The accumulation of plastic wastes in different environments has become a topic of major concern over the past decades; therefore, technologies and strategies aimed at mitigating the environmental ...impacts of petroleum products have gained worldwide relevance. In this scenario, the production of bioplastics mainly from polysaccharides such as starch is a growing strategy and a field of intense research. The use of plasticizers, the preparation of blends, and the reinforcement of bioplastics with lignocellulosic components have shown promising and environmentally safe alternatives for overcoming the limitations of bioplastics, mainly due to the availability, biodegradability, and biocompatibility of such resources. This review addresses the production of bioplastics composed of polysaccharides from plant biomass and its advantages and disadvantages.
Fears concerning microplastics (MPs) environmental fate and persistence are progressively expanding on a global basis, with the emphasis given to manufacturing bioplastics for substituting ...petro-derived plastics extensively growing. Among them, poly(lactic acid) (PLA) holds a pioneering role towards the replacement of conventional polymeric materials, owing to its multifunctional properties, enclosing superior mechanical properties, low cost, renewability, great biocompatibility, transparency, and thermoplasticity launching many fields of application. Due to the wide applicability of PLA in several sectors of everyday life, its waste to be released into the environment is expected to follow a growing tendency during the upcoming years. Even though PLA is a biodegradable polyester, it actually degrades under specific composting environments, including a rich oxygen environment with high temperatures (58–80 °C), high humidity (>60% moisture) as well as the presence of micro-organisms (thermophilic bacteria). Additionally, in various studies it has been implied that PLA displays slower degradation performance when found in blends with other conventional polymers, underlining the unspecified effects on PLA degradation profile, keeping thus the information about PLA degradation from a blur standpoint. Therefore, a deepened understanding of the fate and dynamic effects of PLA MPs is of primary importance. Nevertheless, the current examination of the effects of PLA MPs in terms of sorption capacities and toxicity is so far limited and broadly unexplored since the current scientific emphasis has been merely centered on the conventional MPs' behavior. In this light, the present review provides an inclusive overview of the ongoing research of poly(lactic acid) in the framework of microplastics' pollution, while the future trends and missing points in this context are highlighted.
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•The growing production of polylactic acid generates queries about MPs formation.•(Bio)degradation of PLA has a slow pace and selective character in the environment.•Adsorption capacities and toxicity data about PLA MPs are included.•Scarce data about the impact of PLA MPs on the natural ecosystems.•Current research status and knowledge gaps in the frame of PLA MPs are highlighted.
Traditional plastics reshaped the society thanks to their brilliant properties and cut-price manufacturing costs. However, their protracted durability and limited recycling threaten the environment. ...Worthy alternatives seem to be polyhydroxyalkanoates, compostable biopolymers produced by several microbes. The most common 3-hydroxybutyrate homopolymer has limited applications calling for copolymers biosynthesis to enhance material properties. As a growing number of researches assess the discovery of novel comonomers, great endeavors are dedicated as well to copolymers production scale-up, where the choice of the microbial carbon source significantly affects the overall economic feasibility. Diving into novel metabolic pathways, engineered strains, and cutting-edge bioprocess strategies, this review aims to survey up-to-date publications about copolymers production, focusing primarily on precursors origins. Specifically, in the core of the review, copolymers precursors have been divided into three categories based on their economic value: the costliest structurally related ones, the structurally unrelated ones, and finally various low-cost waste streams. The combination of cheap biomasses, efficient pretreatment strategies, and robust microorganisms paths the way towards the development of versatile and circular polymers. Conceived to researchers and industries interested in tackling polyhydroxyalkanoates production, this review explores an angle often underestimated yet of prime importance: if PHAs copolymers offer advanced properties and sustainable end-of-life, the feedstock choice for their upstream becomes a major factor in the development of plastic substitutes.Traditional plastics reshaped the society thanks to their brilliant properties and cut-price manufacturing costs. However, their protracted durability and limited recycling threaten the environment. Worthy alternatives seem to be polyhydroxyalkanoates, compostable biopolymers produced by several microbes. The most common 3-hydroxybutyrate homopolymer has limited applications calling for copolymers biosynthesis to enhance material properties. As a growing number of researches assess the discovery of novel comonomers, great endeavors are dedicated as well to copolymers production scale-up, where the choice of the microbial carbon source significantly affects the overall economic feasibility. Diving into novel metabolic pathways, engineered strains, and cutting-edge bioprocess strategies, this review aims to survey up-to-date publications about copolymers production, focusing primarily on precursors origins. Specifically, in the core of the review, copolymers precursors have been divided into three categories based on their economic value: the costliest structurally related ones, the structurally unrelated ones, and finally various low-cost waste streams. The combination of cheap biomasses, efficient pretreatment strategies, and robust microorganisms paths the way towards the development of versatile and circular polymers. Conceived to researchers and industries interested in tackling polyhydroxyalkanoates production, this review explores an angle often underestimated yet of prime importance: if PHAs copolymers offer advanced properties and sustainable end-of-life, the feedstock choice for their upstream becomes a major factor in the development of plastic substitutes.
