Evaluation of Thermal Degradation Kinetics of Hybrid Cellulose Acetate Membranes using Isoconversional Methods
DOI:
https://doi.org/10.14295/vetor.v32i1.13766Keywords:
Degradation Kinetics, Cellulose Acetate Membranes, Hybrid Membranes, Isoconversional MethodsAbstract
Cellulose acetate membranes are widely used in industry, emphasizing water purification processes, such as desalination. With some limiting mechanical properties, the synthesis of hybrid membranes appears as an alternative for developing high-performance materials. For its application, knowledge of thermal stability is crucial. In this work, the thermal degradation kinetics of AC-SiO2-(CH2)3NH2 hybrid cellulose acetate membranes are evaluated from thermogravimetric analysis, at three heating rates, 5, 10, and 20°C/min. The isoconversional methods proposed by Kissinger, Flynn-Wall-Ozawa, and Friedman were used for the present study of degradation kinetics. It was observed that insertion of silicon to polymeric structure promoted thermal stability to the membrane, presenting higher activation energy than pure cellulose acetate membrane, increasing from 240.28 to 1039.01 KJ/mol, using the method of Friedman. In contrast, the increase in nitrogen concentration decreases its thermal stability compared to the cellulose acetate membrane with incorporated silicon, reducing the activation energy from 1039.01 to 250.50 KJ/mol. However, it is more stable than the pure cellulose acetate membrane. The evaluation carried out in this study explained the influence of the minimum variation in the chemical composition against the thermal stability of hybrid membranes, being a factor of great importance for its application.
Downloads
References
N. M. José, L. A. S. A. Prado, “Hybrid organic-inorganic materials: preparation and some applications,” Química Nova, vol. 28, no. 2, pp. 281-288, 2005.
M. C. Andrade, J. C. Pereira, N. de Almeida, P. Marques, M. Faria, M. C. Gonçalves, “Improving hydraulic permeability, mechanical properties, and chemical functionality of cellulose acetate-based membranes by co-polymerization with tetraethyl orthosilicate and 3-(aminopropyl)triethoxysilane," Carbohydrate Polymers, vol. 261, 2021. Available at: https://doi.org/10.1016/j.carbpol.2021.117813
G. Mendes, M. Faria, A. Carvalho, M. C. Gonçalves, M. N. de Pinho, “Structure of water in hybrid cellulose acetate-silica ultrafiltration membranes and permeation properties,” Carbohydrate Polymers, vol. 189, 2018. Available at: https://doi.org/10.1016/j.carbpol.2018.02.030
I. Peixoto, M. Faria, M.C. Gonçalves, “Synthesis and Characterization of Novel Integral Asymmetric Monophasic Cellulose–Acetate/Silica/Titania And Cellulose–Acetate/Titania Membranes,” Membranes, vol. 10, no. 9, 2020. Available at: https://doi.org/10.3390/membranes10090195
F. M. B. Coutinho, I. L. Mello, L. C. de Santa Maria, “Polyethylene: Main Types, Properties and Applications,” Polymers: Science and Technology, vol. 13, no. 1, pp. 1-13, 2003. Available at: https://doi.org/10.1590/S0104-14282003000100005
G. D. G. Mendes, “New Asymmetric Mixed Matrix Membranes of Cellulose and Silica Acetate,” Master's Dissertation, Post-Graduate Integrated Master's Program in Chemical Engineering, Instituto Superior Técnico de Lisboa, Lisbon, Portugal, 2016. Available at: https://fenix.tecnico.ulisboa.pt/cursos/meq/dissertacao/1691203502342679
V. M. K. da Rocha, “Study of The Degradation Kinetics of Polyester Resin From a Renewable Source,” Master's Dissertation, Postgraduate Program in Mining, Metallurgical and Materials Engineering, Federal University of Rio Grande do Sul, Porto Alegre, Brazil, 2018. Available at: https://lume.ufrgs.br/handle/10183/195760
S. Djalma, “Thermal Stability Study of Cellulose Acetate Propionate Modified With Short-Chain Polyhydroxyalkanes,” Master's Dissertation, Graduate Program in Engineering and Materials Science, State University of Norte Fluminense, Campos do Goytacazes, Brazil, 2006. Available at: https://uenf.br/posgraduacao/engenharia-de-materiais/Mestrado-Djalma.pdf
I. C. de Miranda, “Study of The Kinetic Parameters of Thermal Decomposition of Lignocellulosic Residues And Characterization By Ta, Ftir And Edxrf,” Doctoral Thesis, Postgraduate Program in Chemical and Biochemical Process Technology, Federal University of Rio de Janeiro, Rio de Janeiro, 2013. Available at: http://epqb.eq.ufrj.br/wp-content/uploads/2021/10/d13_17.pdf