Bio-based Plastics Research Articles

Development of a plastic waste treatment process by combining deep eutectic solvent (DES) pretreatment and bioaugmentation with a plastic-degrading bacterial consortium

Polyethylene terephthalate (PET), a petroleum-based plastic, and polylactic acid (PLA), a biobased plastic, have a similar visual appearance thus they usually end up in municipal waste treatment facilities. The objective of this project was to develop an effective PET and PLA waste treatment process that involves pretreatment with deep eutectic solvent (DES) followed by biodegradation with a plastic-degrading bacterial consortium in a composting system. The DES used was a mixture of choline chloride and glycerol, while the bacterial strains (Chitinophaga jiangningensis EA02, Nocardioides zeae EA12, Stenotrophomonas pavanii EA33, Gordonia desulfuricans EA63, Achromobacter xylosoxidans A9 and Mycolicibacterium parafortuitum J101) used to prepare the bacterial consortium were selected based on their ability to biodegrade PET, PLA, and plasticizer. The plastic samples (a PET bottle, PLA cup, and PLA film) were pretreated with DES through a dip-coating method. The DES-coated plastic samples exhibited higher surface wettability and biofilm formation, indicating that DES increases the hydrophilicity of the plastic and facilitates bacterial attachment to the plastic surface. The combined action of DES pretreatment and bioaugmentation with a plastic-degrading bacterial consortium led to improved degradation of PET and PLA samples in various environments, including aqueous media at ambient temperature, lab-scale traditional composting, and pilot-scale composting.

Metabolic engineering of genome-streamlined strain Pseudomonas putida KTU-U27 for medium-chain-length polyhydroxyalkanoate production from xylose and cellobiose

Bio-based plastics polyhydroxyalkanoates (PHAs) are considered as a good substitutive to traditional fossil-based plastics because PHAs outcompete chemical plastics in several important properties, such as biodegradability, biocompatibility, and renewability. However, the industrial production of PHA (especially medium-chain-length PHA, mcl-PHA) is greatly restricted by the cost of carbon sources. Currently, xylose and cellobiose derived from lignocellulose are potential substrates for mcl-PHA production. In this study, Pseudomonas putida KTU-U27, a genome-streamlined strain derived from a mcl-PHA producer P. putida KT2440, was used as the optimal chassis for the construction of microbial cell factories with the capacity to efficiently produce mcl-PHA from xylose and cellobiose by introducing the xylose and cellobiose metabolism modules and enhancing the transport of xylose and cellobiose. The lag phases of the xylose- and cellobiose-grown engineered strains were almost completely eliminated and the xylose- and cellobiose-utilizing performance was greatly improved via adaptive laboratory evolution. In shake-flask fermentation, the engineered strain 27A-P13-xylABE-Ptac-tt and 27A-P13-bglC-P13-gts had a mcl-PHA content of 41.67 wt% and 45.18 wt%, respectively, and were able to efficiently utilize xylose or cellobiose as the sole carbon source for cell growth. Herein, microbial production of mcl-PHA using xylose as the sole carbon source has been demonstrated for the first time. Meanwhile, the highest yield of mcl-PHA produced from cellobiose has been obtained in this study. Interestingly, the engineered strains derived from genome-reduced P. putida strains showed higher xylose- and cellobiose-utilizing performance and higher PHA yield than those derived from P. putida KT2440. This study highlights enormous potential of the engineered strains as promising platforms for low-cost production of mcl-PHA from xylose- and cellobiose-rich substrates.

Overview: Biodegradable Packaging Film Materials

Currently, bioplastics, which are bio-based (biodegradable/non-biodegradable) plastics, account for about 1% of the approximately 390 million tons of plastic produced annually. But as demand is rising, and with more new materials demerging, the market is already growing very dynamically. Europe ranks the 1st place in the field of research and development of bioplastics. About a fifth part of the world’s volume of such materials, produce here. The development of such technologies in Russia goes slowly. Biodegradable plastics are mainly produced from starch, polylactic acid and cellulose. Moreover, all of components are biodegradable. So-called biocomposites are also available, which are a mixture of a polymer with a filler introduced in order to reduce the cost of materials and/or to improve the chemical-mechanical properties of the product. The obtaining of biodegradable packaging materials by fermentation process is very expensive. Traditional synthetic plastics with biodegradable additives introduced into them need special composting conditions. In this article, there is the market’s analysis of the packaging biodegradable products. It also contains the ways to obtain such products from natural raw materials. A large number of studies are devoted to the chemical modification of such polymers, which makes it possible to obtain flexible packaging materials with improved physical and mechanical characteristics compared to the original and not inferior to traditional synthetic plastics.

