Production of Bitumen Modified with Low-Molecular Organic Compounds from Petroleum Residues. 6. Temperature Effect on the Chemical Modification of Bitumen with Maleic Anhydride

The oxidized bitumen produced at the Ukrainian refinery was modified with maleic anhydride. The process temperature was proved to have the most significant effect on modification. The chemical interaction of maleic anhydride with the components of oxidized bitumen was confirmed. At low temperatures (up to 403 K) the chemistry of the modification process is another than chemistry of the process carried out at high temperatures. The structures of the modified bitumen were established at different process temperatures (403, 423 and 443 K) using FTIR spectroscopy. A thin film heating at 436 K (RTFOT method) was performed for the bitumen under study. It was found that for bitumen modified at 403 K, the formed structure is destroyed after heating by RTFOT, which is confirmed by a decrease in the softening point of the bitumen. The FTIR spectra of the original oxidized bitumen and bitumen modified with maleic anhydride at 403 and 443 K were recorded after the RTFOT heating process. Based on the obtained data, the structural transformations that occurred during heating were established.