shows the band at 3,000-3,500 cm-1 which is
attributed to O-H bond, that can be related to water, ethanol
and/or silanol group, but it is possible to observe a decrease
of this band with the increase of the curing temperature,
and at 1,000-1,100 cm-1 the reverse can be seen, indicating
that there are more Si-O-Si bonds at 150 ºC.