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Visco, A.;  Scolaro, C.;  Facchin, M.;  Brahimi, S.;  Belhamdi, H.;  Gatto, V.;  Beghetto, V. Agri-Food Wastes for Bioplastics. Encyclopedia. Available online: https://encyclopedia.pub/entry/27245 (accessed on 25 June 2024).
Visco A,  Scolaro C,  Facchin M,  Brahimi S,  Belhamdi H,  Gatto V, et al. Agri-Food Wastes for Bioplastics. Encyclopedia. Available at: https://encyclopedia.pub/entry/27245. Accessed June 25, 2024.
Visco, Annamaria, Cristina Scolaro, Manuela Facchin, Salim Brahimi, Hossem Belhamdi, Vanessa Gatto, Valentina Beghetto. "Agri-Food Wastes for Bioplastics" Encyclopedia, https://encyclopedia.pub/entry/27245 (accessed June 25, 2024).
Visco, A.,  Scolaro, C.,  Facchin, M.,  Brahimi, S.,  Belhamdi, H.,  Gatto, V., & Beghetto, V. (2022, September 16). Agri-Food Wastes for Bioplastics. In Encyclopedia. https://encyclopedia.pub/entry/27245
Visco, Annamaria, et al. "Agri-Food Wastes for Bioplastics." Encyclopedia. Web. 16 September, 2022.
Agri-Food Wastes for Bioplastics
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Agri-food wastes (such as brewer’s spent grain, olive pomace, residual pulp from fruit juice production, etc.) are produced annually in very high quantities posing a serious problem, both environmentally and economically. These wastes can be used as secondary starting materials to produce value-added goods within the principles of the circular economy. Agri-food waste is produced in large quantities and derives from many sources (from breweries, from the pressing of olives, from the production of fruit and vegetables, etc.). Consequently, the problem of their disposal arises both from the point of view of costs and means. However, precisely because these wastes represent a great added value for the substances they contain and which can be exploited, it is profitable to reuse and recycle them.

biopolymer biowaste upcycle circular economy

1. Introduction

Bioplastics are bio-based, biodegradable or compostable materials that constitute one of the most appealing alternatives for the substitution of fossil-based polymers, which can perhaps address the most pressing challenges facing Europe and the world for the protection of planet (microplastic pollution and plastic islands in the oceans and seas) [1][2].
Traditional plastics come from petrochemicals and are classified as non-biodegradable materials. Oil resources cause enormous and concerning global pollution and constitute a limited resource [3]. The transition from a linear economy to a circular economy model is necessary to plan an efficient end-of-life treatment for plastics. The present and future use of new bioplastics must be based on eco-design and the development of materials not only for their usefulness but considering their reuse and recyclability afterlife [4][5]. Fossil-based plastics production has been based on a linear economy, leading to the environmental pollution researchers face today, which has only begun to be addressed globally [6].
The growing interest in safeguarding the world has led the scientific community to develop 100% bio-based and totally biodegradable plastics, such as polylactic acid (PLA), polybutylene succinate (PBS), poly ε-caprolactone (PCL), polybutylene adipate terephthalate (PBAT), polyhydroxyalkanoate (PHA), as well as bio-polyethylene (bio-PE), bio-polypropylene (bio-PP), bio-polyethylene terephthalate (bio-PET) made from bio-based building blocks [1].

