Techniques to Reduce Hydrolytic Degradation in Polylactic Acid Packaging

A biodegradable packaging material with improved durability and barrier properties, comprising a paper substrate coated with a composition of polyhydroxyalkanoate (PHA) and two or more types of polylactic acid (PLA) with different melting indices. The PHA provides thermal stability and the PLA enhances barrier properties, while the combination of both enables the material to meet both industrial and household composting standards.

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Biaxially stretched film comprising polylactic acid with a tear strength of 50-100 N/mm, enabling both punching processability and heat resistance. The film is suitable for applications such as protective films for electronic devices, where it provides a balance of mechanical strength, thermal stability, and ease of processing.

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Resin composition comprising a β-methyl-δ-valerolactone copolymer and a polylactic acid polymer, where the copolymer has a specific molecular structure that enhances the plasticity and elongation of the polylactic acid polymer. The composition can be molded into various shapes and used as a modifier for polylactic acid-based polymers.

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Biodegradable barrier film for packaging applications that has improved oxygen barrier properties and transparency compared to existing biodegradable films. The film is made by alternately laminating layers of an aliphatic polyester like polylactic acid and a polyvinyl alcohol. This structure provides both oxygen barrier and transparency. The layers are melt extruded, alternated, and then biaxially stretched and heat set to form the film.

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Degradable plastic bottle for pesticides that can meet the storage requirements of pesticide products. The bottle is made by melt extrusion of a resin blend containing polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polymethyl ethylene carbonate (PMEC), polyglycolic acid (PGA), and calcium carbonate. The resin mixture is extruded into a preform, which is then blown into the final bottle shape. The PMEC and PGA nucleate PLA crystallization, improving its crystallinity without decreasing barrier properties compared to PLA blends without these additives. The calcium carbonate reinforces the bottle. The degradable bottle can be recycled and degrades under biodegradation conditions.

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Biodegradable and bio-based polymers, including polyhydroxyalkanoate (PHA), polylactic acid (PLA), and poly(butylene succinate-

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Lime essential oil (LEO) has the potential to be incorporated into a film. Biodegradable polylactic acid (PLA) has shown potential in packaging applications. In this study, Lime extraction was carried out using a simple distillation method, and solvent casting methods were used to form the films. FT-IR result shows that the PLA primary functional group was visible at the frequency region of 495-560 cm-1 and 1740-1750 cm-1. With the addition of polyethylene glycol (PEG) and lime essential oil, the composite shows improvement in thermal stability. Even after being heated to 500 C, none of the three samples completely disintegrated after being given lime essential oil as an additive.

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Biaxially oriented film for environmentally friendly packaging with improved properties like flexibility, noise reduction, and biodegradability. The film contains a specific range of polylactic acid (PLA) and polyhydroxyalkanoate (PHA) copolymer. The film has a low loop stiffness (LS) value of 20 or less, indicating flexibility. It also has a biodegradability of 90% or more. The copolymer composition is 0-30 wt% PHA based on total film weight. This provides balanced properties for packaging applications. The film can be made by coextrusion and biaxial stretching.

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A biodegradable plastic composition with improved processability and mechanical properties, comprising a blend of polylactic acid (PLA) and suberin or suberin-based compounds extracted from plant sources, such as cork and potato periderm. The composition exhibits enhanced plasticity and biodegradability compared to conventional PLA-based bioplastics, making it suitable for various applications including disposable products, packaging, and agricultural materials.

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Polylactic acid (PLA) is a biodegradable thermoplastic made from lactic acid monomers obtained through fermented glucose in crops like wheat and corn. PLA has numerous applications, including industrial packaging, biomedical equipment, and membranes, due to its low toxicity, biodegradability, and recycling potential. However, little is known about the short-term aging effects of particulate reinforced PLA composites in complex environments. This study investigates the chemical endurance of various PLA composites before and after exposure to different chemicals and hygrothermal conditions. The results reveal that the fabrication processing method greatly affects the degradation rate. The PLA/Carbon Fiber Powder (CFP) samples had the highest chemical resistance towards degradation in 1% HNO followed by 2% NaOH with a maximum mass increase of 2.8% and 3.9% respectively. The PLA/CFP samples showed lowest chemical resistance under a combination of water and aging temperature, with an average maximum weight gain of 9.64% throughout the three CFP loadings. Continuous test for 15wt% CFP sam... Read More

