Chem. Biochem. and application of biodegradable polymers. F. Lefebvre, A. Daro, and C. David, Macromol. In this study, co-solvent for levan/PLA blend film preparation . X. H. Li, Y. This will partly depend on how It can be used as an adhesive for food coatings, as packaging for use in horticulture, guaranteeing its function as both container and fertilizer [76]. Z. Fillip, Europ. Chem. For use as fertilizers, the residue can be treated by adding more essential mineral salts to the soil with phosphorus and potassium. A PS-degrading bacterial strain Exiguobacterium sp. Environ. 90(7), 1900 (2003). Drug delivery inside the human body can be relatively easily The nat-ural isomer is L-lactide, while the synthetic mixture is D-lactide (Ayala et al . [35] Composting is a human-driven process in which biodegradation occurs under a specific set of circumstances. I. Chet, E. Cohen and I. Elster, in Chitin in Nature and Technology, edited by R. A. Muzarelli, C. Jeuniaux, and G. W. Gooday (Plenum Press, New York, 1986), p. 237. K. H. Guruprasad, G. M. Shashidara, J. Appld. The apparatus combines a pneumatic and an electric system. Biodegradable polymers are the ones that get easily decomposed in nature by the aerobic and anaerobic processes. Environmental conditions such as atmospheric pollutants, humidity, and weather strongly contribute to the overall process. 79, 977 (1976). Complete solubilization of PE in water by a Pseudomonas fluorescens treated for a month followed by biosurfactant treatment for a subsequent month in the second month and finally a 10% sodium dodecyl sulfate treatment at 60C for a third month led to complete polymer degradation. The ingested PS mass was efficiently depolymerized within the larval gut during the retention time of 24hours and converted to CO2 [51]. controlled with biodegradable capsules. 37, 1169 (1973). Chemistry, Cambridge, England, 1992), p. 245. Polymers are constructed of long chains of atoms, organized in repeating components or units often exceeding those found in nature. The microorganisms benefit from the input of energy, electrons and elements (i.e., carbon, nitrogen, oxygen, phosphorus, sulfur and so forth) required for the cell growth. [19]. The volume of waste from these activities can generate high environmental impact, since there is very little reuse on them. Reference [27] extracted microcrystalline cellulose (MCC) and spherical nanocrystalline cellulose (SNCC) by acid hydrolysis from cotton fabric waste, concluding that the developed process is suitable for industrial scale application, since the generation of cotton waste is high, as well as the cellulose content contained in them (about 94%). and Bioeng. Associated with the concern to replace materials of fossil origin, attention to the reuse of wastes/by-products of agricultural or agroindustrial origin is of extreme importance. Despite its high protein content, its reuse is restricted due to its high stiffness and low water resistance [75]. in Chitin, Chitosan and Related Enzymes, edited by J. P. Zikakis (Academic Press, Orlando, 1984), p. 147. Env. A. When combined with wind effects, pollution, and atmospheric gases, the overall process of deterioration can be quite formable. E. Schwach, L. Averous, Polymer International, 53 (12),2115 (2004). These are those polymers which get decomposed under aerobic or anaerobic conditions, as a result of the action of microorganism/enzymes. Biodegradability testing measures the complex biochemical process that occurs when microorganisms consume a given type of material. Y. Toikawa, T. Ando, T. Suzuki, and K. Takeda, in Agricultural and Synthetic Polymers. A. L. Andrady, V. R. Parthasarathy, and Ye Song, Tappi 75, April, (1992). At the end of the second biodegradation trial, a cumulated CO2 emission for the inoculum triplicates equal to gCO2vessel1 was also detected, a value then subtracted from the total cumulated CO2 emissions recorded for the reference and specimen vessels, as specified in (3). Bacteria have been found to be good sources for enzymes capable of degrading PUR polymers [75, 76, 77, 78, 79, 80, 81, 82]. 43, 253 (1953). Treatment technology for massive waste polymer treatment must be sufficiently robust to be reliable at large scale use and adaptable to conditions throughout the environment where this treatment is required. Technologies available for current polymer degradation strategies are chemical, thermal, photo, and biological techniques [2, 3, 4, 5, 6]. in Biodegradable Polymers and Plastics, edited by M. Vert, J. Feijen, A. Albertsson, et al. Recent usage finds it to be a name for materials called polymers. L. Kravetz, in Agricultural and Synthetic Polymers. 211, no. Degrad. Chem. 17, pp. Obtaining of magnetically activated cellulose fibers by moist spinning cellulose/Fe. synthesized from renewable sources, and the other class are Sci., Polym. To achieve this objective, different techniques are studied to promote modifications of biodegradable polymers, as shown in Table 3. Polypropylene (PP) is very similar to PE, in solution behavior and electrical properties. X. Ramis, A. Cadenato, Polymer Degradation and Stability, 86, 483-491 (2004). Under such energy regimes, the biofilm can detach. When used in biocomposites with PHAs, they improve biodegradation rates in all environments. Superworms (Zophobas morio) were found to exhibit similar activity toward Styrofoam. Significant polymer application can be found in the automotive, building and construction, and packaging industries [12]. 77, 445 (1977). Biodegradable Polymers: Definition Biodegradable polymers can be easily degraded by microorganisms within a reasonable period, ensuring that biodegradable polymers and their degraded products have a minimal environmental impact. The use of biodegradable polymers is spreading in agriculture to replace those materials derived from petroleum, thus reducing the environmental concerns. between 1 and 150 MPa. Investigation of polyol mixtures including glycerol as plasticizer and high molecular weight polyol such as xylitol, sorbitol and maltitol used to plasticize corn starch, it being understood that the extra addition of high molecular weight polyol together with glycerol favored an improvement of the thermal stability and mechanical strength of the starch composite. market share of biodegradable polymers is currently (2016) rather Open Access is an initiative that aims to make scientific research freely available to all. Many aliphatic polyesters have