Because of increasing environmental concerns/legislative pressure for plastics waste and rapid increases in the cost of petroleum, the development of ＂environmental friendly＂ materials has attracted extensive intere...Because of increasing environmental concerns/legislative pressure for plastics waste and rapid increases in the cost of petroleum, the development of ＂environmental friendly＂ materials has attracted extensive interest. Recently, bioplastics are one of the most innovative environmental friendly materials developed. Therefore, this paper will look at aspects of the bioplastics from the perspective of sustainability, advantages/disadvantages and standards. The global bioplastics market is thought to be growing at a rate of 20%-25% per year. They have some advantages such as lower carbon footprint, independence, energy efficiency, and eco-safety. However, they have some disadvantages such as high cost, recycling, reducing raw materials, misused of terms and lack of legislation. For the sustainability, recycling systems and production technology may be developed for bioplastics and by-product should be used for their production. Also, there is much standardization about them. It is important to have comparable international standard methods. Therefore, there is an urgent need to standardize all details. A new guide and standard for just bioplastics should be developed for production, usage and bioplastic waste management for every country in the world.展开更多
Polylactic acid(PLA)bioplastic is a common material used in Fused Deposition Modeling(FDM)3D printing.It is biodegradable and environmentally friendly biopolymer which made out of corn.However,it exhibits weak mechan...Polylactic acid(PLA)bioplastic is a common material used in Fused Deposition Modeling(FDM)3D printing.It is biodegradable and environmentally friendly biopolymer which made out of corn.However,it exhibits weak mechanical properties which reduced its usability as a functional prototype in a real-world application.In the present study,two PLA composites are created through coextruded with 3K carbon fibres and twisted Kevlar string(as core fibre)to form a fibre reinforced parts(FRP).The mechanical strength of printed parts was examined using ASTM D638 standard with a strain rate of 1 mm/min.It has been demonstrated that the FRPs coextruded with 3K carbon fibres had achieved significant improvement in Young’s modulus(+180.6%,9.205 GPa),ultimate tensile strength(+175.3%,103 MPa)and maximum tensile strain(+21.6%,1.833%).Although the Young’s modulus of Kevlar FRP was found to be similar to as compared to unreinforced PLA(~3.29 GPa),it has gained significant increment in terms of maximum tensile strain(+179.7%,104.64 MPa),and maximum tensile strain(+257%,5.384%).Thus,this study revealed two unique composite materials,in which the 3K carbon FRP can offer stiff and high strength structure while Kevlar FRP offers similar strength but at a higher elasticity.展开更多
Degradation of three kinds of bioplastics and their effects on microbial biomass and microbial diversity in soil environment were analyzed. The degradation rate of bioplastic in soil was closely related to the main co...Degradation of three kinds of bioplastics and their effects on microbial biomass and microbial diversity in soil environment were analyzed. The degradation rate of bioplastic in soil was closely related to the main components in the bioplastics. Poly (butylene succinate)-starch (PBS-starch) and poly (butylene succinate) (PBS) were degraded by 1% to 7% after 28 days in a soil with an initial bacterial biomass of 1.4 × 10<sup>9</sup> cells/g-soil, however poly lactic acid (PLA) was not degraded in the soil after 28 days. When the powdered-bioplastics were examined for the degradation in the soil, PBS-starch also showed the highest degradability (24.4% degradation after 28 days), and the similar results were obtained in the case of long-term degradation experiment (2 years). To investigate the effect of bacterial biomass in soil on biodegradability of bioplastics, PBS-starch was buried in three kinds of soils differing in bacterial biomass (7.5 × 10<sup>6</sup>, 7.5 × 10<sup>7</sup>, and 7.5 × 10<sup>8</sup> cells/g-soil). The rate of bioplastic degradation was enhanced accompanied with an increase of the bacterial biomass in soil. 16S rDNA PCR-DGGE analysis indicated that the bacterial diversity in the soil was not affected by the degradation of bioplastics. Moreover, the degradation of bioplastic did not affect the nitrogen circulation activity in the soil.展开更多
1 Introduction Haloarchaea represents a distinct group of Archaea that typically inhabits hypersaline environments,such as salt lakes and sea salterns.They are easy to culture and many haloarchaea are genetically trac...1 Introduction Haloarchaea represents a distinct group of Archaea that typically inhabits hypersaline environments,such as salt lakes and sea salterns.They are easy to culture and many haloarchaea are genetically tractable,hence they are excellent model systems for research of archaeal genetics,展开更多