It is crucial and significant to boost the utilization of renewable resources and exploitation of biodegradable materials alternative to petrochemical plastics. Waste paper, mainly composed of ...cellulose (82–95 wt%) and derived from the lignocellulose, is a type of abundant, renewable, and biodegradable resource, whose recycling use and conversion to high value‐added products can reduce the pressure on the environment and exert immense economic benefits. Herein, four kinds of common waste paper (e.g., printing paper, newspaper, straw paper and roll paper) were converted into cellulose‐based bioplastic membranes by using ionic liquid 1‐butyl‐3‐methyl‐imidazolium chloride as solvent. The cellulose‐based membranes are smooth and compact, and their mechanical strength is prominently improved about 3–100 times comparison with the original paper. The maximum tensile strength of the film (F4) is over 127 Mpa and its optical transmittance reaches 80% at 450–800 nm wavelength. Besides, this kind of cellulose‐based films have excellent biodegradability. Thus, the results demonstrated that the cellulose‐based bioplastic membranes stemmed from waste paper possess a magnificent application prospect.
Plastics have become indispensable in modern life and the material of choice in packaging applications, but they have also caused increasing plastic waste accumulation in oceans and landfills. ...Although there have been continuous efforts to develop biodegradable plastics, the mechanical and/or transport properties of these materials still need to be significantly improved to be suitable for replacing conventional plastic packaging materials. Here we report a class of biorenewable and degradable plastics, based on copolymers of γ-butyrolactone and its ring-fused derivative, with competitive permeability and elongation at break compared to commodity polymers and superior mechanical and transport properties to those of most promising biobased plastics. Importantly, these materials are designed with full chemical recyclability built into their performance with desired mechanical and barrier properties, thus representing a circular economy approach to plastic packaging materials.
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•Assessment of bioplastic degradation during mesophilic treatments at pilot scale.•Bioplastics degraded by 17 % and 30 % total solids after AD and AD plus composting.•Compost showed ...high bioplastic content (18 % TS) and did not meet legal limits.•Starch-based bioplastics degrades faster than polylactic acid polymer in soil.•Bioplastics in soil degrade completely in 8–9 years according to calculated kinetic.
The aim of the study was to assess the effects of high concentrations (10 % w/w, data projected for 2030) of commercial bioplastics, i.e. starch based shopping bags (SBSB) and polylactic acid (PLA) tableware, in the organic fraction of municipal solid wastes (MSW) on compost quality obtained by pilot-scale dry mesophilic anaerobic digestion and subsequent composting of the digestate.
After the biological processes, 48.1 % total solids (TS) of SBSB and 15 % TS of PLA degraded, resulting in a high bioplastics content (about 18 % TS) in compost. Subsequent compost incubation in soils indicated that bioplastics degraded by pseudo-zero order kinetics (0.014 and 0.010 mg C cm−2 d-1 for SBSB and PLA, respectively), i.e. complete degradation was expected in 1.6 years (SBSB) and 7.2 years (PLA), confirming the intrinsic biodegradability of bioplastics. Nevertheless, enhancing the rate and amount of bioplastics degradation during waste management represents a goal to decrease the amount of bioplastics reaching the environment.
Abstract
Native cassava starch was modified by dry heating treatment, and sodic montmorillonite was modified using an alkylpolyglucoside biosurfactant to produce a novel montmorillonite‐filled starch ...bionanocomposites with improved performance. The bionanocomposites were produced in two extrusion steps using a co‐rotating twin‐screw extruder. The structural properties of the bionanocomposites were studied by X‐ray diffraction. The reinforcement effect and material performance were evaluated by hydrophobicity, solubility, opacity, barrier, thermal and mechanical properties. In general, the dispersion of the nanofillers resulted in bionanocomposites with intercalated structures and improved properties compared with unfilled bioplastics. The main results exhibited that modified montmorillonite showed better compatibility with starch, improving nanofiller dispersion and interaction than the native one. As a result, it increased the hydrophobicity and reduced solubility, water, and oxygen permeabilities in comparison with bionanocomposites based on native starch by 36%, 48%, and 68%, respectively. Also, the tensile strength and Young
modulus
increased from 0.60 to 2.56 MPa and from 2.99 to 15.68 MPa, respectively. In conclusion, modification of MMT by the biosurfactant is a good approach to enhance dispersion/interaction with the starch matrix.
