Freeze-thaw (F-T) poly(vinyl alcohol) (PVA) as a soft network and ionic-crosslinked sodium carboxymethyl cellulose (CMC) as a hard network were applied to fabricate a double network (DN) gel using a one-step process. Mechanical properties of the DN gel using a high degree of hydrolysis PVA (PVA-CMC of 60-1) were significantly improved compared to that of a single network gel of PVA. The tensile strength of ~0.55 MPa and elongation at break of 179% could be achieved. The mechanical properties of PVA-poly(acrylic acid) DN gel were lower than that of PVA-CMC samples. Fourier-transformed infrared (FTIR) spectroscopy results showed less compatibility between polyacrylic acid (PAA) and PVA compared to that of CMC. The solution made from the lower hydrolysis degree PVA (PVA1788) could form a strong gel after being treated with NaOH 1 M. The FTIR result showed the disappearance of acetate groups. A large melting peak in differential scanning calorimetry (DSC) results showed high crystallinity of the hydrolyzed-PVA1788. The effect of various multivalent cations on the mechanical properties of PVA1788-CMC DN gel was performed. The properties of the samples followed the order: Fe³⁺<Co²⁺<Ni²⁺<Cu²⁺<Zn²⁺<Ca²⁺~Ba²⁺<Al³⁺. The tensile strength of DN gel fabricated using AlCl3 solution could reach 0.87 MPa, and the elongation at break was 330%.

Biodegradable biopolymers like polyhydroxybutyrate (PHB) hold promise for sustainable packaging, but their inherent degradability reduces material stability. Synthetic stabilizers, though effective, raise environmental and potential toxicity concerns. This study explores a multifunctional natural anti-aging agent: a hemp extract rich in cannabidiol (CBD) and cannabichromene (CBC). PHB composites with varying hemp extract concentrations were prepared and subjected to thermooxidative and weathering aging. Characterization employed FTIR-ATR, carbonyl index, and spectrophotometry. Static mechanical properties, DSC, and surface free energy (SFE) were also assessed. Notably, the hemp extract exhibited stability under ambient conditions but showed migration with time and aging. The results suggest a plasticizing effect on PHB and highlight the contrasting roles of the extract: inhibiting thermooxidative aging while potentially accelerating aging under atmospheric conditions. This opens avenues for tailoring material durability, further evaluated by life cycle analysis (LCA). This work represents one of the first investigations into hemp extract as an anti-aging agent for eco-friendly polymers, expanding the knowledge base of natural multifunctional additives.

Seaweed from macroalgae and cellulose from nonwood materials have gained attention in various fields. This study explores how seaweed and cellulose nanofibers (CNF) interact to form 3D networks in composite bioaerogels. The ratio of CNF and seaweed was varied to see how it affects the aerogel’s inside and its properties. The observations show that the biocomposite aerogel is more rigid and shrinks less than using a single biopolymer. The CNF aerogel has a fine, thin network structure, and the seaweed aerogel has a thin sheet structure. The biocomposite aerogel combines both a fine network and a thin sheet structure. The composite aerogel’s mechanical properties are significantly influenced by seaweed composition. The introduction of CNF increases elasticity, while seaweed enhances firmness. Generated computer modelling revealed that the abundant hydroxyl groups in CNF facilitated the formation of intermolecular bonds with seaweed. The bonding led to increased adhesion and entanglement between biopolymers, consequently enhancing elasticity and establishing a stable intermolecular interaction. The 3D X-ray imaging model shows that the skeletal framework primarily consists of seaweed biopolymer, with CNF serving to reinforce this structure thus enhancing the mechanical properties and robustness of the composite bioaerogels.

The effect of swelling and plasticizer content of a plastic, as well as the ethanol content of the food simulant on the migration kinetics of three stabilizer-type additives from polylactic acid (PLA)-based food contact plastics has been investigated. The results proved that the parameters that affect the diffusion of substances inside the polymer matrix, i.e., swelling, plasticization, and the size of migrants, are the decisive factors in the migration from PLA to ethanolic food simulants. Both swelling and migration were negligible when ethanol 10% (v/v) was used. Contrarily, the specific migration limits of Commission Regulation (European Union, EU) No. 10/2011 were exceeded in ethanol 50% (v/v) for all investigated stabilizers. Migration was promoted by plasticization, but this effect could only be observed when the applied food simulant swelled the plastic (at least 20% (v/v) ethanol content). The dependence of the plasticizer’s migration-enhancing effect on the swelling has not been shown before. When the plasticization caused increased migration, it also led to specific migration limit exceeding within a shorter period of time. It happens even if PLA-based plastics are dedicated to the storage of hydrophilic food, which is the most common application area of these products. These results can support the improvement of both consumer safety and active packaging development.

The proliferation of flexible electronics has entirely transformed the field of antenna design and paved the door for cutting-edge uses in communication, sensing, and other areas. The present research lends a succinct overview of the intriguing advancements in flexible antenna technology, with specific emphasis on the implementation of polymer substrates. As we refer to poly-flex antennas in this article, they stand for the incorporation of polymer substrates in antenna design. Polymer substrates are the optimum candidate for flexible antenna applications as they have specific advantages, including being lightweight, conformable, and inexpensive. The main features of poly-flex antennas, such as their design concepts, fabrication processes, and performance characteristics, are being explored in this proposed article. We delve into the wide variety of polymer substrates that are appropriate for antennas, taking into account their dielectric characteristics, flexibility, and environmental resistance. Their dielectric characterization, bending effects, challenges, and future prospects of this burgeoning field are also addressed. We conclude by emphasizing the immense potential of poly-flex-antennas to shape the future of wireless communication and sensing systems, and how the adoption of polymer substrates is driving innovation in antenna engineering.