The threat posed by plastics to the environment has prompted the development of bioplastics. Starch plasticized by glycerol is a key renewable resource in the production of high-quality bioplastics. Previous studies h...The threat posed by plastics to the environment has prompted the development of bioplastics. Starch plasticized by glycerol is a key renewable resource in the production of high-quality bioplastics. Previous studies have availed information on the mechanical quality of starch-based bioplastics however there is limited information about their degradation pattern in the natural environment which this research presents. Bioplastics were buried in holes in loam sandy soil and weekly photographic data and weight were collected to reveal the effect of degradation. Weather parameters of rainfall, temperature, relative humidity, sunshine intensity and sunshine hours were recorded to establish influence of weather on degradation. A control set up in the laboratory was used to compare the results. Over time the tests revealed that as the hydrophilic enzymes break down the bioplastic, its weight initially increases (up to 87%) due to absorption of moisture and after saturation, the bioplastic is disintegrated which initiates decomposition and the bioplastic weight is steadily reduced. Degradation was further enhanced by invasion of soil organisms like worms, termites among other soil microbes. Rainfall (r = 0.857) increased the moisture in the soil which initially increased the weight of the bioplastic up to a point when the hydrophilic enzymes set into breakdown the bioplastic then the weight started to drop. This was the same case for relative humidity (r = ﹣0.04) however;the sunlight intensity (r = 515) and hours of illumination indirectly affect the process by influencing microbial activity. An increase in the sunshine intensity increased the activity of soil organisms up to a point beyond which increased exposure caused the organisms to burrow deeper in the soil. Increase in microbial activity increased the rate of degradation of the buried bioplastics which took five to ten weeks to fully decompose (98.3%). The reduced time of degradation means that starch-based bioplastics have a high potential as sustainable substitute for petroleum-based plastics.展开更多
Bio plastics products have a rapid growing demand and market across the globe. Polymers synthesized from renewable resources have gained immense popularity, in numerous applications ranging from films, bottles, food p...Bio plastics products have a rapid growing demand and market across the globe. Polymers synthesized from renewable resources have gained immense popularity, in numerous applications ranging from films, bottles, food packaging, drug delivery, bags to agriculture mulch films. Various naturally occurring resources available for starch and PLA extraction and the associated polymer processing techniques are discussed. Alongside some basic concepts on blown film extrusion, the modifications needed for such specialized polymer processing techniques are also explored, giving a comprehensive outlook on bioplastics. Special process analysis, for its application as films are discussed. In the current scenario, as the world aspires for environmental and polymer sustainability, Bioplastic products are of high value. The review article would be beneficial to those embarked on designing bio-plastics products from renewable resources.展开更多
The strength of starch-based bioplastics is a challenge, we tried to overcome this limitation by using electromagnetic radiation in the visible range. Synthetically obtained retrograde bioplastics were subjected to ra...The strength of starch-based bioplastics is a challenge, we tried to overcome this limitation by using electromagnetic radiation in the visible range. Synthetically obtained retrograde bioplastics were subjected to radiation from an Edison-type incandescent lamp. A cross-linked network is obtained within the bioplastic matrix considerably attenuating the usual hygroscopicity of starch and increasing the ability to resist rupture. After this positive behavior, the bioplastics were colored in order to optimize the action of light radiation. The results show a stronger and more compact bioplastic. The green-colored bioplastics show the best performance in the optimization of the resistance.展开更多
In a circular economy,bio-based plastics or bioplastics as emerging innovative materials are increasingly being used in many industries,from packaging to building materials and agricultural products to electronic and ...In a circular economy,bio-based plastics or bioplastics as emerging innovative materials are increasingly being used in many industries,from packaging to building materials and agricultural products to electronic and biomedical devices.Further,there is increasing research on the evaluation of bioplastics in architecture,both as a material or as a design element in interior design.Therefore,this article is a step toward understanding the importance of bioplastic materials in circular economies and in architecture regarding the negative carbon footprint and long-term environmental effects of fossil-based plastics.展开更多
The work carried out here opens another perspective in the valorization of sw<span>eet potatoes produced in Congo Brazzaville other than those proposed by <b><i>BOULA</i></b> <b><...The work carried out here opens another perspective in the valorization of sw<span>eet potatoes produced in Congo Brazzaville other than those proposed by <b><i>BOULA</i></b> <b><i>and</i></b><span> <b><i>all</i></b></span>. We have shown in this work that the hydrophilic property of starch which limits the production of starch-based bioplastics can be inhibited by using the effects of photonic incandescence. Indeed, light significantly impacts the bioplastic matrix causing a decrease of the sites likely to bind water molecules. However, it would be desirable to apply rheology for a better follow-up of this cross-linking phenomenon. The synthesized retrograde bioplastic having undergone a photonic stress shows better physical properties to be used as packaging and thus to answer the environmental protection.展开更多
