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As an emerging science, tissue engineering and regenerative medicine focus on developing materials to replace, restore or improve organs or tissues and enhancing the cellular capacity to proliferate, migrate and differentiate into different cell types and specific tissues. Renewable resources have been used to develop new materials, resulting in attempts to produce various environmentally friendly biomaterials. Poly (lactic acid) (PLA) is a biopolymer known to be biodegradable and it is produced from the fermentation of carbohydrates. PLA can be combined with other polymers to produce new biomaterials with suitable physicochemical properties for tissue engineering applications. Here, the advances in modified PLA as tissue engineering materials are discussed in light of its drawbacks, such as biological inertness, low cell adhesion, and low degradation rate, and the efforts conducted to address these challenges toward the design of new enhanced alternative biomaterials. [ABSTRACT FROM AUTHOR]

The increasing concerns about plastic pollution and climate change have encouraged research into bioderived and biodegradable materials. Much attention has been focused on nanocellulose due to its abundance, biodegradability, and excellent mechanical properties. Nanocellulose-based biocomposites are a viable option to fabricate functional and sustainable materials for important engineering applications. This review addresses the most recent advances in composites, with a particular focus on biopolymer matrices such as starch, chitosan, polylactic acid, and polyvinyl alcohol. Additionally, the effects of the processing methods, the influence of additives, and the outturn of nanocellulose surface modification on the biocomposite's properties are outlined in detail. Moreover, the change in the composites' morphological, mechanical, and other physiochemical properties due to reinforcement loading is reviewed. Further, mechanical strength, thermal resistance, and the oxygen–water vapor barrier properties are enhanced with the incorporation of nanocellulose into biopolymer matrices. Furthermore, the life cycle assessment of nanocellulose and composites were considered to analyze their environmental profile. The sustainability of this alternative material is compared through different preparation routes and options. [ABSTRACT FROM AUTHOR]

Fungal biomass (FB), a by-product of the fermentation processes produced in large volumes, is a promising biomaterial that can be incorporated into poly(lactic acid) (PLA) to develop enhanced biocomposites that fully comply with the biobased circular economy concept. The PLA/FB composites, with the addition of triethyl citrate (TEC) as a biobased plasticizer, were fabricated by a microcompounder at 150 °C followed by injection molding. The effects of FB (10 and 20 wt %) and TEC (5, 10, and 15 wt %) contents on the mechanical, thermal and surface properties of the biocomposites were analyzed by several techniques. The PLA/FB/TEC composites showed a rough surface in their fracture section. A progressive decrease in tensile strength and Young's modulus was observed with increasing FB and TEC, while elongation at break and impact strength started to increase. The neat PLA and biocomposite containing 10% FB and 15% TEC exhibited the lowest (3.84%) and highest (224%) elongation at break, respectively. For all blends containing FB, the glass transition, crystallization and melting temperatures were shifted toward lower values compared to the neat PLA. The incorporation of FB to PLA thus offers the possibility to overcome one of the main drawbacks of PLA, which is brittleness. [ABSTRACT FROM AUTHOR]

Purpose: The objective of the present study was to better understand the potential environmental benefit of using vine shoots (ViShs), an agricultural residue, as filler in composite materials. For that purpose, a comparative life cycle assessment (LCA) of a rigid tray made of virgin poly(3-hydroxybutyrate-co-3-hydroxyvalerate) PHBV, polylactic acid (PLA) or polypropylene (PP), and increasing content of ViSh particles was performed. The contribution of each processing step in the life cycle on the different environmental impacts was identified and discussed. Furthermore, the balance between the environmental and the economic benefits of composite trays was discussed. Methods: This work presents a cradle-to-grave LCA of composite rigid trays. Once collected in vineyards, ViShs were dried and ground using dry fractionation processes, then mixed with a polymer matrix by melt extrusion to produce compounds that were finally injected to obtain rigid trays for food packaging. The density of each component was taken into account in order to compare trays with the same volume. The maximum filler content was set to 30 vol% according to recommendations from literature and industrial data. The ReCiPe 2016 Midpoint Hierarchist (H) methodology was used for the assessment using the cutoff system model. Results and discussion: This study showed that bioplastics are currently less eco-friendly than PP. This is in part due to the fact that LCA does not account for, in existing tools, effects of microplastic accumulation and that bioplastic technologies are still under development with low tonnage. This study also demonstrated the environmental interest of the development of biocomposites by the incorporation of ViSh particles. The minimal filler content of interest depended on the matrices and the impact categories. Concerning global warming, composite trays had less impact than virgin plastic trays from 5 vol% for PHBV or PLA and from 20 vol% for PP. Concerning PHBV, the only biodegradable polymer in natural conditions in this study, the price and the impact on global warming are reduced by 25% and 20% respectively when 30 vol% of ViSh are added. Conclusion: The benefit of using vine shoots in composite materials from an environmental and economical point of view was demonstrated. As a recommendation, the polymer production step, which constitutes the most important impact, should be optimized and the maximum filler content in composite materials should be increased. [ABSTRACT FROM AUTHOR]

