorption sites and their concentration is governed by hydroxyl group population. Mobile hydroxo species of CrO3 may migrate on the silica surface, anchoring to preferable adsorption sites and forming stable chromate-like species. It was also found that water is involved in the hydrolytic process of monochromated species destabilization, resulting in partial transition Cr(VI) _ Cr(III). Thermodynamically favored chromium sintering process, chromates CrO4 2_ _crystalline _-Cr2O3, requires water as destabilization agent for hydrolytic splitting of Cr - O - Si linkages and chromium oxide agglomeration.

6

Badanie właściwości sorpcyjnych i stopnia dyspersji katalizatorów palladowych otrzymanych metodą zol-żel

Ignaczak W., Jóźwiak W. K., Góralski J., Paryjczak T., Kincel D. M.

Przemysł Chemiczny

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1999

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T. 78, nr 4

140-141

7

Infrared spectroscopic study of magnesium oxide catalysts doped with sodium ions

Ignaczak W., Jóżwiak W., Szubiakiewicz E., Paryjczak T.

Polish Journal of Chemistry

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1999

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vol. 73 nr 4

645-654

EN

Infrared results concerning the surface species in MgO catalysts doped with Na+ ions are presented. Different surface carbonate structures and hydroxyls groups have been found. It was assumed that created carbonate compounds could be involved in decreasing of MgO specific surface area. Sodium carbonate and unidentate carbonate structures may cause elimination and blockage of low coordination sites of MgO surface, being responsible both for hydrogen detachment from CH4 molecules and for oxidation of methyl radicals to carbon oxides - the undesired reactions of oxidative coupling of methane (OCM). It was observed that increasing temperature led to decomposition of surface bicarbonate and unidentate carbonate structures. Some of them are being reconverted to more stable bicarbonate structures. Carbon dioxide and water desorptions result in gradual restoration of low coordinated sites of MgO, corresponding to high selectivity to C2 hydrocarbon formation. Sodium ions may also cause structural changes in MgO lattice. The catalysts were active and selective above 950 K for C2 hydrocarbon formation, although sodium carbonate is sufficiently stable under the conditions of the OCM process.

8

Reaktywność powierzchniowa tlenku wapnia w stosunku do dwutlenku węgla

Jóźwiak. W.K., Szubiakiewicz E., Gebauer D., Ignaczak W., Paryjczak T.

Zeszyty Naukowe. Chemia / Politechnika Łódzka

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1998

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Z. 46

67-79

PL

Przedmiotem poniższej pracy są badania reaktywności powierzchniowej tlenku wapnia, zarówno monoskładnikowego, jak i dotowanego jonami alkalicznymi Na+ i K+, w stosunku do CO2. Dla scharakteryzowania właściwości fizykochemicznych badanych układów zastosowano metody BET i temperaturowo programowanej desorpcji (TPD). W pracy przedstawiono również ocenę wpływu dodatku metalu alkalicznego na aktywność i selektywność badanych materiałów katalitycznych w reakcji utleniającego sprzęgania metanu.

EN

The surface reactivity of calcium oxide (both monoxide and doped with Na+ and K+ ions) towards carbon dioxide was measured in wide temperature range 25-900°C, using BET and TPD methods. The influence of alkaline metals on the catalyst activity and selectivity was tested in the reaction of the oxidative coupling of methane.