Poly Laevo Lactic Acid (PLLA), in spite of being an excellent bioplastic, has exorbitantly high market price due to the high cost of raw material (lactose, glucose, sucrose). Hence, its manufacture is being attempted ...Poly Laevo Lactic Acid (PLLA), in spite of being an excellent bioplastic, has exorbitantly high market price due to the high cost of raw material (lactose, glucose, sucrose). Hence, its manufacture is being attempted starting from waste effluents such as cheese whey and molasses. Earlier studies on the same in fluidized bed and semifluidized bed biofilm reactors yielded encouraging results. The present study therefore involves design and analysis of inverse fluidized bed biofilm reactors for lactic acid synthesis. The performance features of the bioreactor have been studied both mathematically as well as experimentally. The inverse fluidized bed biofilm reactor has been found to provide more than 75% conversion of sucrose/lactose even at high capacities (high feed flow rates) exceeding 56,000 L/hr, within a reasonably low reactor volume. The fractional substrate conversion increases, though sluggishly, with increase in feed flow rate due to bed expansion and also with increase in cell mass concentration in biofilm due to enhancement in intrinsic rate of bioconversion. The inverse fluidized bed biofilm reactor of proposed design could be safely recommended for the commercial synthesis of polymer grade lactic acid from waste effluents such as cheese whey and molasses. The low operating cost of the bioreactor (due to downflow mode of operation) enhances the economy of the process. This would also help in significantly lowering the market price of the green plastic (PLLA) and shall promote its large scale manufacture and utilisation.展开更多
Bioplastics were first introduced as environmentally friendly materials,with properties similar to those of conventional plastics.A bioplastic is defined as biodegradable if it can be decomposed into carbon dioxide un...Bioplastics were first introduced as environmentally friendly materials,with properties similar to those of conventional plastics.A bioplastic is defined as biodegradable if it can be decomposed into carbon dioxide under aerobic degradation,or methane and CO_(2)under anaerobic conditions,inorganic compounds,and new cellular biomass,by the action of naturally occurring microorganisms.This definition however does not provide any information on the environmental conditions,timescale and extent at which decomposition processes should occur.With regard to the aquatic environment,recognized standards have been established to assess the ability of plastics to undergo biodegradation;however,these standards fail to provide clear targets to be met to allow labelling of a bioplastic as biodegradable.Moreover,these standards grant the user an extensive leeway in the choice of process parameters.For these reasons,the comparison of results deriving from different studies is challenging.The authors analysed and discussed the degree of biodegradability of a series of biodegradable bioplastics in aquatic environments(both fresh and salt water)using the results obtained in the laboratory and from on-site testing in the context of different research studies.Biochemical Oxygen Demand(BOD),CO_(2)evolution,surface erosion and weight loss were the main parameters used by researchers to describe the percentage of biodegradation.The results showed a large variability both in weight loss and BOD,even when evaluating the same type of bioplastics.This confirms the need for a reference range of values to be established with regard to parameters applied in defining the biodegradability of bioplastics.展开更多
Poly(vinyl alcohol)(PVA)is biodegradable,recyclable,and has high tensile strength.Therefore,it is ideal for the development of environment-friendly sustainable bioplastics.However,at elevated humidity,the mechanical p...Poly(vinyl alcohol)(PVA)is biodegradable,recyclable,and has high tensile strength.Therefore,it is ideal for the development of environment-friendly sustainable bioplastics.However,at elevated humidity,the mechanical properties of PVA bioplastic films undergo degradation owing to their intrinsic hydrophilic and hygroscopic nature,hindering their applications.This study proposes a nanoconfined assembly strategy to produce humidity-adaptive,mechanically robust,and recyclable bioplastic film.The strong hydrogen bonds between PVA and cellulose nanofibrils inhibit the penetration of water molecules into the film to promote humidity resistance.Further,the robust coordination interactions between bentonite nanoplates,PVA,and cellulose nanofibrils restrict the slip of polymer chains during deformation,leading to enhanced mechanical properties.Benefiting from the nanoconfined assembly architecture in aggregated composites,the resulting reinforced PVA film simultaneously exhibits strength,stiffness,toughness,fracture energy,and tearing energy of 55.9 MPa,1,275.6 MPa,162.9 MJ m^(−3),630.9 kJ m^(−2),and 465.0 kJ m^(−2),respectively.Moreover,the film maintains a strength of approximately 48.7 MPa even at 80%relative humidity for 180 days.This efficient design strategy applies to diverse scales and structured cellulose biomacromolecules.Moreover,it facilitates the application of recyclable high-performance bioplastic films to settings that require high humidity tolerance.展开更多