an asymmetrical carbon atom in the repeat unit which enables it to become optically active. PLA is a lactic acid cyclic dimer made from D-or L-lactic acid polycondensation or lactide ring opening polymerization. Food waste. (Wiley Interscience, New York, 1984), p. 626. Chem. Brominated high impact polystyrene (blend of polystyrene and polybutadiene) has been found to be degraded by Pseudomonas and Bacillus strains [58]. The schematic diagram of the pneumatic system is shown in Figure 1. a small number of biodegradable polyesters have found limited use outside the The blending of biodegradable polymers is one approach of reducing the overall cost of the material and modifying the desired properties and degradation rates. A. Ohtakara, H. Ogata, Y. Taketomi, and M. Mitsutomi, in Chitin, Chitosan, and Related Enzymes, edited by J. P. Zikakis (Academic Press, Orlando, 1984), p. 147. This process is experimental and the keywords may be updated as the learning algorithm improves. The copolymers of ethylene and propylene are produced in quantities that exceed 40% of plastics produced perannum with no production leveling in sight. Acta. Response to these conditions has elicited an effort to devise innovative strategies for plastic waste management, invention of biodegradable polymers, and education to promote proper disposal. As PhD students, we found it difficult to access the research we needed, so we decided to create a new Open Access publisher that levels the playing field for scientists across the world. Microbiol. Ser. Chem. Consortia composed of a combination of different bacterial strains of Pseudomonas otitidis, Bacillus cereus, and Acanthopleurobacter pedis have the ability to degrade PVC in the environment [64]. The exo-enzymes generally degrade complex polymer structure to smaller, simple units that can take in the microbial cell to complete the process of degradation. Since most polymer disposal occurs in our oxygen atmosphere, it is important to recognize that aerobic biodegradation will be our focus but environmental anaerobic conditions do exist that may be useful to polymer degradation. European Committee for Standardization (CEN), Packagingrequirements for packaging recoverable through composting and biodegradationtest scheme and evaluation criteria for the final acceptance of packaging, CEN EN 13432:2000, 2000. If called for, a specific alarm signal appears on the screen for each vessel. Res. 35, no. The biodegradation reaction for a carbon-based polymer under aerobic conditions can be formulated as follows: Assimilation of the carbon comprising the polymer (Cpolymer) by microorganisms results in conversion to CO2 and H2O with production of more microbial biomass (Cbiomass). Significant efforts have been extended to developing an understanding of the enzymatic activity of high-performing candidate enzymes through selection processes, mechanistic probes, and enzyme engineering. Figure 4 shows a very high degradation rate for both plastic polymers testedeven higher than that of the biodegradable standard (cellulose)starting right from the early stages of the trial. The inoculum employed in the biodegradation trials was the compost obtained at the end of a static composting procedure set up for OMW management, as described in Altieri and Esposito [18] and Altieri et al. Y. Toikawa and T. Suzuki, Agric. And [37] developed and evaluated an antioxidant film and pH indicator based on sources of chitosan and food waste. Thus, it is sought to use biological macromolecular materials, such as starch, chitosan, cellulose, for the formation of films [78]. Characteristics of the samples used in the trials of the experimental apparatus. Reduction of polymeric molecule size is indispensable to this process. A sheet of PS buried for 32years. Synthetic polymers are constructed of long chains of smaller molecules connected by strong chemical bonds and arranged in repeating units which provide desirable properties. The polymer properties of molecular weight, shape, size and additives are each unique features which can limit biodegradability. Biodegradability and Utilization, vol. There is an outside change that a polymer recycling technology based on these findings is a future possibility. Sci. The converse is also possible where surfaces contaminated with certain chemicals can prohibit biofilm formation. Therefore, blending with other polymers has been often reported in the literature. niger, and Aspergillus sydowii [64]. [10] also tested their own respirometric apparatus. Aliphatic polyesters are often blended with other resins to improve their Schematic diagram of the experimental apparatus. soil retention sheething and other agriculture films, waste bags, and the use T. K. Ng, A. ben-Bessat, and J. G. Zeikus, Appl. Since starch can come from a variety of plant sources, it is therefore comprehensive and has high availability, recent studies highlight the use of this biopolymer through alternative sources such as starch recovery or reuse of waste in various applications, such as residual starch from the milling process, or maize residues to obtain bioethanol [60, 61] and applications as biodegradable films as shown in Table 2. However, tensile strength and elongation at break decreased upon loading the films with wool nanoparticles. Plastics in the Environment, Submitted: April 11th, 2018 Reviewed: February 11th, 2019 Published: May 13th, 2019, Total Chapter Downloads on intechopen.com. As the microbial-colonized surface area increases, a faster biodegradation rate will be observed assuming all other environmental conditions to be equal [24]. Agricultural polymers. Ph-modified polymer compositions with enhanced biodegradability US5814404A (en) * 1994-06-03: 1998-09-29: Minnesota Mining And Manufacturing Company . PubMedGoogle Scholar, Distinguished Research Profess, UNITED KINGDOM. Sci. A polymer is easily recognized as a valuable chemical made of many repeating units [10]. Biodegradability is particularly desired in biomedical applications, in which degradation of the polymer ensures clearance from the body and eliminates the need for retrieval or explant. The biological activity inferred in the term biodegradation is predominantly composed of, biological effects but within nature biotic and abiotic features act synergistically in the organic matter degradation process. OECD Guidelines for Testing Chemicals (Organization of Economic Corporation and Development, Paris, 1981). 