Effect of polymer blending on mechanical and barrier properties of starch-polyvinyl alcohol based biodegradable composite films

pH-responsive starch-based bilayer film functionalized with alliin loaded MIL-101 (Fe) for active food packaging

Food packaging films containing antimicrobial reagents play a crucial role in preventing bacterial-induced fruit decay. This study proposes a bilayer film consisting of an internal amino-modified starch hydrophilic layer and an external amino-modified polyvinyl alcohol/polylactic acid hydrophobic layer, embedding alliin@MIL-101(Fe) as an antibacterial agent, utilizing the pH reduction of fruit decay sites to achieve pH-responsive release, enhancing antibacterial performance. Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) analyses confirm successful crosslinking between amino and aldehyde groups, resulting in the formation of imine bonds and a mesh-like structure conducive to adsorption. Under acidic conditions, the cumulative release rate of alliin reached 74 % within 36 h. Compared to a simple mixture, the tensile strength of the alliin@MIL/NST-NPVA/PLA film reached 34.771 MPa, and transmittance in the wavelength range of 200-370 nm decreased to 0. The scavenging rate of DPPH free radicals in the film can reach 83 %. In addition, the water vapor permeability and oxygen permeability of the film are approximately 7.62 × 10-16 [g/ (m2‧24 h‧0.1 mm)] and 6.83 (m2‧24 h‧0.1 MPa), respectively; moisture content and water solubility decreased to 10.99 % and 20.77 %. This composite film extended the shelf life of strawberries from 2 to 7 days, significantly enhancing freshness.

Active starch-based film using polyvinyl alcohol and chlorogenic acid for strawberry preservation: A comparative analysis of mechanical, barrier, and antibacterial properties

The broad application of starch films has been significantly limited by their insufficient hydrophobicity and antibacterial activity. To overcome these challenges, this study developed a new starch film by incorporating polyvinyl alcohol (PVA) and chlorogenic acid. The study explored the impact of PVA polymerization on the physical and functional characteristics of the resulting films, with particular emphasis on enhancing antimicrobial functionality by incorporating chlorogenic acid. Scanning electron microscopy (SEM) and rheological tests demonstrated the excellent compatibility and exceptional film-forming performance. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses validated the presence of intermolecular entanglements and hydrogen bonding within the films. Incorporating PVA with a polymerization degree of 2400 resulted in a contact angle (CA) of 79.81 ± 1.74°, a water absorption capacity (WAC) of 10.29 ± 0.71 %, and a water vapor permeability (WVP) of (0.44 ± 0.11) × 10-11 g × m-1 × s-1 × Pa-1. Notably, the SCP 2488 film exhibited superior mechanical properties, including the highest Young's modulus of 71.29 MPa, tensile strength of 11.77 MPa, and elongation at break of 106.75 %. Additionally, such a modified film displayed enhanced UV-blocking performance and antibacterial efficacy. Consequently, the SCP 2488 film showed great potential for maintaining the freshness and quality of strawberries.

Waterborne blocked isocyanate crosslinked cationic starch/polyvinyl alcohol coating for improving barrier and mechanical properties of paper-based materials

Green and renewable paper-based packaging materials are gaining more and more popularity, however, issues such as poor barrier and mechanical properties need to be solved. Herein, cationic starch (CS) and polyvinyl alcohol (PVA) were used as paper coatings, with waterborne blocked isocyanate (WBI) serving as a cross-linking agent to eliminate the hydroxyl groups. CS/PVA and CS/PVA/WBI were coated on kraft paper using a bar coating machine at 8 g/m2. The composite paper exhibited excellent liquid and gas barrier properties with water and oil absorption values of 8.28 and 9.60 g/m2, which were reduced by 71.27 % and 57.29 %, respectively, compared to the control sample. The WVTR and OTR were reduced from the original 2393.38 g/(m2⸱24 h), 13,235.68 cm3/(m2⸱24 h⸱0.1 MPa) to 600.20 g/(m2⸱24 h) and 951.25 cm3/(m2⸱24 h⸱0.1 MPa), respectively. Furthermore, the composite paper showed high mechanical strength (tensile strength: 11.51 kN/m, tear strength: 634.73 mN) and retained nearly 40 % of its tensile strength after 15 min of immersion in water. In addition, the composite paper had good organic solvent barrier and recyclability. This paper presents a simple and effective method for improving the barrier and mechanical properties of paper-based materials, and makes a new attempt for the research and development of paper-based packaging materials.

Enhancing slow-release performance of biochar-based fertilizers with kaolinite-infused polyvinyl alcohol/starch coating: From fertilizer development to field application

Conventional biochar-based fertilizers, which typically consist of a mixture of biochar, chemical fertilizers, and additives, offer benefits but often exhibit rapid nutrient release, limiting their long-term effectiveness. Herein, we explored the enhancement of slow-release performance in biochar-based compound fertilizers by incorporating a kaolinite-infused polyvinyl alcohol/starch (K-PVA/ST) coating, resulting in a new formulation denoted as K-PVA/ST-BCF. The results demonstrated that, compared to traditional NPK fertilizers, nitrogen leaching from K-PVA/ST-BCF in soil column leaching tests was reduced to 19.1 % over 29 days, while phosphorus and potassium leaching were reduced to 48.5 % and 72.3 %, respectively. Mechanistic investigations revealed that the inclusion of kaolinite in the PVA/ST matrix reduces swelling, improves water retention, and enhances mechanical properties, leading to a more gradual and sustained release of nutrients. Field trials on reclaimed land showed that K-PVA/ST-BCF increased wheat yield by up to 100 % compared to conventional NPK treatment. It also enhanced soil nitrogen content and organic matter, with organic matter reaching 22.7 g/kg at grain maturity. The economic assessment indicated that despite higher initial production costs compared to conventional NPK fertilizers, K-PVA/ST-BCF offers higher nutrient use efficiency, reduced management costs, and a net profit increase of $1525.86 per hectare.

A sustainable approach to develop antimicrobial composite film incorporating novel Dalbergia reniformis seed-derived microcrystalline cellulose and medicinal Mikania micrantha extract in PVA

This study presents a sustainable approach to develop antimicrobial films (AMFs) using agricultural wastes. Microcrystalline cellulose (MCC) was extracted from a novel source of Dalbergia reniformis seeds (DRS) through chemical hydrolysis, and bioactive powder from Mikania micrantha (MM) leaves was reinforced into a polyvinyl alcohol (PVA) matrix to create antimicrobial films. The morphological, antimicrobial, physical, mechanical, and thermal properties of the films were investigated. MCC (5 %, 10 %, and 15 %) and MM (5 % and 10 %) concentrations were varied to study their effects on film properties. Fourier transform infrared spectroscopy confirmed the elimination of non-cellulosic compounds in MCC and the chemical interactions among film components, while X-ray diffraction analysis revealed improved crystallinity of MCC compared to raw pulp and enhanced crystallinity of AMFs compared to pure PVA. Scanning electron microscopic images demonstrated better adhesion and homogeneous MCC distribution in the PVA matrix up to a concentration 10 % MCC, while higher concentrations caused self-aggregation. The AMFs showed strong antibacterial activity, with inhibition zones of 18.83 mm for S. aureus and 18.55 mm for E. coli at 10 % MM. Anti-inflammatory properties were confirmed, with pure MM reducing swelling by 46.8 % and AMFs with 10 % MM achieving 33.9 % inhibition. Mechanical properties, including tensile strength, increased by 57.7 % with 10 % MCC but declined at 15 % MCC due to aggregation. Conversely, the moisture content, water solubility, and water vapor permeability of the films significantly decreased with up to 10 % MCC. These findings highlight the potential of the developed AMFs for antimicrobial applications in healthcare, food packaging, and other industries.

