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Wyszukujesz frazę "methylcellulose" wg kryterium: Temat


Wyświetlanie 1-5 z 5
Tytuł:
Application of chitosan in the formulation of methyl cellulose-based hydrogels
Autorzy:
Szcześniak, Maria
Grimling, Bożena
Meler, Jan
Pluta, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/1035190.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
chitosan
methylcellulose
pharmaceutical availability
rheological parameters
Opis:
The aim of this work was to study the properties of methylcellulose hydrogels with supplements containing chitosan and 1% hydrocortisone. Depending on the composition of the substrate, gels are characterised by a variety of pharmaceutical availabilities. Increasing the concentration of chitosan has an influence on increasing the viscosity, hardness, and cohesiveness of the tested gels.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2014, 19; 139-144
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rheological behavior of polymer-based drilling fluids: experimental study of temperature effects
Autorzy:
Safi, Brahim
Aboutaleb, Djamila
Haider, Soumya
Powiązania:
https://bibliotekanauki.pl/articles/45423959.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
polimery
naprężenie
lepkość
reologia
polymers
methylcellulose carboxylate
drilling fluid
shear stress
viscosity
rheological behavior
Opis:
Drilling fluids most commonly used are generally based on polymers. Polymers such as methylcellulose carboxylate (CMC), polyanionic cellulose (PAC) and xanthan (Xn) have a very important role in the success of drilling operations. Indeed, they are also used to improve certain properties, in particular rheological. However, these polymers can lose their characteristics under the influence of increasing temperature at the bottom of oil wells, thus affecting the ability of the mud to perform its useful role in the drilling operation, namely to raise the cuttings from the bottom of the well to the surface. The present work aims to study the effect of temperature on the main rheological properties (shear stress and plastic viscosity) as well as on the rheological behavior of water-based drilling muds (WBM). WBM_CMC and WBM_PAC (at Xn content fixed) were selected to evaluate the temperature effect (20°C; 40°C; 60°C and 80°C) on the rheological parameters and the rheological behavior. The results revealed that the shear stress and the plastic viscosity of the studied muds were considerably affected by an increase in temperature. A significant decrease in these drilling mud parameters as a function of temperature up to 80°C. A reduction of 58.8% in shear stress and 78.5% in plastic viscosity was observed. The results show that regardless of the test temperature, the shear thinning behavior of the WBM_CMC and WBM_PAC drilling muds is the same as the Herschel-Bulkley model.
Źródło:
International Journal of Applied Mechanics and Engineering; 2023, 28, 1; 95-104
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and validation of analytical method for assessment of calcium dobesilate in varied hydrogel compositions
Autorzy:
Lisik, Anna
Pilch, Ewa
Słowiak, Laura
Musiał, Witold
Powiązania:
https://bibliotekanauki.pl/articles/895665.pdf
Data publikacji:
2018-08-31
Wydawca:
Polskie Towarzystwo Farmaceutyczne
Tematy:
HPLC
Hydrogel
validation
calcium dobesilate
methylcellulose
Opis:
Standardized analytical methods for testing pharmaceutical preparations are not readily available in the literature for calcium dobesilate hydrogels. The aim of the study was to develop and validate analytical method for methylcellulose gel containing calcium dobesilate as an active ingredient. Samples from dissolution experiments were assessed via HPLC with UV-VIS detector. The optimal composition of mobile phase included acetonitrile with water 1:1, acidified to 2.5 pH value. The applied column was Standard Purospher Star 18e 250 x 4.6 (5µm), and the maximum wavelength was set on 240 nm, at 25 °C. The total run time of analysis was set at 5 min and acquired retention time was 2.7 and 3.1 min for calcium dobesilate depending on the hydrogel formulation. Validity study of the method revealed that all obtained calibration curves showed good linearity (r2 > 0.9927). Linearity (100% level) was found to be 99.42, 100.12, 99.48, 99.89, 100.70, 100.08, 99.82, 100.23 for A, B, C, D, E, F, G and H formulation, respectively. Accuracy was in the range of 98-102% on three different spike levels for all eight formulations. Precision results was around 100% with RSD lower than 1% in all cases indicating that the method can be used as a validated method. Limit of quantitation (LOQ) was found to be 13.25 μg∙ml-1 for all eight formulations. The method is feasible for evaluation of hydrophilic gels with calcium dobesilate.