11, 313 (1973). Polymer biodegradation is a . Mixed and complex microbial communities have been used and encountered in different bioremediation environments [43]. Microorganisms and enzymes involved in AP degradation have been identified. It was also much lower than the rates registered in the first trial for specimens A and B (Figure 4). Ecol. In accordance with ISO 14855-1, we designed and used an experimental apparatus to evaluate the biodegradation rate of three biopolymers based on renewable resources, two poly(-caprolactone) (PCL) composites, and a compatibilized polylactic acid and polybutyrate (PLA/PBAT) blend. 297, no. Y. Yakabe and M. Kitano, in Biodegradable Plastics and Polymers, edited by Y. Doi and K. Fukuda (Elsevier Science, 1994), p. 331. Recent studies have turned their efforts to provide reuse and value adding to industrial waste. Biodegradation utilizes the functions of microbial species to convert organic substrates (polymers) to small molecular weight fragments that can be further degraded to carbon dioxide and water [16, 17, 18, 19, 20, 21]. are commercially available for controlled drug releases, implantable composites, bone fixation parts, packaging and paper coatings, sustained release systems for pesticides and fertilizers and compost bags etc. A.-C. Albertsson, B. Erlandsson, M. Hakkarainen, S. Karlsson, J. Environ. plastic surgery surgery concerned with the restoration . Polymer additives are generally low molecular weight organic chemicals that can provide a starting point for microbial colonization due to their ease of biodegradation (Figure 2). 24, 447 (1988). 11, 405 (1977). What is biodegradability? Molecules transported across the cell membrane can be oxidized through catabolic pathways for energy storage and structural cell elements. It can be found in one of the residues that in recent years have generated many problems for dairy products: whey. S. Lee, T. Ohkita, J. Appld. 57, 117 (1977). Characterization of photo-oxidative degradation process of polyolefins containing oxo . A. Corti, F. Cristiano, 7th World Conference on Biodegradable Poly- mers and Plastics, Terrenia, Ital, Kluwer Academic/Plenum Pub- lishers (2002). Polym. This corresponds to % and % biodegradation. The carbon and nitrogen content of the samples was determined using a CHNS analyser (Macro Cube, Elemental, Germany) equipped with selective traps for CO2, H2O, and SO2 and detected by thermal conductivity. The chitosan is a molecule with a carbohydrate structure like cellulose, consisting of two types of repeating units, N-acetyl-D-glucosamine and D-glucosamine, linked by 1-4 glycosidic bonds [30]. However, to issue a significant assessment, biodegradation rate must be measured in case-specific standardized conditions. There is a significant need for biodegradable polymers as a part of a new circular strategies in the "plastics age". The unique capabilities of Pseudomonas species related to degradation and metabolism of synthetic polymers requires a focus on: the interactions controlling cell surface attachment of biofilms to polymer surfaces, extracellular polymer oxidation and/or hydrolytic enzyme activity, metabolic pathways mediating polymer uptake and degradation of polymer fragments within the microbial cell through catabolism, and the importance of development of the implementation of enhancing factors such as pretreatments, microbial consortia and nutrient availability while minimizing the effects of constraining factors such as alternative carbon sources and inhibitory by-products. . Throughout the trial, we shook the samples manually once per week to achieve more homogeneity in the degradation process of the specimen. Enzyme modification may be effectively employed to improve the efficiency and specificity of the polyester degrading enzymes acknowledged to be active degraders of PET [102]. and poor hydrolytic stability, that is, they are rather hydrophilic and, therefore, will have a moderate to high water uptake when exposed to moisture. These thermosetting and thermoplastic polymers have been utilized to form microcellular foams, high performance adhesives, synthetic fibers, surface coatings, and automobile parts along with a myriad of other applications. Biodegradability and Utilization, vol. Visual observations, weight loss measurements, molar mass and mechanical properties, carbon dioxide evolution and/or oxygen consumption, radiolabeling, clear-zone formation, enzymatic degradation, and compost test under controlled conditions have been cited for their utility [27]. Anaerobic biodegradation can occur in the environment in a variety of situations. The high molar mass of PP prohibits permeation through the microbial cell membrane which thwarts metabolism by living organisms. American Chemical Society, Washington DC, 1990), p. 76. 128, 1183 (1973). D. Jendrossek, I. Knoke, R. B. Habibian, et al., J. Environ. Manufacture of a series of cellulose hydrogels directly from the cellulose solution followed by crosslinking with epichlorohydrin (ECH) via heating and freezing. Thus, the agreement was very good (1.24%). Some of the samples reached more than 80% biodegradation in less than 20 days. D. Preechawong, M. Peesan, Macromolecular Symposia 216, 217 (2004). R. D. Fields and F. Rodriguez, in Proceedings of the Third International Biodegradation Symposium, edited by J. M. Sharpley and A. M. Kaplan (Applied Science, Barking, England, 1976), p. 775. And, more recently, Pantani and Sorrentino [11] carried out biodegradation tests using a homemade respirometric machine equipped with 3L glass flasks and an infrared gas analyser. Chem. Sets of 5 labels were sealed in mesh bags to allow biodegradation and easy retrieval. Readily available exoenzymes from the colonized area can initiate the degradation process. Depending upon the Polymer biodegradation is a process in which any change in the polymer structure occurs as a result of polymer properties alteration resulting from the transformative action of microbial enzymes, molecular weight reduction, and changes to mechanical strength and surface properties attributable to microbial action. S. Doi, Mokuzai Gakkaishi 31, 843 (1985). S. Hara, Y. Yamamura, Y. Fuji, et al., in Proc. A. C. Albertsson, C. Barnstedt, and S. Karlsson, J. Environ. systems, wound The molecular weight of a polymer can be very limiting since the microbial colonization depends on surface features that enable the microorganisms to establish a locus from which to expand growth. The technological advance has