Next-Generation Edible Packaging: Development of Water-Soluble, Oil-Resistant, and Antioxidant-Loaded Pouches for Use in Noodle Sauces

The development of sustainable biodegradable packaging materials is essential for enhancing food quality and shelf life while reducing plastic waste. This study explored polymer-based monolayer, composite, and bilayer films to produce water-soluble, oil-proof pouches. Single-serving seasoning oil pouches were prepared from bilayer films with polyvinyl alcohol (PVA) as the inner and sodium alginate (SA) as the outer layer. The PVA/SA films exhibited excellent UV protection, low oil permeability (0.18 × 10-6 g·mm/mm2·day), hydrophilic surface (water contact angle < 90°), and rapid solubility in hot water (87 ± 2 °C). Incorporating curcumin, a natural antioxidant, into PVA/SA films (Cur-PVA/SA) improved thermal stability, reduced light transmittance, and decreased water vapor permeability (0.28 × 10-10 g/m·Pa·s). Curcumin release followed a biphasic diffusion model, with 94.8% released at 96 h (diffusion coefficient: 1.30 × 10-11 m2/s), ensuring prolonged antioxidant activity. The Cur-PVA/SA pouches delayed lipid oxidation more effectively, with peroxide values of 6.48 and 10.35 meq/kg after 45 days at 35 °C, respectively. The Q10 model, which is commonly used to predict the shelf life of oils based on temperature-dependent oxidation rates, estimated that the oil packaged in Cur-PVA/SA pouches would remain stable for 12 months at 23 °C. This represents a 37% longer shelf life compared to oil packaged in PVA/SA pouches without curcumin. Cur-PVA/SA pouches also reduced noodle moisture migration, limiting weight loss to 2.73% over 14 days compared to 5.80% in controls. These findings highlight their potential as eco-friendly active packaging solutions.

Influence of additives on the development, mechanical, functional characteristics and biodegradability of banana starch-based bio plastic films

Starch-based bio plastics, due to their abundance, recyclability, and biodegradability, offer a promising alternative to conventional petrochemical-based plastics. Additives significantly influences the functionality of bioplastics. This study investigates the effects of polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) at varying concentrations on banana starch-based bioplastic films, using glycerol as a plasticizer. CMC-based films exhibited higher L* values and thickness (0.51-1.55 mm) compared to PVA films. Due to hydrophilicity, CMC films demonstrated 2-3 times greater solubility (17-23 %) and water absorption (75.29 %). Moisture-rich films, C3 and PC2:1, showed the highest WVTR values of 25.73 and 24.10 g/m2/day, respectively, while PVA-rich films (1-1.5 %) had lower WVTR. Increasing CMC concentration reduced OTR values (2.59-3.58 cm3/m2/day) compared to PVA (4.19-5.23 cm3/m2/day). PVA enhanced transparency and smoother morphology, while CMC imparted texture and fibrous structures. Gloss values ranged from 9.82 (P1) to 40.88 (PC2:1), with CMC films exhibiting 3-4 times higher gloss. Tensile strengths varied from 8.34 MPa (C1) to 24.73 MPa (C2), highlighting CMC's mechanical enhancement, while P1 achieved the highest elongation of 90.23 %. FTIR spectra confirmed banana starch matrices, and CMC's crystalline nature at 2θ = 23° reduced polarity and crystallinity, influencing water absorption. These insights support designing banana starch-based bioplastics for a sustainable future.

Recyclable PVA/starch/Ti3C2Tx MXene nanocomposite films with superior mechanical and barrier properties

The fabrication of eco-friendly and high-performance composite materials has gained significant attention for multifunctional applications. Polyvinyl alcohol (PVA)/starch composite films containing varying amounts of Ti3C2Tx MXene (2.5-10 wt%) were produced using a simple casting method. The impact of MXene nanoplatelets on the films' chemical structure and physical properties were thoroughly analysed. It was revealed that MXene formed hydrogen bonding with the polymer matrix and tended to align in the plane of the films. The mechanical properties of the PVA/starch blend were significantly improved with increasing MXene loading. With 10 wt% MXene, the Young's modulus (YM) and tensile strength (TS) increased by 669 % (from 255.7 to 1965.3 MPa) and 292 % (from 9.2 to 36.1 MPa), respectively. Additionally, the presence of MXene greatly improved the films' water and oxygen barrier properties, reducing water vapor permeability (WVP) by 91 % and oxygen permeability (OP) by 79 %. These improvements are attributed to the homogeneous dispersion of MXene within the blend and the interfacial interactions between the components. Furthermore, the PVA/starch/MXene composite films exhibited excellent recyclability, maintaining their mechanical and barrier properties even after recycling, demonstrating their potential for repeated use without performance loss. Overall, the developed composite films present a promising sustainable solution for applications in materials requiring advanced mechanical and barrier performance.

Biodegradable PVA/chitosan-based films enriched with rose hip extract and seed oil: Investigation of the influence of tragacanth gum ratio on functional properties and its application in cherry preservation

This study focuses on the development of polyvinyl alcohol-chitosan-tragacanth gum composite films enriched with rosehip extract and seed oil for the packaging of active foods. The films were tested for their antioxidant activity, transparency, biodegradability, water vapor permeability and effectiveness in preserving sweet cherries under seasonal high temperature conditions. The addition of tragacanth, rosehip extract and rosehip seed oil significantly influenced the mechanical properties by increasing elongation at break and tensile strength. Films enriched with rosehip seed oil effectively reduced weight loss and preserved the sensory properties of the cherries, while films based on rosehip extract exhibited superior antioxidant properties with increased free radical scavenging activity. Biodegradability tests showed that all films degraded under soil conditions, with the rate of degradation depending on the concentration of tragacanth gum. The water vapor permeability results showed that the addition of rosehip extract and seed oil significantly reduced the water vapor permeability and improved the barrier properties of the films. Preservation tests showed that these films minimized titratable acidity, oxidative stress and moisture loss, effectively extending the shelf life of sweet cherries under highly stressful conditions. These results highlight the potential of rosehip-enriched biopolymer films as a sustainable and environmentally friendly packaging alternative to extend the shelf life of perishable fruits.

