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In this study, biofilaments based on cocoa shell waste, a by‐product of the chocolate industry, and biodegradable poly(ε‐caprolactone), PCL, have been prepared using a single‐screw extruder. Micronized cocoa shell waste is compounded in the polymer up to 50% by weight without significant alteration of its crystalline structure. Resultant elastic (Young's) modulus of biofilaments remains close to that of pure PCL. Scanning electron microscopy results indicate that micronized cocoa shell waste is homogeneously dispersed in the polymer during the extrusion process. Detailed thermal characterization measurements on the extruded filaments allow tuning of the fused deposition modeling 3D printing parameters. 3D printed items display a well‐defined structure with good adhesion between deposition layers and fine resolution. Hence, with this simple and solvent‐free fabrication technique, uniformly structured cocoa shell waste biofilaments can be produced in a very reproducible manner and can be used in 3D printing of diverse objects with potential household and biomedical applications.

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Sustainable biocomposites have been developed by solvent mixing of poly(lactic acid) (PLA) with a fine powder of cocoa bean shells (CBS) and subsequent solution casting, using different concentrations of CBS. The inclusion of CBS recovers the crystallinity of the initially amorphous PLA films and improves the physical properties of the composites. Young's modulus increases by 80% with 75 wt % CBS inclusion; however, the composites maintain plasticity. The barrier properties of the hydrophobic composites were characterized, and the water vapor permeability is found to be ca. 3.5 × 10 −5 g•m −1 •day −1 •Pa −1 and independent of the CBS content. On the other hand, oxygen permeability is found to depend on the CBS content, with values as low as 10 000 mL•μm•m −2 •day −1 • atm −1 for 50 wt % CBS. Furthermore, CBS confer antioxidant activity to the composites and improve swelling properties rendering the composites biodegradable in aquatic environments, reaching 70% of the maximum biodegradability in just 30 days. The above, in conjunction with the low level of migration measured in food simulant, make the PLA/CBS composites a highly promising material for active food packaging.

In this study, a new strategy for the utilization of cocoa shell waste, a by‐product of cocoa industry, is presented for the development of new bioelastomers. The cocoa shell waste (CSW) is first micronized and then incorporated into single component acetoxy‐poly(dimethylsiloxane) (acetoxy‐PDMS) macromolecular matrix by a mixing process to produce bioelastomer composites with tunable properties. A detailed study is carried out to investigate the influence of micronized cocoa waste concentration on the curing process and on the properties of final materials. It is found that addition of CSWs has a strong effect on the curing behavior of PDMS due to establishment of an intermolecular hydrogen bond network between the two components. CSW bioelastomers are hydrophobic and exhibit good water barrier properties. In addition, the bioelastomers show effective antioxidant scavenging activity against 2,2‐diphenyl‐1‐picrylhydrazyl free radical (DPPH•) and 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) radical cation (ABTS•+). The incorporation of micronized CSW into PDMS is also found to significantly enhance the Young's modulus of the elastomers. Hence, these antioxidant bioelastomers originating from food industry waste can be highly suitable as materials for active food packaging applications.

The first sonochemically induced reversible addition− fragmentation chain transfer by the polymerization-induced selfassembly process (Sono-RAFT-PISA) has been investigated. Highfrequency ultrasound (490 kHz, 40 W) was applied for the controlled polymerization of N-isopropylacrylamide (NIPAM) in aqueous dispersion via the Sono-RAFT-PISA technique using poly(poly-(ethylene glycol) methyl ether acrylate) (PPEGA) as both macromolecular chain transfer agent and surfactant (macro-transurf). The synthesis of PPEGA-b-PNIPAM copolymers in aqueous media at 20 °C (DP n,NIPAM = 204) was found to reach total NIPAM conversion in a short time (60 min.) with narrow molecular weight distribution (Đ < 1.26). Furthermore, PNIPAM-based spherical nanogels (D h ≤ 69 nm, pdi ≤ 0.26) were successfully synthesized by Sono-RAFT-PISA (aqueous dispersion, 45 °C), qualifying as a highly "green" method due to the complete monomer conversion, absence of organic initiator, of residues, and to the unique use of water as initiator and solvent (inisolv).

Hydrogen‐bonding upper critical solution temperature (UCST) thermosensitive nanogels based on poly(N‐acryloyl glycinamide) (PNAGA) are synthesized by photo‐reversible addition‐fragmentation chain transfer mediated polymerization‐induced self‐assembly (photo‐RAFT PISA) in aqueous dispersion using N,N′‐methylenebis(acrylamide) as crosslinker and poly(oligo(ethylene glycol) methyl ether acrylate) as both stabilizer and macromolecular chain transfer agent (macro‐CTA). Highly stable, spherical nanogels with narrow polydispersity are efficiently produced up to complete monomer conversion within 1 h under UV irradiation at low temperature (3 °C). The thermosensitive behavior of PNAGA‐based nanogels, as assessed by dynamic light scattering and UV–vis spectrophotometry, exhibits reversible heating‐induced swelling and cooling‐induced shrinking corresponding to the expected UCST behavior. The hydrodynamic diameter, swelling ratio, and phase transition temperature of nanogels can be tuned by modifying the initial molar ratio of monomer‐to‐macro‐CTA and the amount of crosslinker in the photo‐RAFT PISA of NAGA.