2. Bioplastic Upcycling

As is known, polymer upcycling may be achieved by different recycling techniques: primary and secondary recycling are mechanical recycling, followed by tertiary or chemical recycling (feedstock recycling), and the last or quaternary recycling is an incineration process to recover energy. During mechanical recycling, thermoplastic materials are subjected to repeated processing steps that melt and stress the molten macromolecules. Thus, thermo-oxidative ageing occurs, which progressively shortens the life of the material [7].
For biobased non-biodegradable plastics, such as olefin biopolymers (i.e., bio-PE, bio-PP and biopolyamides (bio-PAs), the recycling process is equivalent to that employed for fossil-based polymers. According to literature studies and waste hierarchy, primary and secondary mechanical recycling are envisioned, followed by chemical recycling and energy recovery [8]. Bio-based/non-biodegradable bioplastics (like Bio-PET and bio-PE) maintain their mechanical properties for a reasonable number of recycled materials, then they may be chemically treated to recover the monomers used for re-polymerization [7][9].
Regarding biodegradable bioplastics, most of today’s post-consumer biodegradable biopolymers are used to produce compost, fertilizers, or biogas [10]. In the case of biopolymers, a distinction must be made between non-biodegradable and biodegradable polymers. It is possible to evaluate a recycling scenario for biodegradable biopolymers before their final biodegradation. In general, mechanical recycling is the simplest method from an economic, technological, and environmental point of view.
Maga and co-workers carried out a Life Cycle Assessment study (LCA) to evaluate the environmental impact of different recycling techniques starting from virgin PLA or blends of virgin and recycled PLA, compared to incineration. Depending on the recycling technology, savings in greenhouse emissions are 0.3 to 1.2 times higher compared to thermal treatment. The LCA study also evaluates the benefits derived from reduced fossil resource depletion, agricultural land occupation, photochemical ozone formation, terrestrial and aquatic eutrophication, and acidification. The study amply demonstrates that the recycling of PLA can contribute to a better environmental performance of PLA products in their life cycle. More information on LCA studies regarding different biodegradable biopolymers has also been reported [11][12][13].
Nevertheless, although the recyclability of biopolymers has been demonstrated, industrialization is still struggling [14]. It should be considered that for meaningful and cost-effective recycling of plastics and bioplastic, a critical mass of recyclable plastic is needed. In the case of biopolymers, this is difficult to obtain since their actual production still represents only a few units in terms of a percentage compared to the production of fossil-based plastics [15]. It has been estimated that 200 thousand tons are the minimum production quantity required to justify, from an economic point of view, the construction of a dedicated recycling plant processing around 5 and 18 kT/year of the polymer [7]. Considering that PLA production has reached approximately 200 kT worldwide in 2018 [16], these recycling facilities may soon be available. Nevertheless, this will be possible only if an adequate separation of PLA is carried out by converters and consumers. It is for this reason that the association of Plastics Recyclers Europe recently launched a call for the development of separate recycling streams for biodegradable plastics to improve waste management efficiency throughout Europe.
Few examples are reported in the literature relative to primary mechanical recycling of biodegradable aliphatic polyesters, and in particular of PLA, which is the most used biodegradable plastic [8][17][18]. The primary mechanical recycling of PLA takes place through the collection, washing and subsequent reprocessing of the material. This last step takes place with heat treatment and can compromise the properties of the material since thermomechanical degradation decreases the molecular weight of the polymer. This implies that recycled PLA is downgraded to a less demanding use. The 3D-printed PLA can only go through two recycles. A possible alternative to extend recycling could be to combine recycled PLA together with virgin PLA; however, the number of cycles is limited [8].
Examples of secondary mechanical recycling of bio-derived biodegradable post-consumer plastics show that compared to fossil-based plastics, biopolymers are less resistant to mechanical recycling and present greater problems, including thermal degradation, strong hygroscopicity, low glass transition value and low crystallization kinetics.
Furthermore, plastics are often loaded with fillers to specifically enhance certain properties. Both small percentages by weight (e.g., 0.5 wt%) [19] but also up to consistent percentages by weight (even 40–50 wt%) [20] are used. These fillers can be of biological origin as well as other types of reinforcing fillers. Additives and compatibilisers can also be added to the bioplastic blend and, in some cases, negatively influence mechanical recycling [18].
Hubbe and co-workers summarised literature works published between 2009 and 2021 in their review regarding the recycling of cellulose-reinforced PLA and PHB composites. These data show that given the nature of the fibres used, the material could be reprocessed up to 10 times in the best conditions, down to no more than three times in the worst conditions [14].
Overall, mechanically recycled post-consumer biodegradable bioplastics generally fail to guarantee good mechanical performance, so much is to be done to achieve this important target.

2.1. Blends of Bio-Based and Fossil-Based Polymers

Bio-based Plastics (B-bP) may be processed in combination with Fossil-based Polymers (F-bP) to achieve polymeric blends. In general, different parameters must be evaluated to obtain suitable physical-mechanical characteristics of the final polymeric blends [21][22]. This strategy may be adopted to reduce production costs improving market competitiveness, but it must be considered that polymeric blends’ recyclability may be compromised since increasing percentages of B-bP added to F-bP ones, or vice versa, may interfere with conventional recycling techniques [23].
Even in the best cases, when bio-based non-biodegradable plastics, such as bio-PP, bio-PE, and bio-PET are recycled together with their fossil counterparts, they can only be mechanically recycled or incinerated to produce energy [21]. If small quantities of PLA, even as low as 1 wt%, are mixed with PET in mechanical recycling operations, the thermomechanical properties of recycled PET are compromised. These data further highlight the complexity of bio- and fossil-based plastics disposal and management, requiring accurate separation by consumers [8].
Blends made primarily of biopolymers containing small quantities of fossil-based plastics may lose biodegradability and compostability [24][25][26].
The low miscibility of bio-derived, biodegradable plastics with other fossil-based plastics makes it difficult to recycle bioplastics; consequently, only very small quantities, around 2%, may be added not to compromise the final quantities of the product [17].
Overall blends containing bio- and fossil-based polymers, although less expensive, have not yet raised the interest of the industry, and further studies are necessary to reach the quality standards necessary for the scope.

2.2. The Composting/Landfilling of Bioplastics

Compost is the result of the bio-oxidation and humification of organic materials by macro- and microorganisms in the presence of oxygen. The gases generated during these processes in the soil (such as carbon dioxide (CO2) and/or methane (CH4) increase the GWP100 parameter (global warming potential), which indicates the number of greenhouse gases (GHG) produced. Landfill represents the final stage of bioplastics disposal and must be carried out according to specific regulations [10].
The industrial composting process of PLA, for example, is done at 60 °C for approximately 30 days and produces only water and carbon dioxide with a slow rate of biodegradation [27]. Despite the advantageous property of polymers made from renewable resources, inappropriate end-of-life management can contribute to plastic pollution: bioplastics need to be collected and appropriately treated industrially and not left free as waste in the environment. Furthermore, contradictory scientific data exist in the literature on the biodegradability of PLA [28]. In soil or domestic composting machines, degradation can take up to a year with temperatures of 20 °C.

