Biodegradable mulch films are essential for reducing plastic pollution in agriculture; however, current production methods often rely on complex and costly chemical processes. This study presents an innovative, ecofriendly approach to developing fully biodegradable mulch films using untreated vegetable stalks and sodium alginate through a simple blending method. By eliminating the need for pretreatment, this process significantly reduces energy consumption and maximizes agricultural waste utilization. The optimized film formulation (30 % vegetable stalk, 3 % solution, 40 % glycerin) demonstrated excellent mechanical and barrier properties, including tensile strength (6.8 MPa), elongation at break (29 %), water vapor permeability (1.88 x 10-12 g & sdot;cm-1 & sdot;Pa-1 & sdot;s-1), and UV-blocking efficiency (98.5 %), and thermal insulation and moisture retention properties. Rheological analysis showed that the addition of vegetable stalks impacted the film-forming solution's properties, enhancing processing and application performance. Additionally, the films facilitated seed germination and maintained functionality on the surface of moist soil, while rapidly degrading when buried in moist soil. Life Cycle Assessment confirmed that the biodegradable films significantly reduce environmental impacts, supporting their potential for widespread adoption in sustainable agricultural practices. This study provides a scalable and cost-effective strategy for converting agricultural residues into high-performance biodegradable films, addressing the need for sustainable solutions in agriculture and environmental protection.

Conventional nondegradable packaging and mulch films, after reaching the end of their use, become a major source of waste and are primarily disposed of in landfills. Accumulation of non-degradable film residues in the soil leads to diminished soil fertility, reduced crop yield, and can potentially affect humans. Application of degradable films is still limited due to the high cost, poor mechanical, and gas barrier properties of current biobased synthetic polymers. In this respect, natural polysaccharides and proteins can offer potential solutions. Having versatile functional groups, three-dimensional network structures, biodegradability, ease of processing, and the potential for surface modifications make polysaccharides and proteins excellent candidates for quality films. Besides, their low-cost availability as industrial waste/byproducts makes them cost-effective alternatives. This review paper covers the performance properties, cost assessment, and in-depth analysis of macromolecular structures of some natural polysaccharides and proteins-based films that have great potential for packaging and mulch applications. Proper dissolution of biopolymers to improve molecular interactions and entanglement, and establishment of crosslinkages to form an ordered and cohesive polymeric structure can help to obtain films with good properties. Simple aqueous-based film formulation techniques and utilization of waste/byproducts can stimulate the adoption of affordable biobased films on a large-scale.

A green process was devised to effectively extract cellulose from recycled rice straw waste, subsequently ethylating and modifying it into ethyl cellulose (EC), and ultimately blending the EC with ethanol to obtain biodegradable films. The optimal process conditions at each stage were investigated. An assessment was conducted on the crystallinity and thermal stability of rice straw cellulose (RSC), the degree of substitution of EC, and the biodegradability and mechanical properties of EC-ethanol films. The results demonstrated the following: The optimal process conditions resulted in a 95.73 % yield of extracted RSC, a type I crystalline structure, a 31.20 % increase in relative crystallinity, and thermal stability with a main weight loss peak at 340 C-degrees. Under ideal ethylation conditions, the EC production reached 79.60 %, while the degree of substitution ranged from 2.0 to 2.5. After being landfilled in soil for 100 days, the EC-ethanol films degraded at rates of 6.77 %, 4.78 %, and 3.13 % (film concentrations were 0.02, 0.04, and 0.06 g/mL (w/v, EC/ethanol), respectively). Based on the analysis of the films' FT-IR and SEM images, it was concluded that the EC-ethanol films exhibit favorable biodegradability. Moreover, the tensile strength of 0.04 g/mL film reaches up to 44.60 MPa. Hence, the EC-ethanol films in this research could be an environmentally friendly and sustainable alternative to plastic films.

Plastics thrown out as trash are an everlasting threat to our biosphere and ecosystem. A sustainable remedy within our reach is the use of agricultural biomass. Herein, the lignocellulosic residue of switchgrass biomass, extracted using alkaline and bleaching treatments and solubilized in ZnCl2 solution followed by crosslinking with calcium ions, is used to develop biodegradable films. The films have been characterized for color, transparency, thickness, moisture, water solubility, water absorption, water vapor permeability, tensile strength, elongation, and soil biodegradation. Mathematical modeling of the water absorption and biodegradation behavior have also been studied. The films are transparent, possess high tensile strength and low water vapor permeability, and biodegrade completely within 40 days at 30% soil moisture. The tensile strength and whiteness of films increase with CaCl2 concentration, but elongation, water absorption, water solubility, water vapor permeability, and biodegradation decrease. Overall, the strong and biodegradable switchgrass residue-based films open up a new window of opportunities to design and develop reusable, recyclable, and compostable films from underutilized, inexpensive, and abundant agricultural biomass contributing to the circular bioeconomy in a friendly and sus-tainable manner.