Agricultural biomass is a sustainable source for developing biodegradable film to address mounting plastic perils. This study aims to investigate the influence of CaCl2 concentration on the properties of lignocellulose-based biodegradable film produced from oat straw biomass. Lignocellulose is extracted from oat biomass, and a green technique is employed to solubilize it in ZnCl2 solution and crosslinked with varying CaCl2 concentrations (200 mM-800 mM) to make films. The films containing 800 mM CaCl2 concentration demonstrated the lowest moisture content (12.81 f 0.81 %), water solubility (43.91 f 0.42), water vapor permeability (4.96 f 0.14 x 10-11 gm- 1s-1Pa- 1), visible light transmittance (53.27 f 0.69 %), and moisture absorption (42.42 f 1.32 %). The tensile strength has increased remarkably from 4.24 f 0.76 to 17.24 f 3.68 MPa due to increased CaCl2 concentration from 200 mM to 800 mM. They degraded up to 83 % in soil with 20 % moisture after 28 days. Overall, films made of lignocellulose from oat straw biomass films demonstrate high strength and moisture barrier capabilities, rendering them suitable for use as food packaging materials.

In this paper, carboxymethyl cellulose (CMC) and hemicellulose derived from water hyacinth were used to prepare hemicellulose-based biodegradable mulch film by covalent cross-linking and ionic cross-linking in order to expand its application in agricultural production practice. The esterification reaction between hemicellulose, CMC and citric acid resulted in an increase in tensile strength and elongation at break of the membranes. When citric acid was not used as cross-linking agent and the pH was lowered, the sodium carboxylate group was protonated into carboxylic acid group, which provided abundant active sites for chemical cross-linking of hydroxyl group on hemicellulose and hydroxyl group on CMC. Furthermore Zn2+ could cross-link with carboxylic acid group through hydrogen bonding, and when the DS of carboxymethyl group was high, the cross-linking of Zn2+ with Zn2+ was higher, and the conversion into nano ZnO was lower, which was conducive to the uniform distribution and reduction of agglomeration phenomenon in the films. It is favorable for its uniform distribution in the film and reduces the agglomeration phenomenon. The mulch films made from water hyacinth has excellent mechanical properties, light transmittance, water absorption, soil moisture retention and heat preservation, and is biodegradable. This study will provide new ideas for water pollution control and farmland pollution for sustainable agricultural production.

Excessive use of nondegradable plastics has raised environmental concerns, promoting the development of high-performance and eco-friendly materials. Polysaccharides and proteins, which offer advantages such as affordability and biodegradability, have potential in packaging but are limited in barrier and mechanical properties. Herein, using 30% acetic acid as a solvent for soy protein isolate (SPI) and introducing oxidized arabinogalactan (OAG) into the system, highly transparent (90%) and ultraviolet-shielding SPI/OAG flexible films were successfully prepared via Schiff base chemical cross-linking and hydrogen bond interactions between the components. The synergistic cross-linking of SPI and OAG effectively increased mechanical strength (tensile strength of 6.93 MPa), improved oxygen and water vapor barrier properties, and reduced swelling in the SPI/OAG films. The films exhibited good antioxidant activity (81.75% for ABTS and 85.34% for DPPH), effectively retarded browning and weight loss of strawberry and apple pieces, and were biodegradable in soil. The prepared SPI/OAG films had advantages over existing SPI-based films, including a uniform structure, low oxygen permeability, and excellent sustainability. This research demonstrates that SPI/OAG cross-linked films have strong potential in biodegradable packaging and as a substitute for petroleum-based plastics.

Composite polymer materials as soil improvers are developed to enhance soil cohesion and aggregate stability. However, the improved soil still struggles to overcome the reduction in strength caused by day-to-day freeze-thaw (FT) cycle in the plateau area with large temperature difference. In this study, the natural power of FT cycle was used to drive the crosslinking of poly (vinyl alcohol) (PVA) and sodium alginate (SA) to form the interpenetrating networks of PVA-SA hydrogel. Then, this hydrogel was applied to stabilize the soil. The characterizations by FTIR, TGA, SEM and XRD indicated that the PVA-SA hydrogel had a porous, multi-channel and multi-chamber structure. Under the action of FT driving force, a series of studies including physical, chemical, water retention, direct shear, permeability, and aggregate stability were carried out on the soil with hydrogel applied. Compared to the control group, the data indicated that the cohesion of soil is significantly improved to 80 kPa. And the saturated hydraulic conductivity of the soil was reduced to 1/45 of the pre-modification rate, which had a positive impact on the water retention of the soil. What's more, the results revealed that the PVA-SA hydrogel had effects on the aggregate stability, the submerged soil with added PVA-SA hydrogel still had no sign of disintegration and its mass percentage was greater than 99% after 70 days. In a word, this composite material can effectively improve the cohesion and aggregate stability of the soil with the help of natural driving forces, which is potential to be used as remediation material for the plant layer in ecological restoration process.

