The application of coating materials to regulate nitrogen release is a crucial strategy for minimizing fertilizer loss and alleviating agricultural nitrogen pollution. However, it remains a significant challenge to develop ecofriendly coatings that are both biodegradable and effective in slow-release. In this study, Ca/Al layered double hydroxides (LDHs) were incorporated into a conventional polyvinyl alcohol/polyvinylpyrrolidone (PVA/ PVP) matrix to create PVA/PVP-LDHs composite films. The inclusion of LDHs (1.0 %, w/w) resulted in a 32 % enhancement in water resistance, a 10 % reduction in water vapor/ammonia permeability, and a 16 % improvement in mechanical properties. These enhanced performances by addition of LDHs were attributed to the combined effects of the tortuous diffusion pathways, and the formation of robust hydrogen bonding networks between the hydroxyl groups of LDHs and PVA/PVP at the organic-inorganic interface. These interactions could reduce free hydroxyl groups on the film surface, leading to hydrophobicity and structural integrity. The composite films exhibited significantly reduced nitrogen permeability under various pH conditions, indicating the improved stability in both acidic and alkaline soil environments. Degradation experiments revealed that the composite film lost 40 % of its mass over 120 days, with a half-life only 8.0 % longer than pure PVA/PVP. These results indicated that the incorporation of LDHs had minimal impact on biodegradability, maintaining the environmental compatibility of the films. These findings highlight the potential of PVA/PVP-LDHs composite films as sustainable, eco-friendly, and efficient slow-release fertilizer coatings, offering a practical solution for improving nitrogen use efficiency and reducing agricultural nitrogen pollution.

Natural rubber latex (NRL) is a biopolymer consisting of isoprene monomers in a cis configuration connected by double bonds that can degrade naturally. Most natural rubber (NR) based products are single-use items and its microbial degradation process is relatively slow. Hence, this review highlights the importance in the enhancement of biodegradation of NR, the methods applied to increase the biodegradation rate, and characterization of biodegradation of rubber. The biodegradability of NR-based products is enhanced via selective microorganism strains, suitable composting environment and the addition of biofillers. Rubber oxygenase enzymes and latex cleavage protein are major contributors in the biodegradation of NR-based products, while biofillers such as chitosan, cellulose whiskers and starch enhances biodegradation rate up to 60 %. Biodegradation of NR-based products is confirmed through characterization of physicochemical, thermal and mechanical properties using SEM, XRD, FTIR, GPC, TGA, UTM, physical appearance and weight loss. NR-based materials with enhanced biodegradability have many uses, thus its customizability should be studied further in terms of different product forms, fabrication method, orientation of biofiller used and incorporation of metal organic frameworks.

Environmental issues caused by plastic films promote the development of biodegradability packaging materials. Copper ion-modified nanocellulose films were prepared through a one-pot reaction and systematically investigated their structural characteristics, thermal stability, mechanical properties, antibacterial activity, and biodegradability. The results indicate that the film prepared by co-soaking CNCs and copper in NaOH solution for 12 h has favorable performance. Introduction of copper ions as crosslinkers increases tensile strength of film from 36.8 MPa to 56.4 MPa and water contact angle of film from 46 degrees to 92 degrees. Copper coordination also endows the film excellent antibacterial activity, inhibiting growth of Escherichia coli and Staphylococcus aureus. Moreover, biodegradability tests indicate that although the introduction of copper ions slightly reduce biodegradation rate of films, they could still be decomposed significantly within four weeks as burying in soil. This simple process for preparing cellulosic films with water resistance, thermal stable, antibacterial ability, and biodegradable shows potential application in flexible packaging film.

Mulching films serve various functions, such as temperature regulation, moisture retention, and weed suppression. They can substantially increase crop yields and are widely adopted in agricultural practices. However, the use of traditional plastic mulch films is limited by their difficult recycling processes and poor biodegradability, leading to soil contamination and negatively affecting crop growth. Consequently, eco-friendly alternatives are gaining attention as replacements for conventional petroleum-based films in agricultural applications. Enhancing the performance of these eco-friendly films remains a crucial challenge. Traditional polyvinyl alcohol (PVA) films have inherent limitations, including low mechanical strength and poor water resistance. In this work, a PVA/sodium alginate (SA)/glycerol (GLY)/glutaraldehyde (GA) film was prepared that is biodegradable, demonstrates superior mechanical properties, and offers exceptional transparency through glutaraldehyde crosslinking. The impact of GA on films was examined using characterization techniques. The findings revealed that the composite film has a uniform, compact surface with no observable holes or aggregation. The mechanical performance and water vapor barrier properties (WVP) of the film were significantly enhanced after GA crosslinking. The tensile strength and elongation at the break of the PVA/SA/GLY/GA film reached 33.73 MPa and 362.89%, respectively. This work offers a straightforward approach to the development of sustainable agricultural materials.