stimulated the search for alternatives that can contribute to sustainability. CO2 emissions, automatically calculated for each measurement cycle and then cumulated, are converted to mass values with the following general equation:where is the flow rate measured with the gas mass meter, CO2 is the CO2 concentration measured with the IRGA sensors and corrected for the background CO2 concentration of the inlet CO2-free air, is the period of the measurement cycle, (CO2) is the molar mass of CO2, and is the volume occupied by one mole of CO2 at the exhaust-air temperature, as determined by the local in-line sensor. *Address all correspondence to: glaser.john@epa.gov. A second in-line dryer consisting of a polymethylmethacrylate, air-tight tube (diameter 3cm) containing granular calcium chloride (SIGMA-Aldrich, USA) removes the residual moisture from the exhausted air before it enters the IRGA sensors. Changes to the film surface as cavities and pits were observed using scanning electron microscopy and atomic-force microscopy. Degrad. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources) or from biological resources (renewable resources). The remarkable ability to digest a polymer considered non-edible may parallel the worms ability utilize beeswax as a food source. Oil Chem. T. L. Highley, Wood and Fiber 5, 50 (1973). Sci., 44 (11),2134 (2004). Factors affecting polymer biodegradation All polymers are more or less biodegradable to some extent due to the organic nature of their principle elements like resin and hardener. A new analysis is necessary to assist the formulation of comparative protocols to estimate biodegradability. Microorganisms can break organic chemicals into simpler chemical forms through biochemical transformation. Contrasting aerobic degradation with anaerobic conditions, the aerobic process is found to be more efficient. Sci. The automation and monitoring of all parameters is performed by means of a customized software developed within a LabVIEW environment. J. Biodegradation efficiency achieved by the microorganisms is directly related to the key properties such as molecular weight and crystallinity of the polymers. Y. Doi, in Microbial Polyesters (VCH Publisher, 1990). J. 11.5 percent. This is another factor that may imply its applicability, generating a water absorption in the material larger than the desired one. Mater. C. M. Buchanan, D. Dorschel, R. M. Gardner, R. J. Komarek, and A. W. White, J. Macromol. Zeneca, in Biopol, Natures Plastic: Properties and Processing (Zeneca, Billingham, United Kingdom, 1993). A. M. Kinnersley, T. C. Scott III, Plant Growth Regul., 137 (1990). Manufacture of flexible, transparent and fortified regenerated films by crosslinking the cellulose with epichlorohydrin (ECH) in NaOH/Urea. Most 29532972, 1997. M. Shimada and M. Takahashi, in Wood and Cellulosic Chemistry, edited by D. N.-S. Hon and N. Shiraishi (Marcel Dekker, Inc., New York, 1992), p. 625. Preparation of macroporous spheres with viscose cellulose xanthogenate densified with high density tungsten carbide via thermal regeneration in water-in-oil suspension with starch as a porogenic. Aliphatic polyesters Each of these polymers is subject to very slow fragmentation to form small particles in a process expected to require centuries of exposure to photo-, physical, and biological degradation processes. 433, edited by J. E. Glass and G. Swift (ACS Symposium Series, Washington, DC, 1989), p. 136. Their biodegradation conducted in olive-mill waste compost used as inoculum was proved in a very short time. 31, 1200 (1992). 2022 Springer Nature Switzerland AG. By Alessio Gomiero, Pierluigi Strafella and Gianna Fabi. The best solution for decreasing this plastic pollution is using biodegradable plastics. In addition, a large amount of partially biodegradable polymer blends may be inadvertently produced as a consequence of the recycling of biodegradable polymers together with conventional non-biodegradable polymers. Gelatin from leather residue can be reused to produce films for soil cover [72]. Deg. Micro- biol. The development and innovation of products and processes considering the environment are highlighted in this book. 77, 224 (1983). Microbial ureases, esterases and proteases can enable the hydrolysis the carbamate and ester bonds of a PUR polymer [71, 73, 74]. A polyethylene (PE) film (sample D) was used as negative reference. Today, the global competition to produce biodegradable materials is attracting the attention of a variety of scientific branches and commercial sectors (food, packaging, and agroindustries), and it has become even more crucial to identify the true biodegradability of new goods put on the marketsome of which are merely self-proclaimed biodegradable. Biodegradation results from the action of naturally occurring heterotrophic microorganisms, such as bacteria and fungi. Polym. Aliphatic polyesters are the most commonly used polymers of this type. Globally consumed at a pace of some 311 million tons per year with 90% having a petroleum origin, plastic materials have become a major worldwide solid waste problem. However, during the weekly shaking procedure, moisture was controlled by weighing each vessel and distilled water was added if necessary. 1, 241 (1993). (Royal Soc. Publishing on IntechOpen allows authors to earn citations and find new collaborators, meaning more people see your work not only from your own field of study, but from other related fields too. In 1869, the first synthetic polymer was invented in response to a commercial $10,000 prize to provide a suitable replacement to ivory. Microbiol., 40, 445 (1994). Factors controlling polymer biodegradation [30]. R. A. 10061016, 2006. Biophys. A significant literature exists from which developmental directions for possible biological technologies can be discerned. For the food area, as referred in films for food coating, gelatin extracted from fish waste (bone and cartilage) can be used without contraindications, however gelatin extracted from tanning waste leather is not allowed for use by legislation, due to chrome remnants that exist in the solution. Z. Meng, Polymer Eng. Chem. The polymer chemically reacts under the influence of either cellular or extracellular enzymes whereby the polymer chain is split. When plastics are used as substrates for microorganisms, evaluation of . building blocks (aromatic acids or anhydrides). It appears that Styrofoam feeding did not lead to any lethality for the mealworms. Polymer degradation proceeds to form new products during the degradation path leading to mineralization which results in the formation of process end-products such as, e.g., CO2, H2O or CH4 [22]. In this sense, the cellulose modification has been the focus of several studies, aiming to evaluate it as a substitute raw material to obtain synthetic polymers, fibers, films and membranes, hydrogels and aerogels, bioplastics, beads and microspheres as shown in (Table 1). Collagen, in its natural form, has little application. The adsorbed pollutants can assist the material colonization by microbial species. 