Thermal properties of siliconized epoxy interpenetrating coatings

This work involves the development of a novel siliconized epoxy interpenetrating coating system using epoxy resin as base, hydroxyl-terminated polydimethylsiloxane (HTPDMS) as modifier, γ-aminopropyltriethoxysilane (γ-APS) as crosslinking agent and dibutyltindilaurate (DBTDL) as catalyst. Polyamidoamine and aromatic polyamine adduct were used as curing agents for the above coating systems. The thermal behaviour, glass transition temperature (Tg) and morphological characteristics of unmodified epoxy and siliconized epoxy coating systems cured by polyamidoamine (B) and aromatic polyamine adduct (D) were studied using thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy, respectively, and the results are discussed. From the study, it is observed that the thermal stability of epoxy coating systems is enhanced when siloxane is incorporated to them. There is a slight decrease in the glass transition temperature observed for silicone-modified epoxy coatings and SEM analyses reveal that siliconized epoxy coating systems show heterogeneous morphology.