Aerobic aquatic biodegradation of bio-based and biodegradable polymers: Kinetic modeling and key factors for biodegradability

With the increasing concern about plastic waste, numerous efforts have been made to find substitutes for existing non-biodegradable synthetic polymers. Bio-based and/or purported petroleum-based biodegradable polymers are considered probable plastic replacement candidates. However, the durability of non-biodegradable plastic is a key feature of plastics. Thus, a balance must be achieved between biodegradation and environmental material stability. The objective of this study is to determine the impact of crystallinity, molecular chemistry, and hydrophilicity on the rate of aquatic biodegradation of biobased plastic materials. In the present study, twelve bio-based/purported biodegradable materials were investigated under aerobic aquatic biodegradation conditions for 56 days by tracking oxygen consumption. Crystallinity, hydrophobicity, chemistry, and chemical structure were varied to understand potential means for controlling the rate of biodegradation. The biodegradation kinetics were analyzed and discussed, relating to the characteristics of polymers. Polyvinyl alcohol (PVA), Chitosan, Rayon, Polyhydroxy-butyrate-co-valerate (PHBV), PHBH, and Polybutylene succinate (PBS) showed the biodegradation extents over 70% at 56 days. Cellulose acetates (CAs) and Polylactic acid (PLA) showed biodegradation extent lower than 20%. The chemistry of the polymer backbone chain, substituent structure, and degree of substitution were the dominant factors affecting biodegradation. The crystallinity of the polyesters had a negative correlation with the initial biodegradation rate and the ultimate biodegradation of polyesters, and the hydrophobicity of the polymers delayed the initiation of biodegradation. The aerobic aquatic biodegradation results related to the polymer characteristics are useful for product designers and environmental scientists to understand the fate of these polymeric materials in the environment.

Petroleum-Based Plastics Versus Bio-Based Plastics: A Review

Plastic needs have expanded along with population growth, industrialization, and urbanization. Plastic is unrivaled due to its useful properties and is used to prepare numerous important goods daily. This paper encloses the different kinds and applications of petroleum-based plastic and the drawbacks related to their use, i.e., its nonbiodegradability which leads to their stay in the environment for a very long time. Additionally, there are not enough effective disposal techniques for the large volume of plastic waste produced; thus, plastic garbage builds up in the environment and endangers it. Limiting the usage of plastic is necessary to protect the environment. This can be done with the help of bioplastic, which is an excellent substitute for plastic. The different kinds of bioplastic and their biodegradability in different mediums, viz., soil compost and aquatic systems, are addressed in this paper. Along this, the different areas of application of bioplastic have been explored. The present study also addresses the underlying mechanism of plastic polymerization and biodegradation and the current status of bioplastics in the global market.

Effect of Time on the Properties of Bio-Nanocomposite Films Based on Chitosan with Bio-Based Plasticizer Reinforced with Nanofiber Cellulose.

The deterioration of the performance of polysaccharide-based films over time, particularly their hydrophilicity and mechanical properties, is one of the main problems limiting their applications in the packaging industry. In the present study, we proposed to improve the performance of chitosan-based films through the use of: (1) nanocellulose as an additive to reduce their hydrophilic nature; (2) bio-based plasticizer to improve their mechanical properties; and (3) chestnut extract as an antimicrobial agent. To evaluate their stability over time, the properties of as-formed films (mechanical, hydrophilic, barrier and antibacterial) were studied immediately after preparation and after 7, 14 and 30 days. In addition, the morphological properties of the films were characterized by scanning electron microscopy, their structure by FTIR, their transparency by UV-Vis and their thermal properties by TGA. The films showed a hydrophobic character (contact angle above 100°), barrier properties to oxygen and carbon dioxide and strong antibacterial activity against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria. Moreover, the use of nanofillers did not deteriorate the elongation at breaks or the thermal properties of the films, but their addition reduced the transparency. In addition, the results showed that the greatest change in film properties occurred within the first 7 days after sample preparation, after which the properties were found to stabilize.