44, 311 (1966). Evaluation of the effect of irradiation on the physicochemical properties, rheological and invitro digestibility of the Kithul starch (. A32, 843 (1995). The distinction between aerobic and anaerobic degradation is quite important since it has been observed that anaerobic conditions support slower biodegradation kinetics. Biotechnology 2, 535 (1984). Crystallinity has been shown to play a very directing role in certain biodegradation processes on select polymers. H. Yang, J. Yoon, Polymer Degradation and Stability 87(1), 131 (2005). of Chitin and Chitosan, p. 125. Polym. 5582, pp. Sci. The characteristics are hydrophobicity/hydrophilicity, crystallinity, surface topography, functional groups on the surface, mechanical properties, and molecular weight distribution. An example of biofilm attachment and utility can be found in the waste water treatment sector where large polypropylene disks are rotated through industrial or agriculture waste water and then exposed to the atmosphere to treat pollutants through the intermediacy of cultured biofilms attached to the rotating polypropylene disk. The hydrophobicity of the polymer surface, a function of molecular structure and composition, detracts from the effectiveness of microbial attachment [56, 57]. Bacillus and Pseudomonas strains isolated from soil samples have been shown to degrade brominated high impact PS. These polymers have been so far used successfully in alternatives to more common non-biodegradable plastics to produce consumer & garbage bags, tableware, or mulch films. into two types according to the preparation method; the first class are polymers For example, L-PLA has two to three times New method of preparation of hydrated membranes of cellulose in NaOH/Urea, employing a process of pregelatinization. V. Mezanotte, R. Bertani, Polymer Degradation and Stability 87(1), 51 (2004). The activity was seen in weight loss and surface changes to the PS film. Most aliphatic polyesters are currently produced from fossil fuels. For example, they can be blended Also, in the expectation of optimizing the environmental benefits in this process, it is possible to value the agroindustrial residues, using them as raw material in the synthesis of the polymer, the physical, chemical and mechanical properties of these polymers are important to evaluate the possible applications. The question of whether bioremediation can play a significant role in the necessary management of polymer waste remains to be determined. adj. fibers. Various forms of PS such as general purpose (GPPS)/oriented polystyrene (OPS), polystyrene foam, and expanded polystyrene (EPS) foam are available for different commercial leading to a broad solid waste composition. R. A. resource utilization due to increasing population growth accompanied by the urge to manage the industrial waste has led polymers industry to adopt eco-friendly . Sci., Pure Appl. Polym. The challenge is to obtain materials with properties equivalent to synthetic products [45]. Polym. The polymer can be broken down in a hydrolysis reaction with an acid or alkali catalyst. This widespread use of plastics raises a significant threat to the environment due to the lack of proper waste management and a until recently cavalier community behavior to maintain proper control of this waste stream. Fruits. Hydro-biodegradable. H. Eya, N. Iwaki, and Y. Otsuji, in Biodegradable Plastics and Polymers, edited by Y. Doi and K. Fukuda (Elsevier Science, New York, 1994), p. 337. Aiming to reduce the environmental impacts caused in aquatic life due to the contamination of water by complex substances such as petroleum and vegetable oils, [29] developed a hydrophobic aerogel with high sorption capacity, from cellulose nanofibres obtained from waste from the furniture industry, processed via acidic hydrolysis by steam explosion for oil sorption. 2, pp. 433, edited by J. E. Glass and G. Swift (ACS Symposium Series, Washington, DC, 1990), p. 96. Deg. A. C. Albertsson, Z. G. Banhidi, and L. L. Beyer-Ericcsson, J. Appl. Biodegradable Polymer Biodegradable polymers degrade within the body as a result of natural biological processes. The molar volume of CO2 is calculated using the following:where is the ideal gas constant, is the temperature of the outlet flow, and is the atmospheric air pressure. S. M. Goheen, R. P. Wool J. Appld. Vol. The durability and the resulting low biodegradability of PET are due to the presence of repeating aromatic terephthalate units in its backbone and the corresponding limited mobility of the polymer chains [92]. When the starch is heated at a characteristic temperature called the gelatinization temperature (6070C) in aqueous solution, the swelling step of the grain occurs, where the amylose is solubilized. 2330, 1990. Biodegradable plastics are plastics that can be decomposed by the action of living organisms, usually microbes, into water, carbon dioxide, and biomass. Varying M. Weiland, C. David, Polymer Degradation and Stability 48, 275 (1995). R. Altieri, A. Esposito, and T. Nair, Novel static composting method for bioremediation of olive mill waste, International Biodeterioration & Biodegradation, vol. The worms could macerate PE as thin film shopping bags and metabolize the film to ethylene glycol which in turn biodegrades rapidly. 2, 49 (1994). Ed. (eds) Physical Properties of Polymers Handbook. These are based mainly on measuring carbon dioxide (CO2) emissions or oxygen consumption under environmentally controlled conditions [8]. Biodegradability of Polymers Anthony L. Andrady Chapter 21k Accesses 4 Citations Keywords Sewage Sludge Activate Sludge Biochemical Oxygen Demand Synthetic Polymer Biodegradable Polymer These keywords were added by machine and not by the authors. A product's ability to biodegrade depends on the amount of carbon available for microbial consumption. Their action on the polymer can be generally described as depolymerization. resorbable nonwovens are used as replacement of human tissue. Other factors couple with solar radiation synergistically to significantly influence the weathering processes. J. Biochem. This makes it possible to evaluate a wide range of different biodegradation scenarios. 