3. BioWaste for Bioplastic: Pros and Cons

3.1. From Agri-Food Waste to Biopolymers

According to the Food and Agriculture Organization (FAO) 2019 annual report, agri-food production worldwide was around 1.3 billion tons [29]. Food Losses and Waste (FLW) are serious economic and environmental problems, so FLW represents a global challenge due to its environmental impact [30]. FLWs contain high levels of vitamins, minerals, fibres, and proteins but do not meet food standards adequately and cannot be converted back into food. In these conditions, agri-food by-products become waste requiring disposal, possibly in landfills.
Alternatively, organic food waste can be transformed into materials with high added value. Consequently, there is a growing interest in the exploitation of this waste for other purposes, such as the production of bioplastics [31][32]. Thanks to their protein and polysaccharide content, indeed, eco-friendly bioplastics can be produced from renewable sources like casein [33], pear pomace and ricotta whey [34], watermelon [35], starch and sugarcane bagasse pulp [36], banana peel [37], lignin-cellulosic crop residues [38][39], soybean oil [40], grass pea [41], and algae [42].
The production of bio-based polymers from renewable sources and microbial synthesis has the advantages in that they are cheap, scalable, and have a minimal impact on the environment compared to the chemical synthesis of plastics from fossil sources (pros) [43].
The most common applications of bioplastics from agri-food waste are food packaging, hygiene products, coatings, scaffolds, absorbent and superabsorbent materials, as well as agriculture, automotive, construction, and medical materials [40][44]. Despite the development of advanced synthetic methods and their possible applications in the various sectors, commercial production is limited by production costs, which can be high to make them competitive compared to traditional plastics [30]. In addition, it will be necessary to implement production technologies specifically for bioplastics (such as electrospinning or 3D printing) [44].
Bioplastic production is also limited by other problems (cons):
  • The life of the product is limited by the fact that natural biopolymers are susceptible to hydrolytic attack by water, which compromises their mechanical strength;
  • The final biodegradation process can be another problem because it can be long and difficult and should be carried out industrially according to the required standards;
  • The availability of virgin biomass and of agri-food waste is linked to the global variability of the various geographical areas based on the typical crops of the various countries. Sustainability is a primary criterion that conditions the choice of the type of starting material;
  • The production of biopolymers requires high quantities of agro-waste: this is made difficult by the fact that there is still no well-organised separate collection of agri-food waste.
Considering a balance between the pros and cons listed thus far, it is immediately clear that there are more organizational difficulties and cons than advantages. However, factors such as the primary good of public health, and the protection of the planet, combined with the need to dispose of large quantities of waste produced, make it necessary to search for more adequate technologies and organizational methods than those currently existing for agri-food waste treatment. This also coincides with the necessity to solve the problem of plastic pollution.
Bioplastics are used in an increasing number of markets, from packaging, catering products, consumer electronics, automotive, agriculture/horticulture and toys to textiles and several other segments. Packaging remains the largest field of application for bioplastics with 47 percent (0.99 million tonnes) of the total bioplastics market in 2020. However, the portfolio of the application continues to diversify. Certain industries, such as automotive and transport, building and construction, or electric and electronics, remain on the rise with growing capacities of functional polymers. With a growing number of materials, applications, and products, the number of manufacturers, converters and end-users also increases steadily. Significant financial investments have been made into production and marketing to guide and accompany this development.
The factors driving market development are both internal and external. External factors make bioplastics an attractive choice. This is reflected in the high rate of consumer acceptance. Moreover, the extensively publicized effects of climate change, price increases of fossil materials, and the increasing dependence on fossil resources also contribute to bioplastics being viewed favorably. According to the latest Eurobarometer survey conducted by the European Commission, about 90 percent of European customers want to buy products with a minimal impact on the environment [45].
From an internal perspective, bioplastics are efficient and technologically mature materials. They can improve the balance between the environmental benefits and the environmental impact of plastics. Life cycle analyses demonstrate that bioplastics can significantly reduce CO2 emissions compared to conventional plastics (depending on the material and application).
Biopolymers currently have a higher cost compared to FbP polymers. Thus, in theory, it should be more convenient to use FbP. Nonetheless, there is a key factor that contributes to changing the rules of the game and economic perspectives—today’s consumers accept that they must pay more for products with higher sustainability. The higher prices of finished goods made with biopolymers drive more of a margin in the supply chain, thus neutralising the difference in the price of biomass-derived feedstocks and polymers. This fact is clearly demonstrated by plastic and bioplastic coffee capsules. Coffee capsules from fossil-based plastics have a price between 18.50/20.00 €, while bioplastic capsules have a premium price of about 25 € euro for 100 pieces.
This is a clear example that customers will pay higher prices for more sustainable products. Interestingly, even if biopolymers have higher prices, the higher price paid by final consumers for PLA capsules generates higher margins, making bioplastics profitable.