The current transition to sustainability and the circular economy can be viewed as a socio-technical response to environmental impacts and the need to enhance the overall performance of the linear production and consu...The current transition to sustainability and the circular economy can be viewed as a socio-technical response to environmental impacts and the need to enhance the overall performance of the linear production and consumption paradigm.The concept of biowaste refineries as a feasible alternative to petroleum refineries has gained popularity.Biowaste has become an important raw material source for developing bioproducts and biofuels.Therefore,effective environmental biowaste management systems for the production of bioproducts and biofuels are crucial and can be employed as pillars of a circular economy.Bioplastics,typically plastics manufactured from bio-based polymers,stand to contribute to more sustainable commercial plastic life cycles as part of a circular economy in which virgin polymers are made from renewable or recycled raw materials.Various frameworks and strategies are utilized to model and illustrate additional patterns in fossil fuel and bioplastic feedstock prices for various governments'long-term policies.This review paper highlights the harmful impacts of fossil-based plastic on the environment and human health,as well as the mass need for eco-friendly alternatives such as biodegradable bioplastics.Utilizing new types of bioplastics derived from renewable resources(e.g.,biowastes,agricultural wastes,or microalgae)and choosing the appropriate end-of-life option(e.g.,anaerobic digestion)may be the right direction to ensure the sustainability of bioplastic production.Clear regulation and financial incentives are still required to scale from niche polymers to large-scale bioplastic market applications with a truly sustainable impact.展开更多
Agricultural wastes,including cocoa pod husk(waste from the chocolate industry)and sugarcane bagasse(waste from the sugar industry),are increasing day by day.The development of food packaging biofilms from these two w...Agricultural wastes,including cocoa pod husk(waste from the chocolate industry)and sugarcane bagasse(waste from the sugar industry),are increasing day by day.The development of food packaging biofilms from these two wastes could be beneficial to the environment and human.Therefore,this study was conducted to develop biodegradable plastic films by using cocoa pod husk and sugarcane bagasse.Cellulose and fibre were extracted from cocoa pod husk and sugar-cane bagasse,respectively.The developed bioplastic films were divided into several concentration ratios of cellulose and fibre which are 100꞉0(100%cellulose),75꞉25(cellulose꞉fibre),50꞉50(cel-lulose꞉fibre),25꞉75(cellulose꞉fibre),and 0꞉100(100%fibre).The physicochemical properties for all bioplastic concentration ratios were determined in terms of sensory evaluation,drying time,moisture content,water absorption and water vapor permeability.From the observation and anal-ysis of the physicochemical properties of bioplastic,we found that the most suitable bioplastic film for food packaging goes to the combination of 75%cellulose and 25%fibre bioplastic,as it demonstrated the lowest water absorption percentage and water vapor permeability.展开更多
Conventional plastics exacerbate climate change by generating substantial amounts of greenhouse gases and solid wastes throughout their lifecycle.To address the environmental and economic challenges associated with pe...Conventional plastics exacerbate climate change by generating substantial amounts of greenhouse gases and solid wastes throughout their lifecycle.To address the environmental and economic challenges associated with petroleum-based plastics,bioplastics have emerged as a viable alternative.Bioplastics are a type of plastic that are either biobased,biodegradable,or both.Due to their biodegradability and renewability,bioplastics are established as earth-friendly materials that can replace nonrenewable plastics.However,early bioplastic development has been hindered by higher production costs and inferior mechanical and barrier properties compared to conventional plastics.Nevertheless,studies have shown that the addition of additives and fillers can enhance bioplastic properties.Recent advancements in bioplastics have incorporated special additives like antibacterial,antifungal,and antioxidant agents,offering added values and unique properties for specific applications in various sectors.For instance,integrating antibacterial additives into bioplastics enables the creation of active food packaging,extending the shelf-life of food by inhibiting spoilage-causing bacteria and microorganisms.Moreover,bioplastics with antioxidant additives can be applied in wound dressings,accelerating wound healing by preventing oxidative damage to cells and tissues.These innovative bioplastic developments offer promising opportunities for developing sustainable and practical solutions in various fields.Within this review are two main focuses:an outline of the bioplastic classifications to understand how they fit in as the coveted conventional plastics substitute and an overview of the recent bioplastic innovations in the antibacterial,antifungal,and antioxidant applications.We cover the use of different polymers and additives,presenting the findings and potential applications within the last decade.Although current research primarily focuses on food packaging and biomedicine,the exploration of bioplastics with specialized properties is still in its early stages,offering a wide range of undiscovered opportunities.展开更多
The environment suffers more and more from the accumulation of plastics made by petrochemical rows,which are non-biodegradable.That is why this study aims to develop bio-based films by incorporating fibers concentrate...The environment suffers more and more from the accumulation of plastics made by petrochemical rows,which are non-biodegradable.That is why this study aims to develop bio-based films by incorporating fibers concentrate of parthenocarpic date(FCPD)as easily available ingredients.The FCPD based film showed enhanced thickness,water solubility,phenol content and antioxidant capacity.However,the transparency was reduced which enhanced the film opacity by the addition of FCPD.Scanning electronic microscopy(SEM)showed homogeneity between fibers and the constituents of the film.The addition of FCPD did not change the FTIR peaks in comparison with starch-based film.The hydroxyl index value and water contact angle showed that the hydrophilicity increases with the film FCPD percentage.In addition,the FCPDs have enhanced the microbial biodegradation of the developed films as showed by SEM.Quantitative PCR using specific primers for nine target microbial groups showed that fungi were the predominant agent of the biodegradation.Among bacteria,realtime PCR showed thatβ-Proteobacteria,Acidobacteria,Bacteriodetes andα-Proteobacteria groups were involved in film biodegradation.展开更多