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To use polylactic acid in demanding technical applications, sufficient long-term thermal stability is required. In this work, the thermal aging of polylactic acid (PLA) in the solid phase at 100 C and 150 C is investigated. PLA has only limited aging stability without the addition of stabilizers. Therefore, the degradation mechanism in thermal aging was subsequently investigated in more detail to identify a suitable stabilization strategy. Investigations using nuclear magnetic resonance spectroscopy showed that, contrary to expectations, even under thermal aging conditions, hydrolytic degradation rather than oxidative degradation is the primary degradation mechanism. This was further confirmed by the investigation of suitable stabilizers. While the addition of phenols, phosphites and thioethers as antioxidants leads only to a limited improvement in aging stability, the addition of an additive composition to provide hydrolytic stabilization results in extended durability. Efficient compositions consist of an aziridine-based hydrolysis inhibitor and a hydrotalcite co-stabilizer. At a... Read More

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The hydrolytic degradation of polyhydroxyalkanoates, polylactide and their mixtures in vitro in physiological solution and phosphate-salt buffer as well was researched. The hydrolysis intensity of biopolymers was evaluated via the mass loss, change in molecular weight as well as the water absorption applying the methods of infrared spectroscopy and complex thermal analysis. It was determined that films based on the researched biodegradable polymers thermostated in a phosphate-salt buffer have been degrading faster than in physiological solution.

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A multiblock copolymer for toughening polylactic acid (PLA) comprises a polyamide 11 (PA11) block and a PLA block, where the PA11 block is covalently linked to the PLA block through a urethane bond. The copolymer is prepared by first synthesizing a diamine-terminated PA11, then ring-opening polymerizing lactide to form a hydroxyl-telechelic PLA-PA11-PLA triblock, and finally reacting the triblock with a diisocyanate to form the multiblock copolymer. The resulting copolymer exhibits improved toughness and ductility compared to pure PLA, while maintaining its initial modulus and strain-hardening behavior.

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Blends of polylactic acid (PLA) with amorphous polyhydroxyalkanoate (aPHA) are less brittle than neat PLA, thus enabling their use as biodegradable packaging. This work investigated the impact of recycling on the properties of neat PLA and PLA/aPHA blends with 90 and 75 wt. % PLA. After the materials were subjected to five heat histories in a single-screw extruder, the mechanical, rheological, and thermal properties were measured. All recycled compounds with 100% PLA and 75% PLA had similar decomposition behavior, whereas the decomposition temperatures for the blends with 90% PLA decreased with each additional heat cycle. The glass transition and melting temperatures were not impacted by reprocessing, but the crystallinity increased with more heat cycles. The complex viscosity of the reprocessed PLA and PLA/aPHA blends was much lower than for the neat PLA and increasing the number of heat cycles produced smaller reductions in the complex viscosity of 100% PLA and the blend with 90% PLA; no change in complex viscosity was observed for blends with 75% PLA exposed to 2 to 5 heat cycles.... Read More

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Nowadays, increased food safety and decreased food waste are two of the major global interests. Self-healable active packaging materials are an attractive option to achieve such targets. This property is critical for the hygiene and the consumption appropriateness of the food. Polylactic acid is a very promising polymeric matrix that potentially could replace the widely used low-density polyethylene due to its biobased origin and its easy biodegradable nature. The main drawback of this polymeric matrix is its brittle, fragile nature. On the other hand, tetraethyl citrate is a biobased approved food additive which became an attractive option as a plasticizer for industries seeking alternative materials to replace the traditional petrochemically derived compounds. A novel biobased film exhibiting self-healing behavior suitable for food-active packaging was developed during this study. Polylactic acids brittleness was reduced drastically by incorporating tetraethyl citrate, and a random cut on the original self-repairing film was fully healed after 120 s. The optimum concentration of t... Read More

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Polylactic Acid (PLA) is a biodegradable and bioactive polyester derived from renewable sources such as corn and sugar cane. Because PLA is eco-friendly, researchers have recently tried to make PLA replace other polymers that cause greenhouse gases and other pollution. However, for many industries, PLA has limitations of unsatisfactory toughness, heat resistance, etc. In this case, it is necessary to invest in the modification of PLA, which can offer PLA desired traits to adapt to different situations. This review focuses on the recent modifications that successfully improve PLA to fit the aims, as well as the advantages and disadvantages of each method that is used for modification. There is no doubt that these methods provide a path to expand the use of PLA in different fields, such as packaging, medicine, agriculture, and textiles. The paper concludes by emphasizing the need for continued research and technological development to fully release PLA's potential in promoting a sustainable and eco-friendly future.