Effect of Different Natural Fibers on Mechanical and Disintegration Properties of Compostable Biobased Plastics

ABSTRACT This study evaluates the economic and degradation properties of natural fiber-reinforced PHBH (Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)). Compounds containing the compostable biobased plastic PHBH and 30 mass% of cotton, merino wool, wood fibers, and hemp fibers were produced, and 0.4 mm thick foils were manufactured using a laboratory hot press. Samples for mechanical characterization were produced by injection molding and were buried in bioactive soil for 16 weeks to determine the influence of fiber type on the disintegration speed in soil. The disintegration was measured by subsequent excavation, determination of dry mass loss and visual inspection. All kinds of natural fibers generally improve disintegration speed. The most significant improvement was reached by samples containing cotton and wool, respectively, which experienced similar mass loss, followed by the ones containing hemp fibers. The smallest increase in disintegration speed was achieved by samples containing wood fibers. Mechanical properties and cost-saving potential increased in the cotton and hemp samples. * Long version of a presentation at Composites Meet Sustainability – Proceedings of the 20th European Conference on Composite Materials, ECCM20. 26–30 June, 2022, Lausanne, Switzerland

Flexible, thermal processable, self-healing, and fully bio-based starch plastics by constructing dynamic imine network

The serious environmental threat caused by petroleum-based plastics has spurred more researches in developing substitutes from renewable sources. Starch is desirable for fabricating bioplastic due to its abundance and renewable nature. However, limitations such as brittleness, hydrophilicity, and thermal properties restrict its widespread application. To overcome these issues, covalent adaptable network was constructed to fabricate a fully bio-based starch plastic with multiple advantages via Schiff base reactions. This strategy endowed starch plastic with excellent thermal processability, as evidenced by a low glass transition temperature (Tg = 20.15 °C). Through introducing Priamine with long carbon chains, the starch plastic demonstrated superior flexibility (elongation at break = 45.2%) and waterproof capability (water contact angle = 109.2°). Besides, it possessed a good thermal stability and self-adaptability, as well as solvent resistance and chemical degradability. This work provides a promising method to fabricate fully bio-based plastics as alternative to petroleum-based plastics.

Bio-based Hyperbranched Ester Plasticizers from Woody Oil Based on Cohesive Energy via a One-Pot Synthesis Reaction

Bio-based Hyperbranched Ester Plasticizers from Woody Oil Based on Cohesive Energy via a One-Pot Synthesis Reaction

Lignocellulosic biomass feedstock: A benchmarking green resource for sustainable production of bioplastics

Presence of plastics in the surroundings is ubiquitous, as generation of plastics is booming globally and it gets accumulated in oceans leading to deleterious impacts on marine life, public health and the surrounding environment. Owing to its non-degradable nature, plastic particles remain in surroundings for extended periods which automatically facilitate its out spreading. Therefore, there is a need to shift to bio-based plastics, as bio-based green economy hinges on sustainable employment of bioresources for generating a broad spectrum of products, biofuels, chemicals and bioplastics. Typically bioplastics are synthesized from bio-based resources considered to contribute more to sustainable production of plastic as a part of the circular economy. Bioplastics are luring attention and growing as counterfeit material for petroleum-derived plastics owing to their biodegradability. Recently an engrossed interest has been burgeoning in producing drop-in polymers and new-fangled bioplastics by utilizing lignocellulosic feedstock. This paper reviews the enormous potential of lignocellulosic feedstock as a significant inedible substrate for bioplastic synthesis. Polyhydroxyalkanoates, polyurethanes, polylactic acid and starch-bioplastic are prevailing bio-based plastic comparably derived from lignocellulosic biomass. In forthcoming years bioplastic derived years’ bioplastic derived from lignocellulose will loom as valuable material in numerous fields for an extensive range of cutting-edge applications.