In this work, agave fibers were surface treated using maleated PLA (MAPLA) in order to increase the fiber content (from 10 up to 40% wt.) in polylactic acid (PLA) biocomposites produced by rotational molding and to study the effect of the agave fiber and its treatment on the physical, mechanical and thermal properties of the biocomposites. This chemical modification between agave fibers and MAPLA was evaluated by FTIR spectroscopy. In general the results indicate that MAPLA surface treatment produces a more homogeneous morphology with lower interfacial gaps and overall porosity, especially at higher agave contents. This improved compatibility promoted better stress transfer leading to increased mechanical properties. For example, the tensile strength and modulus of treated fiber composites increased by up to 68% (from 25 to 41 MPa) and 32% (from 1.30 to 1.74 GPa) respectively, in comparison with untreated fiber composites. Fiber surface treatment also decreases hydrophilicity, lowering water absorption and diffusion coefficient. From thermo-mechanical analyses, the damping behavior of the biocomposites decreased with MAPLA treatment since a stronger interface is able to sustain higher stresses and dissipates less energy. Finally, the thermal stability was also improved as a result of better interfacial chemical bonding leading to a 12 °C increase in thermal stability (from 254 to 266 °C). [ABSTRACT FROM AUTHOR]

Over the last decade, biopolymers have seen a sharp increase in their market share as an alternative to conventional oil-based plastic materials. Among them, degradable biopolymers are rarely employed, especially in the field of durable end-goods, because of their often limited chemical, mechanical and thermal behaviours. In contrast, stringent international regulations encourage the employment of low-impact materials in several manufacturing domains, with degradable polymers considered par excellence. In the present work, an innovative route to control the final properties of an extrusion-compounded, high-performance biocomposite composed of polylactic acid (PLA) reinforced with micro-lamellar talc is proposed. For this purpose, talc was first modified via surface reaction with organic (i.e., belonging to the class of polyisocyanates) or hybrid organic-inorganic (i.e., belonging to the class of organosilanes) compatibilizers, respectively. Custom-built formulations were then achieved by the dispersion of the pretreated micro-lamellar talc in commercial-grade PLA. The resulting compounds were analysed by differential scanning calorimetry (DSC) and attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy. The experimental findings show that PLAs with different properties can be achieved as a result of chemical and physical interactions among the functional groups on the surface of the pretreated talc and the terminal groups of the PLA chains. These results are extremely promising for the achievement of innovative grades of PLAs suitable for melt processing and to ensure the greatly improved chemical inertness, thermal stability and mechanical strength of the resulting end-goods. [ABSTRACT FROM AUTHOR]

Disposable containers made of non-biodegradable polymers are considered as one of the most prevalent environmental pollutants. It is very important and desirable to make fully biodegradable disposable containers for food packaging that does not endanger the health of consumers. In this research, fully biodegradable polymer composites were prepared by melt mixing of polylactic acid (PLA), polybutylene succinate (PBS), and natural polymers including corn starch and wheat straw, and their physical and mechanical properties were evaluated. For this purpose, by conducting experiments according to the optimal custom mixture design of the response surface methodology, the effect of 3 independent variables including the concentration of the PLA and PBS biopolymers blend (50/50% w/w) (CBB) in the range of 30–70, the concentration of corn starch (CCS) in the range of 30–60 and the concentration of wheat straw (CWS) in the range of 0–8 wt percentage of biocomposite on the dependent variables including the elastic modulus (EM), elongation at break (EB), impact strength (IS) and equilibrium moisture content (EMC) of the biocomposite sheet were investigated. According to the results of this research, with the increase in the concentration of corn starch and wheat straw in the studied range, the EM and EMC of the biocomposite increased, while its EB and IS decreased. According to the results obtained from optimizing the effects of independent variables on the physicomechanical properties of the biocomposite sheet, the optimal values predicted by the models for CBB, CCS and CWS were 48.2 wt%, 45.4 wt%, and 6.4 wt%, respectively and predicted values for EM, EB, IS and EMC were 80.8 MPa, 11.4%, 2 kJ/m2 and 4.1%, respectively. Also, the biodegradability rate of the biocomposite with the optimal formulation was 71.1% in the fifth month of the test. • Biocomposites of biopolyester blend filled with two natural polymers were prepared. • Biocomposites contained polylactic acid, polybutylene succinate, starch, and wheat straw. • Constituents concentration had main effects on the sheet's physicomechanical properties. • Optimal sheet contains 48.2 wt% biopolyester blend and 51.8 wt% natural polymers. • The biocomposite sheet with optimal formulation had a high degree of biodegradability. [ABSTRACT FROM AUTHOR]

Over recent years, enthusiasm towards the manufacturing of biopolymers has attracted considerable attention due to the rising concern about depleting resources and worsening pollution. Among the biopolymers available in the world, polylactic acid (PLA) is one of the highest biopolymers produced globally and thus, making it suitable for product commercialisation. Therefore, the effectiveness of natural fibre reinforced PLA composite as an alternative material to substitute the non-renewable petroleum-based materials has been examined by researchers. The type of fibre used in fibre/matrix adhesion is very important because it influences the biocomposites' mechanical properties. Besides that, an outline of the present circumstance of natural fibre-reinforced PLA 3D printing, as well as its functions in 4D printing for applications of stimuli-responsive polymers were also discussed. This research paper aims to present the development and conducted studies on PLA-based natural fibre bio-composites over the last decade. This work reviews recent PLA-derived bio-composite research related to PLA synthesis and biodegradation, its properties, processes, challenges and prospects. [ABSTRACT FROM AUTHOR]