Incorporating iron oxide nanoparticles in polyvinyl alcohol/starch hydrogel membrane with biochar for enhanced slow-release properties of compound fertilizers

Biochar-based fertilizers show promise in enhancing nutrient utilization and soil health, but their slow-release performance remains a challenge. Herein, hydrogel membranes incorporating iron oxide nanoparticles within a polyvinyl alcohol and starch matrix (Fe/PVA/ST) were synthesized. These membranes were utilized to coat compound fertilizer particles, with biochar powder applied to the outer layer to form what is known as Fe/PVA/ST-BSRFs. The results revealed that Fe/PVA/ST-BSRFs exhibit markedly improved slow-release performance compared to both PVA/ST-BSRFs lacking iron nanoparticles and commercial compound fertilizers. Within a 30-day period, the cumulative leaching ratios of N, P, and K from Fe/PVA/ST-BSRFs with 0.75 % iron content were significantly lower compared to other tested fertilizers, with values of 22.87 %, 34.93 %, and 84.08 %, respectively. Furthermore, the incorporation of iron oxide nanoparticles into the PVA/ST membrane enhanced its swelling and water-retention properties without compromising its biodegradability. Mechanistic investigations revealed that the exceptional slow-release properties of Fe/PVA/ST-BSRFs stem from a combination of nutrient diffusion control outside the membrane and the loose control mechanism of the membrane. Pot tests demonstrated that Fe/PVA/ST-BSRFs effectively promoted the growth of chili plants while ensuring high utilization of N-P-K and improving the nutritional indices of chili fruits. Economic analysis further underscored the promising application prospects of Fe/PVA/ST-BSRFs.

Production of Starch-Based Flexible Food Packaging in Developing Countries: Analysis of the Processes, Challenges, and Requirements

Biodegradable packaging offers an affordable and sustainable solution to global pollution, particularly in developing countries with limited recycling infrastructure. Starch is well suited to develop biodegradable packages for foods due to its wide availability and simple, low-tech production process. Although the development of starch-based packaging is well documented, most studies focus on the laboratory stages of formulation and plasticization, leaving gaps in understanding key phases such as raw material conditioning, industrial-scale molding, post-production processes, and storage. This work evaluates the value chain of starch-based packaging in developing countries. It addresses the challenges, equipment, and process conditions at each stage, highlighting the critical role of moisture resistance in the final product's functionality. A particular focus is placed on replacing single-use plastic packaging, which dominates food industries in regions with agricultural economies and rich biodiversity. A comprehensive analysis of starch-based packaging production, with a detailed understanding of each stage and the overall process, should contribute to the development of more sustainable and scalable solutions, particularly for the replacement of single-use packages, helping to protect vulnerable biodiverse regions from the growing impact of plastic waste.

Development of Eco-Friendly Packaging Films from Soyhull Lignocellulose: Towards Valorizing Agro-Industrial Byproducts

Due to their inability to biodegrade, petroleum-based plastics pose significant environmental challenges by disrupting aquatic, marine, and terrestrial ecosystems. Additionally, the widespread presence of microplastics and nanoplastics induces serious health risks for humans and animals. These pressing issues create an urgent need for designing and developing eco-friendly, biodegradable, renewable, and non-toxic plastic alternatives. To this end, agro-industrial byproducts such as soyhulls, which contain 29-50% lignocellulosic residue, are handy. This study extracted lignocellulosic residue from soyhulls using alkali treatment, dissolved it in ZnCl2 solution, and crosslinked it with calcium ions and glycerol to create biodegradable films. The film formulation was optimized using the Box-Behnken design, with response to tensile strength (TS), elongation at break (EB), and water vapor permeability (WVP). The optimized films were further characterized for color, light transmittance, UV-blocking capacity, water absorption, contact angle, and biodegradability. The resulting optimized film demonstrated a tensile strength of 10.4 ± 1.0 MPa, an elongation at break of 9.4 ± 1.8%, and a WVP of 3.5 ± 0.4 × 10-11 g·m-1·s-1·Pa-1. Importantly, 90% of the film degrades within 37 days at 24% soil moisture. This outcome underscores the potential of soyhull-derived films as a sustainable, innovative alternative to plastic packaging, contributing to the circular economy and generating additional income for farmers and allied industries.

Thermoplastic starch-ZnO nanocomposites: A comprehensive review of their applications in functional food packaging

The increasing demand for environmentally friendly food packaging solutions has driven extensive research on biodegradable materials, particularly thermoplastic starch (TPS), which is an eco-friendly alternative to petroleum-based plastics. Despite its eco-friendliness, TPS exhibits limitations, including inadequate mechanical and thermal properties, high water sensitivity, and low antibacterial activity. Although strategies such as chemical modification, blending, and compatibilizers have been employed to enhance TPS for functional packaging applications, they often fail to address these fundamental issues. A promising approach involves incorporating zinc oxide (ZnO) nanoparticles, which significantly improve the mechanical strength, thermal stability, and antimicrobial properties of TPS. This review focuses on TPS-ZnO nanocomposites, a notable subcategory of bio-nanocomposites recognized for their enhanced functional properties in food packaging applications. It discusses the synthesis and properties of these nanocomposites, particularly their mechanical, thermal, antimicrobial, and antioxidant properties. Moreover, this review explores the various applications of TPS-ZnO nanocomposites in active, intelligent, and sustainable food packaging, emphasizing their potential to address the pressing challenges of food waste and environmental impact.

Improving water barrier properties of starch based bioplastics by lignocellulosic biomass addition: Synthesis, characterization and antibacterial properties

Global population growth has led to an increase in the demand for polymers, along with concerns about environmental pollution caused by solid polymers (such as consumer plastics), as well as the threat of global warming resulting from the production of polymer feedstock. Therefore, the polymer industry must develop sustainable and innovative strategies. The present study focuses on testing the potential of corn starch (CS) to produce bioplastic films and the impact of olive pits powder (OPP) addition, a natural agricultural waste material mainly containing lignocellulose, as filler on their properties. The developed bioplastic films containing starch, plasticizer, crosslinker and different amounts of OPP natural filler were prepared by casting solvent method according to a "green chemistry" process. The chemical, morphological, and thermal characterization of the prepared films was investigated using transformed infrared spectroscopy (FTIR), X-rays diffraction (XRD), atomic force microscopy (AFM) and thermogravimetric analysis (TGA). The physico-chemical, optical, water and oxygen barrier properties of the developed bioplastic films were evaluated as a function of OPP concentrations. Moreover, attention was paid to evaluate their biodegradability and their antibacterial activity. The addition of OPP from 10 to 70 % w/w led to an improvement of oxygen and water barrier properties (contact angle, water adsorption and moisture adsorption) due to specific interactions between starch matrix and lignocellulosic biopolymers present in OPP filler. The soil-biodegradability tests revealed that the control film was totally decomposed and the weight loss of all other films was upper than 70 % after only 14 days of exposure to soil. Antibacterial tests showed that the developed bioplastic films had an affective activity against both gram positive and gram negative bacteria strains.