3.2. Use of Agri-Food Waste as Filler

As an alternative to the use of agri-food waste to produce building blocks for biopolymer synthesis, as discussed in Section 3.1, FLW can be used as filler in plastics or bioplastics. Typical bioproducts employed as fillers are lignocellulosic, starch, or fats from food waste in which the protein fraction is mostly relegated to low-value applications (e.g., animal food).
The interest in this direction is increasingly pushing researchers to study new methods to integrate fillers deriving from agri-food waste in different weight percentages with various thermoplastic and thermoset polymers.
Many studies have been carried out on the biodegradability of biocomposites from agricultural waste to push the industry to implement these materials on a large-scale [46][47].
Petroleum-based thermoplastics (such as HDPE-high density polyethylene, PP-polypropylene, and PVC-polyvinyl chloride) can be blended with fillers obtained from waste produced from the processing of grain, rice, sorghum, millet, walnuts, coconut, coffee, cotton, peanuts, sugar cane, flax, hemp, jute, straw, wood fibre, rice husk, wheat, barley, oats, rye, bamboo, kenaf, ramie, sisal, coconut fibre, kapok, raffia, banana fibre, pineapple leaf and papyrus fibre [46][47].
Petroleum-based thermoset polymeric matrixes (like epoxy resin, polyester, vinyl-ester, polybutylenes adipate-co-terephthalate (PBAT), polybutylene succinate (PBS) [48] or rubber [49] can also be blended with natural fibres. The latter can be useful for lightweight structural applications (wall insulation boards, roofing sheets, building boards, tiles) [50], and the evaluation of the best filler content is a key factor in the resulting mechanical and wear behaviour of such composites [51].
The scientific community at large agrees that the big plus of these types of composites is the low cost of agricultural waste used as filler. The moderate mechanical properties, and the long procedural steps to lower the fibre’s moisture content for the hydrophilic character of these materials, especially the lignin cellulosic, are important aspects to consider. This could be the consequence of the incompatibility between the hydrophobic thermoplastic matrix and the hydrophilic fibres [52]. Thus, the fibre–polymer interface interactions should be optimised for the improvement of the physical-mechanical features of such composites [53]. The intrinsic hydrophilicity of natural fibres deteriorates the bond between the polymer matrix and the fibre, thus compromising the final properties of the composite. In addition, the thermal instability of the natural fibres constitutes a drawback in the application and, therefore, in the temperature of use of composite materials reinforced with natural fibres [54].
However, the replacement of harmful petroleum-derived materials, such as polymers and additives, with more sustainable alternatives is the current trend in the modern polymer composite industry; therefore, everything must be done to overcome these limits.
Current applications in this direction are focused specifically on the use of bioplastics, rather than fossil-derived plastics, to have a 100% bioproduct filled with biowaste. The most common biopolymers are PHA (poly-hydroxy-alkenoate), PHBV (poly (3-hydroxybutyrate-co-3-hydroxyvalerate), PHB-co-HH (poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), PBS (polybutylene succinate), PLA (polylactic acid), PCL (poly-ε caprolactone), PBAT (polybutylene-adipate-co-terephthalate).
Generally, PHA or PHBV are blended with biofillers such as agave fibre, wood flour, bran fibre, pineapple leaf fibre, jute, or hemp, or they are coated with olive leaf extract to observe the change in thermal and mechanical behaviour, water absorption, the degree of biodegradation, and to check the fibre–matrix interface with and without surface treatments to compatibilise the two phases to enhance their adhesion [55][56][57][58][59].
Below, researachers present the main findings of the publications on thermoplastic biopolymers mixed with agri-food waste as filler. These studies have highlighted the importance of the pre-treatment of agri-food waste and the optimization of both qualitative and quantitative chemical composition before the creation of mixtures with bioplastics to obtain the best physical-mechanical performance of the final products.
Giubilini and co-workers [60] studied mixtures of oat shells (8% by weight) with biopolymers PHB-co-HH to obtain a composite in which the presence of the filler slightly increases the mechanical properties in terms of stiffness without compromising deformability. A compatibiliser (silane) is necessary to increase the affinity between filler and matrix. They highlighted that the proposed blend represents a worthy valorisation of an agri-food industrial waste.
Nanni and Messori considered agri-food waste derived from wine. The fillers were extracts of seeds and wine lees mixed with PHB for different purposes. After the physical-mechanical characterization of the blends and their biodegradation analysis, the researchers stated that these eco-friendly and cost-effective bio composites could find space in large-scale disposable applications where heat resistance and fast biodegradability are required simultaneously [61].
In addition, Chan and co-workers studied the natural weathering of a composite based on PHBV and wood flour (WF) at 50% by weight. The presence of WF slows down the degradation induced by humidity, and it controls the stability of the composites under natural atmospheric agents [62].
Another interesting study proposed the production of disposable cutlery made using three flours (grape, millet, wheat) mixed with xanthan and palm oil as possible replacement products for plastic materials. The researchers created biodegradable spoons as an example of an ecological way to reduce the consumption of plastic [63].
PBS can be blended with hollow fruit bunch fibre (FFB), bamboo fibre (BF), rice straws and apple pomace (AP), typically with an extruder blending process [64][65][66][67]. Sometimes the fibres are treated as in the case of bamboo fibres, with an alkali treatment to remove the hydrophobic component from the surface of the fibres. Physical, morphological, and mechanical characterizations were carried out. The best percentages by weight of the filler were determined in order to not compromise the mechanical properties of the PBS. Particularly interesting results were obtained, with apple pomace added even up to 50 wt%. In this case, the PBS was crimped with maleic anhydride to increase interfacial adhesion with AP. It has been verified that the resilience of PBS can reach up to 150%, confirming that AP acts as a reinforcing filler [67].
The PLA can be reinforced with other biofibres such as jute for making linen, Kenaf, and lemongrass (besides bamboo) to have fully biodegradable green composites. Usually, the presence of the fibres enhances the thermal stability of the composites and their mechanical tensile/flexural modulus and strength [68][69][70]. Some researchers considered PLA blended with PBS [71][72], with natural rubber [73], or PLA grafted with maleic anhydride to improve the fibre–matrix compatibility.
Hejna studied PCL filled with waste lignocellulose materials, such as brewers’ spent grain (BSG). This also highlights the need for a pre-treatment of the filling due to the insufficient interfacial biopolymer/biological waste interaction. Thermomechanical treatment can change the chemical structure of the agro-waste; the filler size decreases, and the surface area increases with an improvement in compatibility and mechanical performance of the composite. The same researchers suggested that BSG and other natural materials (e.g., by-products of the coffee industry and other waste from various industrial sectors) may also be used as antioxidants to improve the oxidative stability of polymeric materials [74].
PBAT can be added with micro-crystalline cellulose (MCC) with coffee husk (CH) and rice husk (RH) with hemp fibre (HF) or grape pomace (GP) [75][76]. When the filler is added without a compatibiliser, smaller quantities can be used (for example, up to 20% by weight in the case of MCC) because, beyond this threshold, the presence of the filler can create cracks in the interface matrix of the fibre, which propagate premature fracturing of the the materials [77]. On the other hand, if compatibilisers (for example, silanes) are used, the higher wt% of filler can be used. Lule and co-workers prepared a biocomposite PBAT containing a high biofiller load (up to 40 wt%). In addition, in this case, there was an increase in the Young’s modulus and a reduction in production cost by 32%, making this composite competitive with the other polymers [78].
Some researchers studied specific applications (of both animal and vegetable wastes) to be added to thermosetting matrices: Savio and co-workers [79] considered sheep’s wool, used as a matrix mixed with filling powders (pre-treated with various chemical steps and heat treatments) to produce panels for thermo-acoustic insulation in a circular economy perspective. Hidayat and co-workers [80] proposed the production of an eco-friendly and formaldehyde-free particleboard panel from agro-industrial residues (cassava stem, sengon wood waste, and rice husk) bonded with a natural rubber latex-based adhesive. The researchers of [80] suggested that agricultural waste (corn cob, peanut peel, cassava peel, cocoa peel, plantain peel, rubber seed husk) can be added to natural gums to reduce consumption or improve product quality. Some researchers studied natural rubber with cocoa pod husks and rubber seed husks in the amount of 40 wt%: the encouraging results of these studies indicate again that agricultural waste products have great potential also as fillers for natural rubber compounds [81][82].
A deep evaluation of the features of bio-based blends is necessary to implement the use of biofillers for new bioplastics as alternatives to traditional fossil-based ones. The physical-chemical-mechanical performances of traditional fossil plastics have been studied for a long time and implemented with various expedients since the last century, and the process has continued in recent decades. Given the new geopolitical trends for the protection of the planet and for a circular economy, these studies will be a starting point for the almost complete future replacement of fossil plastics with bioplastics. From the encouraging results of the scientific community, it is believed researchers are headed in the right direction to advance these sustainable methods.