65, no. Polym. They are broken down into biologically acceptable molecules that are metabolized and removed from the body via normal metabolic pathways. In general natural polymers offer fewer advantages than synthetic polymers. In this context, the use of biodegradable polymers, that use raw materials from renewable sources stand out because they have that ability to form films and come from abundant sources. These polymers have very different mechanical properties. An important property of biodegradable polyesters is the degradation time, The two strains of bacteria were shown to reduce the polymer film hydrophobicity during a 28-day incubation. At the end of the pneumatic circuit, adjacent to the IRGA sensors, there is a gas mass flow meter (Dwyer, Germany), with a flow range of 080Lh1, and an in-line thermocouple (Tersid, Italy). In 225 minutes, polymer A vessel emitted 287.8mgCO2 according to the titration method and 266.7mgCO2 according to the IRGA, a difference of 7.33%. Extraction and characterization of pineapple stems using common mechanical extraction with water. The soft and flexible form can be made through the incorporation of plasticizers such as phthalates. 83908393, 2008. Polymeric materials complexicity, structures and compositions is one of the important aspects which govern polymer biodegradation. Polym. Rev. Further research is required to provide the understanding of microbial components involved in biofilm development and regulation of their production to assemble to various facets of this complex microbial phenomenon [38]. 10, no. Am. Sci. King, in Biodeterioration of Materials, edited by A. H. Walters and J. J. Elphick (Elsevier, NY, 1968), p. 558. Crystallinity exceeding 30% in PET beverage bottles and fibers having even higher crystalline compositions presents major hurdles to enzyme-induced degradation [93, 94]. In this context divergent opinions arise about the acceptability of biodegradable polymers in industry. Biol. L. Averous, J. Macromolecular Science, Polymer Reviews C44(3), 231 (2004). The residue flow of potato starch produced during chip manufacturing was used as an economical source to produce biomass and bioethanol by, Production of biodegradable films based on thermoplastic corn starch and starch extraction residues from. Several investigations of soil bacteria for the ability to degrade PVC from enrichment cultures were conducted on different locations [66]. In order to obtain improvements in starch properties, as well as to solve some problems, starch modification has occurred, that can occur genetically, physically, chemically or even enzymatically [55]. Preparation of hydrogel from a cellulose solution in an ionic liquid of 1-butyl-3-methylimidazolium chloride and water at room temperature. It is worth noting that the check-tests were performed on days 11 and 12 of the trial, during a very active biodegradation phase. J. Biochem. Assimilation describes the integration of atoms from fragments of polymeric materials inside microbial cells. Weathering may mechanically affect the structural integrity of the plastic to permit intrusion of bacteria or fungal hyphae to initiate biodegradation at inner loci of the plastic. Books > Phys. Recovery of mixed biopolymers composed of starch and curcuminoids from the extraction of supercritical fluid and pressurized liquid. J. Appl. At that time point, the amount of cumulated CO2 emission for the inoculum triplicates was gCO2vessel1, which is the value subtracted from the cumulated CO2 emissions registered both for the reference and specimen vessels, as specified in (3). E. B. Cowling and W. Brown, Adv. 41, 2417 (1977). PUR encompass a broad field of polymer synthesis where a di- or polyisocyanate is chemically linked through carbamate (urethane) formation. / Progress in Polymer Science 71 (2017) 144-189 1. The conventional polymers such as (PE), (PP), (PS), (PUR), and (PET) are recognized for their persistence in the environment [41]. Ideal Characteristics Of Polymers In Biodegradable Delivery System Inert . Its based on principles of collaboration, unobstructed discovery, and, most importantly, scientific progression. Sci. Y. Otake, T. Kobayashi, J. Appld. 4478, pp. 27, 517 (1981). L. H. Stevenson, Microbiol. H. Shimazono, Arch. A. Cameron, and S. J. Huang, in Polmers as Biomaterials, edited by S. W. Shalaby, A. S. Hoffmann, B. D. Ratner, and T. A. Hobart (Plenum Publishers, New York, 1983), p. 3. Because it is widely applied in the industry, it is also capable of generating a lot of waste. Polym. The polyolefins such as polyethylene (PE) have been recognized as a polymer remarkably resistant to degradation [42]. 4, 127 (1978). M. Ishihara and K. Shimizu, Mokuzai Gakkaishi 30, 79 (1984). Characterization of rice starch gels reinforced with enzymatically produced resistant starch, resulting in an increase in the gel strength of about 60%, while cohesion decreased and the elasticity remained stable. UNITED KINGDOM, Marieli Rosseto, Cesar V.T. Compared to copolymerization method, blending may be a much easier and faster way to achieve the desired properties. P. Gerike and W. K. Fischer, Ecotoxicol. 25, 1655 (1980). Polym. Sci., Pure Appl. The following sections discuss the main sources of biodegradable polymers, aiming to know their specificities, so that to facilitate the link between possible sources to obtain them from agricultural or industrial waste, as well as the applicability of the material. These use biodegradable compounds as food, converting them into metabolic by-products that have chemical structures remarkably different than the original materials [ 5 ]. Polym. This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. acid. The physical properties displayed in Table 1 show little differences in density but remarkable differences in crystallinity and lifespan. Casein is the protein found in milk, of high nutritional value. Depending on the origin of the residue, salts such as chromium and sodium can be found (residues of leather trimmings, for example). Non-natural polymers are structured in a way that microbes are unable to break down. These results offer the opportunity to optimization conditions