Fluorinated compounds in paper and paperboard based food packaging materials

Paper- and paperboard-based materials are alternatives to petroleum-based plastics in food packaging but unsuitable for their poor moisture and oil resistance. In this sense, fluorinated compounds improve water and grease repellency, though their use is controversial. This Perspective discusses main techniques to combine fluorinated compounds with paper and paperboard, including water and oil contact angles and grease resistance values, and summarizes main legal aspects in Europe and the United States.

Development and characterization of eco-friendly guar gum-agar-beeswax-based active packaging film for cheese preservation

In this work, an attempt has been made to develop a novel natural polysaccharide-based composite packaging biofilm prepared through a solution casting method. The biofilm is prepared from guar gum (GG) and agar-agar (AA) beeswax (BE). The incorporation of 20 % wt./wt.glycerol BE in the blended polymer GG/AA (50:50) (GG/AA/BE20 (50:50)) film shows a reduction in water solubility (66.67 %), water vapour permeability (69.28 %) and oxygen permeability (72.23 %). Moreover, GG/AA/BE20 (50:50) shows an increment in the tensile strength and elongation of a break by 48.32 % and 26.05 %, respectively, compared to pristine GG film. The scanning electron microscopy (SEM) image reveals defects-free smooth surfaces of the film. The Fourier transform-infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) demonstrated the strong hydrogen bonding between GG, AA, and BE. The biodegradable film shows 99 % degradation within 28 days when placed in the soil. The developed film plays a crucial role in extending the shelf life of cheese, effectively maintaining its moisture content, texture, colour, and pH over a span of up to two months from the point of packaging. These results suggest that GG/AA/BE20 (50:50) composite film is a promising packaging film for cheese preservation.

Novel nano composites from Citrus limon and Citrullus colocynthis agricultural wastes for biomedical applications

In recent years, academic and industrial research has focused on using agro-waste for energy and new material production to promote sustainable development and lessen environmental issues. In this study, new nanocomposites based on polyvinyl alcohol (PVA)-Starch using two affordable agricultural wastes, Citrus limon peels (LP) and Citrullus colocynthis (Cc) shells and seeds powders with different concentrations (2, 5, 10, and 15 wt%) as bio-fillers were prepared. The nanocomposites were characterized by Dielectric Spectroscopy, Fourier-Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and water swelling ratio. The antimicrobial properties of the nanocomposites against Escherichia coli, Staphylococcus aureus, and Candida albicans were examined to investigate the possibility of using such composites in biomedical applications. Additionally, the biocompatibility of the composites on human normal fibroblast cell lines (HFB4) was tested using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. The results demonstrate that the filler type and concentration strongly affect the film's properties. The permittivity ε', dielectric loss ε″ and conductivity σdc increased by increasing filler content but still in the insulators range that recommend such composites to be used in the insulation purposes. Both bio fillers control the water uptake, and the samples filled with LP were more water resistant. The polyvinyl alcohol/starch incorporated with 5 wt% LP and Cc have antimicrobial effects against all the tested microorganisms. Increasing the filler content has a negative impact on cell viability.

Enhancing the Biodegradability, Water Solubility, and Thermal Properties of Polyvinyl Alcohol through Natural Polymer Blending: An Approach toward Sustainable Polymer Applications

The escalating environmental crisis posed by single-use plastics underscores the urgent need for sustainable alternatives. This study provides an approach to introduce biodegradable polymer blends by blending synthetic polyvinyl alcohol (PVA) with natural polymers-corn starch (CS) and hydroxypropyl methylcellulose (HPMC)-to address this challenge. Through a comprehensive analysis, including of the structure, mechanical strength, water solubility, biodegradability, and thermal properties, we investigated the enhanced performance of PVA-CS and PVA-HPMC blends over conventional polymers. Scanning electron microscopy (SEM) findings of pure PVA and its blends were studied, and we found a complete homogeneity between the PVA and both types of natural polymers in the case of a high concentration of PVA, whereas at lower concentration of PVA, some granules of CS and HMPC appear in the SEM. Blending corn starch (CS) with PVA significantly boosts its biodegradability in soil environments, since adding starch of 50 w/w duplicates the rate of PVA biodegradation. Incorporating hydroxypropyl methylcellulose (HPMC) with PVA not only improves water solubility but also enhances biodegradation rates, as the addition of HPMC increases the biodegradation of pure PVA from 10 to 100% and raises the water solubility from 80 to 100%, highlighting the significant acceleration of the biodegradation process and water solubility caused by HPMC addition, making these blends suitable for a wide range of applications, from packaging and agricultural films to biomedical engineering. The thermal properties of pure PVA and its blends with natural were studied using diffraction scanning calorimetry (DSC). It is found that the glass transition temperature (Tg) increases after adding natural polymers to PVA, referring to an improvement in the molecular weight and intermolecular interactions between blend molecules. Moreover, the amorphous structure of natural polymers makes the melting temperature ™ lessen after adding natural polymer, so the blends require lower temperature to remelt and be recycled again. For the mechanical properties, both types of natural polymer decrease the tensile strength and elongation at break, which overall weakens the mechanical properties of PVA. Our findings offer a promising pathway for the development of environmentally friendly polymers that do not compromise on performance, marking a significant step forward in polymer science's contribution to sustainability. This work presents detailed experimental and theoretical insights into novel polymerization methods and the utilization of biological strategies for advanced material design.

Diels-Alder Network Blends as Self-Healing Encapsulants for Liquid Metal-Based Stretchable Electronics

Two dynamic covalent networks based on the Diels-Alder reaction were blended to exploit the properties of the dissimilar polymer backbones. Furan-functionalized polyether amines based on poly(propylene oxide) (PPO) FD4000 and polydimethylsiloxane (PDMS) FS5000 were mixed in a common solvent and reversibly cross-linked with the same bismaleimide DPBM. The morphology of the phase-separated blends is primarily controlled by the concentration of backbones. Increasing the PDMS content of the blends results in a dilute droplet morphology at 25 wt %, with a growing size and concentration of droplets and the formation of two separate PPO- and PDMS-rich layers at 50 wt %. Further increasing the PDMS content to 75 wt % leads to larger droplets and a thicker layer of the secondary phase. The hydrophobic PDMS phase creates a barrier against water, while the more hydrophilic PPO phase enhances the resistance against oxygen diffusion. Lowering the maleimide-to-furan stoichiometric ratio resulted in a decrease in cross-link density and thus more flexible and stretchable encapsulants. Changes in the stoichiometric ratio also affected the phase morphology due to resulting changes in phase separation and network formation kinetics. Lowering the stoichiometric ratio also resulted in enhanced self-healing properties of 96% at room temperature as a consequence of the increased chain mobility in the blended networks. The self-healing blends were used to encapsulate liquid metal circuits to create stretchable strain sensors with a linear electro-mechanical response without much drift or hysteresis, which could be efficiently recovered by 90% after the damage-healing cycles.