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Polylactic acid (PLA) has garnered significant attention due to its advantages of excellent biodegradability, biocompatibility, and renewable raw materials. This article begins by briefly introducing the research progress in the synthesis and modification of PLA, as well as its specific applications such as medical sutures and textiles, and the pros and cons of PLA itself. It then provides a detailed overview of the direct polymerization methods of PLA, including melt condensation and solution polymerization, and ring-opening polymerization methods such as cationic, anionic, and coordination. The process mechanisms, advantages, and disadvantages of each method are discussed, along with their suitability for practical industrial production and current limitations. Several specific modification methods of PLA are also discussed, such as low-temperature plasma modification and blending modification, highlighting the advantages, disadvantages, and specific research examples. These modifications aim to improve the deficiencies of PLA in areas such as mechanical strength or biological acti... Read More

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Polylactic acid (PLA) possesses characteristics such as biodegradability, ease of processing, and environmental friendliness, making it an ideal alternative to petroleum-based polymers. However, PLA has drawbacks such as susceptibility to hydrolysis and sensitivity to ultraviolet (UV) light, limiting its application in certain areas. In this study, poly(carbazole diimide) (PCDI) and the epoxy chain extender Joncryl ADR4468 (CE) were employed as a synergistic anti-hydrolysis agent for PLA, and tannic acid (TA) was used as a UV-resistant agent. A melt-blending process was employed to prepare PLA composite materials with enhanced resistance to both hydrolysis and UV radiation. The results indicate that the addition of PCDI-TA-CE significantly improved the performance of PLA. After 8 h of hydrolysis at 80 C, the tensile strength of PLA increased from 38.31 MPa for pure PLA to 77.69 MPa with the incorporation of PCDI-TA-CE. The elongation at break increased from 0.6% to 1.5%, and the Ultraviolet Protection Factor (UPF) value elevated from 3.19 for pure PLA to 503.46.This demonstrates tha... Read More

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Biodegradable poly(L-lactic acid) (PLLA) has seldom used for dairy packaging due to medium permeability and brittleness. Novel PLLA copolymers, poly (L-lactic acid-co-butylene itaconate-co-glycolic acid) (PLBIGA), were developed by integrating glycolic acid (GA) and poly(butylene itaconate) (PBI) into PLLA's structure using low molecular weight PLLA as a key initiator. Then, packaging materials with better barrier and mechanical properties were obtained by blended PLBIGA with PLLA. Both PLLA/PLBIGA films and polyethylene nylon composite film (PE/NY) were used for stirred yogurt packaging and storage at 4 C for 25 days. Results revealed that yogurt packed by PLLA/PLBIGA films maintained stabler water-holding capacity, color, and viscosity over the storage period. Moreover, the integrity of the gel structure and the total viable count of lactic acid bacteria in yogurt packaged in PLLA/40-PLBIGA8 were also found to be superior to those in PE/NY packages, highlighting its eco-friendly advantages in dairy packaging.

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Polylactic acid (PLA) is a biobased and biodegradable thermoplastic polyester with great potential to replace petroleum-based plastics. However, its poor toughness and slow biodegradation rate affect broad applications of PLA in many areas. In this study, a glycerol triester existing in natural butter, glycerol tributyrate, was creatively explored and compared with previously investigated triacetin and tributyl citrate, as potential plasticizers of PLA for achieving improved mechanical and biodegradation performances. The compatibilities of these agents with PLA were assessed quantitively via the Hansen solubility parameter (HSP) and measured by using different testing methods. The incorporation of these compounds with varied contents ranging from 1 to 30 % in PLA altered thermal, mechanical, and biodegradation properties consistently, and the relationship and impacts of chemical structures and properties of these agents were systematically investigated. The results demonstrated that glycerol tributyrate is a novel excellent plasticizer for PLA and the addition of this triester not o... Read More