References

  1. Di Bartolo, A.; Infurna, G.; Dintcheva, N.T. A review of bioplastics and their adoption in the circular economy. Polymers 2021, 13, 1229.
  2. European Bioplastics. Market Update 2020: Bioplastics Continue to Become Mainstream as the Global Bioplastics Market Is Set to Grow by 36 Percent over the Next 5 Years. Available online: https://www.european-bioplastics.org/market-update-2020-bioplastics-continue-to-become-mainstream-as-the-global-bioplastics-market-is-set-to-grow-by-36-percent-over-the-next-5-years/ (accessed on 26 April 2022).
  3. Shafiee, S.; Topal, E. When will fossil fuel reserves be diminished? Energy Policy. 2009, 37, 181–189.
  4. Payne, J.; McKeown, P.; Jones, M.D. Stability. A circular economy approach to plastic waste. Polym. Degrad. Stab. 2019, 165, 170–181.
  5. Huysman, S.; De Schaepmeester, J.; Ragaert, K.; Dewulf, J.; De Meester, S. Performance indicators for a circular economy: A case study on post-industrial plastic waste. Resour. Conserv. Recycl. 2017, 120, 46–54.
  6. The Earthbound Report. Plastics in a Linear Economy. Available online: https://earthbound.report/2016/01/26/plastics-in-a-linear-economy/ (accessed on 26 April 2022).
  7. Lamberti, F.M.; Román-Ramírez, L.A.; Wood, J. Environment, t. Recycling of bioplastics: Routes and benefits. J. Polym. Environ. 2020, 28, 2551–2571.
  8. Fredi, G.; Dorigato, A. Recycling of bioplastic waste: A review. Adv. Ind. Eng. Polym. Res. 2021, 4, 159–177.
  9. Goodship, V. Plastic recycling. Sci. Prog. 2007, 90, 245–268.
  10. Hottle, T.A.; Bilec, M.M.; Landis, A.E. Biopolymer production and end of life comparisons using life cycle assessment. Resour. Conserva. Recycl. 2017, 122, 295–306.
  11. Ramesh, P.; Vinodh, S. State of art review on Life Cycle Assessment of polymers. Int. J. Sust. Eng. 2020, 13, 411–422.
  12. Bishop, G.; Styles, D.; Lens, P.N. Environmental performance comparison of bioplastics and petrochemical plastics: A review of life cycle assessment (LCA) methodological decisions. Resour. Conserv. Recycl. 2021, 168, 105451.
  13. Cosate de Andrade, M.F.; Souza, P.; Cavalett, O.; Morales, A.R. Life cycle assessment of poly (lactic acid)(PLA): Comparison between chemical recycling, mechanical recycling and composting. J. Polym. Environ. 2016, 24, 372–384.
  14. Hubbe, M.A.; Lavoine, N.; Lucia, L.A.; Dou, C. Formulating bioplastic composites for biodegradability, recycling, and performance: A Review. Bioresources 2021, 16, 2021–2083.
  15. Cornell, D.D. Biopolymers in the existing postconsumer plastics recycling stream. J. Polym. Environ. 2007, 15, 295–299.
  16. Beltrán, F.R.; Gaspar, G.; Dadras Chomachayi, M.; Jalali-Arani, A.; Lozano-Pérez, A.A.; Cenis, J.L.; de la Orden, M.U.; Pérez, E.; Martínez Urreaga, J.M. Influence of addition of organic fillers on the properties of mechanically recycled PLA. Environ. Sci. Pollut. Res. 2021, 28, 24291–24304.
  17. Niaounakis, M. Recycling of biopolymers–the patent perspective. Eur. Polym. J. 2019, 114, 464–475.
  18. Soroudi, A.; Jakubowicz, I. Recycling of bioplastics, their blends and biocomposites: A review. Eur. Polym. J. 2013, 49, 2839–2858.
  19. Vidakis, N.; Petousis, M.; Velidakis, E.; Tzounis, L.; Mountakis, N.; Kechagias, J.; Grammatikos, S.J. Optimization of the filler concentration on fused filament fabrication 3d printed polypropylene with titanium dioxide nanocomposites. Materials 2021, 14, 3076.
  20. Fallon, J.J.; McKnight, S.H.; Bortner, M.J. Highly loaded fiber filled polymers for material extrusion: A review of current understanding. Addit. Manuf. 2019, 30, 100810.
  21. Luzi, F.; Torre, L.; Kenny, J.M.; Puglia, D. Bio-and fossil-based polymeric blends and nanocomposites for packaging: Structure–property relationship. Materials 2019, 12, 471.
  22. Aontee, A.; Sutapun, W. Effect of blend ratio on phase morphology and mechanical properties of high density polyethylene and poly (butylene succinate) blend. Proc. Adv. Mater. Res. 2013, 747, 555–559.