Preparation of degradable chemically cross-linked polylactic acid films and its application on disposable straws

The semi-rigidity of the polylactic acid (PLA) molecular chain makes it brittle, poor impact resistance and barrier properties, which severely limits its practical applications. In this paper, a bio-based reactive plasticizer epoxy soybean oil (ESO) was used to improve the mechanical and barrier properties of maleic anhydride grafted polylactic acid (MAPLA) by the chemical reaction between the epoxy and anhydride group. Firstly, the optimum curing conditions were 93.5 °C, 100 °C, and 110.8 °C for 2 h. The effects of different mass fractions of ESO on the properties of MAPLA-ESO (ME) films were systematically investigated. It was found that when the content of ESO was 10 wt%, the tensile properties of the resulting ME films were the best, with a tensile strength of 35.2 MPa. And it had an elongation at break of 20.0 % and toughness of 5.4 MJ/m3, which increased to 690 % and 675 %, respectively, compared with pure MAPLA films. The chemically crosslinked ME films also displayed excellent water resistance, well degradation, low migration properties, and better performance than that of commercial paper straws and PLA straws, exhibiting great application potential as degradable disposable straws. Therefore, this work provides an effective way to develop high-performance, green, and degradable PLA films and products.

Role of microalgae as a sustainable alternative of biopolymers and its application in industries

The escalating accumulation of petroleum-based polymers has depleted resources and raised environmental concerns due to their non-recyclable and non-biodegradable nature. Consequently, there has been a growing interest in bio-based plastics, particularly algal-based biopolymers, which offer recyclability and eco-friendliness. Algae-derived polymers have distinct advantages, such as autotrophic growth reducing greenhouse gas emissions, rapid growth rate, low nutritional requirements, and resilience to harsh environments. Additionally, algae exhibit higher photosynthetic potential (10-20%) compared to terrestrial plants (1%-2%). The range of algal-derived polymers includes alginate, laminarin, fucoidan, carrageenan, agar, ulvan, polyhydroxyalkanoates (PHA), and poly-(Hydroxybutyrate) (PHB). However, further efforts are required to implement them on a large scale. This review highlights algae's potential as a raw material for biopolymer production, exploring their characteristics and applications in diverse industries like food and pharmaceuticals.

Characterization of antimicrobial and antioxidant performance of dihydroeugenol and its glycoside incorporated into whey protein isolate films

Bio-based plastics are gaining attention as environmentally friendly alternatives to traditional petroleum-based plastics in food packaging. Biodegradable films made from biocompatible macromolecules like polysaccharides and proteins offer promising solutions. This study investigated the effects of incorporating dihydroeugenol and glycoside into whey protein isolate (WPI) films to enhance their antimicrobial and antioxidant properties for food packaging. The findings showed that the glycoside film surpassed the dihydroeugenol film in inhibiting bacterial growth, forming larger inhibition halos against Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Salmonella Enteritidis (inhibition halos ≥15 mm). The glycoside film exhibited superior effectiveness against Gram-positive bacteria, indicating enhanced penetration through their cell membranes. Additionally, the synthesized compounds significantly boosted the antioxidant activity of the films compared to the control film without dihydroeugenol and glycoside. With a relatively low solubility (23% ± 2.87% and 24% ± 3.92% for dihydroeugenol and glycoside, respectively), these films are suitable for packaging and safeguarding food products with medium to high humidity. This study concluded that incorporating dihydroeugenol and its glycoside into WPI films holds great promise for developing active packaging solutions in the food industry. These films offer both antibacterial and antioxidant properties, particularly advantageous for food products with medium to high humidity.