This study explored mycelium-based composites (MBCs) as a sustainable alternative to conventional materials, focusing on the role of lignocellulosic substrates in optimizing their physical, mechanical, and biodegradability properties. It also addressed the valorization of agroforestry by-products, particularly European hazelnut shells (HZ) and radiata pine sawdust (SW), in an effort to reduce waste and minimize environmental impacts. The MBCs were obtained using two formulations (HZ100 and HZ75-SW25) of local agroforestry by-products bound together with natural growth of fungal mycelium from Ganoderma sp. We examined the physical and mechanical properties of these novel materials, including the density, shrinkage, water absorption, hydrophobicity, moduli of rupture and elasticity, and internal bond strength. Additionally, we assessed the biodegradability of the MBCs in soil to estimate the time required for complete degradation. The results clearly indicated differences in performance between the MBCs from HZ100 and HZ75-SW25. In general, HZ75-SW25 demonstrated superior mechanical performance compared to HZ100. Water absorption was low in both cases, suggesting a degree of hydrophobicity on the surface. The biodegradation results indicated that the fabricated MBCs could fully decompose in less than one year when buried in soil, confirming that these biocomposites are entirely biodegradable.

Development of bio-based active packaging systems for lipid stabilization presents critical importance in preserving lipid integrity and ensuring food safety. Zein/citric acid (Z/CA) composite films containing grape seed ethanol extract (GSEE) (0-8% w/w) were prepared by the solvent casting method. The structural, functional, and environmental properties of the films, including physical and chemical properties, mechanical properties, antioxidant capacity, antibacterial activity, oxidation inhibition effect, and biodegradability, were comprehensively characterized and evaluated. Progressive GSEE enrichment significantly enhanced film thickness (p < 0.05), hydrophobicity, and total phenolic content, while increasing water vapor permeability by 61.29%. Antioxidant capacity demonstrated radical scavenging enhancements of 83.75% (DPPH) and 89.33% (ABTS) at maximal GSEE loading compared to control films. Mechanical parameters exhibited inverse proportionality to GSEE concentration, with tensile strength and elongation at break decreasing by 28.13% and 59.43%, respectively. SEM microstructural analysis revealed concentration-dependent increases in surface asperity and cross-sectional phase heterogeneity. Antimicrobial assays demonstrated selective bacteriostatic effects against Gram-negative pathogens. Notably, the composite film containing 6 wt% GSEE had a remarkable restraining effect on the oxidation of lard. The soil degradation experiment has confirmed that the Z/CA/GSEE composite film can achieve obvious degradation within 28 days. The above results indicate that the Z/CA/GSEE composite material emerges as a promising candidate for sustainable active food packaging applications.

In this study, novel block copolymers consisting of poly(ethylene succinate) (PES) and poly(amino acid)s were synthesized, and their thermal and mechanical properties and biodegradability characteristics were investigated. Various types of poly(amino acid) units were successfully introduced using N-phenyloxycarbonyl amino acids (NPCs). The reactions between the terminally aminated PES and the NPCs were conducted by heating in N,N-dimethylacetamide at 65 degrees C. Structural analyses of the obtained polymers confirmed that the reaction with the NPCs proceeded from both ends of the terminally aminated PES. The results of material property measurements demonstrated that the melting point of the block copolymer containing poly(alanine) units increased beyond 200 degrees C while that of the original PES was similar to 100 degrees C. Additionally, its strain at break increased similar to 80-fold compared to that of PES with a similar molecular weight. The results of biodegradability tests using a soil suspension as an inoculum indicated that some of the block copolymers underwent biodegradation, and a correlation was observed between the biodegradability and the type and feed amount of NPC. Therefore, it was proposed that the degree, rate, and onset time of biodegradation could be controlled by altering the type and amount of incorporated poly(amino acid) units. This research may contribute to the optimal and facile synthesis of polyester-b-poly(amino acid) copolymers and to the expansion of the range of available biodegradable materials.