  23. Lackner, M. Bioplastics-Biobased plastics as renewable and/or biodegradable alternatives to petroplastics. In Kirk-Othmer Encyclopedia of Chemical Technology, 6th ed.; Wiley: Hoboken, NJ, USA, 2015; Volume 1, pp. 1–41.
  24. Alaerts, L.; Augustinus, M.; Van Acker, K. Impact of bio-based plastics on current recycling of plastics. Sustainability 2018, 10, 1487.
  25. Lambert, S.; Wagner, M. Environmental performance of bio-based and biodegradable plastics: The road ahead. Chem. Soc. Rev. 2017, 46, 6855–6871.
  26. Gironi, F.; Piemonte, V. Bioplastics and petroleum-based plastics: Strengths and weaknesses. Energ. Source, Part A 2011, 33, 1949–1959.
  27. McKeown, P.; Jones, M.D. The chemical recycling of PLA: A review. Sustain. Chem. 2020, 1, 1.
  28. Haider, T.P.; Völker, C.; Kramm, J.; Landfester, K.; Wurm, F.R. Plastics of the future? The impact of biodegradable polymers on the environment and on society. Angew. Chem. Int. Ed. 2019, 58, 50–62.
  29. Tsang, Y.F.; Kumar, V.; Samadar, P.; Yang, Y.; Lee, J.; Ok, Y.S.; Song, H.; Kim, K.-H.; Kwon, E.E.; Jeon, Y.J. Production of bioplastic through food waste valorization. Environ. Int. 2019, 127, 625–644.
  30. Otoni, C.G.; Azeredo, H.M.; Mattos, B.D.; Beaumont, M.; Correa, D.S.; Rojas, O.J. The Food–Materials Nexus: Next Generation Bioplastics and Advanced Materials from Agri-Food Residues. Adv. Mater. 2021, 33, 2102520.
  31. Yu, J. Production of green bioplastics from agri-food chain residues and co-products. In Handbook of Waste Management and Co-Product Recovery in Food Processing; Woodhead Publishing: Cambridge, UK, 2009; Volume 2, pp. 515–536.
  32. Gill, M. Bioplastic: A better alternative to plastics. Int. J. Res. Appl. Nat. Soc. Sci. 2014, 2, 115–120.
  33. Ohga. A Sustainable Bioplastic from a Milk Protein. Available online: https://www.ohga.it/una-bioplastica-sostenibile-da-una-proteina-del-latte/ (accessed on 27 April 2022).
  34. Dedenaro, G.; Costa, S.; Rugiero, I.; Pedrini, P.; Tamburini, E. Valorization of agri-food waste via fermentation: Production of L-lactic acid as a building block for the synthesis of biopolymers. Appl. Sci. 2016, 6, 379.
  35. Awasthi, M.K.; Kumar, V.; Yadav, V.; Sarsaiya, S.; Awasthi, S.K.; Sindhu, R.; Binod, P.; Kumar, V.; Pandey, A.; Zhang, Z. Current state of the art biotechnological strategies for conversion of watermelon wastes residues to biopolymers production: A review. Chemosphere 2021, 290, 133310.
  36. Hamid, L.; Elhady, S.; Abdelkareem, A.; Fahim, I. Fabricating Starch-Based Bioplastic Reinforced with Bagasse for Food Packaging. Circ. Econ. Sustain. 2022, 2, 1–12.
  37. Manimaran, D.S.; Nadaraja, K.; Vellu, J.; Francisco, V.; Kanesen, K.; BinYusoff, Z. Production of biodegradable plastic from banana peel. Petrochem. Eng. 2016, 1, 1–7.
  38. Wang, J.; Liu, S.; Huang, J.; Qu, Z. A review on polyhydroxyalkanoate production from agricultural waste Biomass: Development, Advances, circular Approach, and challenges. Bioresour. Technol. 2021, 342, 126008.
  39. Koul, B.; Yakoob, M.; Shah, M.P. Agricultural waste management strategies for environmental sustainability. Environ. Res. 2022, 206, 112285.
  40. Jiménez-Rosado, M.; Maigret, J.-E.; Perez-Puyana, V.; Romero, A.; Lourdin, D. Revaluation of a Soy Protein By-product in Eco-friendly Bioplastics by Extrusion. J. Polym. Environ. 2022, 30, 1587–1599.
  41. Giosafatto, C.V.L.; Al-Asmar, A.; D’Angelo, A.; Roviello, V.; Esposito, M.; Mariniello, L. Preparation and characterization of bioplastics from grass pea flour cast in the presence of microbial transglutaminase. Coatings 2018, 8, 435.
  42. Chia, W.Y.; Tang, D.Y.Y.; Khoo, K.S.; Lup, A.N.K.; Chew, K.W. Nature’s fight against plastic pollution: Algae for plastic biodegradation and bioplastics production. Envir. Sci. Ecotech. 2020, 4, 100065.
  43. Maraveas, C. Production of sustainable and biodegradable polymers from agricultural waste. Polymers 2020, 12, 1127.
  44. Álvarez-Castillo, E.; Felix, M.; Bengoechea, C.; Guerrero, A. Proteins from agri-food industrial biowastes or co-products and their applications as green materials. Foods 2021, 10, 981.
