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The use of biodegradable polymers in the plastics industry has been increasing in recent years. The study of the chemical, physical, thermal, and mechanical properties of films based on biodegradable components is of interest to technologists because these properties determine their applicability for food packaging. In this work, films based on natural polymers such as linseed mucilage (LM) and chitosan (CH), as well as poly(acrylic acid) (PAA) were obtained through the casting method and using V‐50 as the initiator. The films were characterized through Fourier Transform Infrared spectroscopy, and thermogravimetric analysis, and their water absorption and swelling capacity, and thermal and mechanical properties were determined. Homogenous flexible, translucid, amber‐colored films, with low absorption and solubility in water were obtained. It was demonstrated through Fourier Transform Infrared analysis the chemical interaction between C–H, CO, and C–O chemical groups of LM, CH, and PAA. In addition, films showed high resistance to thermal decomposition between 125 and 425°C. The mechanical tests of tension allowed the composition of LM in the film, the behavior variates between a plastic and/or elastic material and with tensile strength (Rm) values between 10.8 and 16.4 MPa and elastic modulus (E) values between 56.2 and 169.2 GPa, we observed that at higher quantities of LM and thickness, both E and Rm tend to increase, while %EL decreases. This led us to conclude that the material transitioned from ductile and malleable to rigid and brittle. The films obtained with different ratios of LM/CH/PAA may exhibit a semi‐interpenetrating polymeric networking type morphology. Highlights: Thermal and mechanical properties are of interest in food packaging materials.Water absorption can impact the packaged food.Films can be processed on existing machines for conventional plastics.Some conventional plastics could be replaced by these biodegradable films.Biodegradable films are of great interest to the industry of food packaging. [ABSTRACT FROM AUTHOR]

Polymer blends based on plastic waste and natural biodegradable polymers is an interesting strategy in view of environmental and technical concerns. This article investigates the structure, thermal and physical properties of virgin and post‐industrial polymethyl methacrylate (PMMA) waste/pristine chitosan (Cs) bio‐blends. Waste PMMA was generated by an extrusion process for the manufacturing of sheets. The results of gel permeation chromatography analysis (GPC) show a slight decrease (about 8%) in the average molecular weight of PMMA after extrusion. Fourier transform infrared spectroscopy in attenuated total reflectance mode (FTIR‐ATR) spectra do not reveal changes in the chemical structure of post‐industrial PMMA/Cs blends compared to virgin PMMA/Cs samples, indicating that chain scission reactions are the dominant degradation mechanism of PMMA during processing. Dynamic mechanical analysis (DMA) results reveal a single glass transition temperature (Tg) for the blends, implying miscibility of the components. Post‐industrial PMMA/Cs samples exhibit slightly lower values of Tg compared to virgin PMMA/Cs blends. The post‐industrial PMMA waste slightly reduces nano‐mechanical properties and thermal stability of the blends relative to those from virgin PMMA. In contrast, it increases the water uptake of the bio‐blends compared with virgin PMMA. Highlights: Chain scission is the dominant degradation mechanism of PMMA during extrusion.Miscibility between the homopolymers within the blends.PMMA waste slightly reduced the nano‐mechanical properties of the bio‐blends.Post‐industrial PMMA waste increased the water uptake of the bio‐blends.Possibility of using post‐industrial PMMA waste by blending with chitosan. [ABSTRACT FROM AUTHOR]

This work aimed to manufacture bioplastics with mechanical and electrical properties for monitoring the Rhizopus stolonifer growth in tomato fruit packaging. Bioplastics were based on chitosan/polyvinyl alcohol (Ch/PVA), chitosan/polyvinyl pyrrolidone (Ch/PVP), and nanoparticles (NPs) of plant extracts at 10% and 30% of concentrations. Bioplastics were exposed to tomato inoculated with R. stolonifer for 6 d at 25°C. Water vapor permeability (WVP), mechanical properties, FTIR, UV–vis, morphology, electrical resistance of bioplastics, and the NPs size were assessed. In bioplastics added with plant extracts, 1.5 times more WVP than in the control group (18–35 gs−1m−1Pa−1) were quantified. Ch/PVA bioplastic showed 51% more tensile strength, 44% more elongation at break, and 40% more Young's modulus than Ch/PVP, regardless of the plant extract. The electrical resistance in Ch/PVA bioplastics with 30% mushroom extract and 10% radish allowed the differentiation between inoculated (109–1010 Ω) and non‐inoculated tomatoes (1010–1011 Ω). The FTIR assay confirmed the presence of each compound used in the bioplastic, and UV–vis confirmed phenols at 300 nm. The NPs measured less than 50 nm. Only Ch/PVA with 30% mushroom and 10% radish can be useful to monitor fungi in tomatoes based on their electrical behavior. [ABSTRACT FROM AUTHOR]

Biodegradable polymers are gaining momentum to resolve the globally acknowledged plastic waste problem. Understanding, characterizing, and developing new generations of biodegradable plastics is crucial to provide industries with alternative green materials that can fully satisfy biodegradation rates and lifetime specifications. This study evaluates the influence of metal pro‐oxidant additives on the degradation properties of various biodegradable polymer systems. For this purpose, iron (III) stearate (FeSt3) and bismuth oxide (Bi2O3), as oxidant agents, were incorporated into poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV), poly(butylene adipate‐co‐terephthalate) (PBAT), cellulose acetate (CA), poly(lactic acid) (PLA), and thermoplastic starch (TPS) bioplastics. The material performances and biodegradability properties due to the additives on the resulting bioplastic formulations were investigated. A mechanism was proposed in which both pro‐oxidant additives can accelerate the thermo‐oxidation processes under composting conditions and cleave the polymer chains into smaller fragments to stimulate the biodegradation rate through microorganisms' activity. The study revealed that both pro‐oxidant additives, FeSt3 and Bi2O3, effectively improved the biodegradation process for all tested polymers except TPS, which already had a very high biodegradation rate. The observed change in the barrier and mechanical properties due to the additives were within tolerable limits of corresponding neat polymers. [ABSTRACT FROM AUTHOR]

Biopolymers have gained popularity as an alternative product to traditional plastics due to environmental concerns. Polyhydroxyalkanoates (PHAs), one of the most well‐known forms of biopolymers, are among the many that have been discovered so far. PHA has a wide range of applications, is biodegradable and compatible with living things, but its expensive extraction and production make it difficult to compete with traditional plastics. Solvents are the most popular extraction technique but have serious economic and environmental downsides. The "green method of extraction" has become a cutting‐edge remedy for addressing the shortcomings of downstream processing. However, developing the extraction technique for affordable and environmentally friendly biopolymer production is a difficult study topic. To make it easier to choose green recovery techniques for future study, this review combines the benefits and drawbacks of the numerous PHA recovery methods that are already in use. Also, advanced green downstream methods are scrutinized that undoubtedly makes PHA replace conventional plastics and reach a market globally promoting sustainability. [ABSTRACT FROM AUTHOR]

