THERMOGRAVIMETRIC STUDY OF THE FORMATION OF CROSS-LINKED STRUCTURES IN THE SYNTHESIS OF POLY(METHYLSILOXANE)

The thermogravimetric analysis resulted to be an analytical technique, very illustrative that allowed us to determine the thermal stability, molecular structure and the formation process of cross-linked structures, in the synthesis of poly(methylsiloxane). Poly(methylsiloxane) was synthesized by cat...

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Autores principales:	Rodríguez-Baeza,Mario, Neira C.,Andrónico, Aguilera J.,Carlos
Lenguaje:	English
Publicado:	Sociedad Chilena de Química 2003
Materias:	Poly(methylsiloxane) thermogravimetry cross-linking degree linear and cross-linked structures
Acceso en línea:	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072003000200013
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spelling	oai:scielo:S0717-970720030002000132004-01-29THERMOGRAVIMETRIC STUDY OF THE FORMATION OF CROSS-LINKED STRUCTURES IN THE SYNTHESIS OF POLY(METHYLSILOXANE)Rodríguez-Baeza,MarioNeira C.,AndrónicoAguilera J.,Carlos Poly(methylsiloxane) thermogravimetry cross-linking degree linear and cross-linked structures The thermogravimetric analysis resulted to be an analytical technique, very illustrative that allowed us to determine the thermal stability, molecular structure and the formation process of cross-linked structures, in the synthesis of poly(methylsiloxane). Poly(methylsiloxane) was synthesized by cationic ring-opening polymerization of the cyclic monomer 1, 3, 5, 7-tetramethylcyclotetrasiloxane. A series of polymers were obtained by varying polymerization times. The initial and maximum decomposition temperatures increase to higher polymerization time until constant values are reached. At short polymerization time mainly linear polymers are formed with small fraction of cross-linked structures. At higher polymerization time partial and total cross-linked polymers are obtained. Formation of cross-linked structures stabilizes thermically the whole polymeric matrix, being the stability proportional to the cross-linking degree. The thermogravimetric analysis allowed us to formulate a method to determine the cross-linking degree of these polymers. FT-IR analysis showed the existence of the absorption band of variable intensity, corresponding to the vibration of the Si-H bond, in all the studied polymers. FT-IR spectra of the residual ceramic powder obtained by pyrolysis showed the typical absorption bands of these materials. The characterization of the polymers was also carried out by thermomechanical analysis. Kinetic decomposition parameters such us pre-exponential factors, decomposition reaction orders and activation energies were determined by thermogravimetry.info:eu-repo/semantics/openAccessSociedad Chilena de QuímicaJournal of the Chilean Chemical Society v.48 n.2 20032003-06-01text/htmlhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072003000200013en10.4067/S0717-97072003000200013
institution	Scielo Chile
collection	Scielo Chile
language	English
topic	Poly(methylsiloxane) thermogravimetry cross-linking degree linear and cross-linked structures
spellingShingle	Poly(methylsiloxane) thermogravimetry cross-linking degree linear and cross-linked structures Rodríguez-Baeza,Mario Neira C.,Andrónico Aguilera J.,Carlos THERMOGRAVIMETRIC STUDY OF THE FORMATION OF CROSS-LINKED STRUCTURES IN THE SYNTHESIS OF POLY(METHYLSILOXANE)
description	The thermogravimetric analysis resulted to be an analytical technique, very illustrative that allowed us to determine the thermal stability, molecular structure and the formation process of cross-linked structures, in the synthesis of poly(methylsiloxane). Poly(methylsiloxane) was synthesized by cationic ring-opening polymerization of the cyclic monomer 1, 3, 5, 7-tetramethylcyclotetrasiloxane. A series of polymers were obtained by varying polymerization times. The initial and maximum decomposition temperatures increase to higher polymerization time until constant values are reached. At short polymerization time mainly linear polymers are formed with small fraction of cross-linked structures. At higher polymerization time partial and total cross-linked polymers are obtained. Formation of cross-linked structures stabilizes thermically the whole polymeric matrix, being the stability proportional to the cross-linking degree. The thermogravimetric analysis allowed us to formulate a method to determine the cross-linking degree of these polymers. FT-IR analysis showed the existence of the absorption band of variable intensity, corresponding to the vibration of the Si-H bond, in all the studied polymers. FT-IR spectra of the residual ceramic powder obtained by pyrolysis showed the typical absorption bands of these materials. The characterization of the polymers was also carried out by thermomechanical analysis. Kinetic decomposition parameters such us pre-exponential factors, decomposition reaction orders and activation energies were determined by thermogravimetry.
author	Rodríguez-Baeza,Mario Neira C.,Andrónico Aguilera J.,Carlos
author_facet	Rodríguez-Baeza,Mario Neira C.,Andrónico Aguilera J.,Carlos
author_sort	Rodríguez-Baeza,Mario
title	THERMOGRAVIMETRIC STUDY OF THE FORMATION OF CROSS-LINKED STRUCTURES IN THE SYNTHESIS OF POLY(METHYLSILOXANE)
title_short	THERMOGRAVIMETRIC STUDY OF THE FORMATION OF CROSS-LINKED STRUCTURES IN THE SYNTHESIS OF POLY(METHYLSILOXANE)
title_full	THERMOGRAVIMETRIC STUDY OF THE FORMATION OF CROSS-LINKED STRUCTURES IN THE SYNTHESIS OF POLY(METHYLSILOXANE)
title_fullStr	THERMOGRAVIMETRIC STUDY OF THE FORMATION OF CROSS-LINKED STRUCTURES IN THE SYNTHESIS OF POLY(METHYLSILOXANE)
title_full_unstemmed	THERMOGRAVIMETRIC STUDY OF THE FORMATION OF CROSS-LINKED STRUCTURES IN THE SYNTHESIS OF POLY(METHYLSILOXANE)
title_sort	thermogravimetric study of the formation of cross-linked structures in the synthesis of poly(methylsiloxane)
publisher	Sociedad Chilena de Química
publishDate	2003
url	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072003000200013
work_keys_str_mv	AT rodriguezbaezamario thermogravimetricstudyoftheformationofcrosslinkedstructuresinthesynthesisofpolymethylsiloxane AT neiracandronico thermogravimetricstudyoftheformationofcrosslinkedstructuresinthesynthesisofpolymethylsiloxane AT aguilerajcarlos thermogravimetricstudyoftheformationofcrosslinkedstructuresinthesynthesisofpolymethylsiloxane
_version_	1718445325591511040

THERMOGRAVIMETRIC STUDY OF THE FORMATION OF CROSS-LINKED STRUCTURES IN THE SYNTHESIS OF POLY(METHYLSILOXANE)

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