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As a bio-based degradable plastic, polylactic acid (PLA) is highly commercialized, but its inherent brittleness limits its widespread use. In-situ polymerization techniques are effective in improving the toughness of PLA. However, the enhancement of the toughening effect in polyurethanes (PUs) through in-situ self-crosslinking still requires improvement and heavily relies on petroleum-derived feedstocks in certain approaches. In this paper, 1,3-polypropanediol (PO3G) of bio-based origin rather than conventional polyols like polyethylene glycol (PEG) and poly propylene glycol (PPG) was used. PLA/PO3G-PU blends were prepared via an in-situ self-crosslinking strategy. With a notch impact and tensile strength of 55.95 kJ/m2 and 47.77 MPa (a retention rate of 68.9 % compared with pure PLA), respectively, PLA/PO3G-PU blends achieved a better balance between stiffness and toughness. This work provides a new option for PLA to achieve a stiffness-toughness balance and get rid of dependence on petrochemical resources.

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Biodegradable polylactic acid (PLA) melt-blown nonwovens are attractive candidates to replace non-degradable polypropylene melt-blown nonwovens. However, it is still an extremely challenging task to prepare PLA melt-blown nonwovens with sufficient mechanical properties for practical application. Herein, we report a simple strategy for the large-scale preparation of biodegradable PLA/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) melt-blown nonwovens with high strength and excellent toughness. In this process, a small amount of PHBV is added to PLA to improve the latter's crystallization rate and crystallinity. In addition, when the PHBV content increases from 0 to 7.5 wt%, the diameters of the PLA/PHBV melt-blown fibers decrease significantly (with the+ proportion of nanofibers increasing from 7.7% to 42.9%). The resultant PLA/PHBV (5 wt% PHBV) melt-blown nonwovens exhibit the highest mechanical properties. The tensile stress, elongation, and toughness of PLA/PHBV (5 wt% PHBV) melt-blown nonwovens reach 2.5 MPa, 45%, and 1.0 MJm3, respectively. More importantly, PLA/PHBV melt-... Read More

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Polylactic acid (PLA) is an emerging bioplastic used to manufacture food containers and packaging. In addition to its biodegradability, good transparency, and low toxicity, PLA has poor mechanical and barrier properties that can be overcome by carbonaceous particles, natural fibers and oils, and metal nanoparticles, among others. This chapter describes the principles of PLA synthesis and the results of the recently discovered byproducts of its degradation, together with the international standards aimed at preventing bioplastics into the environment and harming aquatic and terrestrial life. A section highlights the current status of additives and fillers that impart vapor and gas permeability, strength, and antimicrobial properties relevant to food applications. Furthermore, single-use products and packaging based on PLA composites from China, North America, and Latin America are examined in detail, along with their commercial properties and prices.

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The integrity of a package must be maintained by a material that can be heat sealed, particularly in medical, food, and pharmaceutical packaging applications. Obtaining an appropriate heat seal in packaging is crucial since, compared to package failure, heat seal failure is a more common reason for product degradation. Material selection and packaging methods should be evaluated carefully to choose the proper material that can effectively function under proper conditions. Hermetic seal property ensures the effectiveness of barrier layers in preventing oxygen permeation, loss of odor, and transmission of water vapor. Polylactic acid (PLA) is one of the biodegradable polymers with the greatest potential for heat sealing and thermal processing. To establish manufacturing protocols, verify seal effectiveness, and ensure product integrity, it is essential to consider the effects of controlling process parameters during package design. Therefore, to undercover the role of PLA structure on its properties, the factors impacting its heat-sealing feature are elaborated on in this chapter. More... Read More