Starch is an appealing natural polymer for the scaled‐up production of biodegradable plastics. However, the low water resistance of starch has made its broad applicability largely doubted. In this study, starch was combined with beeswax (BW) through a pilot scale continuous solution casting (CSC) technique to reduce water affinity while keeping the ensuing films totally biodegradable. The phase morphology, surface wettability, and water vapor permeability (WVP) of films were examined over a broad BW–starch mass ratio (0.3–0.7). Emulsified, surfactant‐free starch/BW films were successfully obtained at a productivity of 0.55 m2 film h−1. The water contact angle increased nearly by 100% at 30 wt% BW, leading to remarkable reductions in WVP. BW droplets well distributed within the starch matrix played a key role in enhancing the water barrier properties of films. CSC of starch/BW films offers a basis to design new hydrophobic formulations for applications that require biodegradable plastics with high moisture resistance. [ABSTRACT FROM AUTHOR]

Plastics have been produced for over a century, but definitive evidence of complete plastic biodegradation in different habitats, particularly freshwater ecosystems, is still missing. Using 13C‐labelled polyethylene microplastics (PE‐MP) and stable isotope analysis of produced gas and microbial membrane lipids, we determined the biodegradation rate and fate of carbon in PE‐MP in different freshwater types. The biodegradation rate in the humic‐lake waters was much higher (0.45% ± 0.21% per year) than in the clear‐lake waters (0.07% ± 0.06% per year) or the artificial freshwater medium (0.02% ± 0.02% per year). Complete biodegradation of PE‐MP was calculated to last 100–200 years in humic‐lake waters, 300–4000 years in clear‐lake waters, and 2000–20,000 years in the artificial freshwater medium. The concentration of 18:1ω7, characteristic phospholipid fatty acid in Alpha‐ and Gammaproteobacteria, was a predictor of faster biodegradation of PE. Uncultured Acetobacteraceae and Comamonadaceae among Alpha‐ and Gammaproteobacteria, respectively, were major bacteria related to the biodegradation of PE‐MP. Overall, it appears that microorganisms in humic lakes with naturally occurring refractory polymers are more adept at decomposing PE than those in other waters. [ABSTRACT FROM AUTHOR]

Plastics have benefited our lives in many ways, but their long persistence in the environment causes serious problems. Rapid decomposition and detoxification of plastics after use are significant challenges. As a possible solution, biodegradable plastics have attracted attention, and for environmental risk assessment research on polymer toxicity, use of indicator organisms, like water fleas and fish, has increased globally. However, such research often focuses on standardized substances without considering changes in toxicity due to plastic degradation products. Additionally, tests generally focus on acute toxicity, while long‐term effects on organismal reproduction and lifespan are largely unknown. Understanding the impact of degraded polymers on biological activities is crucial for accurate risk assessment. In this study, we investigated the biological toxicity of substances generated during degradation of polycaprolactone (PCL), a common biodegradable plastic, using the indicator organism, Daphnia magna. We examined PCL, oligocaprolactones (OCLs), and monomers resulting from polymer cleavage, as well as carbodiimides, added during polyester synthesis. As a result, PCL, which is insoluble in water, reduced individual survival and total number of offspring at an exposure concentration of 100 mg/L, while no toxicity was observed for water‐soluble degradation products, OCLs, and monomers. Furthermore, carbodiimides, which are expected to be released during PCL degradation, showed strong toxicity, significantly reducing individual survival and total number of offspring at 0.1–10 mg/L. These findings suggest that changes in physical properties due to polymer degradation and release of additives can significantly alter their toxicity. Plastics cause serious environmental problems due to their persistence, prompting research on biodegradable alternatives. This study investigated toxicity of substances generated during degradation of polycaprolactone (PCL), using Daphnia magna. PCL reduced survival and numbers of offspring at 100 mg/L, whereas water‐soluble degradation products showed no toxicity. Carbodiimides, expected to be released during PCL degradation, exhibited strong toxicity. These results highlight the importance of considering changes in toxicity due to polymer degradation and additive release. [ABSTRACT FROM AUTHOR]

Polyhydroxybutyrates (PHBs) are produced by microorganisms. PHBs are chosen as biodegradable plastic alternatives due to their rapid degradability under natural circumstances. In this study, the isolation and identification of PHB‐producing organisms by Sudan black, fermentation, solvent extraction, and characterization of purified PHB are all discussed in detail. Serratia sp. was employed to produce PHB biopolymer from lignocellulose waste coconut coir and a response surface software tool was used to optimize it. PHB characterization, FTIR (1730 cm−1 C = O stretch), TGA (268.53°C), and DTA (276.67°C) results. Sudan Black B stain was employed for the pre‐screening of these vital bacteria that produced intracellular granules of PHB. The best optimized parameters are used during the fermentation process, including 20 g/L coconut coir hydrolysate, pH 7, 30°C temperature, 1.5 g/L peptone, and 48 h. The optimization of the response surface methodology yields a high biomass output of 9.34 g/L, PHB yield of 5.48 g/L, and dry cell weight of 58.67%. The ANOVA findings, F and R2 value of biomass (10.04 and 0.9036) and PHB (23.33 and 0.9561). The results show that employing coconut coir as a feedstock allows for the enhanced production of PHB. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) is one of the most commonly used bioplastics thanks to its mechanical performance and low environmental impact. Strategies to overcome excessive rigidity of PLA are constantly investigated. Poor viscoelastic behavior and brittleness of PLA seriously limit its potential application as a common film material. Herein highly amorphous Poly(3-hydroxybutyrate-4-hydroxybutyrate) (P(3HB)(4HB)) was introduced to improve toughness and reduce brittleness of PLA. Anti-blocking (silica) and anti-slipping agent (Ethylene bis-stearamide (EBS)) were added to improve the processability of the blends, specifically to solve winding issues of the blown film and unfolding of the layflat. In this study three formulations containing PLA and different ratios of P(3HB)(4HB), specifically 10-20-30% were extruded. The mechanical, thermal and surface characterization of the films was performed. The tensile and the tear strength test results show that P(3HB)(4HB) increased the ductility of PLA based films. Increasing amounts of P(3HB)(4HB) provide a toughening effect on PLA/P(3HB)(4HB) blown films without altering transparency of PLA. Moreover, the processing additives proved to be efficient in improving film blowing stability and avoiding tackiness during the winding phase of the film. [ABSTRACT FROM AUTHOR]

Byproducts of the processing of foods are usually non‐edible residues that are typically discarded, even though they contain large amounts of natural polymers with great potential in bioplastics and biocomposites preparation. Herein, a new method of production of vegetable‐waste‐derived biocomposites is developed. It consists of the thermomechanical processing of different residues in the presence of small amounts of water, representing an advancement in the state‐of‐the‐art in the complete conversion of fruit and vegetable biomass into biocomposites. In particular, carrot pomace (CP) is processed by compression molding at different temperatures, pressures, and times. Selected processing conditions are also applied to other food processing byproducts. The morphological, mechanical, barrier, optical, and antioxidant properties of the obtained biocomposites and their interaction with water in terms of moisture content, water solubility, and moisture absorption are reported here. Results indicate that biocomposites obtained by this method present similar properties compared to biocomposites prepared by acid or alkaline hydrolysis of biomass reported in the literature, but still inferior compared to bioplastics currently in the market. Improvements in the materials' interaction with water are highlighted here as the necessary next step to achieving the transition toward greener bioplastics. [ABSTRACT FROM AUTHOR]

