Biodegradability and nutrients release of thermoplastic starch and poly (ε-caprolactone) blends for agricultural uses.

Driven by the environmental stress caused by plastics, the interest on eco-friendly polymers has attracted the attention of researchers and industry. Thermoplastic starch (TPS) and poly (ε-caprolactone) (PCL) blends are good examples of sustainable material, exhibiting synergism between economic viability and properties. However, its biodegradability aligned to nutrients release has been less explored in agricultural applications. Herein, it is proposed the investigation of biodegradability of urea plasticized TPS and PCL blends, compatibilized with PCL grafted with maleic anhydride (PCL-g-MA), aiming fertilizers and sustainable agricultural products. The blends were prepared in a twin-screw extruder using a flat film die. The mechanical, thermal, morphological, and physical properties of TPS-PCL films were characterized, including biodegradation analysis via Bartha respirometer and nitrogen release in the soil. The films presented biodegradability and nitrogen release as a function of TPS content on blends formulation, presenting flexibility and robust mechanical properties. These findings may open a way of multifunctional agricultural products applied as fertilizer materials through economical and sustainable mulching films.

Curaua and eucalyptus nanofibers films by continuous casting: Mechanical and thermal properties.

A wide variety of new green materials such as curaua leaf fibers (CLFs) has potential applications in nanotechnology. This study aims to investigate the thermomechanical properties and morphological structure of cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) films obtained by continuous casting. The CNCs were obtained by acid hydrolysis and CNFs by mechanical shearing from bleached CLFs and eucalyptus pulp. The morphology after continuous casting resulted in oriented nanofibers, and as a consequence there was mechanical anisotropy. CNCs films showed the greatest values of tensile strength (36±4MPa) and the more effective fibrillation provided better mechanical strength of eucalyptus CNFs films than curaua CNFs films. Sulfur groups and mechanical shear degradation affected the stability of CNCs and CNFs films, respectively. Thus, the type of nanostructure, the way they interact to each other, the cellulose source and the process interfere significantly on the properties of the films.

Biotransformation of poly (epsilon-caprolactone) and poly (vinyl chloride) blend

Poly (caprolactone) is a famous biodegradable polymer and miscible with PVC, a commercial synthetic polymer, thermal susceptible and non-biodegradable. This blend is important concerning its mechanical properties and biodegradability. In this work, we testified the biomodification of blend films of PVC/PCL by UV-Vis. spectroscopy. The results show us that there is an interaction between the PVC/PCL film and the microrganisms.

Poli épsilon-caprolactona é um importante polímero biodegradável e miscível com o PVC, um polímero sintético industrial, termo susceptível e não biodegradável. A blenda PVC/PCL é importante em propriedades mecânicas e biodegradabilidade. Neste trabalho, há indicações que há interação dos microrganismos com a superfície polimérica e esta causa mudanças estruturais na blenda PVC/PCL.