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Polylactic acid (PLA) has emerged as a desirable bioplastic due to its production from renewable materials and biodegradability. However, its low toughness and fragility limit its applications, prompting the blending of PLA with other biopolymers to enhance its properties. As the global demand for bioplastics increases, efficient processes for PLA degradation are needed to match the high rate of plastic production. Chemical, microbial, and enzymatic processing are the major methods of PLA degradation, with enzymatic processing being environmentally friendly and sustainable. recyclable products like lactic acid can also be recovered. This creates a need to determine suitable enzymes that can hydrolyze polylactic acid. PLA exhibits high resistance to direct microbial degradation, making microbial enzymatic processing a more attractive alternative. Microbial enzymes, including proteases, lipases, esterases, and cutinases, have shown potential for PLA degradation. Nevertheless, current research on the enzymatic degradation of PLA needs comprehensive studies on optimal processes, conditio... Read More

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Composite material for manufacturing barrier layers with improved barrier properties for packaging applications. The composite contains Polyhydroxyalkanoate, polylactic acid, modified layered silicate, polyalkylene carbonate, and an auxiliary agent. The composite is extruded or injection molded into barrier layers for packaging materials like films and boxes. The composite's barrier properties can reduce fluid penetration compared to pure Polyhydroxyalkanoate. The modified layered silicate and polyalkylene carbonate improve barrier properties.

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The biodegradable biopolymer polylactic acid (PLA) has been used in the recent past in single-use packaging as a suitable replacement for non-biodegradable fossil fuel-based plastics, such as polyethylene terephthalate (PET). Under FDA and EU regulations, lactic acid (LA), the building block of PLA, is considered safe to use as a food contact material. The mechanical, thermal, and barrier properties of PLA are, however, major challenges for this material. PLA is a brittle material with a Youngs modulus of 29963750 MPa and an elongation at break of 1.37%. PLA has a glass transition temperature (Tg) of 60 C, exhibiting structural distortion at this temperature. The water permeability of PLA can lead to hydrolytic degradation of the material. These properties can be improved with biopolymer blending and composites. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), for instance, increases the thermal stability of PLA while decreasing the water permeability by up to 59%. Polypropylene (PP) is one of the most common plastics in reusable food containers. This study will compare PLA-b... Read More

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A biodegradable resin with enhanced degradation speed and improved film properties. The resin contains carboxyl groups at a specific concentration, which accelerates biodegradation while maintaining processing stability and film performance. The resin can be formulated with polylactic acid as the primary component, achieving high biodegradation rates in home composting environments. The biodegradable resin can be processed into films with excellent optical properties, mechanical strength, and barrier properties, making it suitable for food packaging applications.

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Biodegradable packaging materials with enhanced gas barrier properties that replace traditional petroleum-based polymers. The materials incorporate biocarbon-based fillers in combination with conventional biodegradable polymers, achieving superior oxygen and water barrier performance. The biocarbon fillers, derived from renewable biomass sources, provide enhanced oxygen barrier properties compared to conventional oxygen scavengers, while maintaining high water barrier performance. The materials exhibit excellent gas barrier properties, making them suitable for applications requiring high oxygen and water barrier performance, such as food packaging and pharmaceutical applications.

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A resin composition comprising a polylactic acid polymer and a β-methyl-δ-valerolactone polymer, wherein the composition exhibits improved tensile elongation at break and suppressed decrease in glass transition temperature.

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A biodegradable foamed polylactic acid sheet with improved environmental hygiene, produced by a novel method that prevents hydrolysis of the polylactic acid resin during processing. The method involves kneading the polylactic acid resin at a temperature of 150°C or lower, resulting in a sheet with oligomers and monomers having molecular weights of 3,000 or less in a total amount of 1,000 ppm or less. This approach enables the production of a foamed polylactic acid sheet with excellent bacteriostatic properties and reduced contamination risk.

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Abstract Polylactic acid (PLA) is a thermoplastic polyester that has received widespread attention for its environmentally friendly origin and excellent performance, and its potential to address the current problems of severe white pollution and scarcity of petroleum resources. This article focuses on the synthesis, modification, degradation and application of PLA. The main focus is on the modification of PLA with different environmentally friendly materials (natural organic materials, biodegradable polymers, inorganic minerals) in blends for defects such as the brittleness of PLA. In addition, the applications of PLA composites in the fields of construction, medical, packaging and oil and water separation are also introduced, which hopefully will provide some help to the promotion of PLA.