The serious environmental threat caused by petroleum-based plastics has spurred more researches in developing substitutes from renewable sources.Starch is desirable for fabricating bioplastic due to its abundance and ...The serious environmental threat caused by petroleum-based plastics has spurred more researches in developing substitutes from renewable sources.Starch is desirable for fabricating bioplastic due to its abundance and renewable nature.However,limitations such as brittleness,hydrophilicity,and thermal properties restrict its widespread application.To overcome these issues,covalent adaptable network was constructed to fabricate a fully bio-based starch plastic with multiple advantages via Schiff base reactions.This strategy endowed starch plastic with excellent thermal processability,as evidenced by a low glass transition temperature(T_(g)=20.15℃).Through introducing Priamine with long carbon chains,the starch plastic demonstrated superior flexibility(elongation at break=45.2%)and waterproof capability(water contact angle=109.2°).Besides,it possessed a good thermal stability and self-adaptability,as well as solvent resistance and chemical degradability.This work provides a promising method to fabricate fully bio-based plastics as alternative to petroleum-based plastics.展开更多
文摘Because of increasing environmental concerns/legislative pressure for plastics waste and rapid increases in the cost of petroleum, the development of ＂environmental friendly＂ materials has attracted extensive interest. Recently, bioplastics are one of the most innovative environmental friendly materials developed. Therefore, this paper will look at aspects of the bioplastics from the perspective of sustainability, advantages/disadvantages and standards. The global bioplastics market is thought to be growing at a rate of 20%-25% per year. They have some advantages such as lower carbon footprint, independence, energy efficiency, and eco-safety. However, they have some disadvantages such as high cost, recycling, reducing raw materials, misused of terms and lack of legislation. For the sustainability, recycling systems and production technology may be developed for bioplastics and by-product should be used for their production. Also, there is much standardization about them. It is important to have comparable international standard methods. Therefore, there is an urgent need to standardize all details. A new guide and standard for just bioplastics should be developed for production, usage and bioplastic waste management for every country in the world.
基金This project is funded by Universiti Tunku Abdul Rahman through the grant number IPSR/RMC/UTARRF/2018-C2/T02.
文摘Polylactic acid(PLA)bioplastic is a common material used in Fused Deposition Modeling(FDM)3D printing.It is biodegradable and environmentally friendly biopolymer which made out of corn.However,it exhibits weak mechanical properties which reduced its usability as a functional prototype in a real-world application.In the present study,two PLA composites are created through coextruded with 3K carbon fibres and twisted Kevlar string(as core fibre)to form a fibre reinforced parts(FRP).The mechanical strength of printed parts was examined using ASTM D638 standard with a strain rate of 1 mm/min.It has been demonstrated that the FRPs coextruded with 3K carbon fibres had achieved significant improvement in Young’s modulus(+180.6%,9.205 GPa),ultimate tensile strength(+175.3%,103 MPa)and maximum tensile strain(+21.6%,1.833%).Although the Young’s modulus of Kevlar FRP was found to be similar to as compared to unreinforced PLA(~3.29 GPa),it has gained significant increment in terms of maximum tensile strain(+179.7%,104.64 MPa),and maximum tensile strain(+257%,5.384%).Thus,this study revealed two unique composite materials,in which the 3K carbon FRP can offer stiff and high strength structure while Kevlar FRP offers similar strength but at a higher elasticity.
文摘Degradation of three kinds of bioplastics and their effects on microbial biomass and microbial diversity in soil environment were analyzed. The degradation rate of bioplastic in soil was closely related to the main components in the bioplastics. Poly (butylene succinate)-starch (PBS-starch) and poly (butylene succinate) (PBS) were degraded by 1% to 7% after 28 days in a soil with an initial bacterial biomass of 1.4 × 10<sup>9</sup> cells/g-soil, however poly lactic acid (PLA) was not degraded in the soil after 28 days. When the powdered-bioplastics were examined for the degradation in the soil, PBS-starch also showed the highest degradability (24.4% degradation after 28 days), and the similar results were obtained in the case of long-term degradation experiment (2 years). To investigate the effect of bacterial biomass in soil on biodegradability of bioplastics, PBS-starch was buried in three kinds of soils differing in bacterial biomass (7.5 × 10<sup>6</sup>, 7.5 × 10<sup>7</sup>, and 7.5 × 10<sup>8</sup> cells/g-soil). The rate of bioplastic degradation was enhanced accompanied with an increase of the bacterial biomass in soil. 16S rDNA PCR-DGGE analysis indicated that the bacterial diversity in the soil was not affected by the degradation of bioplastics. Moreover, the degradation of bioplastic did not affect the nitrogen circulation activity in the soil.