Aerial robots can autonomously collect temporal and spatial high‐resolution environmental data. This data can be utilized to develop mathematical ecology models to understand the impact of climate change on the habitat. In case of drone malfunction, the incorporated materials can threaten vulnerable environments. The recent introduction of transient robotics enables the development of biodegradable, environmental‐sensing drones capable of degrading in their environment. However, manufacturing methods for environmental‐sensing transient drones are rarely discussed. Herein, a manufacturing framework and material selection process featuring biopolymer‐based, high‐strength composite cryogels, and printed carbon‐based electronics for transient drones are highlighted. It is found that gelatin‐ and cellulose‐based cryogels mechanically outperform other biopolymer composites while having a homogeneous microstructure and high stiffness‐to‐weight ratio. The selected materials are used to manufacture a flying‐wing air‐frame, while the incorporated sensing skin is capable of measuring the elevons' deflection angles as well as ambient temperature. It is demonstrated in the results how gelatin–cellulose cryogels can be used to manufacture lightweight transient drones, while printing carbon‐conductive electronics is a viable method for designing sustainable, integrated sensors. The proposed methods can be used to guide the development of lightweight and rapidly degrading robots, featuring eco‐friendly sensing capabilities. An interactive preprint version of the article can be found here: https://doi.org/10.22541/au.167506513.33779420/v1. [ABSTRACT FROM AUTHOR]

Cellulose is the most abundant plant based biopolymer on earth which provides excellent properties to polymer nanocomposites such as high mechanical properties, high strength, low thermal expansion properties, low density, and biodegradability. The recent demand in materials research is to develop smart materials which comprise excellent features such as enhanced mechanical properties and thermal stability, biodegradability, being eco‐friendly, and low‐cost. Therefore, the objective of this research is to extract cellulose fibers from agricultural waste, i.e., peanut shell as an abundant source of agricultural byproducts and explore the potentiality of polyvinyl alcohol (PVA)/polyvinyl pyrrolidone (PVP)/cellulose blends as an alternative of conventional plastics. The blend which has higher concentration of cellulose shows the higher acid absorption. FT‐IR of PVA/PVP/cellulose confirms the good interaction between the constituents of the blend. Antimicrobial activities of cellulose and their blend with polymer are evaluated and found maximum against Gram negative bacteria (Escherichia coli) than the Gram positive bacteria (Bacillus subtilis). Degradation behavior of blend is found directly proportional to cellulose content, i.e., highest shown by 20% cellulose film. Hence, PVP/PVA/cellulose blends show desired degradable properties and hence can be an alternative for use of conventional plastics. [ABSTRACT FROM AUTHOR]

Even though the use of petroleum products is quite prevalent but their non‐biodegradability is a great cause of concern. In recent decades, stupendous research in the field of bio‐degradable material has been carried out from which biodegradable polymers or biopolymers are come out as a popular substitute for petroleum‐based plastics. However, these biopolymers possess average mechanical properties, so they need to be reinforced with some stuff that is bio‐degradable such that their addition maintains their bio‐degradability and enhances the mechanical properties. Even though the reinforcement of natural fiber improves the physical and mechanical properties however various modifications in the fiber it needs to be done to improve the fiber–matrix bonding so as to increase its competence against non‐biodegradable products such as petrochemical‐based polymer composite. Also, it has been reported that various type of fiber has been reinforced simultaneously in a single matrix to produce a superior hybrid bio‐degradable composite. The various studies have been focused on the characterization and processing of bio‐based materials, as well as their synergistic application and future potential as biopolymer composites in the aerospace and automotive industries. [ABSTRACT FROM AUTHOR]

Lately, environmentally benign packaging materials with biodegradability, flexibility, and high barrier properties are sought after as a substitute for conventional plastic packaging materials due to increasing plastic pollution and microplastics in the environment. Although natural polymers can be sustainable alternatives to petro‐sourced, non‐biodegradable plastics, they suffer from the poor barrier and mechanical properties. In this study, a mechanically stable, biodegradable film of tree gum kondagogu with remarkable barrier properties is fabricated. The introduction of spray‐coated, waterborne, large‐aspect ratio sodium‐hectorite dispersion on tree‐gum films ensured very high barrier properties even at high relative humidity conditions (oxygen transmission rate (OTR) ≈1.7 cm3 m−2 day−1 bar−1 at 75% relative humidity). The coating not only decreases gas permeability through the films but also minimizes the sensitivity of performance to humidity levels. The clay‐coated nanocomposite films outperformed various commercial polymers and are comparable to high‐performance packaging films in terms of oxygen barrier properties. Further, the coating improved the mechanical properties of the films rendering them a prospective packaging material. These biodegradable, high‐barrier and mechanically robust films are a promising advance in the field of sustainable packaging. [ABSTRACT FROM AUTHOR]

Due to the growing environmental threat associated with the accumulation of plastic waste, the development of biodegradable polymers based on low‐density polyethylene with the addition of natural fillers is of great importance. At the same time, the experimental studies of such materials require a huge amount of time: the production cycle from the development of a new formulation of a biopolymer to market launch can take up to 36 months. To reduce this time, a new approach based on mathematical modeling is proposed. Verification of this approach is carried out using the example of low‐density polyethylene composites with natural rubber filler. The high accuracy of the proposed mathematical models for predicting the properties of biodegradable polymers is shown. [ABSTRACT FROM AUTHOR]

In order to reduce the threat of 'plastic pollution' and reduce or eliminate some traditional polymer packaging materials, in this study, soybean protein isolate (SPI) composite film, a biodegradable natural polymer film, was prepared by tape casting method with Thyme (Thy) and mangosteen peel extracts (MPE) as antibacterial agents. The antibacterial rates of the composite films against E. coli and S. aureus were 95.79% and 92.63%, respectively, and the DPPH free radical scavenging rate was 70.28%. The composite film had good UV–visible barrier properties. Compared with the pure SPI film, the tensile strength of the composite film was improved, the water absorption, water solubility, and water vapor permeability were reduced, and the contact angle was improved. The maximum thermal decomposition temperature of the composite film increased and the thermal stability increased. Fourier Transform Infrared Spectroscopy (FTIR) studies showed the polyphenol‐protein of the composite film was bound by hydrophobic interaction. X‐ray Photoelectron Spectroscopy (XPS) showed good interaction with the protein structure by adding antibacterial substances and their aromatic quinone structures. X‐ray Diffraction (XRD) studies showed that the crystallinity of the composite films increased. Therefore, the composite membrane in this study can be used to prepare high‐strength packaging materials with antibacterial functions. [ABSTRACT FROM AUTHOR]

