Temat: katalizator kwasowy - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Kinetic investigations on esterification of maleic anhydride with butanols
Autorzy:: Bartoszewicz, Maria
Kulawska, Maria
Organek, Wiesław
Powiązania:: https://bibliotekanauki.pl/articles/2034054.pdf
Data publikacji:: 2020
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: acidic catalysts
butyl alcohol
dibutyl maleate
esterification reaction
plasticizer
katalizator kwasowy
alkohol butylowy
reakcja estryfikacji
plastyfikator
Opis:: Kinetic studies of esterification reaction of maleic anhydride with butan-1-ol, 2-methylpropan-1-ol and butan-2-ol were carried out in a semibatch reactor, in the presence of four acidic catalysts: sulfuric acid, phosphotungstic acid, ion exchange resin Dowex 50WX8 and tetrabutyl zirconate. Phosphotungstic acid proved to be the most active catalyst. The temperature range was 383–413 K, the initial molar ratio of alcohol to acid ranged 2.2-5:1. The kinetic parameters were given. The kinetics appeared to be that of the second order with respect both to the acid and to the alcohol. The reaction carried out in the presence of tetrabutyl zirconate was very slow and depended only on acid concentration. The effect of temperature on the reaction rate follows the Arrhenius equation well.
Źródło:: Chemical and Process Engineering; 2020, 41, 4; 293-306
0208-6425
2300-1925
Pojawia się w:: Chemical and Process Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Curing Properties of Furotec 132 Resin- Bonded Foundry Sand
Autorzy:: Mashingaidze, M. M.
Powiązania:: https://bibliotekanauki.pl/articles/382717.pdf
Data publikacji:: 2019
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: Furotec 132 resin
Furocure CH
curing properties
foundry sand
acid catalyst
curing temperature
żywica Furotec 132
właściwości utwardzające
piasek odlewniczy
katalizator kwasowy
temperatura utwardzania
Opis:: The study evaluated the curing properties of natural silica sand moulded with 1% by weight Furotec 132 resin binder catalysed by Furocure CH Fast acid and Furocure CH Slow acid. Physical properties of this sand included an AFS number of 47.35, 4.40 % clay, 0 % magnetic components, 0.13 % moisture, and 64.5 % of the size distribution spread over three consecutive sieves (150 – 600 μm). The sand was washed repeatedly to remove all the clay and oven dried. 2 kg washed sand samples were mulled with pre-determined weights of either catalyst to give 30 %, 50 % and 70 % by weight of 20 g Furotec 132 resin which was added last. Furotec 132 resin + Furocure CH Slow acid catalyst system gives longer bench lives and strip times but the maximum compressive strength in excess of 5000 N/cm2 is attained after more than 8.5 hours curing time irrespective of the weight % of catalyst added relative to the resin. On that basis, exceeding 30 weight % Furocure CH Slow acid catalyst when sand moulding with Furotec 132 resin has neither technical nor economic justification. In comparison, the Furotec 132 resin + Furocure CH Fast acid catalyst system was only capable of producing mould specimens with maximum compressive strength above 5000 N/cm2 at 30 weight % catalyst addition rate. At 50 and 70 weight % catalyst addition rates, the mulled sand rapidly turned dark green then bluish with a significant spike in temperature to about 40 oC, far exceeding the optimum curing temperature of Furotec 132. This high temperature accelerates the curing rate but with a very low degree of resin curing which explains the low compressive strength. In fact the sand grains fail to bond and have a dry, crumbly texture implying dehydration. Thus, not more than 30 weight % Furocure CH Fast acid catalyst should be used in sand moulding.
Źródło:: Archives of Foundry Engineering; 2019, 4; 117-123
1897-3310
2299-2944
Pojawia się w:: Archives of Foundry Engineering
Dostawca treści:: Biblioteka Nauki

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