A review of starch/polyvinyl alcohol (PVA) blend film: A potential replacement for traditional plastic-based food packaging film

In recent years, the development of environmentally friendly packaging materials using biodegradable polymers has emerged as a key challenge for scientists and consumers in response to resource depletion and environmental issues caused by plastic packaging materials. Starch and polyvinyl alcohol (PVA) are being recognized as excellent candidates for producing biodegradable food packaging films. Polymer blending has emerged as a practical approach to overcome the limitations of biopolymer films by developing films with unique properties and enhancing overall performance. This review briefly introduces the molecular structure and properties of starch and PVA, summarizes the common preparation methods and properties of starch/PVA blend films, and focuses on different strategies used to enhance starch/PVA blend films, including nanoparticles, plant extracts, and cross-linking agents. Additionally, this study summarizes the application of starch/PVA blend films as active and smart packaging in food preservation systems. This study demonstrates that starch and PVA blends have potential in manufacturing biodegradable food films with excellent properties due to their excellent compatibility and intermolecular interactions, and can be used as packaging films for a variety of foods to extend their shelf life.

Antioxidant Edible Films Derived from Belitung Taro Tubers (Xanthosoma sagittifolium) Incorporated with Moringa Leaf Extract (Moringa oleifera)

Edible films are thin films frequently manufactured using natural bioresources and are employed in food packaging to safeguard food quality. This research prepared edible films from renewable biomass consisting of Belitung taro tuber starch (Xanthosoma sagittifolium) and incorporated sorbitol as a plasticizer, carboxymethyl cellulose as a reinforcing agent, and moringa leaf extract (Moringa oleifera) as an antioxidant. The physicochemical characteristics of the resulting edible films were examined. The most favorable treatment was identified in an edible film containing 3% (v/v based on the total volume of 100 mL) of moringa leaf extract. This exhibited a tensile strength of 6.86 N/mm2, percent elongation of 73.71%, elasticity of 9.37×10-3 kgf/mm2, water absorption of 349.03%, solubility of 93.18%, and water vapor transmission speed of 3.18 g/h m2. Its shelf life was five days at ambient temperature. The edible film was found to have 135.074 ppm of half maximal inhibitory concentration (IC50) based on the antioxidant analysis of inhibition concentration (IC50) value measurements, and was classified as having moderate antioxidant activity. Additionally, the biodegradability assessment revealed that the edible films degraded within 14 days. Based on this data, it can be deduced that adding moringa leaf extract enhances the physicochemical and functional characteristics of the film. These edible films can be used as substitutes for nonrenewable and nonbiodegradable packaging materials.

Synthetic Degradable Polyvinyl Alcohol Polymer and Its Blends with Starch and Cellulose-A Comprehensive Overview

Approximately 50% of global plastic wastes are produced from plastic packaging, a substantial amount of which is disposed of within a few minutes of its use. Although many plastic types are designed for single use, they are not always disposable. It is now widely acknowledged that the production and disposal of plastics have led to a plethora of negative consequences, including the contamination of both groundwater and soil resources and the deterioration of human health. The undeniable impact of excessive plastic manufacturing and waste generation on the global plastic pollution crisis has been well documented. Therefore, degradable polymers are a crucial solution to the problem of the non-degradation of plastic wastes. The disadvantage of degradable polymers is their high cost, so blending them with natural polymers will reduce the cost of final products and maximize their degradation rate, making degradable polymers competitive with industrial polymers that are currently in use daily. In this work, we will delineate various degradable polymers, including polycaprolactone, starch, and cellulose. Furthermore, we will elucidate several aspects of polyvinyl alcohol (PVA) and its blends with natural polymers to show the effects of adding natural polymers on PVA properties. This paper will study cost-effective and ecologically acceptable polymers by combining inexpensive natural polymers with readily accessible biodegradable polymers such as polyvinyl alcohol (PVA).

Effects of PVA and yerba mate extract on extruded films of carboxymethyl cassava starch/PVA blends for antioxidant and mechanically resistant food packaging

Global concerns over environmental damage caused by non-biodegradable single-use packaging have sparked interest in developing biomaterials. The food packaging industry is a major contributor to non-degradable plastic waste. This study investigates the impact of incorporating different concentrations of polyvinyl alcohol (PVA) and yerba mate extract as a natural antioxidant into carboxymethyl cassava starch films to possibly use as active degradable packaging to enhance food shelf life. Films with starch and PVA blends (SP) at different ratios (SP radios of 100:0, 90:10, 80:20 and 70:30) with and without yerba mate extract (Y) were successfully produced through extrusion and thermoforming. The incorporation of up to 20 wt% PVA improved starch extrusion processing and enhanced film transparency. PVA played a crucial role in improving the hydrophobicity, tensile strength and flexibility of the starch films but led to a slight deceleration in their degradation in compost. In contrast, yerba mate extract contributed to better compost degradation of the blend films. Additionally, it provided antioxidant activity, particularly in hydrophilic and lipophilic food simulants, suggesting its potential to extend the shelf life of food products. Starch-PVA blend films with yerba mate extract emerged as a promising alternative for mechanically resistant and active food packaging.

Plasticizer concentration effect on films and coatings based on poly(vinyl alcohol) and cationic starch blends

Films based on poly(vinyl alcohol) (PVA) and cationic starch (CS) were combined with different percentages of sorbitol (S; 15.0, 22.5, and 30.0% w v-1) to assess the effect of plasticizer on the films. Spectroscopic analyses confirmed the interaction between them. However, micrographs indicated the formation of sorbitol crystals on the surface of the films, especially at higher sorbitol concentrations. The blends presented low water vapor transmission rate values, reaching (7.703 ± 0.000) g h-1 m-2 (PVA75CS25S15), and low solubility values for the films containing higher CS amounts. The lack of statistical differences in most parameters suggests that no significant gain comes from increasing the amount of sorbitol at percentages higher than 15%. As a coating, the blend PVA75CS25S15 successfully decreased the loss of moisture content in acerolas by 1.15 times (compared to the control), confirming the suitability of this matrix as a fruit coating.