for consortia growth in PVC and use as a treatment technology to degrade large collections of PVC. The use of residues is seen as an opportunity for sustainability due to its ease of production and low cost, non-toxicity, biocompatibility, biodegradability, chemical and thermal stabilities [6]. M. Streamer, K. E. Eriksson, and B. Pettersson, Eur. Ministry of Trade and Industry, Japan. poly(ethylene succinate) (PESu), poly(propylene succinate) (PPSu) and poly(butylene succinate) (PBSu) T. Kanda, K. Wakabayashi, and K. Nisizawa, J. Biochem. Deg. Eighteen billion pounds of plastic flows into the ocean every year6, Plastic can be found in marine animals, in table salt and in our own bodies.1. Biodegradation results from the action of naturally occurring heterotrophic microorganisms, such as bacteria and fungi. Environ., 9, 91 (2001). Formed by amino acids, the collagen is structured by a helix triple consisting of proline, hydroxyproline and glycine molecules [69]. Subsequently, Kijchavengkul et al. A PhD position is available at the University of Twente (the Netherlands) within the Faculty of Science and Technology. The development of bioplastics has gained a lot attention in recent years. A technology for monitoring aerobic biodegradation has been developed and optimized for small organic pollutants using oxygen respirometry where the pollutant degrades at a sufficiently rapid rate for respirometry to provide expected rates of biodegradation. of biodegradable plastics is to reach ca. 67,19 (1970). Evaluation of the mechanical barrier, and interfacial properties of Methylcellulose (MC) films reinforced Poly (caprolactone)-based biodegradable films. The enzymatic deacetylation that uses chitin deacetylases obtained from different biological sources, such as fungi and insects to effect treatment. National and international efforts have developed such protocols to enable the desired comparisons using rigorous data collecting techniques and interpretation [40]. The high volume and little reuse can be justified by the leftovers during the processing of the raw material and low commercial value of the by-products generated. Many obstacles such as high price, limited production, and E. Zini, M. Baiardo, Macromolecular Bioscience 4(3), 286 (2004). [42] have made antibacterial and ecologically correct membranes of chitosan and polyvinyl alcohol for air filtration. M. Kimura, K. Toyota, M. Iwatsuki, et al., in Biodegradable Plastics and Polymers, edited by Y. Doi and K. Fukuda (Elsevier Science, New York, 1994), p. 92, 237. While [48] make the extraction from abundant shrimp residues (exoskeleton - shells). Five stages of biofilm development: have been identified as (1) initial attachment, (2) irreversible attachment, (3) maturation I, (4) maturation II, and (5) dispersion. 83, 206 (1959). As expected, the rate for the negative reference was almost zero (Figure 6). Our team is growing all the time, so were always on the lookout for smart people who want to help us reshape the world of scientific publishing. resin. Due to its low crystallinity, it also degrades faster than most other polyesters used as pharmaceutical excipients including engineering. Deg. In wound healing, Non-assimilated materials, impermeable to cellular membranes, are subject to biotransformation reactions yielding products that may be assimilated. Microbial depolymerization of poly(ethylene terephthalate). These numbers are expected to increase with the use of more sensitive isolation and characterization techniques using rDNA sequencing. Res. Drying the exhaust air is necessary to ensure a correct operation of the IRGA sensors. 7, 277 (1979). 51, 607 (1975). 22, 3434 (1978). The biodegradation of PE involves use of microbes or microbial communities that modify and consume the polymer as a source of energy leading to changes in its physico-chemical properties such as weight loss, structural deterioration, and eventually carbon fixation as a biomass [ 86, 97 ]. anhydride with a diol with the elimination of water. We carried out two biodegradation trials on three biopolymers: two different poly(-caprolactone) (PCL) composites (sample A and sample B) and a commercially available, compatibilized polylactic acid, and polybutyrate (PLA/PBAT) blend (sample C, ECOVIO IS 1335, BASF, Germany). Biol. R. A. Smucker, in Chitin in Nature and Technology, edited by R. A. Muzarelli, C. Jeuniaux and G. W. Gooday (Plenum Press, New York, 1986), p. 254. The discovery of that invertebrate species (insect larvae) can reduce the size of the waste polymer by ingesting and degradation in the gut via enzymes which aid or complete degradation is rather amazing and requires additional scrutiny. 729741, 2007. By making research easy to access, and puts the academic needs of the researchers before the business interests of publishers. Polym. Plastic composition of solid waste has increased for less than 1% in 1960 to greater than 10% in 2005 which was attributed largely to packaging. The alternate electron acceptors such as nitrate, sulfate, or methanogenic conditions enable the initiation of anaerobic biodegradation. Studies have been conducted to explore the genetic basis of biofilm development with the development of new insights. These use biodegradable compounds as food, converting them into metabolic by-products that have chemical structures remarkably different than the original materials [5]. The ultraviolet (UV) component of the solar spectrum contributes ionizing radiation which plays a significant role in initiating weathering effects. and Brevundimonas diminuta) were isolated from partially degraded polymer samples from a rural market setting and each were found to degrade high impact polystyrene [59]. [36] The predominant difference between the two is that one process is naturally-occurring and . more stable polymers or have been copolymerized with aromatic Ser. S. J. Huang, C. Marci, M. Roby, et al., ACS Symp. A more inclusive approach to assessing community composition, including the non-culturable fraction of microorganisms invisible by traditional microbiology methods is required in future assessments. J.