Biocomposites with inherent advantages such as biodegradable, recyclable, readily available, lower cost, and lower carbon footprint conveniently replace synthetic plastics. Despite being environmentally friendly, biocomposites should be functionally stable and structural in a rigorous environment. Thus, a study of biopolymer composites with exposure to various aging conditions, especially of humidity environment, which is of necessary concern, is considered here in this review. The aging experiments are often conducted at an accelerated rate at a specific time in respective environments to reduce the experimental time called accelerated aging. The vibration behavior of the biocomposites was conducted to determine the damping behavior of the composites is described in detail. [ABSTRACT FROM AUTHOR]

Droplet microfluidics offers precise and simultaneous control of multiple fluids at microscale, which enables synthesis of novel microparticles with compositional and structural diversity in a controllable way. The morphology and functionality of generated microparticles can be well designed by modulating the hydrodynamic profile as well as geometric structures. The synergistic combination of droplet microfluidics with biodegradable materials makes it possible to encapsulate actives/drugs inside microparticles at high efficiency for drug delivery. The utilization of these microfluidic‐generated microparticles with the characteristics of easy biodegradability and good biocompatibility in the field of drug delivery has made considerable progress in recent years. In this review, the commonly used structures of microchannel and methods to generate microparticles with droplet microfluidics are introduced. In addition, recent advances of biodegradable microparticles in the application of drug delivery are discussed and summarized with the focus on two kinds of biopolymers for preparing biodegradable microspheres, natural biopolymers, and synthetic biopolymers. Next, environment‐sensing microencapsulation systems have been discussed because of their ability to release drug upon external stimulation, thereby allowing on‐demand drug delivery. Finally, current challenges of utilizing microparticles in drug delivery are pointed out and some perspectives for the future direction in research and applications are provided. [ABSTRACT FROM AUTHOR]

For many decades, global efforts have been attempted to replace the petrochemical plastics with biodegradable and environment friendly plastics. The petrochemical plastics that require many years to decompose have profound consequences on the environment. A natural, biodegradable, and plastic‐like polymer, polyhydroxyalkanoate (PHA), has been extracted from and synthesized by microbes, particularly bacteria. However, the prospective large‐scale production of PHA faced an economic bottleneck for less production costs. Research has thus shifted to one of the most common alternatives, which is the utilization of less costly raw materials or carbon sources that include industrial by‐products and wastes, such as glycerine pitch and glycerol. This review elucidates the discovery, basic mechanisms, and applications of PHA, as well as provides insights regarding the importance of PHA conversion from glycerine pitch and glycerol. This review also summarizes some possible future modifications to improve the efficiency of glycerine pitch and glycerol as carbon sources in PHA production. The conversion endeavors of wastes to a valuable product, PHA, that not only reduces petrochemical plastic pollution, waste generation, and PHA production costs but also supports economic and resource sustainability, which ultimately further progress towards the cradle‐to‐cradle design and circular bioeconomy concept. [ABSTRACT FROM AUTHOR]

Polyhydroxybutyrate (PHB) is a sought‐after alternative biopolymer to synthetics with its high biodegradability and similar properties to available polymers. However, its high production cost narrows its market application. In this study, cheap, biocompatible, and widely available fillers such as cellulose (CL) and calcium carbonate (CC) were incorporated into PHB using a heat‐assisted solution casting method to reduce the manufacturing cost of the bioplastic while retaining its properties. Characterization tests found that both natural fillers have relatively low miscibility with PHB which may be accounted for by self‐ and co‐agglomeration of the fillers while having improved thermal stability. The Young's modulus of the bioplastic films increased with the introduction of CC, while the mechanical property slightly decreased upon the addition of CL attributing to the aggregation of fillers. Full biodegradation of all composites within 8 weeks was observed in the compost biodegradability tests; PHB 90 CC 10 biodegraded the slowest after the 50th day, while PHB 90 CL 10 fully disintegrated after the 30th day. Further improvements such as the incorporation of cheap, naturally derived crosslinkers or plasticizers can greatly improve the properties of the synthesized biocomposites. [ABSTRACT FROM AUTHOR]

The continuous delivery of E‐waste from petroleum‐based products creates ecological and environmental problems due to non‐biodegradable polymers, which release harmful chemicals and toxic gases. This results in biodegradable polymers/fibers appearance, which are biocompatible and degrade in the surrounding environments without causing any environmental pollution and these relieve environmental burden. However, the bio‐based materials are unable to meet certain properties in the way of flexibility, dielectric properties, electrical properties, water and gas vapor barrier properties. The current day's research focus is towards the implementation of biodegradable composites properties by introducing different nanostructures. The biopolymers/biofibers are used as raw material in concern with environmental aspects. Nowadays researchers are supplementing a new form of materials known as nanofillers in various biopolymer‐based composites in a small amount. This nanofillers will act as additives and helps in enhancing the different properties such as mechanical, thermal, flame retardancy and water absorption behavior of the nano composite materials as well as maintaining the optimum density of them. The nanocomposites applications are extended in various sectors for the reason of higher surface area, aspect ratio, and superior properties. This review outlines the types of biofibers/biopolymers and their characterization, types of nanofillers, and their characterization, and summarizes the various functional properties of nanocomposites with their applications. [ABSTRACT FROM AUTHOR]

Recently, polymer science and engineering research has shifted toward the development of environmentally benign polymers to reduce the impact of plastic leakage on the ecosystems. Stringent regulations and concerns regarding conventional polymers are the main driving forces for the development of renewable, biodegradable, sustainable, and environmentally benign materials. Although biopolymers can alleviate plastic‐related pollution, several factors dictate the utilization of biopolymers. Herein, an overview of the potential and limitations of synthetic biopolymers and their composites in the context of environmentally benign materials for a sustainable future are presented. The synthetic biopolymer market, technical advancements for different applications, lifecycle analysis, and biodegradability are covered. The current trends, challenges, and opportunities for bioplastic recycling are also discussed. In summary, this review is expected to provide guidelines for future development related to synthetic biopolymer‐based sustainable polymeric materials suitable for various applications. [ABSTRACT FROM AUTHOR]

The application of petroleum polymers and plastics in food packaging is exhibiting an increasing trend, due to low price and desirable characteristics. Nevertheless, these polymers are nonbiodegradable, nonrenewable, and require landfills. Edible polymers are suitable alternative for synthetic polymers, which can be consumed by animals or human beings without health risk. Edible packaging can protect the foodstuff from microbial and chemical deterioration during storage and distribution, which can lead to extend the quality and safety of packaged food. The plant gums as natural polymers are able to form films and coatings with good barrier properties against the transfer of gases such as oxygen, carbon dioxide, and moisture. This review summarized the production and characteristics of novel edible films and coatings based on plant gums such as tree exudate, seed, and tubers. [ABSTRACT FROM AUTHOR]