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•Pectocellulosic bioplastic was prepared from fruit peel using a “top-down” strategy.•Pectocellulosic bioplastic shows strong mechanical and water resistance properties.•Bioplastic is ...degradable and recyclable, enabling a perfect closed-loop cycle.•This “top-down” strategy for producing bioplastics has strong universality.
Recyclable and biodegradable bioplastics made from biomass resources are urgently needed to combat the massive amount plastic packaging waste generated by the food sector. Herein, a novel “top-down” strategy is demonstrated for obtaining high-performance pectocellulosic bioplastics from fruit processing waste, specifically citrus peels rich in pectin and cellulose. The pectin, cellulose and lignin in citrus peels were separated, then the pectin and cellulose components recombined to form a pectin-cellulose film-forming slurry for casting into films. After the cast films had dried, they were then immersed in a CaCl2 solution to crosslink the pectin chains. The obtained pectocellulosic bioplastic films possessed a dense lamellae structure due to inter/intra-molecular entanglement between the cross-liked pectin and cellulose micro/nanofibers, offering excellent mechanical properties, easy recycling and rapid biodegradation. Additionally, this pectocellulosic bioplastic exhibited excellent water stability, water vapor barrier properties, and antioxidant activity. Importantly, the same protocol was applicable for the manufacture of bioplastics from other pectin- and cellulose-rich biomass raw materials (such as watermelon rind, pineapple rind and cantaloupe rind). From both an ecological and economic viewpoint, this biomass-derived bioplastics synthesized in this work offer potential as substitutes for petrochemical-derived plastics in many fields, especially active food packaging.
Plastic pollution threatens both terrestrial and aquatic ecosystems. As a result of the pressures of replacing oil-based materials and reducing the accumulation of litter in the environment, the use ...of bioplastics is increasing, despite little being known about their accurate biodegradation in natural conditions. Here, we investigated the weight attrition and degradation behavior of four different bioplastic materials compared to conventional oil-based polyethylene during a 1-year in situ incubation in the brackish Baltic Sea and in controlled 1 month biodegradation experiments in the laboratory. Bacterial communities were also investigated to verify whether putative plastic-degrading bacteria are enriched on bioplastics. Poly-l-lactic acid showed no signs of degradation, whereas poly(3-hydroxybutyrate/3-hydroxyvalerate) (PHB/HV), plasticized starch (PR), and cellulose acetate (CA) degraded completely or almost completely during 1-year in situ incubations. In accordance, bacterial taxa potentially capable of using complex carbon substrates and belonging, e.g., to class Gammaproteobacteria were significantly enriched on PHB/HV, PR, and CA. An increase in gammaproteobacterial abundance was also observed in the biodegradation experiments. The results show substantial differences in the persistence and biodegradation rates among bioplastics, thus highlighting the need for carefully selecting materials for applications with risk of becoming marine litter.
This study employs several approaches to enhance environmental sustainability: First, algal biomass (with 52.5% protein content) was converted into value-added products. Second, residual algal ...biomass from protein extraction and pigment extraction and raw algal biomass were used to manufacture bioplastics. Third, radiation shielding performance of bioplastics has been investigated. As an alternative to plastics originated from petroleum-based raw materials, environmentally friendly bioplastics were derived from residual algae biomass after extraction. The gamma-ray radiation shielding properties of the produced bioplastic have been investigated using WinXCOM theoretical calculation and GEANT4 Monte Carlo (MC) simulation. Fast neutron shielding performance of the considered materials also evaluated with help of theoretical calculation and the same MC simulation. The produced bioplastics are similar to ones with commercially available PLA polymer. Sample 1 was found to be better gamma-ray attenuator while Sample 2 has the highest value of the effective neutron removal cross section. Additionally, the boron addition has resulted in lower water absorption capacity in the prepared samples. Using algae to produce more than one product as a raw material source will be an effective step toward sustainable life, and they could be an alternative gamma-ray shielding material to existing commercial polymers.
•Bioplastics were produced from Algal Biomass.•Characterization of the produced bioplastics are performed.•Radiation shielding capacities were evaluated for the first time.•The obtained shielding results are similar to commercial PLA polymer.
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