Integration of Biological Synthesis & Chemical Catalysis: Bio-based Plasticizer trans-Aconitates

Plasticizers are essential to reduce processing difficulties and improve plastic properties. However, petroleum-based phthalate plasticizers, which are mostly used at present, urgently require alternatives due to their confirmed and serious health risks. In this study, the green mass production of trans-aconitic acid was achieved via synthetic biotechnology and microbial fermentation, which was further expanded to multiple application scenarios using chemical esterification, resulting in trans-aconitate plasticizers that are biosafe and environmentally friendly and have high plasticizing efficiency and long-term stability. Different plasticizers with various core structures and alkyl chains were studied to determine their properties as polyvinyl chloride (PVC) plasticizers, and tributyl trans-aconitate displayed the best comprehensive performance with up to 1.24 plasticizing efficiency. The possible PVC plasticization mechanism with synergistic solvent, support, and shielding effects was discussed and summarized. Tributyl trans-aconitate has significant potential to replace traditional PVC plasticizers in general merchandise, food packaging, medicinal materials, and other products, further promoting the development of the high-quality plastic industry with greener technology and safer applications.

Attributional and consequential life cycle perspectives of second-generation polylactic acid: The benefits of integrating a recycling strategy

The climate crisis calls for a shift from petrochemicals to bio-based products to reduce environmental consequences. Polylactic acid (PLA) is one of the most widely used biopolymers, due to its mechanical properties and renewable origin, to produce bio-based compostable plastic for food packaging. The objective of this study is to determine the environmental feasibility of a second-generation PLA production based on wheat straw; and the role of a chemical recycling plant on the environmental performance of a bioproduct at an early design stage. A holistic assessment was performed through the Life Cycle Assessment (LCA) methodology considering both attributional and consequential perspectives, through a cradle-to-grave approach. The attributional LCA results show that lactic acid production was the main contributor due to the wheat straw pre-treatment and downstream separation and purification (DSP) processes. The integration of a recycling plant leads to a significant reduction of burdens, ranging from 1.38 to 0.44 kg CO2eq in the Global Warming category. Furthermore, consequential LCA results shows that the increased demand for substitute products for activities such as feeding, fertilisation and energy generation and the indirect emissions from land use change related to the conversion of land for the cultivation of raw materials are relevant factors in the environmental effects associated with the possible implementation of straw-based bioPLA production system.

Template-OrientedPolyaniline-Supported Palladium Nanoclusters for Reductive Homocoupling of Furfural Derivatives.

Developing well-defined structures and desired properties for porous organic polymer (POP) supported catalysts by controlling their composition, size, and morphology is of great significance. Herein, we report a preparation of polyaniline (PANI) supported Pd nanoparticles (NPs) with controllable of the structure and morphology. The protocol involves the introduction of MnO2 with different crystal structures (α, β, γ, δ, ε) serving as both reaction templates and oxidants. MnO2 selectively oxidizes the aniline to polyaniline with diverse regular distribution of benzene and quinone, thus leading to the Pd/PANI catalyst growth mode which prominently impacts the charge transfer between Pd and PANI, as well as the dispersion of metal NPs. In particular, Pd/ε-PANI greatly improves the turnover frequency (TOF), up to 88.3 h-1,in the reductive coupling of the furfural derivatives to potential bio-based plasticizers. Systematic characterizations reveal the unique oxidation state of the support in the Pd/ε-PANI catalyst and coordination mode of Pd that drives the formation of highly dispersed Pd nanoclusters. Density functional theory (DFT) calculations show the more electron rich Pd/PANI catalyst has the lower energy barrier in the oxidative addition step, which favors the C-C coupling reaction.

Synthesis, characterization and performance evaluation of “crab” bio-based poly(vinyl chloride) plasticizer based on sustainable lactic acid