基金supported by grants from the National 863 Program of Chinathe National Natural Science Foundation of Chinathe Chinese Academy of Sciences
文摘1 Introduction Haloarchaea represents a distinct group of Archaea that typically inhabits hypersaline environments,such as salt lakes and sea salterns.They are easy to culture and many haloarchaea are genetically tractable,hence they are excellent model systems for research of archaeal genetics,
文摘The threat posed by plastics to the environment has prompted the development of bioplastics. Starch plasticized by glycerol is a key renewable resource in the production of high-quality bioplastics. Previous studies have availed information on the mechanical quality of starch-based bioplastics however there is limited information about their degradation pattern in the natural environment which this research presents. Bioplastics were buried in holes in loam sandy soil and weekly photographic data and weight were collected to reveal the effect of degradation. Weather parameters of rainfall, temperature, relative humidity, sunshine intensity and sunshine hours were recorded to establish influence of weather on degradation. A control set up in the laboratory was used to compare the results. Over time the tests revealed that as the hydrophilic enzymes break down the bioplastic, its weight initially increases (up to 87%) due to absorption of moisture and after saturation, the bioplastic is disintegrated which initiates decomposition and the bioplastic weight is steadily reduced. Degradation was further enhanced by invasion of soil organisms like worms, termites among other soil microbes. Rainfall (r = 0.857) increased the moisture in the soil which initially increased the weight of the bioplastic up to a point when the hydrophilic enzymes set into breakdown the bioplastic then the weight started to drop. This was the same case for relative humidity (r = ﹣0.04) however;the sunlight intensity (r = 515) and hours of illumination indirectly affect the process by influencing microbial activity. An increase in the sunshine intensity increased the activity of soil organisms up to a point beyond which increased exposure caused the organisms to burrow deeper in the soil. Increase in microbial activity increased the rate of degradation of the buried bioplastics which took five to ten weeks to fully decompose (98.3%). The reduced time of degradation means that starch-based bioplastics have a high potential as sustainable substitute for petroleum-based plastics.
文摘Bio plastics products have a rapid growing demand and market across the globe. Polymers synthesized from renewable resources have gained immense popularity, in numerous applications ranging from films, bottles, food packaging, drug delivery, bags to agriculture mulch films. Various naturally occurring resources available for starch and PLA extraction and the associated polymer processing techniques are discussed. Alongside some basic concepts on blown film extrusion, the modifications needed for such specialized polymer processing techniques are also explored, giving a comprehensive outlook on bioplastics. Special process analysis, for its application as films are discussed. In the current scenario, as the world aspires for environmental and polymer sustainability, Bioplastic products are of high value. The review article would be beneficial to those embarked on designing bio-plastics products from renewable resources.
文摘The strength of starch-based bioplastics is a challenge, we tried to overcome this limitation by using electromagnetic radiation in the visible range. Synthetically obtained retrograde bioplastics were subjected to radiation from an Edison-type incandescent lamp. A cross-linked network is obtained within the bioplastic matrix considerably attenuating the usual hygroscopicity of starch and increasing the ability to resist rupture. After this positive behavior, the bioplastics were colored in order to optimize the action of light radiation. The results show a stronger and more compact bioplastic. The green-colored bioplastics show the best performance in the optimization of the resistance.
文摘In a circular economy,bio-based plastics or bioplastics as emerging innovative materials are increasingly being used in many industries,from packaging to building materials and agricultural products to electronic and biomedical devices.Further,there is increasing research on the evaluation of bioplastics in architecture,both as a material or as a design element in interior design.Therefore,this article is a step toward understanding the importance of bioplastic materials in circular economies and in architecture regarding the negative carbon footprint and long-term environmental effects of fossil-based plastics.
文摘The work carried out here opens another perspective in the valorization of sw<span>eet potatoes produced in Congo Brazzaville other than those proposed by <b><i>BOULA</i></b> <b><i>and</i></b><span> <b><i>all</i></b></span>. We have shown in this work that the hydrophilic property of starch which limits the production of starch-based bioplastics can be inhibited by using the effects of photonic incandescence. Indeed, light significantly impacts the bioplastic matrix causing a decrease of the sites likely to bind water molecules. However, it would be desirable to apply rheology for a better follow-up of this cross-linking phenomenon. The synthesized retrograde bioplastic having undergone a photonic stress shows better physical properties to be used as packaging and thus to answer the environmental protection.
文摘Poly Laevo Lactic Acid (PLLA), in spite of being an excellent bioplastic, has exorbitantly high market price due to the high cost of raw material (lactose, glucose, sucrose). Hence, its manufacture is being attempted starting from waste effluents such as cheese whey and molasses. Earlier studies on the same in fluidized bed and semifluidized bed biofilm reactors yielded encouraging results. The present study therefore involves design and analysis of inverse fluidized bed biofilm reactors for lactic acid synthesis. The performance features of the bioreactor have been studied both mathematically as well as experimentally. The inverse fluidized bed biofilm reactor has been found to provide more than 75% conversion of sucrose/lactose even at high capacities (high feed flow rates) exceeding 56,000 L/hr, within a reasonably low reactor volume. The fractional substrate conversion increases, though sluggishly, with increase in feed flow rate due to bed expansion and also with increase in cell mass concentration in biofilm due to enhancement in intrinsic rate of bioconversion. The inverse fluidized bed biofilm reactor of proposed design could be safely recommended for the commercial synthesis of polymer grade lactic acid from waste effluents such as cheese whey and molasses. The low operating cost of the bioreactor (due to downflow mode of operation) enhances the economy of the process. This would also help in significantly lowering the market price of the green plastic (PLLA) and shall promote its large scale manufacture and utilisation.
