Hubina A. Polyurethane networks based on xanthan and blocked polyisocyanate

The thesis concerns the development of synthesis methods of polyurethane networks based on microbial polysaccharide xanthan and caprolactam-blocked polyisocyanate, which could be able to remove transition metal ions from water solutions and also to degrade under influence of natural and aggressive microbial media. There was suggested a method for synthesis of amphiphilic polymer systems consisting of polyglucanurethane network and linear polyamide. The heterogeneity of synthesized amorphous polymers was shown to decrease due to in situ forming of linear polyamide. The water absorption and speed of thermal-oxidative destruction of obtained polymers lowered noticeably with the rise of cross-linking agent amount in reaction mixture. Synthesized polymeric matrices were proved to remove Co2+ and Cu2+ from water solutions due to complexing of metal ions with fragments of polymer matrix. The complexing both with saccharide and urethane components was confirmed. Calculated values of dynamic sorptive ability of the polymer networks as for Co2+ and Cu2+ correlated with amount of PICb in reaction mixture. The principal difference in degradation path of polyglucanurethane in aggressive and natural microbial media was shown. Aggressive microbial medium induces mainly urethane-amide destruction, while natural one influences the polysaccharide part of PGU-PA.