Oxidation, Chain Scission and Cross-Linking Studies of Polysiloxanes upon Ageings

Namrata Singh Tomer (1) , Florence Delor-Jestin (1) , Lawrence Frézet (2) , Jacques Lacoste (1)

1 Photochimie
2 ICCF - Institut de Chimie de Clermont-Ferrand

The comparison between physical properties and chemical structures of several polysiloxanes was studied at initial state and upon ageings. Techniques such as densimetry, gel permeation chromatography, FTIR spectroscopy, thermogravim- etric analysis coupled with IR spectroscopy and the new tool photo-DSC were used to give assessments of average mo- lecular weight, chemical evolution, cristallinity and thermal stability. Different types of ageing such as thermal ageing (60°C and 100°C), photo-ageing and acid vapour ageing were performed. After ageing we observed an evolution of chemical structures and physical properties for all samples. The main pathway of degradation is given for each sample. It results in oxidation, chain scission or cross-linking. Cross-linking levels are dependant on the type of ageing, the chemical structure and the initial rate of cristallinity. Cross-linking reactions are favoured after photo-ageing. Oxidation is higher for polysiloxane with aliphatic carbon chain.

Mots clés: Polysiloxane; Degradation; Thermal Properties; Cross-Linking; Cristallinity

Namrata Singh Tomer, Florence Delor-Jestin, Lawrence Frézet, Jacques Lacoste. Oxidation, Chain Scission and Cross-Linking Studies of Polysiloxanes upon Ageings. Open Journal of Organic Polymer Materials, 2012, 2, pp.13-22. ⟨hal-00787008⟩