chemical modification

Three samples of bituminous material with different softening temperatures of 321, 332, and 356.4 K were obtained by the method of chemical modification of tar with formaldehyde using sulfuric acid as a catalyst. The determination of the group hydrocarbon composition was carried out for the raw materials of the modification process (tar) and the resulting bitumens. An FTIR study of the obtained groups of hydrocarbons (oil, resins, and asphaltenes) was also carried out.

Multi-walled carbon nanotubes and graphite nanoplatelets were functionalized via acid treatment to overcome the problem of agglomeration. Fourier transform infrared spectroscopy showed the chemical modification of the nanocarbons while the general relationship between the chemical treatment and the defects population was analyzed by Raman spectroscopy. The information regarding the mass loss and impurities is obtained from the thermogravimetric analysis. X-ray diffraction showed the effect of acid treatment on the physical states of the nanocarbons including the crystalline texture.

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.

The possibility of modification of oxidized petroleum bitumen 70/100 produced by JSC "Ukrtatnafta" (Kremenchuk, Ukraine) with maleic anhydride was studied. The influence of maleic anhydride amount, process duration, and temperature on the main physical and mechanical characteristics of modified bitumen was studied. The optimal amount of maleic anhydride introduction to bitumen was established. It is found that 2 wt. % maleic anhydride allows to increase the softening temperature of the modified bitumen (from 46 °C to 52 °C).

This paper presents the main aspects regarding the production of biodegradable microspheres, the optimization of parameters in the drug encapsulation process, the techniques available for polymeric systems sterilization and the effects of γ-irradiation on microparticles.

We have studied the possibility of peroxy oligomers synthesis by chemical modification of epoxy resins with tert-butylperoxymethanol or diepoxy compounds telomerization with glycols in the presence of trifluorine boron using tert-butylperoxymethanol as telogen. The reaction conditions have been determined and synthesis procedures have been developed. The structures of synthesized products were proved by chemical, IR- and PMR-spectroscopic investigations.

Resin derivative containing methacrylic fragment and free epoxy group at the same time has been synthesized via chemical modification of ED-24 epoxy dianic resin by methacrylic acid. The structure of the synthesized product has been confirmed by IR-spectroscopic investigations. Derivatography was used to determine the thermal stability of the synthesized compound. It has been suggested to use methacrylate derivative of ED-24 epoxy resin as a component of epoxy-oligoesteric and bitumen-polymeric mixtures.