BACKGROUND: The meat industry is determined to find biodegradable packaging with properties similar to plastic. Furcellaran (FUR) and whey protein isolate (WPI) were used as a film matrix in which Borago officinalis extract (BOE) was incorporated as an antioxidant compound. The film's mechanical properties, water behavior, surface color, and antioxidant power were analyzed.Smoked hams were manufactured using two different types of film application: cured meat covered with film, smoked and cooked or hamsafter smoking, cooking and cooling. Smoked, vacuum packed ham was used as a control sample. The products were stored at 4 °C for 21 days and analyzed every 7 days. RESULTS: The elongation at break (EAB) and tensile strength (TS) of FUR/WPI films without the extract were 6.30% and 20.59 MPa, respectively, and after incorporating BOE, the EAB and TS were 24.30% and 15.33 MPa, respectively. The films with BOE were darker and had greater antioxidant capacity. The water content and activity in the products with films decreased along with storage time while the control remained stable. The results of microbiological, oxidation product accumulation, and sensory analysis were comparable in all the products. CONCLUSIONS: The smoking time can be reduced due to the dark color of the hams covered with BOE film. The barrier properties of those films should be increased. Other parameters were comparable to plastic packaging. The films therefore have the potential to be used instead of plastic packaging in the meat industry. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The global accumulation of single‐use plastic bags made from nonbiodegradable plastics is the most concerning environmental issue nowadays. The utilization of biodegradable materials is a choice to reduce the environmental impact resulting from the use of plastic products. The utilization of renewable resources to produce fully biodegradable plastics is among the technologies used to overcome petroleum plastic's negative impact. On the other hand, the utilization of oxo‐biodegradable plastics where prodegradant additives are incorporated in conventional plastics to promote their degradation under certain conditions has recently received much attention. This review discusses the types and challenges that face the implementation of biodegradable plastics technology that uses renewable resources. This review also covers the debate addressed in the literature about the biodegradability fate of oxo‐biodegradable plastic in the air, compost, soil, landfill, and marine. A comparative study included the potential published literature in the last 10 years was performed. Based on the discussed evidence in this review, it can be concluded that all literature agrees that the addition of pro‐oxidant/prodegradants can accelerate the degradation of oxo‐plastics to small fragments. However, the complete biodegradation of oxo‐plastics by microorganisms remains in doubt. On the other hand, biopolymers produced from natural resources seem to be the future direction for plastics manufacturing especially single‐use plastic bags. [ABSTRACT FROM AUTHOR]

Building new value chains, through the valorization of biomass components for the development of innovative bio‐based products (BBPs) aimed at specific market sectors, will accelerate the transition from traditional production technologies to the concept of biorefineries. Recent studies aimed at mapping the most relevant innovations undergoing in the field of BBPs (Fabbri et al. 2019, Final Report of the Task 3 BIOSPRI Tender Study on Support to R&I Policy in the Area of Bio‐based Products and Services, delivered to the European Commission (DG RTD)), clearly showed the dominant position played by the plastics sector, in which new materials and innovative technical solutions based on renewable resources, concretely contribute to the achievement of relevant global sustainability goals. New sustainable solutions for the plastic sector, either bio‐based or bio‐based and biodegradable, have been intensely investigated in recent years. The global bioplastics and biopolymers market size is expected to grow from USD 10.5 billion in 2020 to USD 27.9 billion by 2025 (Markets and Markets, 2020, Bioplastics & Biopolymers Market by Type (Non‐Biodegradable/Bio‐Based, Biodegradable), End‐Use Industry (Packaging, Consumer Goods, Automotive & Transportation, Textiles, Agriculture & Horticulture), Region ‐ Global Forecast to 2025), and this high growth is driven primarily by the growth of the global packaging end‐use industry. Such relevant opportunities are the outcomes of intensive scientific and technological research devoted to the development of new materials with selected technical features, which can represent feasible substitutes for the fossil‐based plastic materials currently used in the packaging sectors and other main fields. This article offers a map of the latest developments connected to the plastic sector, achieved through the application of biotechnological routes for the preparation of completely new polymeric structures, or drop‐in substitutes derived from renewable resources, and it describes the specific role played by biotechnology in promoting and making this transition faster. [ABSTRACT FROM AUTHOR]

Such resort to water as a polymer solvent and the increased use of oligosaccharides in polymeric applications will be an impetus to tackling the environmental friendliness, green manufacturing, and sustainability of more traditional polymers. In Alessandro Gandini and Talita M. Lacerda's article (2100902), furan-based polymers are critically reviewed as furan offers a versatile platform for producing various polymers from non-fossil sources and ecological benign processes. Self-healing polymers with dynamic bonds are attractive materials, which may also facilitate the recycling of thermosetting polymers SP [ sp 7 SP ] sp and rubbers. SP [ sp 8 SP ] sp However, many self-healing polymers still show inferior properties compared to their non-self-healing counterparts, which needs to be addressed. [Extracted from the article]

Integration of light management solutions relying on biodegradable materials in organic light‐emitting devices could assist the development of sustainable light sources or conformable and wearable display technology. Using industrially relevant processing techniques, it is shown that microlens arrays can be seamlessly integrated into flexible and biodegradable cellulose diacetate substrates to facilitate extraction of the trapped substrate modes in light‐emitting electrochemical cells. The substrates are patterned for light extraction and optimized for scalable printing processes in a single step by thermally embossing microlenses with polydimethylsiloxane molds on one substrate surface and simultaneous flattening of the other. Furthermore, by implementing the biopolymer substrate with microlens arrays, the total volume fraction of biodegradable materials in the microlense equipped device is 99.94%. The embossed microstructures on the biopolymer substrates are investigated by means of scanning electron microscopy and the angular light extraction profile of the devices is measured and compared to ray tracing simulations. Light‐emitting electrochemical cells with integrated microlens array substrates achieve an efficiency enhancement factor of 1.45, exceeding conventional organic light‐emitting diodes on glass substrates with laminated microlens arrays (enhancement factor of 1.23). [ABSTRACT FROM AUTHOR]

Conductive soy protein biocomposite plastics with high performance were fabricated with glycerol as plasticizer and nanosized carbon black (CB) as conductive filler. Adopting a pretreatment of the CB nanofiller, its dispersion, and interaction with matrix was improved. The results indicated the existence of strong hydrogen bonding between soy protein matrix and CB fillers, which improved the interfacial bonding. The strong interactions between CB and protein restricted the mobility of protein segments, resulting in a dramatical reinforcing effect for the CB filled composites and enhanced mechanical properties. Besides, the incorporation of CB into soy protein increased the thermal stability as well as the water resistance of the composites. Moreover, a low percolation threshold of 0.76 vol% and fine electrical conductivity were obtained for the bionanocomposites, resulting in improved electromagnetic interference shielding properties. This work provides a simple and green way for the preparation of conductive and electromagnetic interference shielding materials from natural polymers. [ABSTRACT FROM AUTHOR]

The article focuses on search for plastics capable of decomposing naturally in the environment has been ongoing since the 1970s and undesirable mechanical properties have stymied progress. Topics icnlude the views of Paul Mines, chief executive officer of Biome Technologies, on the Great Britain manufacturer of biodegradable natural polymers, the main reasons for this lag in the market being cost, and the problem is especially pronounced for single-use plastics has used for food packaging.