Introducing renewable resources into the production of biological agents and conducting comprehensive performance evaluations of the products is an inevitable trend in promoting sustainable development. Lactic acid is a sustainable and eco-friendly material that is derived from the fermentation of crops such as corn, sweet potatoes, and potatoes. This study synthesized a novel crab-like lactic acid-based plasticizer IPBL by reacting lactic acid with butanol and isophorone diisocyanate (IPDI). The molecular structure of compound was characterized by FTIR, 1H NMR, and mass spectrum. The IPBL plasticizer was used to blend poly(vinyl chloride) (PVC), and its performance was compared to commercial plasticizers, dioctyl phthalate (DOP) and acetyl tributyl citrate (ATBC). The results demonstrated that the PVC film plasticized by IPBL had comparable optical properties, thermal stability, and migration resistance to PVC/DOP and PVC/ATBC. In addition, PVC/IPBL blends exhibit certain hydrophobicity, which has also been shown in stain resistance tests to have potential for anti-fouling and self-cleaning applications. The DMA test showed that IPBL had a lower glass transition temperature (Tg) than commercial plasticizers, resulting in higher elongation at break. Preliminary commercial cost calculations showed that it is superior to the bio-based plasticizer ATBC. The interaction behavior between IPBL and PVC chains was verified by molecular dynamics simulations. These findings demonstrate that the lactic acid-based plasticizer IPBL has excellent capacity as a bio-based alternative to harmful petroleum-based phthalate plasticizers.

Linear programming approach to design bio-based plastics strategies for Japan: Integration of material characteristics, product applications, and end of life options

There is a growing interest in bio-based plastics for mitigating climate change; however, it remains unclear as to which products should be produced using bio-based plastics and how such plastics should be disposed of to minimize their environmental impact. To investigate the degree to which bio-based plastics can be applied toward the mitigation of climate change based on material characteristics, product applications, and end of life (EoL) options, we developed a linear-programming-based model to represent a plastic system of nine types of fossil-based plastics and 12 types of bio-based plastics in Japan. We found that introducing bio-based plastics could reduce life cycle greenhouse gas (LCGHG) emissions, provided that an appropriate EoL is coupled. Specifically, the ‘drop-in’ plastics were dominantly selected with feedstock recycling when only material property was constrained, and the LCGHG emissions from the system was −15.5 million t-CO2eq/year.

Innovative Bioplasticizers from Residual Cynara cardunculus L. Biomass-Derived Levulinic Acid and Their Environmental Impact Assessment by LCA Methodology.

This work is focused on the application of Life Cycle Assessment (LCA) methodology for the quantification of the potential environmental impacts associated with the obtainment of levulinic acid from residual Cynara cardunculus L. biomass and its subsequent valorization in innovative bioplasticizers for tuning the properties as well as the processability of biopolymers. This potentially allows the production of fully biobased and biodegradable bioplastic formulations, thus addressing the issues related to the fossil origin and nonbiodegradability of conventional additives, such as phthalates. Steam explosion pretreatment was applied to the epigean residue of C. cardunculus L. followed by a microwave-assisted acid-catalyzed hydrolysis. After purification, the as-obtained levulinic acid was used to synthesize different ketal-diester derivatives through a three-step selective synthesis. The levulinic acid-base additives demonstrated remarkable plasticizing efficiency when added to biobased plastics. The LCA results were used in conjunction with those from the experimental activities to find the optimal compromise between environmental impacts and mechanical and thermal properties, induced by the bioadditives in poly(3-hydroxybutyrate), PHB biopolymer.

THE STRENGTH WITHIN LAYERS: ANALYZING PLA TENSILE STRENGTH IN 3D PRINTING

One of the most popular Additive Manufacturing (AM) techniques is Fused Deposition Modelling (FDM), sometimes referred to as 3D printing. It is based on the extrusion of a thermoplastic filament. Lightweight items can be constructed utilising a variety of infill procedures and ratios thanks to layer wise technology. Furthermore, components with varied properties can be produced by adjusting other factors like temperature, printing speed, or layer thickness. Since Polylactic Acid (PLA) is a biobased and biodegradable plastic, it is one of the least expensive and most environmentally friendly materials for 3D printing. It is commonly used in 3D printing among amateurs and in communities like the Fab lab or the Makers movement. In order to determine how key 3D printing factors affect the tensile strength of PLA products, Design of Experiment (DOE) is used in this work. In order to accomplish this, a 4x3 factorial plane with one replication was built and utilised to 3D print tensile PLA material samples. The findings of the tensile test demonstrate that for the resistance of PLA products, the layer thickness is more important than the infill. According to the values of these four factors, a regression model is also suggested to enable the user to forecast the final tensile strength of PLA products