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Growing demands for the use of biodegradable polymer films in food packaging have led to studies on several sources of non-conventional starches. Corn starch (CS), is the most investigated starch source for food packaging due to its abundance and stability under processing and manufacturing conditions. Other sources of starch such as rice, potatoes and cassava have also been investigated and, more recently, babassu mesocarp starch (BMS), native to Northeastern Brazil, has been explored for its innovative potential in the manufacture of biodegradable films. In this work is we have extracted and characterized the starch contained in babassu mesocarp and to compared its morphology, structure, thermal stability and viability for polymer film manufacturing with that of commercial corn starch. Our data showed babassu mesocarp native starch granules to have an oval shape and to display flaking and fractured surfaces while corn starch granules exhibited polygonal shapes with smooth surfaces and without aggregates. XRD analysis revealed two different types of crystalline forms for both starches. Although babassu starch is less thermally stable than commercial corn starch, both starches have similar characteristics and it is believed that babassu mesocarp starch can be used as new renewable and biodegradable resource for food packaging applications.

It is well known that the inadequate disposal of polymeric materials causes significant environmental problems. Recycling and the use of biodegradable polymers are among the methods used to minimize these problems. However, the low mechanical performance of the majority of biodegradable polymers hinders the direct substitution of synthetic polymers, such as polyethylene (PE), polypropylene (PP) and polystyrene (PS), by biodegradable ones. Blending synthetic and biodegradable polymers is a way to develop recyclable biodegradable products with a good set of mechanical properties. Therefore, in this work we investigate the influence of extrusion cycles on the degradation of a polypropylene/poly (butylene adipate-co-terephthalate)/thermoplastic starch blend before and after inoculation with Aspergillus sp. and Penicillium sp. fungi degradaded for 30 days. The samples were exposed to the fungi and their mass loss, chemical structure, hydrophilicity, and morphology were observed as a function of inoculation time and processing cycles. Our results indicate that thermo-mechanical degradation favors the deposition of fungi in the samples and enables changes in film morphology and hydrophilicity. Keywords: Fungi degradation, Mechanical recycling, Hydrophilicity

The aim of this study was to manufacture and characterize bionanocomposites based on a poly(hydroxybutyrate)/polyethylene glycol blend (PHB/PEG) filled with an organobentonite (CLT1 and CLT3) or an organovermiculite (VMT1 and VMT3) in concentrations of 1 and 3 wt%. The systems were prepared by solution intercalation and further characterized by X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. The use of these bionanocomposites aimed at improving the processing and compatibility of this blend in search of new properties and possible applications of these films in food disposable packaging. The thermal stability of the system varied according to the type of clay and, consequently, the chemical structure of the quaternary ammonium salt used. The VMT1, VMT3 and CLT3 systems showed increased degrees of crystallinity compared to neat PHB. Differences in bionanocomposites structure can be related to the type of clay used as two types of PHB/PEG blend. Keywords: PHB, Blends, Bionanocomposites, Clays, Thermal behavior

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 microspheres

Abstract The rheological behavior of poly (butylene adipate-co-terephthalate) (PBAT) and its composites prepared with three different organoclays was investigated. Composites containing up to 7.5%, w/w organoclay, were prepared by two routes: (a) direct melt blending in an internal laboratory mixer with high intensity rotors and (b) concentrates (prepared in the internal mixer) with 50 %, by weight, of the organoclays diluted in a co-rotating twin screw extruder equipped with a high intensity mixing thread operating at a nominal speed of 480 rpm. The samples were characterized by both torque and parallel plate rheometry. Results indicate that nanodispersions in the clay layers were obtained during processing and that, like the pure matrix, at high shear rates, the organoclay compounds follow the power law, although with higher viscosity. It is believed that the interaction of the polymer with the organoclay is responsible for the increase in melt viscosity (observed by increases in torque and relaxation time) of the hybrid systems.

Abstract Blends of Polystyrene (PS) and Poly(ε-caprolactone) (PCL) were twin screw extruded, two PSs, with low and high melt flow rate (MFR) were used and their feasibility within PCL investigated by means of torque rheometry, mechanical tests, heat deflection temperature (HDT) and scanning electron microscopy (SEM); predictive models were utilized to evaluate interfacial adhesion in PS/PCL blends. Results show that no decreasing was verified in torque rheometry plots suggesting thermally stable blends; elastic modulus decreased and elongation at break increased in PS/PCL blends compared to neat PS. PS/PCL blends with low MFR PS and higher PCL amount are more thermodynamically stable. Higher HDT was verified in PS/PCL blends. The trends observed applying predictive models are indicative of poor adhesion between PCL and PS, agreeing with coalescence and phase segregation as verified in SEM images. PS/PCL systems with higher MFR PS presented the best results.