Preparation and characterization of poly(hydroxybutyrate) and hollow glass microspheres composite films: morphological, thermal, and mechanical properties

In this work, of poly(hydroxybutyrate) (PHB) and glass microspheres (HGM) in different compositions with polypropylene-grafted-maleic anhydride (PP-g-MA) composites were developed by melt intercalation, and then, films from the composites and the polymer matrix were obtained. Subsequently, the morphological, thermal, and mechanical properties were evaluated. A good distribution and intermediate dispersion of the filler throughout the matrix with the formation of some agglomerates was observed, while adhesion between the components was not achieved. The HGM did not affect significantly the thermal properties of the systems; there were discrete variations in the initial degradation temperature (Tonset), peak temperature (Tp), and melting temperature (Tm). However, the degree of crystallinity decreased with the addition of the HGM, and the film with 3% HGM had a variation above 11%. Additionally, it was noticed that the composites (regardless of the presence of PP-g-MA) presented small values of elongation and ultimate stress compared with those of pure PHB. Keywords: Polymer composite, PHB, Thin films, Mechanical properties, Thermal properties, Hollow glass microsphere