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dc.creatorRodríguez-Baeza,Mario
dc.creatorNeira C.,Andrónico
dc.creatorAguilera J.,Carlos
dc.date2003-06-01
dc.date.accessioned2019-11-14T12:57:06Z
dc.date.available2019-11-14T12:57:06Z
dc.identifierhttps://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0717-97072003000200013
dc.identifier.urihttps://revistaschilenas.uchile.cl/handle/2250/118101
dc.descriptionThe 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.
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dc.languageen
dc.publisherSociedad Chilena de Química
dc.relation10.4067/S0717-97072003000200013
dc.rightsinfo:eu-repo/semantics/openAccess
dc.sourceJournal of the Chilean Chemical Society v.48 n.2 2003
dc.subjectPoly(methylsiloxane)
dc.subjectthermogravimetry
dc.subjectcross-linking degree
dc.subjectlinear and cross-linked structures
dc.titleTHERMOGRAVIMETRIC STUDY OF THE FORMATION OF CROSS-LINKED STRUCTURES IN THE SYNTHESIS OF POLY(METHYLSILOXANE)


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