Preparation and characterization of biopolymer-based packaging materials have significantly gained importance because of sustainability, biodegradability, and eco-friendly nature. In this study, novel wheat gluten (WG)/cloisite 30B (C30B) organoclay-based bionanocomposite (BNC) films were prepared by solution casting method at various C30B concentrations (5%, 10%, and 15%). X-ray diffraction and field emission scanning electron microscopy revealed intercalation/exfoliation of C30B sheets into the WG matrix. WG-C30B 10% film was thermostable. It showed low surface roughness along with higher water barrier properties and surface hydrophobicity. The tensile strength values of WG and WG-C30B 10% films were found to be 0.7 +/- 0.02 and 1.11 +/- 0.01, respectively, indicating improvement in mechanical properties. WG-C30B 10% film demonstrated antibacterial activity against both Staphylococcus aureus and Salmonella enterica. Shelf life of green grapes was monitored under different conditions: 4 degrees C, ambient conditions, and 42 degrees C. WG-C30B 10% film proved effective in extending shelf life up to 18 days under ambient conditions. More than 50% of the bionanocomposite films were degraded in agricultural soil within 2 weeks, while completely degraded in sewage sludge soil after a few days. WG-C30B 10% film appeared to be promising regarding the demonstrated physico-chemical and antibacterial properties. This report would be useful in preparing biodegradable biopolymer-based packaging materials.

Eco-friendly silk fibroin/poly(D,L-lactide-co-glycolide) (SF/PLGA) materials were successfully fabricated using a facile strategy. The materials were characterized by scanning electron micrograph (SEM), X-ray diffraction (XRD) and infrared spectra (IR). Systematic investigations were completed to examine the degradation rates in natural soil, cytocompatibility and thermostability of the materials. It is interesting to find that after SF was hybridized by PLGA, the thermostability and degradation rate increased. Meanwhile, the materials show good cytocompatibility. SEM, IR and XRD results reveal that there is hardly any interaction between SF and PLGA in the SF/PLGA material, and SF is physically mixed with PLGA. This study opens up a new horizon in the design and preparation of SF-based materials for promising applications in medical and biodegradable material fields.

The need for renewable and biodegradable materials for packaging applications has grown significantly in recent years. Growing environmental worries over the widespread use of synthetic and non-biodegradable polymeric packaging, particularly polyethylene, are linked to this increase in demand. This study investigated the degradation properties of low-density polyethylene (LDPE), a material commonly used in packaging, after incorporating various natural fillers that are sustainable, compatible, and biodegradable. The LDPE was mixed with 2.5, 5, and 10 wt.% of sawdust, cellulose powder, and Nanocrystalline cellulose (CNC). The composites were melted and mixed using a twin-screw extruder machine with a screw speed of 50 rpm at 190 degrees C to produce sheets using a specific die. These sheets were used to prepare samples for rheological tests that measured the viscosity curve, the flow curve, and a non-Newtonian mathematical model using a capillary rheometer at 170, 190, and 210 degrees C. X-ray diffraction analysis was carried out on the 5 wt.% samples, and a short-term degradation test was conducted in soil with a pH of 6.5, 50% humidity, and a temperature of 27 degrees C. The results revealed that the composite melts exhibited non-Newtonian behavior, with shear thinning being the dominant characteristic in the viscosity curves. The shear viscosity increased as the different cellulose additives increased. The 5% ratio had a higher viscosity for all composite melts, and the LDPE/CNC melts showed higher viscosities at different temperatures. The curve fitting results confirmed that the power-law model best described the flow behavior of all composite melts. The LDPE/sawdust and cellulose powder melts showed higher flow index (n) and lower viscosity consistency (k) values compared with LDPE/CNC melted at different temperatures. The sawdust and powder composites had greater weight loss compared with the LD vbbPE/CNC composites; digital images supported these results after 30 days. The degradation test and weight loss illustrated stronger relations with the viscosity values at low shear rates. The higher the shear viscosity, the lower the degradation and vice versa.