  45. Standard Eurobarometer 96—Winter 2021–2022. Available online: https://europa.eu/eurobarometer/surveys/detail/2553 (accessed on 8 June 2022).
  46. Abba, H.A.; Nur, I.Z.; Salit, S.M. Review of agro waste plastic composites production. J. Miner. Mater. Charact. Eng. 2013, 1, 271–279.
  47. Taj, S.; Munawar, M.A.; Khan, S. Natural fiber-reinforced polymer composites. Proc. Pakistan Acad. Sci. 2007, 44, 129.
  48. Raju, G.; Kumarappa, S.; Gaitonde, V.N. Mechanical and physical characterization of agricultural waste reinforced polymer composites. J. Mater. Environ. Sci. 2012, 3, 907–916.
  49. Zaaba, N.F.; Ismail, H. A review on peanut shell powder reinforced polymer composites. Polym-Plast. Technol. Mater. 2019, 58, 349–365.
  50. Dubey, S.C.; Mishra, V.; Sharma, A. A review on polymer composite with waste material as reinforcement. Mater. Today-Proc. 2021, 47, 2846–2851.
  51. Ojha, S.; Raghavendra, G.; Acharya, S.K. A comparative investigation of bio waste filler (wood apple-coconut) reinforced polymer composites. Polym. Compos. 2014, 35, 180–185.
  52. Turmanova, S.; Genieva, S.; Vlaev, L. Obtaining some polymer composites filled with rice husks ash-a review. Int. J. Chem. 2012, 4, 62.
  53. Georgopoulos, S.T.; Tarantili, P.; Avgerinos, E.; Andreopoulos, A.; Koukios, E.G. Thermoplastic polymers reinforced with fibrous agricultural residues. Polym. Degrad. Stab. 2005, 90, 303–312.
  54. Väisänen, T.; Haapala, A.; Lappalainen, R.; Tomppo, L. Utilization of agricultural and forest industry waste and residues in natural fiber-polymer composites: A review. Waste Manag. 2016, 54, 62–73.
  55. Gallardo-Cervantes, M.; González-García, Y.; Pérez-Fonseca, A.A.; González-López, M.E.; Manríquez-González, R.; Rodrigue, D.; Robledo-Ortíz, J.R. Biodegradability and improved mechanical performance of polyhydroxyalkanoates/agave fiber biocomposites compatibilized by different strategies. J. Appl. Polym. Sci. 2021, 138, 50182.
  56. De la Ossa, J.G.; Fusco, A.; Azimi, B.; Esposito Salsano, J.; Digiacomo, M.; Coltelli, M.-B.; De Clerck, K.; Roy, I.; Macchia, M.; Lazzeri, A.J.A.S. Immunomodulatory Activity of electrospun polyhydroxyalkanoate fiber scaffolds incorporating olive leaf extract. Appl. Sci. 2021, 11, 4006.
  57. Gigante, V.; Cinelli, P.; Righetti, M.C.; Sandroni, M.; Polacco, G.; Seggiani, M.; Lazzeri, A. On the use of biobased waxes to tune thermal and mechanical properties of polyhydroxyalkanoates–bran biocomposites. Polymers 2020, 12, 2615.
  58. Wu, C.-S.; Wu, D.-Y.; Wang, S.S. Preparation, characterization, and functionality of bio-based polyhydroxyalkanoate and renewable natural fiber with waste oyster shell composites. Polym. Bull. 2021, 78, 4817–4834.
  59. Kaouche, N.; Mebrek, M.; Mokaddem, A.; Doumi, B.; Belkheir, M.; Boutaous, A. Theoretical study of the effect of the plant and synthetic fibers on the fiber-matrix interface damage of biocomposite materials based on PHAs (polyhydroxyalkanoates) biodegradable matrix. Polym. Bull. 2021, 78, 1–21.
  60. Giubilini, A.; Sciancalepore, C.; Messori, M.; Bondioli, F. Valorization of oat hull fiber from agri-food industrial waste as filler for poly (3-hydroxybutyrate-co-3-hydroxyhexanoate). J. Mater. Cycles Waste 2021, 23, 402–408.
  61. Nanni, A.; Messori, M. Effect of the wine wastes on the thermal stability, mechanical properties, and biodegradation’s rate of poly (3-hydroxybutyrate). J. Appl. Polym. Sci. 2021, 138, 49713.
  62. Chan, C.M.; Pratt, S.; Halley, P.; Richardson, D.; Werker, A.; Laycock, B.; Vandi, L.J. Mechanical and physical stability of polyhydroxyalkanoate (PHA)-based wood plastic composites (WPCs) under natural weathering. Polym. Test. 2019, 73, 214–221.
  63. Dordevic, D.; Necasova, L.; Antonic, B.; Jancikova, S.; Tremlová, B. Plastic Cutlery Alternative: Case Study with Biodegradable Spoons. Foods 2021, 10, 1612.
  64. Ayu, R.S.; Khalina, A.; Harmaen, A.S.; Zaman, K.; Isma, T.; Liu, Q.; Ilyas, R.; Lee, C.H. Characterization study of empty fruit bunch (EFB) fibers reinforcement in poly (butylene) succinate (PBS)/starch/glycerol composite sheet. Polymers 2020, 12, 1571.
