Polimery 2002, No 9, 611
General characteristics of methods of synthesis and possibilities of application of polyalumoxanes, polymers with the main chain built of -Al-O- bonds and containing one organic group at Al atom, has been presented. On the basis of literature data and authors' research the synthesis, structure and reactivity of two groups of organoaluminum polymers have been detaily described. The first group consists of carboxyalumoxanes obtained in the reactions of boehmite LAl(O)OH]n with carboxylic acids [equation 2]. These polymers form nanoparticles with the core of the natural aluminum oxyhydroxide maintained and the organic shell. The type of a shell (hydrophobic or hydrophilic), depending on the type of acid used, enables the formation of stable dispersions in both lipophylic and hydrophylic media. Authors have checked the possibility of using of carboxyalumoxanes with acrylic groups [formulas (IX) and (X)] as crosslinking agents in the systems subject to radical polymerization. The other group of organoaluminum polymers consists of aluminum alkoxycarboxylates formed in the reactions of carboxylic acids with aluminum alkoxides and further either thermal condensation [equation (4)] or hydrolytic condensation [equation (5)] of primary formed Al derivatives. They are coordination polymers of a linear or crosslinked structure, in which Al atoms are linked via bridging bonds formed by organic ligands [formula (XI)]. Various functional groups can be introduced to both these types of polymers what allows to use them as reactiye fillers in composites with organic polymers.
Keywords: organoaluminum polymers, carboxyalumoxanes, aluminum alkoxycarboxylates, synthesis, structure, radical crosslinking agents, reactive fillers