文摘Bioplastics were first introduced as environmentally friendly materials,with properties similar to those of conventional plastics.A bioplastic is defined as biodegradable if it can be decomposed into carbon dioxide under aerobic degradation,or methane and CO_(2)under anaerobic conditions,inorganic compounds,and new cellular biomass,by the action of naturally occurring microorganisms.This definition however does not provide any information on the environmental conditions,timescale and extent at which decomposition processes should occur.With regard to the aquatic environment,recognized standards have been established to assess the ability of plastics to undergo biodegradation;however,these standards fail to provide clear targets to be met to allow labelling of a bioplastic as biodegradable.Moreover,these standards grant the user an extensive leeway in the choice of process parameters.For these reasons,the comparison of results deriving from different studies is challenging.The authors analysed and discussed the degree of biodegradability of a series of biodegradable bioplastics in aquatic environments(both fresh and salt water)using the results obtained in the laboratory and from on-site testing in the context of different research studies.Biochemical Oxygen Demand(BOD),CO_(2)evolution,surface erosion and weight loss were the main parameters used by researchers to describe the percentage of biodegradation.The results showed a large variability both in weight loss and BOD,even when evaluating the same type of bioplastics.This confirms the need for a reference range of values to be established with regard to parameters applied in defining the biodegradability of bioplastics.
基金National Natural Science Foundation of China,Grant/Award Number:31890774Forestry Science and Technology Innovation and Extension Project of Jiangsu Province,Grant/Award Number:LYKJ[2021]04。
文摘Poly(vinyl alcohol)(PVA)is biodegradable,recyclable,and has high tensile strength.Therefore,it is ideal for the development of environment-friendly sustainable bioplastics.However,at elevated humidity,the mechanical properties of PVA bioplastic films undergo degradation owing to their intrinsic hydrophilic and hygroscopic nature,hindering their applications.This study proposes a nanoconfined assembly strategy to produce humidity-adaptive,mechanically robust,and recyclable bioplastic film.The strong hydrogen bonds between PVA and cellulose nanofibrils inhibit the penetration of water molecules into the film to promote humidity resistance.Further,the robust coordination interactions between bentonite nanoplates,PVA,and cellulose nanofibrils restrict the slip of polymer chains during deformation,leading to enhanced mechanical properties.Benefiting from the nanoconfined assembly architecture in aggregated composites,the resulting reinforced PVA film simultaneously exhibits strength,stiffness,toughness,fracture energy,and tearing energy of 55.9 MPa,1,275.6 MPa,162.9 MJ m^(−3),630.9 kJ m^(−2),and 465.0 kJ m^(−2),respectively.Moreover,the film maintains a strength of approximately 48.7 MPa even at 80%relative humidity for 180 days.This efficient design strategy applies to diverse scales and structured cellulose biomacromolecules.Moreover,it facilitates the application of recyclable high-performance bioplastic films to settings that require high humidity tolerance.
基金supported by the National Key R&D Program of China(2018YFE0107100)the National Natural Science Foundation of China(31772529)the Priority of Academic Program Development of Jiangsu Higher Education Institutions(PAPD 4013000011).
文摘The current transition to sustainability and the circular economy can be viewed as a socio-technical response to environmental impacts and the need to enhance the overall performance of the linear production and consumption paradigm.The concept of biowaste refineries as a feasible alternative to petroleum refineries has gained popularity.Biowaste has become an important raw material source for developing bioproducts and biofuels.Therefore,effective environmental biowaste management systems for the production of bioproducts and biofuels are crucial and can be employed as pillars of a circular economy.Bioplastics,typically plastics manufactured from bio-based polymers,stand to contribute to more sustainable commercial plastic life cycles as part of a circular economy in which virgin polymers are made from renewable or recycled raw materials.Various frameworks and strategies are utilized to model and illustrate additional patterns in fossil fuel and bioplastic feedstock prices for various governments'long-term policies.This review paper highlights the harmful impacts of fossil-based plastic on the environment and human health,as well as the mass need for eco-friendly alternatives such as biodegradable bioplastics.Utilizing new types of bioplastics derived from renewable resources(e.g.,biowastes,agricultural wastes,or microalgae)and choosing the appropriate end-of-life option(e.g.,anaerobic digestion)may be the right direction to ensure the sustainability of bioplastic production.Clear regulation and financial incentives are still required to scale from niche polymers to large-scale bioplastic market applications with a truly sustainable impact.
基金supported by Ministry of Education Malaysia,Fundamental Research Grant Scheme for Research Acculturation of Early Career Researchers(FRGS-RACER,R/FRGS/A0700/01552A/003/2019/00665)Universiti Malaysia Kelantan.This support is gratefully acknowledged.
