Thermal decomposition kinetics of benzofuran derived polymer/organosilicate nanocomposites
Keywords:
Activation energy, benzofuran, polymer/silicate nanocomposites, reaction mechanism, thermal decomposition kinetics.Abstract
Benzofuran derived polymer poly(2-(5-bromo benzofuran-2-yl)-2-oxoethylmethacrylate)/organically modified montmorillonite nanocomposites were preparedvia in situ polymerization technique. Vinyl benzyl dimethyl hexadecyl ammoniumchloride was used as organic-modifier. X-ray diffraction analysis showed the silicatedispersion in the polymer matrix with an exfoliated structure.The thermal stabilitiesof nanocomposites were increased with loading organosilicate in the polymermatrix. The decomposition temperature of 5 wt% organosilicate nanocomposite at10% weight loss was approximately 14 °C higher than that of pure polymer. Kineticanalysis of the decomposition process in nanocomposites was evaluated from dynamicexperiments by means of Flynn-Wall-Ozawa and Coats-Redfern methods within 12%- 22% decomposition conversion range. Introduction of the silicate phase in polymerenhanced the apparent activation energy from 163.31 kJ/mol to 195.28 kJ/mol. Themechanism of thermal degradation for pure polymer in this conversion range probablyfollowed a deceleration type phase boundary controlled reaction (R3), whereas in caseof nanocomposites, it shifted to dimensional diffusion type (Dn).
References
Banihashemi, A. & Abdolmaleki, A. (2004) Novel aromatic polyimides derived from benzofuro[2,3-b]
benzofuran-2,3,8,9-tetracarboxylic dianhydride (BBTDA). European Polymer Journal, 40:1629-
Benhacine, F., Yahiaoui, F. & Hadj-Hamou, A.S. (2014) Thermal stability and kinetic study of isotactic
polypropylene/Algerian bentonite nanocomposites prepared via melt blending. Journal of Polymers,
:426470.
Bourbigot, S., Gilman, J.W. & Wilkie, C.A. (2004) Kinetic analysis of the thermal degradation of
polystyrene-montmorillonite nanocomposites. Polymer Degradation and Stability, 84:483-492.
Coats, A.W. & Redfern, J.P. (1964) Kinetic parameters from thermogravimetric data. Nature, 201:
-69.
Fan, X.W., Xia, C.J. & Advincula, R.C. (2003) Intercalation of polymerization initiators into
montmorillonite platelets: free radical vs. anionic initiator clays. Colloids and Surfaces A:
Physicochemical and Engineering Aspects, 219:75-86.
Flynn, J.H. & Wall, L.A. (1966) A quick, direct method for the determination of activation energy from
thermogravimetric data. Journal of Polymer Science Part B: Polymer Letters, 4:323–328.
Fraga, F. & Nunez, E.R. (2001) Activation energies for the epoxy system BADGE n=0/m-XDA obtained
using data from thermogravimetric analysis. Journal of Applied Polymer Science, 80:776-782.
Fu, X. & Qutubuddin, S. (2001) Polymer-clay nanocomposites: exfoliation of organophilic
montmorillonite nanolayers in polystyrene. Polymer, 42:807-813.
Garcia, N., Corrales, T., Guzman, J. & Tiemblo, P. (2007) Understanding the role of nanosilica particle
surfaces in the thermal degradation of nanosilicaepoly(methyl methacrylate) solution-blended
nanocomposites: From low to high silica concentration Polymer Degradation and Stability, 92:635-
Gilman, J.W., Jackson, C.L., Morgan, A.B., Harris, R. & Manias, E. et al. (2000) Flammability
properties of polymer-Layered-silicate nanocomposites.Polypropylene and polystyrene
nanocomposites. Chemistry of Materials, 12:1866-1873.
Hu, Y.H., Chen, C.Y. & Wang, C.C. (2004) Viscoelastic properties and thermal degradation kinetics of
silica/PMMA nanocomposites. Polymer Degradation and Stability, 84:545-553.
Katritzky, A.R., Fali, C.N. & Li, J.Q. (1997) General synthesis of polysubstitutedbenzo[b]furans. Journal
of Organic Chemistry, 62:8205-8209.
Kaya, E., Kurt, A. & Er, M. (2012) Thermal degradation behavior of methyl methacrylate derived
copolymer. Journal of Nanoscience and Nanotechnology, 12:8502-8512.
Koca, M., Dagdelen, F. & Aydogdu, Y. (2004) Thermal and optical properties of benzofuran-2-yl-3-
phenyl-3-methylcyclobutyl thiosemicarbazone. Materials Letters, 58:2901-2905.
