The production of bioplastics has been extensively investigated in recent decades, with the purpose of reducing the global dependence on fossil resources. In this review, the main routes to produce bioplastics and a critical discussion of these technologies are presented. The synthesis routes to produce biodegradable and non-biodegradable bioplastics are discussed. Additionally, approaches to improve the environmental footprint of some conventional plastics that have no immediate solutions of substitution are also addressed. A comparison of the main properties of the bioplastics considered and a general perspective of the bioplastics market are also provided. Because these themes have often been reviewed separately, this article aims to provide a unified general perspective of bioplastics in the context of a biobased economy, as well as pointing out some of the hurdles in such way.

The invasive tree species Acacia dealbata represents a threat to the environment but also a potential lignocellulosic resource. In this work, lignins were extracted from A. dealbata wood using an ionic liquid (IL) and a deep eutectic solvent (DES) and analysed for their purity and structural and thermal properties. For comparison, a lignin isolated from the black liquor of A. dealbata kraft cooking and a commercial lignin were used. Both IL and DES processes yielded high-purity lignins containing less than 1% of residual polysaccharides. IL-lignins showed a higher content of syringyl units and condensed structures than DES-lignins, and were thermally more stable, as evidenced by 31P NMR analysis and thermogravimetry, respectively. Given the higher selectivity of DES extraction for lignin removal, DES-lignins, at 10-30 wt%, were used to produce composites with polybutylene adipate terephthalate (PBAT) via extrusion and injection moulding. Lignin incorporation increased stiffness but reduced tensile strength and elongation at break. At 30 wt% DES-lignin, tensile strength, elongation at break, and Young's modulus were 9.8 MPa, 28%, and 169 MPa, respectively, compared to 14.3 MPa, 523%, and 63 MPa for neat PBAT. DES-lignins decreased the Ton of the blends with PBAT, but increased the char residue, while melting and glass-transition temperatures remained unchanged. Performance limitations of the ensuing composites were attributed to lignin poor dispersion and weak interfacial compatibility. Overall, this study demonstrated that lignin from A. dealbata can be sustainably recovered and valorised as a functional material in PBAT composites, contributing to the circular utilization of invasive resources.

The production of renewable chemicals and plastics has been extensively investigated in recent decades, with the purpose of reducing the global dependence on fossil resources. In this review, the main routes to produce chemicals from biomass are reviewed and a critical discussion on the prospects and techno-economic viability of these technologies is presented. As these topics are often considered as independent from each other, the aim of this work is to provide an unified and interdisciplinary perspective of main possible production routes and their development status for experts and non-experts. The main processes of biomass concentration were reviewed and two main approaches for obtaining renewable chemicals were considered: (i) the production of compounds chemically identical to petroleum derivatives, and (ii) the production of conventional and new oxygenated chemicals. The literature shows that there are sustainable technological alternatives to the substitution of many petroleum derived chemicals, but the complexity of the production processes should not be simplistically evaluated. Solutions and technologies must be carefully evaluated, both from the point of view of their technoeconomic viability and their sustainability.

Herein, we report the concurrent Atom Transfer Radical Polymerization and Degenerative Transfer (ATRP/DT) of butyl methacrylate (BMA) in emulsions containing anionic, cationic, nonionic, and zwitterionic surfactants. Cyclic voltammetry confirmed the stability of the hydrophilic [CuIITPMA]2+ catalyst with these surfactants, and the(KII Surf KI Surf) affinity constant was determined for the anionic and zwitterionic surfactants. Ionic surfactants (except sodium dodecylbenzene sulfonate) provide optimal polymerization control and the most stable latexes. ATRP/DT outperformed ATRP and RAFT when cocamidopropyl betaine, sodium cocoamphoacetate, Brij-98, and cetyltrimethylammonium bromide were used. To solve the partitioning of the chain transfer agent in emulsions, we introduce ATRP/DT polymerization in miniemulsion, which accelerates polymerization and improves control with anionic and zwitterionic surfactants with either the chain transfer agent or its disulfide precursor. The method yields poly(n-butyl methacrylate) (PBMA) with high conversions (up to 99 %), low dispersities (& Dstrok; = 1.09-1.33), and preserved chain-end fidelity; PBMA prepared with cationic, nonionic, and zwitterionic surfactants exhibited living characteristics, extending the accessibility of well-defined polymers via aqueous emulsions to industrially relevant surfactant types. This work demonstrates that ATRP/DT is a versatile and unconventional strategy for polymerization in emulsions, providing access to polymers across various surfactants .

Atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer polymerization (RAFT) are two independent polymer synthesis methods. Here, we show that the synergy between the ATRP and RAFT degenerative transfer mechanisms under emulsion conditions is a promising and attractive option for scalable and efficient polymerization processes, offering significant advantages over stand-alone procedures. They work synergistically, reinforcing each other and relaxing the stringent conditions required for controlled radical polymerization in emulsion. This drastically reduces the metal loading and environmental impact. Stable, well-defined latexes of poly(n-butyl methacrylate) with predetermined molecular weights and & Dstrok; < 1.5 were obtained with only 50 mu M Cu (18.3 ppm) on a 1 L scale and even below this concentration on a 20 mL scale. The latex color imparted by the RAFT chain transfer agent was catalytically decolorized by a one-pot, nondisruptive method using an ATRP Cu catalyst via the oxygen reduction reaction (ORR).

The increasing interest in clinical bacterial photodynamic inactivation has led to the search for photosensitizers with higher bactericidal efficiency and less side effects on the surrounding tissues. We present a novel nonionic porphyrin, the 5,10,15-tris(2,6-dichlorophenyl)-20-[4-N-(6-amino-hexyl)sulfonamido)phenyl]-porphyrin (ACS769F4) with substantial improvements in the efficiency of nonionic sensitizers. This porphyrin causes eradication of both Escherichia coli and Staphylococcus aureus by the photodynamic effect but in higher concentrations compared with 5,10,15,20-tetrakis (4-N,N,N-trimethylammoniumphenyl)-porphyrin p-tosylate (TTAP(4+)), a known bactericidal tetracationic porphyrin. More important, under such conditions, ACS769F4 proved to be harmless to two mammalian cells lines (human embryonic and baby hamster kidney), causing no reduction in their viability or negative impact on their cytoskeleton, despite its accumulation in cellular structures. On the contrary, TTAP(4+) is shown to accumulate in the nucleus of mammalian cells, in association to DNA, causing chromatin condensation after exposure to light. Furthermore, dark incubation with TTAP(4+) was shown to have a deleterious effect on the microtubule network. Based on its bactericidal efficiency, also observed without exposure to light, and on the low tendency to be harmful or genotoxic to mammalian cells, ACS769F4 should be looked at as an interesting photosensitizer to be evaluated for clinical purposes.