Research on starch‐based biopolymers has increased because of their potential as environmentally friendly biodegradable substitutes to typical plastics. This study investigates the effect of rye flour as a main reinforcement agent as well as cellulose and citric acid in biocomposite starches on improving their water vapor permeability (WPF) and mechanical properties. The optimum point of the starch biocomposites obtained by Design of Experiments software 7.1.5 is run with 10% cellulose,and 10% rye flour with a WPF value equal to 8.7E‐10 g s−1 m−1 Pa−1, water uptake (WU) of 3.42%, and good mechanical properties. Validation of the optimum point does not show significant difference between the predicted and the actual values. There is some strong hydrogen and physical bonding in the optimized starch biocomposite that changes the intensity of the absorption bands and improves the mechanical properties. [ABSTRACT FROM AUTHOR]

ABSTRACT: Keratin without plasticizer produces fragile films. 1,8‐Octanediol (OD) was used as a plasticizer to modify keratin films in this study. Two keratins with different structures were extracted from duck feather, including reduced keratin (RK) and native keratin (NK). Formaldehyde was used as the crosslinking agent for RK to prepare crosslinked keratin (CK) films. The addition of OD toughened the CK and RK films. In particular, the plasticized CK films demonstrated good mechanical properties and had satisfactory water resistance. The water vapor permeability varied between 0.106 and 0.808 g/(m s Pa) for CK films without OD and with 0.30 g OD/g keratin, respectively, and the tensile strength decreased from 12.1 to 8.0 MPa and the elongation at break increased from 2.3% to 11.6%. Cell culture experiments suggest that OD‐plasticized NK films are biocompatible. In general, OD‐plasticized keratin films can find applications in food packaging and biomedical materials. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46516. [ABSTRACT FROM AUTHOR]

ABSTRACT: Non‐isocyanate polyurethanes (NIPU) have rapidly emerged as a sustainable, less toxic, and environmentally friendly alternative to traditional isocyanate‐based thermoplastic polyurethane (TPU) synthesis. TPU is widely used in the medical industry due to its excellent mechanical properties and elasticity. However, little work has been done to synthesize and electrospin NIPU into fibrous mats for biomedical applications. In this work, melt polymerization of a plant oil‐based cyclic carbonate monomer with polyether soft segments and various diamines yielded isocyanate‐free, segmented poly(amide hydroxyurethane)s (PAHUs). Electrospinning of segmented PAHUs afforded ductile, free‐standing fibrous mats with Young's modulus values between 7 and 8 MPa, suitable for tissue scaffold applications. PAHU fiber mats exhibited 3–4 times greater water uptake than the electrospun TPU control, demonstrating potential utility in drug delivery. Fibroblasts adhered to electrospun PAHU fibrous mats with viability values over 90% after 72‐h, validating its biocompatibility. The results highlight the high performance and potential of electrospun isocyanate‐free polyurethanes mats for biomedical application. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46464. [ABSTRACT FROM AUTHOR]

Abstract: Functional bionanocomposites are developed from the assembly of naturally occurring polymers and inorganic solids that show at least one dimension at the nanoscale. Our research group focused on the development of bionanocomposites based on clay minerals, including smectites and fibrous silicates, as well as layered double hydroxides. The resulting materials show interesting properties regarding biocompatibility and biodegradability, together with improved mechanical and thermal properties in comparison to the pristine biopolymer. Besides these characteristics, they offer also other interesting functional properties that allow their potential use in a wide range of applications, including sensors, drug delivery and other health care applications, bioplastics and environmental remediation. For these materials, nature provides not only the components but also the inspiration to develop new combinations that may give rise to nanostructured biomaterials with exceptional features. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, the effects of the monotherpenic phenol concentration on the properties of biocomposites containing plasticized poly(lactic acid) (PLA) with acetyl tributyl citrate (ATBC) were investigated. The monotherpenic phenols carvacrol (C) and thymol (T) were added to PLA by a melt-blending method. The prepared samples were characterized by means of tensile testing, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy (SEM), and antibacterial activity tests. The addition of ATBC to PLA resulted in hydrogen bonding between ATBC and PLA. We observed that ATBC, C, and T reduced the glass-transition temperature of PLA. The presence of C and T decreased the maximum degradation temperature slightly. Because of the plasticization effect of the additives, the tensile strength and Young's modulus of PLA decreased, whereas the extent of elongation they experienced before failure increased. This effect was also observed with SEM analysis in terms of plastic deformation at break. The antibacterial activity tests showed that samples containing high concentrations of C demonstrated an improved antibacterial activity against Staphylococcus aureus, Salmonella typhimurium, and Listeria monocytogenes bacteria. We observed that C exhibited a higher inhibition against bacterial strains than T. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45895. [ABSTRACT FROM AUTHOR]

ABSTRACT Miscanthus fibers reinforced biodegradable poly(butylene adipate- co-terephthalate) (PBAT) matrix-based biocomposites were produced by melt processing. The performances of the produced PBAT/miscanthus composites were evaluated by means of mechanical, thermal, and morphological analysis. Compared to neat PBAT, the flexural strength, flexural modulus, storage modulus, and tensile modulus were increased after the addition of miscanthus fibers into the PBAT matrix. These improvements were attributed to the strong reinforcing effect of miscanthus fibers. The polarity difference between the PBAT matrix and the miscanthus fibers leads to weak interaction between the phases in the resulting composites. This weak interaction was evidenced in the impact strength and tensile strength of the uncompatibilized PBAT composites. Therefore, maleic anhydride (MAH)-grafted PBAT was prepared as compatibilizer by melt free radical grafting reaction. The MAH grafting on the PBAT was confirmed by Fourier transform infrared spectroscopy. The interfacial bonding between the miscanthus fibers and PBAT was improved with the addition of 5 wt % of MAH-grafted PBAT (MAH- g-PBAT) compatibilizer. The improved interaction between the PBAT and the miscanthus fiber was corroborated with mechanical and morphological properties. The compatibilized PBAT composite with 40 wt % miscanthus fibers exhibited an average heat deflection temperature of 81 °C, notched Izod impact strength of 184 J/m, tensile strength of 19.4 MPa, and flexural strength of 22 MPa. From the scanning electron microscopy analysis, better interaction between the components can be observed in the compatibilized composites, which contribute to enhanced mechanical properties. Overall, the addition of miscanthus fibers into a PBAT matrix showed a significant benefit in terms of economic competitiveness and functional performances. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45448. [ABSTRACT FROM AUTHOR]

