A study on thermal stability of glycidylsiloxane resins cured with aliphatic amines

Abstract

Oligomeric glycidylsiloxanes are promising components of hybrid amino-epoxy-siloxane coatings with improved properties. The thermal stability of amine-cured glycidylsiloxane resins were studied by means of thermogravimetric analysis. Four samples of glycidylsiloxane resin, with 18 to 30 glycidyl groups per molecule and molar masses from 5 to 10.5 kg/mol, were cured at 140°C with triethylenetetramine (TETA), isophorone diamine (IDA) and a polyamide (PF). The onset temperatures of degradation, residual masses and heat effects were measured. Maximal degradation rates were registered at temperatures above 400°C. Infrared spectra of the residues indicate that the least stable bonds are Si-C, C-H and C-N. A second degradation step takes place above 700°C resulting in disperse silica.