Źródło:
Acta Poloniae Pharmaceutica - Drug Research; 2018, 75, 4; 843-849
0001-6837
2353-5288
Pojawia się w:
Acta Poloniae Pharmaceutica - Drug Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
UV polymerization and property analysis of maleacylated methyl cellulose acrylic acid absorbent resin
Autorzy:
Li, Ying
Sawut, Amatjan
Hou, Gongbo
He, Mingyu
Yimit, Mamatjan
Powiązania:
https://bibliotekanauki.pl/articles/778577.pdf
Data publikacji:
2020
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
ultraviolet
maleylated methylcellulose
absorbent resin
Opis:
In this paper, maleic anhydride (MA) was grafted onto methyl cellulose (MC) and then reacted with acrylic acid to synthesize a high gel strength and fast water absorption resin (AA-co-MC-g-MA) by UV polymerization. The reaction conditions of maleylated methylcellulose (MC-g-MA) were investigated, including the ratio of MC to MA, reaction time and catalyst amount. In addition, the reaction conditions for the synthesis of super absorbent resin were as follows: the amount of MC-g-MA, the degree of substitution of MC-g-MA, polymerization time, and the amount of initiator. Under optimal conditions, the maximum water absorption volume of synthetic resin was 2116 g/g, and the maximum salt absorption rate was 139 g/g. The water absorption resin prepared this time had high water absorption, water retention, excellent pH sensitivity, etc. It was hoped that it will have a good application prospect in the field of industrial production and agriculture in the future.
Źródło:
Polish Journal of Chemical Technology; 2020, 22, 2; 34-41
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative study on physicochemical properties of alpha-TCP / calcium sulphate dihydrate biomicroconcretes containing chitosan, sodium alginate or methylcellulose
Autorzy:
Czechowska, Joanna
Zima, Aneta
Ślósarczyk, Anna
Powiązania:
https://bibliotekanauki.pl/articles/307328.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
alpha-tricalcium phosphate
calcium sulphate
chitosan
sodium alginate
methylcellulose
biomicroconcrete
siarczan wapnia
chitozan
alginian sodu
metyloceluloza
Opis:
Recently, the attention has been drawn to complex systems – biomicroconcretes composed of a bone cement matrix and resorbable granules or microspheres. This paper presents novel bone substitutes composed of α-tricalcium phosphate (α-TCP; cement matrix), calcium sulphate dihydrate granules (GCSD; aggregates in biomicroconcrete) and various polymers (chitosan, sodium alginate, methylcellulose) used for the improvement of material properties. The aim of this work was to study α-TCP-GCSD-polymer interactions and to compare the impact of organic additives on the physicochemical properties of biomicroconcretes. Methods: Scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), X-ray diffractometry (XRD) as well as universal testing machine (INSTRON), Gilmore apparatus and pH/ conduct-meter were used. Results: The chemical bonding between α-TCP matrix and CSD granules resulted in a compressive strength appropriate for low-load bearing applications (7–12 MPa) and clinically relevant setting times (8–33 min). Biomicroconcretes consisting of sodium alginate possessed the highest mechanical strength (12 ± 2 MPa). It has also been found that the dissolution-precipitation reactions of the α-TCP were retarded with the addition of chitosan and acetic acid. This effect was not observed in the case of methylcellulose and sodium alginate. Chemical stability and bioactivity of materials were demonstrated during in vitro studies in simulated body fluid. Conclusions: Materials containing calcium sulphate-based granules were surgically handy, possessed promising physicochemical properties and are supposed to ensure desired macroporosity as well as gradual resorption in vivo. It has been demonstrated that the presence of CSD granules and polymers influenced the physicochemical properties of composites.
Źródło:
Acta of Bioengineering and Biomechanics; 2020, 22, 1; 47-56
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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