ABSTRACT Bottles and other packaging account for approximately 70% of the global market of biopolymers, which include both biodegradable and durable materials. Durable materials account for the vast majority of the market, especially the bottles. Degradable polymers are instead refrained by the often-insufficient mechanical and thermal properties, which limit their usage to single-use packaging items at ambient temperature and in dry conditions. In this respect, the present work deals with the development and manufacturing of innovative and custom-built Poly Lactic Acids (PLAs) for injection and compression molding, which are designed to be compostable, suitable for food contact and characterized by a good compromise of mechanical properties and thermal stability. A commercial grade PLA was, therefore, compounded in a twin-screw co-rotating extruder by the addition of maleated and glycidyl methacrylate PLAs as chain extenders and micro-lamellar talc as mineral filler and nucleation promoter. Compatibilization between PLA, chain extenders and mineral filler was, therefore, investigated. Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR) were performed to evaluate the material structure and thermal response of the pellets after reactive compounding extrusion. The experimental findings show that material structure and, especially, crystallization of the PLA can be controlled by fine-tuning the compound formulation as well as by setting of the operational parameters. In addition, achievement of the appropriate crystallization degree in the polymer is found to lead to composite materials, which can boast very good thermal stability. Accordingly, the custom-built PLA formulations feature the potential to expand significantly the fields of application of non-durable polymers, thus posing a valid alternative to both durable biopolymers and conventional plastics in injection and compression molding process. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44504. [ABSTRACT FROM AUTHOR]

ABSTRACT The purpose of this work was to add economic value to crambe meal, the protein-rich byproduct from the industrial extraction of Crambe abyssinica seed oil, by using it as a potential feedstock for oilseed meal-based plastics. The feasibility to produce continuous, flexible plastic films of glycerol-plasticized crambe meal blended with wheat gluten (WG) to improve extrudate properties and urea as a protein denaturant using extrusion was investigated. The effect of process parameters and blend composition were studied with regard to the extrusion performance and the film properties. Tensile properties and oxygen permeability were determined, and the film morphology was analyzed with scanning electron microscopy. A die temperature between 125 and 130°C resulted in films with the most homogeneous surfaces and highest tensile strength and extensibility. The use of compression molding after extrusion improved the surface quality and film strength and lowered the oxygen permeability. A decrease in the plasticizer content (from 30 to 20 wt %) improved the extrudability and showed the highest tensile strength, whereas the extensibility was essentially unaffected. The importance of the presence of WG was shown by the fact that strength and extensibility decreased when the crambe content was increased from 60 to 80 wt %. It was shown that crambe-based biopolymer blends could be extruded as continuous flexible plastic films that exhibited promising mechanical and oxygen barrier properties. The operational window was, however, found to be narrow. The results provide a first basis to further develop the process and the blend toward industrial applications, for example, as packaging materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42442. [ABSTRACT FROM AUTHOR]

ABSTRACT One of the most significant limitations to widespread industrial implementation of emerging bioplastics such as poly(lactic acid) and poly(hydroxyalkanoate) (PHA) is that they do not match the flexibility and impact resistance of petroleum-based plastics like poly(propylene) or high-density poly(ethylene). The basic goal of this research is to identify alternative, affordable, sustainable, biodegradable materials that can replace petroleum-based polymers in a wide range of industrial applications, with an emphasis on providing a solution for increasing the flexibility of PHA to a level that makes it a superior material for bioplastic nursery-crop containers. A series of bio-based PHA/poly(amide) (PA) blends with different concentrations were mechanically melt processed using a twin-screw extruder and evaluated for physical characteristics. The effects of blending on viscoelastic properties were investigated using small-amplitude oscillatory shear flow experiments to model the physical character as a function of blend composition and angular frequency. The mechanical, thermal, and morphological properties of the blends were investigated using dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and tensile tests. The complex viscosity of the blends increased significantly with increasing concentration of PHA and reached a maximum value for 80 wt % PHA blend. In addition, the tensile strength of the blends increased markedly as the content of PHA increased. For blends containing PA at >50 wt %, samples failed only after a very large elongation (up to 465%) without significant decrease in tensile strength. The particle size significantly increased and the blends became more brittle with increasing concentration of PHA. In addition, the concentration of the PA had a substantial effect on the glass relaxation temperature of the resulting blends. Our results demonstrate that the thermomechanical and rheological properties of PHA/PA blends can be tailored for specific applications, and that blends of PHA/PA can fulfill the mechanical properties required for flexible, impact-resistant bio-based nursery-crop containers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42209. [ABSTRACT FROM AUTHOR]

Currently used plastics are mostly produced from petrochemical products, but there is a growing demand for eco‐friendly plastics. The use of bio‐based plastics, which are produced from renewable resources, and biodegradable plastics, which are degraded in the environment, will lead to a more sustainable society and help us solve global environmental and waste management problems. [ABSTRACT FROM AUTHOR]

ABSTRACT Thiol (SH) containing additives improve the mechanical properties of rigid, glassy gluten materials. However, the underlying molecular mechanism is still unclear. In particular, the importance of the preceding gluten-additive mixing conditions remains to be investigated. Here, different additives containing either only SH, only disulfide or both SH and disulfide functionalities were synthesized and their impact on the gluten network using different mixing conditions prior to subsequent molding were assessed. All SH containing additives decreased the gluten molecular weight (MW) during mixing to a degree depending on the conditions. Additives with only disulfide functionality did not significantly affect protein size during mixing irrespective of the conditions used. Only when mixing induced sufficient MW reduction did the strength and failure strain of rigid gluten materials increase. This shows that factors other than the degree of cross-linking affect the strength of rigid gluten materials. These results support our hypothesis that altered molecular conformations and improved molecular entanglements contribute to material strength. The extent to which such conformational changes occur may depend on the additive and the way of mixing. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41160. [ABSTRACT FROM AUTHOR]

ABSTRACT Bioplastics produced from meat and bone meal (MBM) suffer from rapid and drastic mechanical property deterioration because of their hydrophilic nature. This study investigates mechanical and water stability of composites produced from introduction of a minor component of a synthetic polyethylene as a binder phase to consolidate MBM. The milled and sieved MBM was compounded with 5-60 wt % linear low-density polyethylene (LLDPE) and formed into composite sheets by calendering, which is an industrially relevant process. Results indicated that a minimum of 15 wt % LLDPE content was required to form a nominally continuous binder phase that allowed for good processability and environment stability of the composites. As expected, the water vapor permeability (WVP) and water absorption characteristics of the composites were intermediate between those of MBM and LLDPE. Sheets containing 15 wt % LLDPE absorbed up to 35 wt % water. Composites tested after being soaked in water showed an initial decrease in TS of about 30% for the first hour but then remained fairly unchanged in the next 72 hours, confirming their moderate environment stability. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41145. [ABSTRACT FROM AUTHOR]