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Polylactic acid (PLA) is a popular replacement for conventional plastics such as polyethylene (PE) due to its high biodegradability and recyclability. Previous studies confirmed that PLA MPs and PE MPs pose similar toxicity risks due to that MPs risk is primarily attributed to physical and indirect nutritional effects. Surprisingly, despite the widespread use, there have been very few studies of microparticles released from daily products made by biodegradable materials. We investigated release levels from eight single-use paper cups (SUPCs) lined with PLA and PE film. Under typical hot-beverage preparation conditions, the total number of particles released from PLA SUPCs was 4.2 times, and the microplastics was 3.6 times higher than that from PE SUPCs. Significant levels of cellulose microfibres were released from PLA SUPCs, while no such fibres were released from PE SUPCs. A proportionately higher level of release of additive microparticles together with the release of cellulose microparticles are the key difference between biodegradable PLA and the conventional PE plastic. Cellul... Read More

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The biodegradation of polylactic acid (PLA)-based disposable tableware was assessed under anaerobic mesophilic conditions and the results were compared with previous thermophilic tests. The aim of the study was to investigate the behaviour of commercial bioplastic products when treated biologically in order to understand the potential correlations between their chemical composition and the biodegradation yields/kinetics. The tests lasted 155 days and specific biogas production ranged between 1665 and 1735 mL/g total organic carbon (TOC) in the PLA samples, with biodegradation yields of 8593% for the mesophilic tests and 96100% for the thermophilic tests. With the aid of advanced chemical characterization and principal component analysis, considerations were also derived about the influence of the composition of the polymeric matrix and the operating parameters of the digestion process on the biodegradation profile of the materials. These correlations were meant to build up a framework for a better understanding of the environmental behavior of bioplastic materials. In particular, a... Read More

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Abstract The development of biodegradable packaging is a challenge, as conventional plastics have many advantages in terms of high flexibility, transparency, low cost, strong mechanical characteristics, and high resistance to heat compared with most biodegradable plastics. The quality of biodegradable materials and the research needed for their improvement for meat packaging were critically evaluated in this study. In terms of sustainability, biodegradable packagings are more sustainable than conventional plastics; however, most of them contain unsustainable chemical additives. Cellulose showed a high potential for meat preservation due to high moisture control. Polyhydroxyalkanoates and polylactic acid (PLA) are renewable materials that have been recently introduced to the market, but their application in meat products is still limited. To be classified as an edible film, the mechanical properties and acceptable control over gas and moisture exchange need to be improved. PLA and cellulosebased films possess the advantage of protection against oxygen and water permeation; however, t... Read More

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Polylactic acid (PLA) is a popular replacement for conventional fossil-fuel based plastics products such as polyethylene (PE) due to its high biodegradability and recyclability. Previous studies confirmed that PLA microplastics (MPs) and PE MPs pose similar toxicity risks due to that MPs risk is primarily attributed to physical and indirect nutritional effects. Surprisingly, despite the widespread use, there have been very few studies of microparticles released from daily products made of biodegradable materials. We investigated release levels from eight single-use paper cups (SUPCs) lined with PLA and PE film. Under typical hot-beverage preparation conditions, the total number of particles released from PLA SUPCs was 4.2 times higher than that from PE SUPCs, with total numbers of 180,000 31,000 and 43,000 10,000 particles per litre, respectively. 22,000 6,000 MPs were released per litre from PLA, which was 3.6 times the level of MPs released from PE SUPCs. In addition, significant levels of cellulose microfibres were released from PLA SUPCs, with quantities of 38,000 31,000... Read More

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Abstract The increasing demand for sustainable packaging solutions has led to the widespread adoption of biodegradable polymers such as polylactic acid (PLA) in the packaging industry. However, the efficient recycling of post-consumer PLA packaging remains a challenge due to contamination from residual food and other substances. This study presents the application of Design of Experiments (DoE) in the evaluation of washing parameters, typically used in the recycling industry, in the degradation of post-consumer biodegradable PLA packaging. A series of experiments were conducted using a factorial design to investigate the effect of key washing parameters, including NaOH concentration, washing temperature, washing time, and surfactant concentration, on the degradation of PLA. The degradation was accompanied by rheology employing the Cox-Merz rule, which establishes the relationship between complex viscosity and steady state viscosity. The results indicated that a washing process with lower degradation rates could be obtained by adjusting the washing parameters within specific ranges. T... Read More

