Kinetic of non-isothermal dehydration of equilibrium swollen poly(acrylic acid-co-methacrylic acid) hydrogel
Apstrakt
The kinetic of non-isothermal dehydration of equilibrium swollen poly(acrylic acid-co-methacrylic acid) hydrogel (PAM) has been investigated. Thermogravimetric and conversion dehydration curves were recorded at various heating rates 5-30 K min(-1). The conversion dehydration curves at all investigated temperatures can be mathematically described using the logistic regression function in entire. It was found that activation energy complexly changes with the increasing dehydration degree. Physical meaning of the parameters of logistic function (band w) is given. It was established that, during the dehydration, changes in the fluctuating hydrogel structure occur, and that limiting step on the kinetics of hydrogel dehydration have rate of structural rearrangement of hydrogel (actual relaxation mechanism). A procedure for determining the dependence of effective activation energy on temperature and dehydration degree, based on logistic function, is exposed. Possible explanation for the exist...ence of negative values of activation energy in the certain range of temperature, is given. (C) 2010 Elsevier B.V. All rights reserved.
Ključne reči:
Hydrogel / Non-isothermal dehydration / Kinetic / Logistic functionIzvor:
Thermochimica Acta, 2011, 512, 1-2, 157-162Finansiranje / projekti:
- Fizička hemija dinamičkih stanja i struktura neravnotežnih sistema - od monotone do oscilatorne evolucije i haosa (RS-MESTD-MPN2006-2010-142025)
DOI: 10.1016/j.tca.2010.09.019
ISSN: 0040-6031
WoS: 000286863600025
Scopus: 2-s2.0-78650269708
Kolekcije
Institucija/grupa
VinčaTY - JOUR AU - Adnađević, Borivoj AU - Tasić, Gvozden S. AU - Jovanović, Jelena PY - 2011 UR - https://vinar.vin.bg.ac.rs/handle/123456789/4207 AB - The kinetic of non-isothermal dehydration of equilibrium swollen poly(acrylic acid-co-methacrylic acid) hydrogel (PAM) has been investigated. Thermogravimetric and conversion dehydration curves were recorded at various heating rates 5-30 K min(-1). The conversion dehydration curves at all investigated temperatures can be mathematically described using the logistic regression function in entire. It was found that activation energy complexly changes with the increasing dehydration degree. Physical meaning of the parameters of logistic function (band w) is given. It was established that, during the dehydration, changes in the fluctuating hydrogel structure occur, and that limiting step on the kinetics of hydrogel dehydration have rate of structural rearrangement of hydrogel (actual relaxation mechanism). A procedure for determining the dependence of effective activation energy on temperature and dehydration degree, based on logistic function, is exposed. Possible explanation for the existence of negative values of activation energy in the certain range of temperature, is given. (C) 2010 Elsevier B.V. All rights reserved. T2 - Thermochimica Acta T1 - Kinetic of non-isothermal dehydration of equilibrium swollen poly(acrylic acid-co-methacrylic acid) hydrogel VL - 512 IS - 1-2 SP - 157 EP - 162 DO - 10.1016/j.tca.2010.09.019 ER -
@article{ author = "Adnađević, Borivoj and Tasić, Gvozden S. and Jovanović, Jelena", year = "2011", abstract = "The kinetic of non-isothermal dehydration of equilibrium swollen poly(acrylic acid-co-methacrylic acid) hydrogel (PAM) has been investigated. Thermogravimetric and conversion dehydration curves were recorded at various heating rates 5-30 K min(-1). The conversion dehydration curves at all investigated temperatures can be mathematically described using the logistic regression function in entire. It was found that activation energy complexly changes with the increasing dehydration degree. Physical meaning of the parameters of logistic function (band w) is given. It was established that, during the dehydration, changes in the fluctuating hydrogel structure occur, and that limiting step on the kinetics of hydrogel dehydration have rate of structural rearrangement of hydrogel (actual relaxation mechanism). A procedure for determining the dependence of effective activation energy on temperature and dehydration degree, based on logistic function, is exposed. Possible explanation for the existence of negative values of activation energy in the certain range of temperature, is given. (C) 2010 Elsevier B.V. All rights reserved.", journal = "Thermochimica Acta", title = "Kinetic of non-isothermal dehydration of equilibrium swollen poly(acrylic acid-co-methacrylic acid) hydrogel", volume = "512", number = "1-2", pages = "157-162", doi = "10.1016/j.tca.2010.09.019" }
Adnađević, B., Tasić, G. S.,& Jovanović, J.. (2011). Kinetic of non-isothermal dehydration of equilibrium swollen poly(acrylic acid-co-methacrylic acid) hydrogel. in Thermochimica Acta, 512(1-2), 157-162. https://doi.org/10.1016/j.tca.2010.09.019
Adnađević B, Tasić GS, Jovanović J. Kinetic of non-isothermal dehydration of equilibrium swollen poly(acrylic acid-co-methacrylic acid) hydrogel. in Thermochimica Acta. 2011;512(1-2):157-162. doi:10.1016/j.tca.2010.09.019 .
Adnađević, Borivoj, Tasić, Gvozden S., Jovanović, Jelena, "Kinetic of non-isothermal dehydration of equilibrium swollen poly(acrylic acid-co-methacrylic acid) hydrogel" in Thermochimica Acta, 512, no. 1-2 (2011):157-162, https://doi.org/10.1016/j.tca.2010.09.019 . .