Characterization of biodegradable polybutylene succinate modified by sequential infiltration of Al2O3

Polybutylene succinate (PBS) is one of the most important and commercially available biodegradable polyesters obtained by polycondensation between succinic acid and butanediol [1]. It is endowed with high mechanical properties, comparable to polyethylene (PE) and polypropylene (PP); high thermal, chemical resistance and high heat deflection temperature. However, its applications suffer of some limitations due to softness, gas barrier properties and melt viscosity, limiting its practical use. To overcome these problems, the introduction of inorganic materials into biopolymers has been envisioned as a viable option to improve the structural properties of PBS and promote the exploitation in different application fields. The sequential infiltration synthesis (SIS), based on atomic deposition of Al2O3 on PBS, via trimethylaluminum (TMA) and H2O precursors, provides an attractive option for the production of a polymer-inorganic hybrid material. After the growth of Al2O3 in freestanding ~30 ?m thick PBS films by SIS process at 70°C, changes on PBS microstructure and mass uptake in the films were evaluated as a function of the number of SIS cycles [2]. Results evidenced that mass uptake in the PBS films was much higher than in standard polymethylmethacrylate (PMMA) films, at the same process conditions. This study evaluates changes on PBS microstructure vs mass uptake and explores the reactivity of the PBS functional groups, (ester and ether) after TMA treatment, through solution Nuclear Magnetic Resonance spectroscopy (NMR) thus suggesting a plausible reaction mechanism able to justify structural changes in PBS [3].