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Polylactic acid (PLA) is a brittle biodegradable thermoplastic due to its relatively high glass transition temperature (Tg 60 C). This Tg limits the using of PLA in flexible applications, for example packaging films. In this study, it has been shown for the first time that the Liquidambar Orientalis (LO) oil as a nontoxic, environmentally friendly, and green additive can be successfully used as a natural, renewable, and sustainable plasticizer to produce flexible PLA parts and improve its thermal and physical properties and application potential. Natural oil obtained from Liquidambar Orientalis tree was introduced into PLA (as 10, 20, and 30 phr) by melt compounding (MC) and solution mixing (SM) methods. Effect of LO oil amount on the glass transition temperature, melt and cold crystallization behaviors, and degree of crystallinity values of samples were determined with differential scanning calorimetry (DSC). In addition, solid state viscoelastic properties of PLA films were also characterized with dynamic mechanical analysis (DMA) tests. Results showed that LO oil significantly ... Read More

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In the present study commercial Polylactic Acid-based disposable cups and plates were selected for lab scale anaerobic degradability tests. The experiments were carried out under thermophilic conditions at different inoculum to substrate ratios and test material sizes, and the specific biogas production and associated kinetics were evaluated. Maximum biogas production was comparable for almost all the experimental runs (1620 and 1830 NmL/gTOCPLA) and a biodegradation degree in the range 86-100% was attained. Moreover, physical, chemical and microscopical analyses were used to characterize the tested materials before and after the degradation. The products composition was assessed and the presence of some additives (mainly Ca-based) was detected. Potential correlations among the process parameters and product composition were derived and a delay in process kinetics with increasing amount of additives embedded in the polymeric matrix was observed, confirming the relevant influence of the chemical blend on the biodegradation process.

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Polylactic acid (PLA) is a kind of biopolymer made from non-conventional resources. It is biodegradable and has high mechanical properties. However, its use as the packaging material in the food-packaging sector is limited due to its brittleness and porosity. Therefore, to reduce the brittleness and improve the barrier properties, the compression-molded PLA/ESO films were surface treated with N2 plasma. Water vapour permeability, migration and differential scanning calorimetry tests have been carried out to assess the surface barrier performance and thermal properties of the manufactured films. The surface-treated PLA/ESO showed better barrier properties than pure PLA and PLA/ESO. The water vapor transfer rate of surface-treated PLA/ESO was 3.35 % lower than the PLA/ESO. The improvement in barrier properties, as well as the reduction in glass transition temperature, could increase the potential of the material for packaging.

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The food industry contributes around 40% of the containers and packaging used and discarded until 2020 worldwide. Social, environmental, and political interest in the development of biodegradable containers is growing, as is the demand of consumers for fresh and quality food products. Bioplastics are classified according to their chemical composition, origin, and synthesis process. Polyhydroxyalkanoates (PHA) are materials of microbial origin, while polylactic acid (PLA) is obtained from lactic acid and the chemical reaction of lactide that produces the biomaterial. This work explores, through a bibliographic review, the principles and production of bioplastics made from polylactic acid (PLA) and polyhydroxybutyrate (PHB) and their application in food packaging. These materials constitute particularly interesting materials due to their potential in a wide range of applications. Physical-chemical properties of the biomaterials requested to make food packaging are permeability to moisture, oxygen permeability, and mechanical properties. The requirements established for the different ty... Read More

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A biodegradable polylactic acid (PLA) material with improved toughness and high-temperature resistance. The material comprises 30-60% PLA, 20-50% polybutylene succinate (PBS), 5-12% inorganic filler, 0.5-1.2% chain extender, 1-10% plasticizer, 0.5-10% toughening agent, 0.2-0.6% compatibilizer, and 0.1-0.6% heat stabilizer. The material exhibits enhanced mechanical properties, including improved impact strength, elongation at break, and Vicat softening temperature, making it suitable for applications requiring high performance and biodegradability.

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Biodegradable capsule with improved heat resistance, comprising a capsule container filled with raw material powder and a sealing paper sealing the inside of the capsule container, wherein the capsule container contains a polylactic acid composite resin comprising 40-70% crystalline polylactic acid, 30-60% amorphous polylactic acid, 10-20% ABS resin, 10-20% SAN resin, and 10-30% vegetable polyol.