Fabrication of biodegradable and cold-water-soluble starch/polyvinyl alcohol films as inner packaging materials of pesticides: Enhanced emulsification, dispersibility, and efficacy

Developing environmentally friendly film materials for packaging pesticides is significant yet challenging. The use of native starch for preparing inner packaging materials of pesticides is limited by its physicochemical properties. In this study, a novel strategy of synergetic mechanical activation (MA)-enhanced solid-phase esterification of starch and cooperative combination of starch and polyvinyl alcohol (PVA) was proposed to fabricate biodegradable and cold-water-soluble starch (St)/PVA films. The appropriate esterification of starch and favorable compatibility between starch and PVA contributed to the production of St/PVA films by the extrusion-blowing method. The as-prepared film with St/PVA ratio of 4:6 exhibited outstanding mechanical properties (tensile strengths of 21.0 MPa; elongation at break of 213.9 %), cold-water solubility (dissolution time of 90 s), and oxygen barrier performance (oxygen transmission rate of 1.41 cm3/(m2·day·bar)). The dissolved St/PVA films with amphiphilic groups were conducive to the emulsification of butachlor (a fat-soluble liquid pesticide) and the dispersibility of oxyfluorfen (a fat-soluble solid pesticide). Furthermore, a mechanism of the interaction between pesticides and the surface of weed leaves was proposed to reveal the enhanced efficacy of St/PVA films-packaged pesticides. The strategy based on MA-enhanced esterification and PVA blending is efficient to produce starch-based films suitable for inner packaging materials of pesticides.

Development and characterization of starch/PVA antimicrobial active films with controlled release property by utilizing electrostatic interactions between nanocellulose and lauroyl arginate ethyl ester

The two nanocellulose (nanofibrillated cellulose (NFC) and carboxylated nanofibrillated cellulose (C-NFC)) could interact with lauryl arginine ethyl ester hydrochloride (LAE) through electrostatic bonding. The zeta potential (absolute value) of C-NFC (-27.80 mV) was higher than that of NFC (-10.07 mV). The starch/polyvinyl alcohol active films with controlled release property by utilizing electrostatic interactions between nanocellulose and LAE were prepared and their properties were investigated. For incorporation of the NFC or C-NFC, the cross-section of the films became slightly uneven and some fibrils were observed, the films exhibited an increase in strength, while the film water vapor and oxygen barrier properties decreased. The release of LAE from the films to food simulants (10 % ethanol) decelerated with increasing of NFC or C-NFC. These might be mainly attributed to the enhanced electrostatic interaction between NFC or C-NFC and LAE. It demonstrated that nanocellulose with higher negative charges would exhibit stronger electrostatic interaction with LAE, thus slowing the release of LAE. The film with highest C-NFC content exhibited smallest inhibition zone among LAE-containing films, which was related with its slowest release rate of LAE. It showed a great prospect to develop controlled release active packaging films by utilizing electrostatic interactions between substances.

Effect of apple polyphenols on physicochemical properties of pea starch/pulp cellulose nanofiber composite biodegradable films

A pea starch (PS) and pulp cellulose nanofibers (CNF-P) hybrid matrix biodegradable film was prepared using apple polyphenol (AP) as the active substance. SEM and thermogravimetric analyses showed that apple polyphenols could be uniformly distributed and form hydrogen bonds with the matrix, and the increase in crystallinity improved the thermal stability of the films (the final residue of the films increased from 22.66 % to 31.82 %). The TS and EAB of the films reached their maximum values of 11.14 ± 1.73 MPa and 71.55 ± 8.8 %, respectively, at an AP content of 1.5 %. It should be noted that the antioxidant properties of the films were significantly positively correlated with the AP content, and the DPPH radical scavenging rate of the films reached 73.77 % at an AP content of 4.5 %, which was about 49 times higher than that of the control film. The same trend was observed in the UV-vis spectra. In addition, the total color difference and water solubility of the membranes increased from 4.29 ± 0.29 to 31.86 ± 1.90 and from 20.01 ± 0.97 % to 21.70 ± 1.99 %, respectively, and the biodegradability also showed an upward trend. These findings provide a theoretical basis and data support for the development of multifunctional biodegradable food packaging materials.

Evaluation of Starch-Garlic Husk Polymeric Composites through Mechanical, Thermal, and Thermo-Mechanical Tests

The present work evaluates the influence of different properties of composite materials from natural sources. Films were prepared using the evaporative casting technique from corn starch reinforced with a waste material such as garlic husk (GH), using glycerin as a plasticizer. The results of the syntheses carried out demonstrated the synergy between these materials. In the morphological analysis, the compatibility and adequate dispersion of the reinforcer in the matrix were confirmed. Using Fourier transform infrared spectroscopy (FTIR), the interaction and formation of bonds between the matrix and the reinforcer were confirmed by the presence of some signals such as S-S and C-S. Similarly, thermogravimetric analysis (TGA) revealed that even at low concentrations, GH can slightly increase the decomposition temperature. Finally, from the results of dynamic mechanical analysis (DMA), it was possible to identify that the storage modulus increases significantly, up to 115%, compared to pure starch, especially at low concentrations of the reinforcer.

Biodegradable Packaging Based on Poly(vinyl Alcohol) and Carboxymethyl Cellulose Films Incorporated with Ascorbic Acid for Food Packaging Applications

Petroleum-based plastics are used as packaging materials because of their low cost and high availability; however, continuous use of these nondegradable materials especially in the food industry has led to environmental pollution. The present study aimed to synthesize antibacterial and biodegradable films based on natural biopolymers carboxymethyl cellulose (CMC), poly(vinyl alcohol) (PVA), and ascorbic acid (AA) cross-linked in the presence of glutaraldehyde (GA). The films were synthesized in two different concentrations, 60PVA:40CMC:AA and 70PVA:30CMC:AA with a fixed amount of AA. Films with smooth texture and overall uniform thickness were obtained. Fourier transform infrared spectroscopy (FTIR) confirmed the cross-linking between the aldehyde group of GA and hydroxyl of PVA through detection of acetal and ether bridges. The synthesized films were thermally stable in the temperature range of 180-300 °C; however, 70PVA:30CMC:AA showed higher weight loss in this range as compared to the 60PVA:40CMC:AA film. Soil burial test demonstrated that the 60PVA:40CMC:AA film was more degradable (71% at day 15) as compared to the 70PVA:30CMC:AA film (65% at day 15). The films exhibited excellent antimicrobial activity against Gram-positive staphylococcus aureus(inhibition zone of 21 mm) and Gram-negative Escherichia coli (inhibition zone of 15 mm). In comparison, the 60PVA:40CMC:AA film showed better results in terms of high mechanical strength, uniform morphology, higher soil burial degradation, and lower water vapor transmission rate. Therefore, the prepared film could be used as a promising candidate in the food packaging industry.

