melamine

Melamine formaldehyde oligomers with peroxy groups (MFOP) have been synthesized based on melamine or urea and melamine in the presence of tert-butyl peroxymethanol or tert-butyl hydroperoxide. Zinc oxide was used as a catalyst. The effect of peroxide nature, ratio of the starting components and process time on the characteristics and yield of MFOP has been studied. The structure of the synthesized MFOP was confirmed by IR- and PMR-spectroscopy. The chemistry of the cross-linked structures formation was studied.

Melamine sulfate (Si-MelaSO4H) was prepared by treated melamine, which was immobilized onto silica (Si-Mela) with 0.05 M sulfuric acid at room temperature. The TGA confirmed that the thermal stability could reach 473 K. The XRD pattern showed that in some patterns there were sharp peaks and in other pattern a broad band was shown, which indicated that the surface is a mix of crystalline and non-crystalline nature. The Si-MelaSO4H was used successfully in the preparation of Schiff bases and its derivatives.

The influence of stabilizers – hydrogen donors – on the processes of thermooxidative destruction of pitch-based polymer has been investigated. It is shown that Irganox has not stabilizing effect on pitch-based polymer and melamine slightly retards the destructive process. A mixture of melamine and Irganox exhibits synergetic stabilizing effect and at the optimum ratio it can be used to prevent unwanted thermooxidative processes during pitch-based polymer preparation.