Melt blending is a reliable and well-demonstrated strategy for improving the mechanical, thermal, rheological, and surface properties of biopolymers. Poly(hydroxy-3-butyrate-co-3-hydroxyvalerate) (PHBV) and poly(butylene adipate-co-terephthalate) (PBAT) are the two popular choices for blending polymers due to their diverse properties and complementary soil biodegradable behaviour. Due to their immiscibility, however, blending with the help of processing additives is necessary to reap the most significant benefits from this process and to avoid immiscibility issues. This study utilized the additives (peroxides and epoxy-based chain extender) to compatibilize the biodegradable polymers PHBV and PBAT in a 60:40 blending ratio. The tensile strength and Young's modulus of the PHBV/PBAT(60/40) blend were improved by 32% and 64%, respectively, after adding a combination of peroxide (0.02 phr) and chain extender (0.3 phr) due to the formation of a complex network structure with increased chain length. The positive effect of an additive addition was also reflected by a 30 degrees C increment in heat deflection temperature of biodegradable blend due to its high modulus value as supported by mechanical properties. The combined action of a peroxide and chain extender demonstrated a significantly higher complex viscosity of the PHBV/PBAT(60/40) blend due to the formation of a crosslinked polymer network as analyzed by rheological analysis. Our research demonstrated the effect of additives and their combined impact on analytical properties of PHBV/PBAT(60/40) blend to guide future work in improving their candidature to serve as a drop-in solution in replacing non-biodegradable petro-based plastic products.

In order to attenuate the pollution problem caused by low fertilizer utilization, a biodegradable urea slow-release capsule was prepared in this study using gelatin as the main material. Glycerol was added to the gelatin solution as a plasticizer, and the mechanical properties and water resistance of the gelatin film were enhanced by crosslinking with glutaraldehyde. The addition of nano-SiO2 (nSiO2) and calcium magnesium phosphate fertilizer power (CaMgP) enhanced the hydrophobicity and tensile strength of the gelatin film. X-ray diffractometer confirmed that the nSiO2 could make the gelatin molecular chains more tightly entangled. Scanning electron microscope indicated that the addition contents of nSiO2 and CaMgP was optimal at 2 wt% and 40 wt%, respectively. The gelatin capsules were loaded with urea particles for slow-release experiments, the results of soil column drenching showed that the release rates of urea from nSiO2-modified and CaMgP-modified cross-linked gelatin capsules were 4.1 % and 5 % after 24 h, respectively, and 78.8 % and 75.2 % after 28 d, respectively.

Purpose Sodium alginate (Na-Alg) is a natural polysaccharide with a rich and renewable production that is widely used in the food, pharmaceutical and daily necessities industries, among other fields. The purpose of this study is to obtain a green and degradable shape memory material, calcium alginate (Ca-Alg) film was prepared and the mechanical properties, the shape memory effect of the film were investigated and confirmed. Design/methodology/approach The Ca-Alg films were prepared by Na-Alg, calcium chloride (CaCl2) solution, and flow extension method. Dissolve sodium alginate powder, remove bubbles, pour into petri dish, dry at 60 degrees C, add calcium chloride solution cross-linking and finally dry naturally. The effect of CaCl2 solution concentration on the mechanical properties of the films were investigated and discussed by universal tensile tester. The shape memory behavior and degradation performance of thin films were verified and studied by the fold-deploy shape memory test and soil embedding method, respectively. Findings The Ca-Alg films exhibited good mechanical and shape memory properties, with a 72.2% shape memory fixity ratio and a 92.3% shape memory recovery ratio, respectively. For a period of 120 days, the film treated with a 6 wt% CaCl2 solution degraded at a rate of approximately 53%. Research limitations/implications Shape memory polymers (SMPs) as intelligent materials are an important research direction for the development of modern high-tech materials. On the other hand, plastic pollution is a major problem today; as a result, preparing green degradable SMPs is essential. Originality/value This study synthesized transparent and degradable shape memory Ca-Alg films using Na-Alg and CaCl2 solution and the flow extension method.