Sea and environmental pollution due to microplastics are global problems that in recent years have attracted particular interest in the scientific community. The increase in the world population and the consequent consumerism of non-reusable materials are amplifying these problems. In this manuscript, we present novel bioplastics, which are completely biodegradable, for their potential use in food packaging, to replace fossil-fuel-derived plastic films and slow food degradation due to oxidative processes or microbial contamination. In this study, thin films based on polybutylene succinate (PBS) were prepared to reduce pollution, and different percentages by weight (1, 2 and 3 wt%) of extra virgin olive oil (EVO) and coconut oil (CO) were included to improve the chemico-physical properties of the polymer and possibly improve the functionality of the films in terms of prolonged food preservation. Attenuated total reflectance Fourier transform infrared (ATR/FTIR) spectroscopy was used to evaluate the interactions between the polymer and the oil. Furthermore, the mechanical properties and thermal behavior of the films were evaluated as a function of the oil content. A scanning electron microscopy (SEM) micrograph showed the surface morphology and the thickness of the materials. Finally, apple and kiwi were selected for a food-contact test, and the wrapped sliced fruit was monitored and evaluated for 12 days to macroscopically evaluate the oxidative process and/or eventually occurring contamination. The films were shown to reduce the browning of sliced fruit due to oxidation, and no molds were evidenced up to 10/12 days of observation with the addition of PBS, with 3 wt% of EVO achieving the best outcomes.

Polybutylene adipate-co-terephthalate (PBAT) is a biodegradable polymer with good features for packaging applications. However, the mechanical performance and high prices of PBAT limit its current usage at the commercial level. To improve the properties and reduce the cost of PBAT, pine resin derivatives, gum rosin (GR) and pentaerythritol ester of GR (UT), were proposed as sustainable additives. For this purpose, PBAT was blended with 5, 10, and 15 wt.% of additives by melt-extrusion followed by injection moulding. The overall performance of the formulations was assessed by tensile test, microstructural, thermal, and dynamic mechanical thermal analysis. The results showed that although good miscibility of both resins with PBAT matrix was achieved, GR in 10 wt.% showed better interfacial adhesion with the PBAT matrix than UT. The thermal characterization suggested that GR and UT reduce PBAT melting enthalpy and enhance its thermal stability, improving PBAT processability. A 10 wt.% of GR significantly increased the tensile properties of PBAT, while a 15 wt.% of UT maintained PBAT tensile performance. The obtained materials showed higher hydrophobicity than neat PBAT. Thus, GR and UT demonstrated that they are advantageous additives for PBAT–resin compounding for rigid food packaging which are easy to process and adequate for industrial scalability. At the same time, they enhance its mechanical and hydrophobic performance.

The present work analyzes the influence of modified, epoxidized and maleinized corn oil as a plasticizing and/or compatibilizing agent in the PLA–PHB blend (75% PLA and 25% PHB wt.%). The chemical modification processes of corn oil were successfully carried out and different quantities were used, between 0 and 10% wt.%. The different blends obtained were characterized by thermal, mechanical, morphological, and disintegration tests under composting conditions. It was observed that to achieve the same plasticizing effect, less maleinized corn oil (MCO) is needed than epoxidized corn oil (ECO). Both oils improve the ductile properties of the PLA–PHB blend, such as elongation at break and impact absorb energy, however, the strength properties decrease. The ones that show the highest ductility values are those that contain 10% ECO and 5% MCO, improving the elongation of the break of the PLA–PHB blend by more than 400% and by more than 800% for the sample PLA.

Gum rosin esters are some of the most common gum rosin derivatives used in different applications, such as coatings, paper, varnishes, chewing gum, and food industries. In this study, gum rosin esters are used as additives for polylactic acid (PLA) to improve its processability and thermal stability. Blends of an amorphous PLA with two different gum rosin esters, pentaerythritol ester and glycerol ester, were prepared by melt extrusion process in concentrations from 1, 3, and 5 phr. Besides the comparison of thermal degradation, microstructure assessment, and melt flow index (MFI) analysis, the processability performance during testing samples production by injection molding process was evaluated. Experimental results showed that MFI values of PLA-gum rosin ester blends increased by 100%, 147%, and 164%, along with increasing content of gum rosin esters addition, in both cases. Also, both derivatives slightly improved PLA thermal stability (around 3ºC higher). Injection molding temperature decreased by at least 20 °C for PLA-gum rosin ester blends compared with neat PLA. Furthermore, the maximum tensile strength of PLA-gum rosin esters was negligibly affected in formulations with low content of gum rosin esters, and the FESEM images revealed a good dispersion and compatibility of gum rosin ester particles into PLA matrix in both concentrations.