  65. Pivsa-Art, S.; Pivsa-Art, W. Eco-friendly bamboo fiber-reinforced poly (butylene succinate) biocomposites. Polym. Compos. 2021, 42, 1752–1759.
  66. Bhattacharjee, S.K.; Chakraborty, G.; Kashyap, S.P.; Gupta, R.; Katiyar, V. Study of the thermal, mechanical and melt rheological properties of rice straw filled poly (butylene succinate) bio-composites through reactive extrusion process. J. Polym. Environ. 2021, 29, 1477–1488.
  67. Picard, M.C.; Rodriguez-Uribe, A.; Thimmanagari, M.; Misra, M.; Mohanty, A.K.; Valorization, B. Sustainable biocomposites from poly (butylene succinate) and apple pomace: A study on compatibilization performance. Waste Biomass Valoriz. 2020, 11, 3775–3787.
  68. Reddy, S.R.T.; Prasad, A.R.; Ramanaiah, K. Tensile and flexural properties of biodegradable jute fiber reinforced poly lactic acid composites. Mater. Today-Proc. 2021, 44, 917–921.
  69. Kanakannavar, S.; Pitchaimani, J. Fabrication and mechanical properties of braided flax fabric polylactic acid bio-composites. J. Text. Inst. 2021, 113, 833–845.
  70. Jing, H.; He, H.; Liu, H.; Huang, B.; Zhang, C. Study on properties of polylactic acid/lemongrass fiber biocomposites prepared by fused deposition modeling. Polym. Compos. 2021, 42, 973–986.
  71. Ketata, N.; Seantier, B.; Guermazi, N.; Grohens, Y. On the development of a green composites based on poly (lactic acid)/poly (butylene succinate) blend matrix reinforced by long flax fibers. Mater. Today-Proc. 2022, 52, 95–103.
  72. Rasheed, M.; Jawaid, M.; Parveez, B. Bamboo fiber based cellulose nanocrystals/poly (Lactic acid)/poly (butylene succinate) nanocomposites: Morphological, mechanical and thermal properties. Polymers 2021, 13, 1076.
  73. Alias, N.F.; Ismail, H.; Ishak, K.M.K. Poly (lactic acid)/natural rubber/kenaf biocomposites production using poly (methyl methacrylate) and epoxidized natural rubber as co-compatibilizers. Iran. Polym. J. 2021, 30, 737–749.
  74. Hejna, A. Poly (ε-Caprolactone)/Brewers’ Spent Grain Composites—The Impact of Filler Treatment on the Mechanical Performance. J. Compos. Sci. 2020, 4, 167.
  75. Zeng, D.; Zhang, L.; Jin, S.; Zhang, Y.; Xu, C.; Zhou, K.; Lu, W. Mechanical Properties and Tensile Model of Hemp-Fiber-Reinforced Poly (butylene adipate-co-terephthalate) Composite. Materials 2022, 15, 2445.
  76. Spada, J.C.; Seibert, S.F.; Tessaro, I.C. Impact of PLA Poly (Lactic Acid) and PBAT Poly (butylene adipate-co-terephthalate) coating on the properties of composites with high content of rice husk. J. Polym. Environ. 2021, 29, 1324–1331.
  77. Giri, J.; Lach, R.; Le, H.H.; Grellmann, W.; Saiter, J.-M.; Henning, S.; Radusch, H.-J.; Adhikari, R. Structural, thermal and mechanical properties of composites of poly (butylene adipate-co-terephthalate) with wheat straw microcrystalline cellulose. Polym. Bull. 2021, 78, 4779–4795.
  78. Lule, Z.C.; Wondu, E.; Kim, J. Highly rigid, fire-resistant, and sustainable polybutylene adipate terephthalate/polybutylene succinate composites reinforced with surface-treated coffee husks. J. Clean. Prod. 2021, 315, 128095.
  79. Savio, L.; Pennacchio, R.; Patrucco, A.; Manni, V.; Bosia, D. Natural Fibre Insulation Materials: Use of Textile and Agri-food Waste in a Circular Economy Perspective. Mater. Circ. Econ. 2022, 4, 1–13.
  80. Hidayat, W.; Aprilliana, N.; Asmara, S.; Bakri, S.; Hidayati, S.; Banuwa, I.S.; Lubis, M.A.R.; Iswanto, A.H. Performance of eco-friendly particleboard from agro-industrial residues bonded with formaldehyde-free natural rubber latex adhesive for interior applications. Polym. Compos. 2022, 43, 2222–2233.
  81. Masłowski, M.; Miedzianowska, J.; Strzelec, K. Natural rubber biocomposites containing corn, barley and wheat straw. Polym. Test. 2017, 63, 84–91.
  82. Okieimen, F.; Imanah, J.E. Studies in the utilization of agricultural waste products as filler in natural rubber compounds. J. Appl. Polym. Sci. 2006, 100, 2561–2564.
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