Study of the thermal degradation mechanism of nanoclay modified phenolic resin

ASARO LUCIA; VERA A ALVAREZ; EXEQUIEL S RODRIGUEZ

Congreso; 13er Congreso Internacional en Ciencia y Tecnologia de Metalurgia y Materiales; 2013

When adding an inorganic nano filler (filler with at least one dimension in the nanometer order) to a polymeric matrix some properties can be optimized as the mechanical, barrier and thermal stability, or reduced as the flammability and water absorption. It is important to emphasized that these properties can be considerably modified with low filler content (less than 10 Wt.%). On the other hand, phenolic resins are thermoset polymers, obtained by the reaction between phenol and formaldehyde, which due to its very high resistance to high temperatures are widely used in components that are in contact with the flame. In this work the thermal degradation of phenolic resin modified with different nanoclays was characterized by TGA and DTGA, and the mechanisms involved were studied by fitting the curves with different semi-empirical models. Phenolic resin synthesized in our laboratory and bentonite modified with phosphonium salt in different proportions of CEC (0, 1 and 1.5) were used for the experiments. Also, dynamic mechanical properties were studies by DMA. Glass and rubber modulus, Tg and damping factor were compared among the different clay-modified resins studied. The materials behavior was modified by the addition of clay, there was an increase in the residual mass in all the cases, and the thermal degradation peaks were moved to higher temperatures. The greatest effect was found for the clay with a CEC ratio of 1. This clay was selected and will be used for developing high temperature and ablation resistant composite materials.