Polyhydroxybutyrate (PHB) is a biopolymer that is in the spotlight because of its broad applications in bioplastics, fine chemicals, implant biomaterials and biofuels. PhaA from Ralstonia eutropha ( RePhaA) is the first enzyme in the PHB biosynthetic pathway and catalyzes the condensation reaction of two acetyl-CoA molecules to give acetoacetyl-CoA. RePhaA was crystallized using the hanging-drop vapour-diffusion method in the presence of 20% polyethylene glycol monomethyl ether 2K, 0.1 M Tris-HCl pH 8.5 and 0.2 M trimethylamine N-oxide dihydrate at 295 K. X-ray diffraction data were collected to a maximum resolution of 1.96 Å on a synchrotron beamline. The crystal belonged to space group P21, with unit-cell parameters a = 68.38, b = 105.47, c = 106.91 Å, α = γ = 90, β = 106.18°. With four subunits per asymmetric unit, the crystal volume per unit protein weight ( VM) is 2.3 Å3 Da−1, which corresponds to a solvent content of approximately 46.2%. The structure was solved by the molecular-replacement method and refinement of the structure is in progress. [ABSTRACT FROM AUTHOR]

ABSTRACT This research study focuses on the thermomechanical polymerization of microalgae protein biomass such as Chlorella and Spirulina to develop algal-based bioplastics and thermoplastic blends. The algal protein biomass can grow on nutrient-rich wastewater from livestock farms, municipal or industrial effluent sources, remediating the excess nitrogen and phosphorus. The algal bioplastics provide biodegradability that can be tailored to have a wide range of material properties suitable for various applications-consumable and disposable plastic products, agricultural plastic products, and horticultural planting containers. According to experimental results, pressure, temperature, content of plasticizer, and processing time are major variables in polymerization and structure stabilization during the compression molding process of both algal protein biomass and thermoplastic blends containing polyethylene polymer. Chlorella showed better bioplastic behavior than Spirulina microalgae, whereas Spirulina showed better blend performance. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3263-3275, 2013 [ABSTRACT FROM AUTHOR]

Melt mixing of poly(butylene adipate-co-terephthalate) based biopolymer was performed with synthetic silica and silicate reinforcements in order to attain nanocomposites with superior properties so as to enhance the spectrum of applications of the biopolymers. The addition of 5% of fillers enhanced the modulus of the polymer by 20% and also enhanced or retained the elongation and yield stress. The thermal properties of the polymer were unaffected by the addition of fillers and did not show any decrease in the degradation temperatures occasionally observed due to the acceleration of the degradation by heat accumulated in the filler aggregates. The morphological characterization of the composites confirmed good dispersion of filler particles in the polymer matrix, however, the magnitude of large sized aggregates increased with increasing filler fraction. The addition of filler also nucleated the polymer (peak crystallization temperature increased from 15 to 30°C) but the overall melt enthalpy was a function of filler dispersion. The dynamic properties of the composites enhanced gradually, however, significantly higher properties were observed for composites with 20% filler due to the presence of aggregates. An increase of storage modulus by 400% was observed for silica composites containing 20% filler, whereas same amount of silicate enhanced the storage modulus of the polymer by 300%. The composites with lower filler fractions maintained the similar flow characteristics as pure polymer. The filler phase was observed to be miscible with polymer in all composites except those with 20% filler content. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Effects of cyanuric acid (CA) on nonisothermal and isothermal crystallization, melting behavior, and spherulitic morphology of bacterial copolyesters of poly(3-hydroxybutyrate), i.e., poly(3-hydroxybutyrate- co-3-hydroxyvalerate) (PHBV) and poly(3-hydroxybutyrate- co-3-hydroxyhexanoate) (PHBH), have been investigated. CA has excellent acceleration effectiveness on the melt crystallization of bacterial PHB, PHBV, and PHBH, better than the nucleating agents reported in the literatures, such as boron nitride, uracil, and orotic acid. PHBV and PHBH do not crystallize upon cooling from the melt at 10°C/min, while they are able to complete crystallization under the same conditions with an addition of 1% CA, with a presence of sharp crystallization exotherm at 75-95°C. Isothermal crystallization kinetics of neat and CA-containing PHBV and PHBH were analyzed by Avrami model. Crystallization half-times ( t1/2) of PHBV and PHBH decrease dramatically with an addition of CA. The melting behavior of isothermally melt-crystallized PHBV and PHBH is almost not influenced by CA. Spherulitic numbers of PHBV and PHBH increase and the spherulite sizes reduce with an incorporation of CA. Nucleation densities of PHBV and PHBH increase by 3-4 orders of magnitude with a presence of 1% CA. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Despite much research, there are very few commercial prolamin bioplastics. The major reason, apart from their high cost, is that they have inferior functional properties compared with synthetic polymer plastics. The inferior functional properties are because the prolamins are complex, each consisting of several classes and subclasses, and the functional properties of their bioplastics are greatly affected by water. Prolamin bioplastics are produced by controlled protein aggregation from a solvent or by thermoplastic processing. Recent research indicates that aggregation occurs by polypeptide self‐assembly into nanostructures. Protein secondary structure in terms of α‐helical and β‐sheet structure seems to play a key but incompletely understood role in assembly. Also, there is inadequate knowledge as to how these nanostructures further assemble and organize into the various forms of prolamin bioplastics such as films, fibers, microparticles, and scaffolds. Many methods have been investigated to improve prolamin bioplastic functionality, including better solvation of the prolamins, plasticization, physical and chemical cross‐linking, derivatization, and blending with synthetic and natural polymers, and some success has been achieved. The most promising area of commercialization is the biomedical field, in which the relative hydrophilicity, compatibility, and biodegradability of, particularly, zein and kafirin are advantageous. With regard to biomedical applications, “supramolecular design” of prolamin bioplastics through control over inter‐ and intramolecular weak interactions and disulfide/sulfhydryl interchange appears to have considerable potential. [ABSTRACT FROM AUTHOR]

The article examines the 2012 Bioplastics Symposium held in Baltimore, Maryland. Remarks by participants including Ramani Narayan, Stan Blade and Dick Lilly on disposal of bioplastics and biopolymers are discussed, particularly composting of biopolymers. Research on biopolymers presented at the conference is discussed including creation of co-polyesters, chain branching and the development of foams made from mycelium.

Silk fibroin (SF) films have been largely studied as biomaterials due to their biocompatibility and biodegradability. Casting a SF aqueous solution at room temperature is a common technique to produce SF films at relative low cost and processing time; however, their brittleness and solubility in water make them unsuitable for certain biomedical applications. In this study, the incorporation of additives, ethanol and glycerin, are presented as an alternative to both improve mechanical properties of SF films and decrease their solubility in water. SF films with additives were further characterized using scanning electron microscopy, X-ray diffraction, Fourier transformed infrared spectroscopy with attenuated total reflection, analysis of water solubility, mechanical test of traction, and in vitro cytotoxicity experiments. The results show that SF films containing additives are stable in water due to the effect of glycerin and ethanol, and do not require post-treatments. Furthermore, great improvements on elongation of the films were achieved, mainly in the presence of both additives. In addition, all films were not toxic to cells, which is a first indication of their biocompatibility. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]