The simultaneous finding of zinc corrosion of the above compounds, obviously, leads to the formation of a complex complex of zincorganic compounds, among which there can be, for example, zinc carbonyl. When heated to 200 ° C, it decomposes into metal zinc and carbon monoxide detected by chromatographic and thermographic analyzes.
Interpretation of the results of differential-termic analysis meets significant difficulties. The thermal effect at 220 ° C can be associated with the decomposition of carbonyl, the effect at 400 ° C – possibly with eutectic editions with metal zinc (the latter, as you know, melts at 419 ° C), and the effect at 700 ° C – with the decomposition of nitrides Or zinc hydrides. However, the data of one differential-termic analysis is not enough to confidently into theDrodal of these compounds.
The presence of highlights with zinc corrosion is naturally associated with the presence of oxides and hydrocarbons and various depths of reactions at various temperatures. The appearance of hydrides, hydroxide and zinc oxide is accompanied by a significant increase in volume. So, when zinc oxide is formed, the volume increases by almost 30%, and hydroxide – by 135%. Partially, this increase in volume leads to a seal of porous coating, but sometimes causes a direct increase in the size of the coating after processing in the autoclave, its warping, bloating, etc. p. This increase in size reaches 20% and, of course, leads to the complete destruction of the coating.