Heat-Induced Actuator Fibers: Starch-Containing Biopolyamide Composites for Functional Textiles

This study introduces the development of a thermally responsive shape-morphing fabric using low-melting-point polyamide shape memory actuators. To facilitate the blending of biomaterials, we report the synthesis and characterization of a biopolyamide with a relatively low melting point. Additionally, we present a straightforward and solvent-free method for the compatibilization of starch particles with the synthesized biopolyamide, aiming to enhance the sustainability of polyamide and customize the actuation temperature. Subsequently, homogeneous dispersion of up to 70 wt % compatibilized starch particles into the matrix is achieved. The resulting composites exhibit excellent mechanical properties comparable to those reported for soft and tough materials, making them well suited for textile integration. Furthermore, cyclic thermomechanical tests were conducted to evaluate the shape memory and shape recovery of both plain polyamide and composites. The results confirmed their remarkable shape recovery properties. To demonstrate the potential application of biocomposites in textiles, a heat-responsive fabric was created using thermoresponsive shape memory polymer actuators composed of a biocomposite containing 50 wt % compatibilized starch. This fabric demonstrates the ability to repeatedly undergo significant heat-induced deformations by opening and closing pores, thereby exposing hidden functionalities through heat stimulation. This innovative approach provides a convenient pathway for designing heat-responsive textiles, adding value to state-of-the-art smart textiles.

Mechanically Robust Poly(vinyl alcohol)-Egg White Composite Hydrogel with Enhancing Biocompatibility by Unidirectional Nanopore Dehydration

A simple and green method, unidirectional nanopore dehydration (UND), directly processes 10% poly(vinyl alcohol) (PVA) aqueous solution containing 20% egg white (EW) into a composite hydrogel membrane (PVA-EW). The tensile strength and elongation of the UND-based PVA-EW at 25 °C were 0.91 MPa and 534.17%, respectively, while the two values at 70 °C were increased by 700 and 38%, respectively. The PVA-EW (70 °C) was still dominated by random coils and α-helical structures. The hydroxyl groups of intramolecules and intermolecules of both PVA and EW could be able to combine and form either more hydrogen bonds or stronger hydrogen bonds. PVA-EW is soft and translucent, has good mechanical properties, and has a porous networked structure with pores that have a diameter of 1-10 μm. L-929 mouse fibroblasts were found to be able to adhere, grow, and proliferate well on the hydrogel composite membrane. This novel PVA-EW biomaterial has potential applications in biomaterials especially medical tissue engineering.

Functional, Physical, and Volatile Characterization of Chitosan/Starch Food Films Functionalized with Mango Leaf Extract

Active packaging is one of the currently thriving methods to preserve highly perishable foods. Nonetheless, the integration of active substances into the formulation of the packaging may alter their properties-particularly mass transfer properties-and therefore, the active compounds acting. Different formulations of chitosan (CH), starch (ST), and their blends (CH-ST), with the addition of mango leaf extract (MLE) have been polymerized by casting to evaluate their food preservation efficiency. A CH-ST blend with 3% MLE using 7.5 mL of the filmogenic solution proved to be the most effective formulation because of its high bioactivity (ca. 80% and 74% of inhibition growth of S. aureus and E. coli, respectively, and 40% antioxidant capacity). The formulation reduced the water solubility and water vapor permeability while increasing UV protection, properties that provide a better preservation of raspberry fruit after 13 days than the control. Moreover, a novel method of Headspace-Gas Chromatography-Ion Mobility Spectrometry to analyze the volatile profiles of the films is employed, to study the potential modification of the food in contact with the active film. These migrated compounds were shown to be closely related to both the mango extract additions and the film's formulation themselves, showing different fingerprints depending on the film.

A Review on Biopolymer-Based Biodegradable Film for Food Packaging: Trends over the Last Decade and Future Research

In recent years, much attention has been paid to the use of biopolymers as food packaging materials due to their important characteristics and properties. These include non-toxicity, ease of availability, biocompatibility, and biodegradability, indicating their potential as an alternative to conventional plastic packaging that has long been under environmental scrutiny. Given the current focus on sustainable development, it is imperative to develop studies on biopolymers as eco-friendly and sustainable food packaging materials. Therefore, the aim of this review is to explore trends and characteristics of biopolymer-based biodegradable films for food packaging, analyze the contribution of various journals and cooperation between countries, highlight the most influential authors and articles, and provide an overview of the social, environmental, and economic aspects of biodegradable films for food packaging. To achieve this goal, a bibliometric analysis and systematic review based on the PRISMA method were conducted. Relevant articles were carefully selected from the Scopus database. A bibliometric analysis was also conducted to discuss holistically, comprehensively, and objectively biodegradable films for food packaging. An increasing interest was found in this study, especially in the last 3 years with Brazil and China leading the number of papers on biodegradable films for food packaging, which were responsible for 20.4% and 12.5% of the published papers, respectively. The results of the keyword analysis based on the period revealed that the addition of bioactive compounds into packaging films is very promising because it can increase the quality and safety of packaged food. These results reveal that biodegradable films demonstrate a positive and promising trend as food packaging materials that are environmentally friendly and promote sustainability.

Preparation of Bio-Foam Material from Steam-Exploded Corn Straw by In Situ Esterification Modification

In this work, we engineered a corn-straw-based bio-foam material under the inspiration of the intrinsic morphology of the corn stem. The explosion pretreatment was applied to obtain a fibrillated cellulose starting material rich in lignin. The in situ esterification of cellulose was adopted to improve the cross-linking network of the as-developed foam bio-material. The esterification of lignin was observed in the same procedure, which provides a better cross-linking interaction. The esterified corn-straw-derived bio-foam material showed excellent elastic resilience performance with an elastic recovery ratio of 83% and an elastic modulus of 20 kPa. Meanwhile, with surface modification by hexachlorocyclotriphosphazene-functionalized lignin as the flame retardant (Lig-HCCP), the as-obtained bio-foam material demonstrated quite a good flame retardancy (with 27.3% of the LOI), as well as a heat insulation property. The corn-straw-derived bio-foam material is prospected to be a potential substitution packaging material for widely used petroleum-derived products. This work provides a new value-added application of the abundant agricultural straw biomass resources.

Recoverable cellulose composite adsorbents for anionic/cationic dyes removal

GO/HEC/PGDE/Fe₃O₄ materials were successfully fabricated using environmentally-friendly hydroxyethyl cellulose (HEC), poly(ethylene glycol) diglycidyl ether (PGDE), graphene oxide (GO) and magnetic Fe₃O₄. Systematic investigations were completed to explore the influences of GO content in GO/HEC/PGDE/Fe₃O₄ and adsorption conditions on the adsorptions of cationic dyes (methylene blue (MB), crystal violet (CV)) and anionic dye acid blue 25 (AB-25). The increase of GO content can remarkably improve the adsorption capacity of GO/HEC/PGDE/Fe₃O₄ for the dyes. The three kinetic, four isothermic and three thermodynamic models were investigated to reveal the adsorption behaviors of the dyes. The formation of HEC/PGDE/Fe₃O₄ and adsorption mechanisms of the dyes by GO/HEC/PGDE/Fe₃O₄ were suggested. The GO/HEC/PGDE/Fe₃O₄ endowed with easy-fabrication, eco-friendly feature, efficient adsorption capacity of anionic/cationic dyes, convenient separation and reusability has potential applications in wastewater purification industry.