Koca, M., Kurt, A., Kirilmis, C. & Aydogdu, Y. (2012) Synthesis, characterization, and thermal
degradation of novel poly(2-(5-bromo benzofuran-2-yl)-2-oxoethyl methacrylate). Polymer
Engineering and Science, 52:323-330.
Krishna, S.V. & Pugazhenthi, G. (2011) Properties and thermal degradation kinetics of polystyrene/
organoclay nanocomposites synthesized by solvent blending method: Effect of processing conditions
and organoclay loading. Journal of Applied Polymer Science, 120:1322-1336.
Kurt, A. & Koca, M. (2014) Blending of poly(ethyl methacrylate) with poly(2-hydroxy-3-phenoxypropyl
methacrylate): Thermal and optical properties. Arabian Journal for Science and Engineering,
:5413-5420.
Kurt, A. & Koca, M. (2015) Optical properties of poly(2-(5-bromo benzofuran-2-yl)-2-oxoethyl
methacrylate)/organoclay nanocomposites. Arabian Journal for Science and Engineering, doi:
1007/s13369-015-1738-2.
Kurt, A. (2009) Thermal decomposition kinetics of poly(nButMA-b-St) diblock copolymer synthesized
by ATRP. Journal of Applied Polymer Science, 114:624-629.
Lee, M.H., Dan, C.H., Kim, J.H., Cha, J. & Kim, S. et al. (2006) Effect of clay on the morphology and
properties of PMMA/poly(styrene-co-acrylonitrile)/clay nanocomposites prepared by melt mixing.
Polymer, 47:4359-4369.
Leszczyńska, A., Njuguna, J., Pielichowski, K. & Banerjee, J.R. (2007) Polymer/montmorillonite nanocomposites with improved thermal properties. Part II: Thermal stability of montmorillonite
nanocomposites based on different polymeric matrixes. Thermochimica Acta, 454:1–22.
Li, L.Q., Guan, C.X., Zhang, A. Q., Chen, D.H. & Qing, Z.B. (2004) Thermal stabilities and the thermal
degradation kinetics of polyimides. Polymer Degradation and Stability, 84:369-373.
Li, S.D., Peng, Z., Kong, L.X. & Zhong, J.P. (2006) Thermal degradation kinetics and morphology of
natural rubber/silica nanocomposites. Nanoscience and Nanotechnology, 6:541-546.
Madejova, J. & Komadel, P. (2001) Baseline studies of the clay minerals society source clays: Infrared
methods. Clays and Clay Minerals, 49:410-432.
Madurai, S.L., Joseph, S.W., Mandal, A.B., Tsibouklis, J. & Reddy, B.S.R. (2011) Intestine-specific,
oral delivery of captopril/montmorillonite: Formulation and release kinetics. Nanoscale Research
Letters, 6:15.
Ozawa, T. (1986) Applicability of Friedman plot. Journal of Thermal Analysis, 31:547–551.
Panwar, A., Choudhary, V. & Sharma, D.K. (2011) A review:polystyrene/clay nanocomposites. Journal
of Reinforced Plastics and Composites, 30:446-459.
Pokladko, M., Sanetra, J., Gondek, E., Bogdal, D. & Niziol, J. et al. (2008) Synthesis and polymerisation
of novel methacrylates with carbazolyl and benzofuranyl pendant groups for photovoltaic
applications. Molecular Crystals and Liquid Crystals, 484:701-710.
Polshettiwar, V. & Varma, R.S. (2007) Greener and sustainable approaches to the synthesis of
pharmaceutically active heterocycles. Current Opinion in Drug Discovery & Development,
:723-737.
Vyazovkin, S., Dranca, I., Fan, X. & Advincula, R. (2004) Kinetics of the thermal and thermo-oxidative
degradation of a polystyrene-clay nanocomposites. Macromolecular Rapid Communications,
:498-503.
Xu, J., Nie, G., Zhang, S., Han, X. & Pu, S. et al. (2005) Electrosyntheses of poly(2,3-benzofuran) films
in boron trifluoride diethyl etherate containing poly(ethylene glycol) oligomers. European Polymer
Journal, 41:1654-1661.
Zhang, H., Guo, E., Fang, Y., Ren, P. & Yang, W. (2009) Synthesis and optoelectronic properties of
alternating benzofuran/terfluorene copolymer with stable blue emission. Journal of Polymer
Science: Part A: Polymer Chemistry, 47:5488-5497.
Zhang, W.A., Chen, D.Z., Xu, H.Y., Shen, X.F. & Fang, Y.E. (2003) Influence of four different types of
organophilic clay on the morphology and thermal properties of polystyrene/clay nanocomposites
prepared by using the γ-ray irradiation technique. European Polymer Journal, 39:2323–2328.
