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This study was aimed at the modulation of poly(lactic acid) (PLA) properties by the addition of both a low-molecular-weight plasticizer, acetyl tributyl citrate (ATBC), and a biodegradable aliphatic-aromatic copolyester, poly(butylene adipate-co-terephthalate) (PBAT). PLA/PBAT, PLA/ATBC, and PLA/PBAT/ATBC mixtures with 10-35 wt % ATBC and/or PBAT were prepared in a discontinuous laboratory mixer, compression-molded, and characterized by thermal, morphological, and mechanical tests to evaluate the effect of the concentration of either the plasticizer or copolyester on the final material flexibility. Materials with modulable properties, Young's modulus in the range 100-3000 MPa and elongation at break in the range 10-300%, were obtained. Moreover, thermal analysis showed a preferential solubilization of ATBC in the PBAT phase. Gas permeability tests were also performed to assess possible use in food packaging applications. The results are discussed with particular emphasis toward the effects of plasticization on physical blending in the determination of the phase morphology and final properties.

The world is confronted with the depletion of natural resources due to their unsustainable use and the increasing size of populations. In this context, the efficient use of by-products, residues and wastes generated from agro-industrial and food processing opens the perspective for a wide range of benefits. In particular, legume residues are produced yearly in very large amounts and may represent an interesting source of plant proteins that contribute to satisfying the steadily increasing global protein demand. Innovative biorefinery extraction cascades may also enable the recovery of further bioactive molecules and fibers from these insufficiently tapped biomass streams. This review article gives a summary of the potential for the valorization of legume residual streams resulting from agro-industrial processing and more particularly for pea, green bean and chickpea by-products/wastes. Valuable information on the annual production volumes, geographical origin and state-of-the-art technologies for the extraction of proteins, fibers and other bioactive molecules from this source of biomass, is exhaustively listed and discussed. Finally, promising applications, already using the recovered fractions from pea, bean and chickpea residues for the formulation of feed, food, cosmetic and packaging products, are listed and discussed.

Consumer awareness about the damages that plastic packaging waste cause to the environment, coupled with bio-economy and circular economy policies, are pushing plastic packaging versus the use of bio-based and biodegradable materials. In this contest, even cosmetic packaging is looking for sustainable solutions, and research is focusing on modifying bio-based and biodegradable polymers to meet the challenging requirements for cosmetic preservation, while maintaining sustainability and biodegradability. Several bio-based and biodegradable polymers such as poly(lactic acid), polyhydroxyalkanoates, polysaccharides, etc., are available, and some first solutions for both rigid and flexible packaging are already present on the market, while many others are under study and optimization. A fruitful cooperation among researchers and industries will drive the cosmetic sector toward being more ecological and contributing to save our environment.

In this work, a new thermal stimuli sensitive multiphase polymer system consisting of a bio-related mixture of poly(lactic acid) (PLA, 85 wt%) and poly(1,4-butylene succinate) (PBS, 15 wt%) was prepared by the controlled incorporation of moderate amounts (<0.2 wt%) of 4,40-bis(2- benzoxazolyl)stilbene (BBS, a food-grade dye). Films obtained from the blend with less than 0.2 wt% of dye showed after melt mixing luminescence typical of monomeric BBS chromophores (blue emission). Composite films containing 0.07 wt% of BBS (the highest concentration allowing dye monomeric dispersion) appeared extremely sensitive to thermal solicitations when annealed at temperatures higher than PLA’s Tg (>60 to 70 C) leading to a clear change of the emission properties due to the occurrence of dye aggregation. Thermal analysis by DSC showed an evident connection between blend morphology features and luminescence response. The results are here discussed with reference to the transition temperatures of the two polymer phases and their effect on aggregation/disaggregation of dispersed BBS

The isothermal cold-crystallization kinetics of the PLA phase is studied by DSC and the crystallization from the melt by PLOM. Even though the blends exhibit two phases by SEM, several pieces of evidence indicate that partial miscibility may be present in these blends: small changes in both T g and T m of the PLA phase; a dependence of the spherulitic growth rate on blend composition and the oclusion of PBAT droplets inside PLA spherulites. Acetyl tributyl citrate is able to plasticize both phases in the blends, but it displays a preference to dissolve within the PBAT rich phase. There is a synergystic effect on the increase in the overall crystallization rate of the PLA rich phase when both ATBC and PBAT are present in the blend.

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