Intermolecular interactions between starch and polyvinyl alcohol for improving mechanical properties of starch-based straws

Starch/polyvinyl alcohol (PVA) degradable straws with different PVA contents were prepared by the twin-screw extrusion method. The results showed that the starch/PVA straws with 40 % PVA (PS4) had the highest dispersion uniformity of starch and PVA to achieve the best compatibility, and the compatibility size was below the micron level. Molecular interactions between starch and 40 % polyvinyl alcohol reached the highest due to the highest strength of hydrogen bonds, hence resulting in the highest texture densities. Consequently, the largest compatibility and molecular interactions significantly improved the mechanical properties and water resistance of PS4. Compared to the starch/PVA straw with 0 % PVA (PS0), swelling volume of PS4 decreased by 45.5 % (4 °C) and 65.2 % (70 °C), respectively. After soaking, the diameter strength increased by 540.1 % (4 °C, 1 h) and 638.7 % (70 °C, 15 min), respectively. Water absorption decreased by 45.3 % (4 °C, 30 min) and 27.6 % (70 °C, 30 min).

The physiochemical and photodynamic inactivation properties of corn starch/erythrosine B composite film and its application on pork preservation

This study explored the effect of erythrosine B (EB) as a photosensitizer in corn starch (CS) film and its physicochemical properties and photodynamic bacteriostatic ability against Staphylococcus aureus, Escherichia coli, and Salmonella both in vitro and inoculated on pork under the irradiation of D65 light-emitting diode (LED) (400-800 nm). The study revealed that the physiochemical properties of CS films: moisture content, water solubility, and water vapor transmission were improved with the addition of EB. In addition, the elasticity and the thermal stability of the film were enhanced. The results showed that the CS-EB films stimulated a maximum of 26.36 μg/mL hydrogen peroxide and 74.5 μg/g hydroxyl radical under irradiation. The CS composite films with a 5 % concentration of EB inhibited the bacterial growth by 4.7 Log CFU/mL in vitro after 30 min of illumination, and 2.4 Log CFU/mL on the pork samples under the same experimental condition. Moreover, the antibacterial ability was enhanced with the increase in EB concentration. Overall, the CS-EB composite films can inhibit the growth of bacteria through photodynamic inactivation and has the potential to become a new type of environmentally friendly packaging material.

Thermoplastic starch composite with oil palm mesocarp fiber waste and its application as biodegradable seeding pot

Thermoplastic starch (TPS) composites with oil palm mesocarp fiber waste were prepared using compression molding. Oil palm mesocarp fiber (PC) was reduced to powder (MPC) by dry grinding in a planetary ball mill at various speeds and grinding times. It was found that fiber powder with the smallest particle size (33 μm) was obtained at a rotation speed of 200 rpm after milling for 90 min. A TPS composite with 50 wt% of MPC showed the highest tensile strength, thermal stability, and water resistance. A biodegradable seeding pot was produced from this TPS composite that was slowly degraded by microorganisms in the soil without releasing pollutants. The pot could support certain commercially and domestically grown plants for the duration of their growth period and showed potential as an innovative product that could replace existing non-biodegradable products.

Optimization of the Formulation of Sago Starch Edible Coatings Incorporated with Nano Cellulose Fiber (CNF)

This study aimed to produce new edible coatings based on the mixture of sago starch, cellulose nanofiber (CNF), glycerol, and tween-80.The effect of sago starch (5–10 g of starch/100 ml of distilled water), CNF (0.5–20% w/w), glycerol (10–30% w/w), and tween-80 (0.5–10% w/w) based on sago starch concentration on contact angle (CA), water vapor permeability (WVP), oxygen permeability (PO2) and tensile strength (TS) properties of the edible coatings were optimized using factorial experimental design (2k).The result showed that the linear model for all independent variables was significant (<i>P</i><0.05) on all responses (dependent variable).The sago starch concentration depicted a significant (p < 0.001) positive effect on contact angle; CNF showed a statistically significant effect on WVP, PO2, and TS; tween-80 showed a significant effect on all dependent variables, whereas glycerol only affected WVP. The optimum concentrations of sago starch, CNF, glycerol, and tween-80 were predicted to be 5 g/100 ml distilled water, 20% w/w, 10% w/w, and 0.5% w/w based on sago starch, respectively to obtain the minimum contact angle, WVP, PO2, and the maximum TS. The predicted data for the optimized coating formulation were in good agreement with the experimental value. This work revealed that the potential of sago starch/CNF based coating formulation could be effectively produced and successfully applied for coating of food.

Preparation and Properties of Pea Starch/ε-Polylysine Composite Films

The composite films comprising pea starch (St) and ε-polylysine (PL) as the matrix and glycerol and sodium alginate as the plasticizers were investigated. The rheological properties, mechanical properties, Fourier transformed infrared spectroscopy, water vapor permeability (WVP), oil permeability, microstructure, thermogravimetry (TGA), and antimicrobial properties of the composite films were analyzed. The properties of the composite films with different mass ratios of St/PL varied significantly. First, the five film solutions were different pseudoplastic fluids. Additionally, as the mass ratio of PL increased, the tensile strength of the blends decreased from 9.49 to 0.14 MPa, the fracture elongation increased from 38.41 to 174.03%, the WVP increased, and the oil resistance decreased substantially. The films with a broad range of St/PL ratios were highly soluble; however, the solubility of the film with a St/PL ratio of 2:8 was reduced. Lastly, the inhibition of E. coli, B.subtilis, and yeast by the films increased with increasing mass ratios of PL, and the inhibition of B.subtilis was the strongest.

Cellulose Nanofiber-Assisted Dispersion of Halloysite Nanotubes via Silane Coupling Agent-Reinforced Starch–PVA Biodegradable Composite Membrane

HNTs (halloysite nanotubes) are widely used in reinforcing material, often used in material reinforcement and particle loading. However, their easy agglomeration causes them to have great limitations in application. In this work, two kinds of silane coupling agents (KH560 and KH570) were introduced to graft the CNF/HNT (cellulose nanofiber) nanoparticles used to reinforce the starch-polyvinyl alcohol (PVA) composite membranes. The mechanical properties, water resistance properties and thermal performance of the composite membrane were tested. The results showed that the CNF/HNTs nanoparticle system modified by two silane coupling agents enhanced the tensile strength (TS) of the starch–PVA composite membranes by increments of 60.11% and 68.35%, and, in addition, the water resistance of starch–PVA composite membrane improved. The introduction of chemical bonds formed associations and a compact network structure, which increased the thermal stability and the crystallinity of the starch–PVA composite membrane. In the study, we creatively used CNF to disperse HNTs. CNF and HNTs were combined under the action of the silane coupling agent, and then mixed into the starch–PVA membranes matrix to prepare high-performance degradable biological composite membranes.