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Polylactic acid (polylactide) is the most widely used biodegradable polymer. To eliminate its brittleness and low flexibility, various approaches to plasticization are used, in particular, compounding with more flexible polymers. The possibilities of plasticizing polylactide with polycaprolactone and polybutylene adipate/terephthalate by mixing polymers in a solution with subsequent film formation have been studied as well as the thermophysical and mechanical characteristics of the resulting film materials have been studied. The effect of plasticizer additives on the phase structure of polylactide with a decrease in its crystallinity and crystallite perfection was found. Thus, a plasticizing effect with polylactide amorphization was observed. The flexibility of the materials increased, as evidenced by the increase in the relative elongation under tensile strain of the films.

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Due to its good biocompatibility, Polylactic Acid (PLA) has always been a research hotspot in the field of biomedical materials. This paper introduces and exemplifies the methods of PLA modification in detail and compares them. Different methods have advantages and disadvantages. In terms of medical materials, it can be selected according to different application requirements.

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The physical ageing of polylactic acid (PLA) is a phenomenon that changes the materials properties over time. This ageing process is highly dependent on ambient variables, such as temperature and humidity. For PLA, the ageing is noticeable even at room temperatures, a process commonly referred to as natural ageing. Stopping the ageing by freezing the material can be helpful to preserve the properties of the PLA and stabilise it at any time during its storage until it is required for testing. However, it is essential to demonstrate that the PLAs mechanical properties are not degraded after defrosting the samples. Four different methods for stopping the ageing (anti-ageing processes) are analysed in this paperall based on freezing and defrosting the PLA samples. We determine the temperature and ambient water vapor influence during the freezing and defrosting process using desiccant and zip bags. The material form selected is PLA filaments (no bulk material or scaffold structures) printed at 190 C with diameters between 400 and 550 m and frozen at 24 C in the presence or absence ... Read More

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Biodegradable composite films for packaging applications that are made from biodegradable materials and have barrier and sealant properties. The composite films have an oxidizing metal barrier layer sandwiched between bio-based outer and inner layers. The oxidizing metal layer prevents oxygen and moisture ingress. The bio-based layers are made from materials like PLA, PHA, or paper that degrade in compost or soil. The composite films can be used in food packaging, like coffee pods, that decompose after disposal.

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A biopolymer composition with enhanced elongation properties, comprising a copolymer resin of lactic acid (LA) and 3-hydroxypropionate (3HP) in 83.5% by weight or greater, an antioxidant, and a lubricant, wherein the biopolymer composition exhibits elongation of 90% to 500% and impact strength of 100 J/m to 200 J/m. The composition is prepared through an extrusion process, which enables mass production and stable property evaluations.

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Abstract Polylactic acid (PLA) is a biodegradable polymer derived from biorenewable resources. The effect of diffused water molecules on the mechanical properties of PLA, before the onset of hydrolytic degradation, has been rarely studied. In this work, PLA fibers produced by meltextrusion were conditioned in chambers with different levels of relative humidity (36%, 75%, and 98%), as well as immersed in distilled water. Creep tests were conducted on dry and conditioned samples and creep compliances were extracted. With the increase of moisture content, the decrease in instantaneous elastic compliance, as well as the more flattened curves in the last stage of the creep tests, indicates the existence of waterbridgeantiplasticization effect. The modified BurgersReimschuessel model developed in our previous work is found to be able to predict the effect of absorbed moisture on the viscoelasticity of PLA. The present work highlights the importance of considering the moisture's antiplasticization effect. The proposed methodology can be adopted to evaluate the effect of moisture on t... Read More

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A biodegradable foam sheet made from polylactic acid (PLA) with improved thermal stability and physical properties. The PLA composition has a specific monomer unit ratio of D-lactic acid and L-lactic acid, and a high PLA content of 97% by mass or greater. The foam sheet exhibits excellent thermal insulation, dimensional stability, and physical properties, making it suitable for applications such as heat-resistant containers. The sheet is produced using a novel processing method that combines kneading and foaming steps, utilizing a compressive fluid as both a plasticizer and foaming agent.

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