Thermal Decomposition of Polymer/Montmorillonite Nanocomposites Synthesized in situ on a Clay Surface
This paper reports the effect of the SWy-1 montmorillonite content on the kinetic thermal degradation of poly(2-hydroxyethyl methacrylate) (PHEMA)/SWy-1 nanocomposites prepared by in situ photopolymerization, using thermogravimetry analysis (TGA). 2-Hydroxyethyl methacrylate was photopolymerized in the presence of SWy-1 clay mineral using 2-hydroxy-3- (3,4-dimethyl-9-oxo-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanium chloride (QTX) and triethanolamine as the photoinitiating system. X-Ray diffraction analysis indicates that the PHEMA/SWy-1 nanocomposites present an intercalated structure. The isoconversional Flynn-Wall-Ozawa method was used to estimate activation energies and pre-exponential factors for the thermal decomposition. All nanocomposites exhibited improvement in their thermal stability, mainly due to the large interaction between the PHEMA intercalated in the SWy-1 structure. The activation energies for PHEMA/SWy-1 nanocomposites increased when increasing the clay content. The SWy-1 clay mineral acts as a better insulator, mass transport barrier and as a "crosslinking agent", increasing the activation energies for the decomposition of the polymer present in the nanocomposites.
Main Authors: | , , , |
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Format: | Digital revista |
Language: | English |
Published: |
Sociedade Brasileira de Química
2016
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Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532016000200278 |
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Summary: | This paper reports the effect of the SWy-1 montmorillonite content on the kinetic thermal degradation of poly(2-hydroxyethyl methacrylate) (PHEMA)/SWy-1 nanocomposites prepared by in situ photopolymerization, using thermogravimetry analysis (TGA). 2-Hydroxyethyl methacrylate was photopolymerized in the presence of SWy-1 clay mineral using 2-hydroxy-3- (3,4-dimethyl-9-oxo-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanium chloride (QTX) and triethanolamine as the photoinitiating system. X-Ray diffraction analysis indicates that the PHEMA/SWy-1 nanocomposites present an intercalated structure. The isoconversional Flynn-Wall-Ozawa method was used to estimate activation energies and pre-exponential factors for the thermal decomposition. All nanocomposites exhibited improvement in their thermal stability, mainly due to the large interaction between the PHEMA intercalated in the SWy-1 structure. The activation energies for PHEMA/SWy-1 nanocomposites increased when increasing the clay content. The SWy-1 clay mineral acts as a better insulator, mass transport barrier and as a "crosslinking agent", increasing the activation energies for the decomposition of the polymer present in the nanocomposites. |
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