Key words: supercritical carbon dioxide, polymer modification, urethane formation reaction
In a supercritical carbon dioxide (SC-CO2), methacrylate derivatives of methoxypolyethyleneglycol (mPEG, 5 kDa) were synthesized via the urethane formation reaction. It was shown that the use of SC-CO2 allows to effectively carry out the reaction both in two stages (the first stage is to obtain the isocyanate derivative, the second stage is to obtain the methacrylate derivative of mPEG) and to combine the two stages into one. The effect of the reagent ratio and reaction conditions on the composition of the reaction products was studied. It was shown that carrying out the reaction in two stages allowed to obtain the methacrylate derivative of mPEG with a yield of up to 80 %. In this case, the production of the isocyanate derivative of polyester and the addition of methacrylate fragments were carried out at different parameters of the SC-CO2: the isocyanate group was introduced under «harsh conditions» (65 °C, 20—24 MPa), and the introduction of the methacrylate group occurred under «soft conditions» (40 °C, 12—13 MPa). Polymerization of the obtained monomers was carried out with the production of spatially cross-linked systems based on both individual modified mPEG and its compositions with metaclylated polylactide (PLA). Such systems can be further used as matrices for cell immobilization and the creation of implants.
doi:10.1134/S199079312570126X