Oxidation induced changes in viscoelastic properties of a thermostable epoxy matrixReport as inadecuate




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1 LAMPA - PMD - Laboratoire des Arts et Métiers ParisTech d-Angers - Procédés Matériaux Durabilité 2 PIMM - Procédés et Ingénierie en Mécanique et Matériaux Paris

Abstract : The thermal ageing of a neat epoxy matrix has been studied at 200°C in air by three complementary analytical techniques: optical microscopy, mechanical spectrometry and nano-indentation. Thermal oxidation is restricted in a superficial layer of about 195 µm of maximal thickness. It consists in a predominant chain scission process involving, in particular, chemical groups whose β motions have the highest degree of cooperativity and thus, are responsible for the high temperature side of β dissipation band. As a result, chain scissions decrease catastrophically the glass transition temperature, but also increase significantly the storage modulus at glassy plateau between Tβ and Tα. This phenomenon is called -internal antiplasticization-. Starting from these observations, the Di Marzio and Gilbert-s theories have been used in order to establish relationships between the glass transition temperature and number of chain scissions, and between the storage modulus and β transition activity respectively. The challenge is now to establish a relationship between the transition activity and the concentration of the corresponding chemical groups

Keywords : neat epoxy matrix thermal ageing chain scissions glass transition temperature Young-s modulus internal antiplasticization





Author: Svetlana Terekhina - Marion Mille - Bruno Fayolle - Xavier Colin -

Source: https://hal.archives-ouvertes.fr/



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