文摘Agricultural wastes,including cocoa pod husk(waste from the chocolate industry)and sugarcane bagasse(waste from the sugar industry),are increasing day by day.The development of food packaging biofilms from these two wastes could be beneficial to the environment and human.Therefore,this study was conducted to develop biodegradable plastic films by using cocoa pod husk and sugarcane bagasse.Cellulose and fibre were extracted from cocoa pod husk and sugar-cane bagasse,respectively.The developed bioplastic films were divided into several concentration ratios of cellulose and fibre which are 100꞉0(100%cellulose),75꞉25(cellulose꞉fibre),50꞉50(cel-lulose꞉fibre),25꞉75(cellulose꞉fibre),and 0꞉100(100%fibre).The physicochemical properties for all bioplastic concentration ratios were determined in terms of sensory evaluation,drying time,moisture content,water absorption and water vapor permeability.From the observation and anal-ysis of the physicochemical properties of bioplastic,we found that the most suitable bioplastic film for food packaging goes to the combination of 75%cellulose and 25%fibre bioplastic,as it demonstrated the lowest water absorption percentage and water vapor permeability.
基金the Ministry of Higher Education Malaysia through the Fundamental Research Grant Scheme(No.FRGS/1/2019/TK10/UMS/02/3)the Universiti Malaysia Sabah through the Niche Fund Scheme(No.SDN0071-2019).
文摘Conventional plastics exacerbate climate change by generating substantial amounts of greenhouse gases and solid wastes throughout their lifecycle.To address the environmental and economic challenges associated with petroleum-based plastics,bioplastics have emerged as a viable alternative.Bioplastics are a type of plastic that are either biobased,biodegradable,or both.Due to their biodegradability and renewability,bioplastics are established as earth-friendly materials that can replace nonrenewable plastics.However,early bioplastic development has been hindered by higher production costs and inferior mechanical and barrier properties compared to conventional plastics.Nevertheless,studies have shown that the addition of additives and fillers can enhance bioplastic properties.Recent advancements in bioplastics have incorporated special additives like antibacterial,antifungal,and antioxidant agents,offering added values and unique properties for specific applications in various sectors.For instance,integrating antibacterial additives into bioplastics enables the creation of active food packaging,extending the shelf-life of food by inhibiting spoilage-causing bacteria and microorganisms.Moreover,bioplastics with antioxidant additives can be applied in wound dressings,accelerating wound healing by preventing oxidative damage to cells and tissues.These innovative bioplastic developments offer promising opportunities for developing sustainable and practical solutions in various fields.Within this review are two main focuses:an outline of the bioplastic classifications to understand how they fit in as the coveted conventional plastics substitute and an overview of the recent bioplastic innovations in the antibacterial,antifungal,and antioxidant applications.We cover the use of different polymers and additives,presenting the findings and potential applications within the last decade.Although current research primarily focuses on food packaging and biomedicine,the exploration of bioplastics with specialized properties is still in its early stages,offering a wide range of undiscovered opportunities.
基金supported by the project GreenPalm of the PRIMA European Action,Project 25/Section II-2019,PCI2020-112088 MINECOsupported by the project"Joint Tunisian Moroccan laboratory:Laboratory of Plant Physiology and Biotechnology and Climate Change(LR11ES09).
文摘The environment suffers more and more from the accumulation of plastics made by petrochemical rows,which are non-biodegradable.That is why this study aims to develop bio-based films by incorporating fibers concentrate of parthenocarpic date(FCPD)as easily available ingredients.The FCPD based film showed enhanced thickness,water solubility,phenol content and antioxidant capacity.However,the transparency was reduced which enhanced the film opacity by the addition of FCPD.Scanning electronic microscopy(SEM)showed homogeneity between fibers and the constituents of the film.The addition of FCPD did not change the FTIR peaks in comparison with starch-based film.The hydroxyl index value and water contact angle showed that the hydrophilicity increases with the film FCPD percentage.In addition,the FCPDs have enhanced the microbial biodegradation of the developed films as showed by SEM.Quantitative PCR using specific primers for nine target microbial groups showed that fungi were the predominant agent of the biodegradation.Among bacteria,realtime PCR showed thatβ-Proteobacteria,Acidobacteria,Bacteriodetes andα-Proteobacteria groups were involved in film biodegradation.
基金supported by the National Natural Science Foundation of China(U23A6005 and 32171721)State Key Laboratory of Pulp and Paper Engineering(202305,2023ZD01,2023C02)+1 种基金Guangdong Province Basic and Application Basic Research Fund(2023B1515040013)the Fundamental Research Funds for the Central Universities(2023ZYGXZR045).
文摘The serious environmental threat caused by petroleum-based plastics has spurred more researches in developing substitutes from renewable sources.Starch is desirable for fabricating bioplastic due to its abundance and renewable nature.However,limitations such as brittleness,hydrophilicity,and thermal properties restrict its widespread application.To overcome these issues,covalent adaptable network was constructed to fabricate a fully bio-based starch plastic with multiple advantages via Schiff base reactions.This strategy endowed starch plastic with excellent thermal processability,as evidenced by a low glass transition temperature(T_(g)=20.15℃).Through introducing Priamine with long carbon chains,the starch plastic demonstrated superior flexibility(elongation at break=45.2%)and waterproof capability(water contact angle=109.2°).Besides,it possessed a good thermal stability and self-adaptability,as well as solvent resistance and chemical degradability.This work provides a promising method to fabricate fully bio-based plastics as alternative to petroleum-based plastics.