-A. Reference [34] discuss the main methods of chitosan extraction, measure alkaline treatment, which is most commonly used at the industrial level, and sodium hydroxide (NaOH), which is commonly used for the deacetylation process. In addition, the membranes without the antimicrobial agent resulted in a decrease in absorption of all physiological solutions tested. Major manufacturers of unfilled and filled bioplastics include NatureWorks, BioMatera, Perstop, Solvay, Novamont, To date our community has made over 100 million downloads. medical and pharmaceutical industry. The recognition of current limiting steps in the biological depolymerization of PET are expected to enable the design of a enzymes-based process to reutilized the natural assets contained in scrap PET [110] (Figure 5). In this study, we(i)describe in detail an experimental apparatus designed and assembled to assess the biodegradation rate of plastic materials under controlled composting conditions, in accordance with the ISO 14855-1:2012 [15];(ii)test the apparatus by evaluating with infrared gas analysis (IRGA) the cumulative CO2 evolution of three biopolymers made of renewable materials for agricultural applications;(iii)check the accuracy of the data by measuring the amount of CO2 released during biodegradation with barium hydroxide, Ba(OH)2, titration method. Conf. Sci., 70, 1643 (1998). 1, 257 (1993). To date our community has made over 100 million downloads. Phys. It seems the softer the matrix polymer is, the lighter the resulting composite will be, while the mechanical properties of the composite seem hardly affected at all. 1. The environmental behavior of polymers can be only discerned through an understanding of the interaction between polymers and environment under ambient conditions. Sci. 10891096, 2013. Department of Chemistry, University of Cincinnati, Crosley Tower, Martin Luther King Drive, 45221-0172, Cincinnati, OH, 2007 Springer Science+Business Media, LLC, Andrady, A.L. See Synonyms at malleable. 57, 405 (1975). As you can assess, most examples of biodegradable polymers are the everyday objects and materials that we possess and normally use. Few reports are available relating the extent of PVC biodegradation. Titration tests confirmed the reliability of the apparatus designed and built for assessing the ultimate biodegradation of plastic polymers under composting condition. The general lack of water solubility of PS prohibits the transport into microbial cells for metabolism. Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. Exhausted air from a randomly chosen vessel was directed towards a series of three 2-L vessels fitted with gas diffusers and containing saturated Ba(OH)2 solution able to capture the CO2 (method 2, Figure 1). Natural fibres like cotton or silk. Acid and base hydrolysis strategies can sever the carbamate bond of the polymer. A. L. Andrady, J. Macromol. This new research shows that a newly isolated microbial species, Ideonella sakaiensis 201-F6, degrades PET through hydrolytic transformations by the action of two enzymes, which are extracellular and intracellular hydrolases. During the regeneration of the cellulose solution, physical and chemical treatments can be applied generating functional and biocompatible materials, organic hybrids or porous membranes, making the use of cellulose comprehensive [12]. CO2 measurements are performed on the exhausted air by means of the appropriate IRGA sensors. The status of information relating to the application of biodegradation treatment to existing and future polymer solid waste is at early stages of development for several waste polymers. It was found that the methylcellulose film acted as a satisfactory reinforcing agent, contributing to the improvement of the mechanical and oxygen barrier properties of the composites for packaging applications. top Disposal of polymers Non-biodegradable polymers are disposed of in three main ways: 1Landfill 2Incineration 3Recycling Landfill is exactly what it sounds like. Development chitosan/gelatin composite films embedded with various amounts of wool nanoparticles. And steam explosion, which performs a hydrothermal treatment where the chitin is treated with a blow gun, with saturation vapor at increased pressure and temperature for several minutes, followed by explosive decomposition. We are a community of more than 103,000 authors and editors from 3,291 institutions spanning 160 countries, including Nobel Prize winners and some of the worlds most-cited researchers. The microorganisms forming a biofilm undergo remarkable changes during the transition from planktonic (free-swimming) biota to components of a complex, surface-attached community (Figure 3). Rigueto, Daniela D.C. Krein, Naiana P. Balb, Lillian A. Massuda and Aline Dettmer, Sources for obtaining biodegradable polymers: opportunities. Ser. Technol. The hydrolysis of PET by enzymes has been identified as a surface erosion process [97, 98, 99, 100]. There have been a number of models developed for the interaction of solid The use of microorganisms in establishing ultimate biodegradation (to carbon substrates with enzymes, which could potentially serve as the basis for more complex dioxide and water) is well known and used commonly in standardised tests with modelling . (2007). A. Copinet, C. Bertrand, J. Polym. Reference [28] isolated microcrystalline cellulose powder (MCC) from waste paper from three sources (books, newspapers and cardboard), evaluating the effect of the treatment using various concentrations of sodium hydroxide (NaOH) on the properties of the powders obtained, concluding that the lowest concentration, which was 5%(m/v) NaOH in the medium, was ideal for MCC isolation in these paper wastes. Chem. 433, edited by J. E. Glass and G. Swift (ACS Symposium Series, Washington, DC, 1990), p. 65. Soil invertebrates such as the larvae of the mealworm (Tenebrio molitor Linnaeus) have been shown to chew and eat Styrofoam [57]. This procedure keeps alive the microorganism populations that drive the biodegradation of the plastic samples. In an ancillary study, thermophilic consortia of Brevibacillus sps. Although the respiration activity of the inoculum should be carefully considered when comparing results, the cumulated CO2 emission registered for the inoculum and the reference material in both biodegradation trials agreed with those reported in the literature [10]. [36] made a comparison between nano-composite films based on gelatin and starch modified by nanocellulose and chitosan for packaging applications. novel biodegradable and/or biobased polymers will gain a significant The semicrystalline PET polymer also contains both amorphous and crystalline fractions with a strong effect on its biodegradability. Suool. N. T. Lotto, M. R. Calil, Material Sciience and Engineering C24(5), 659 (2004). PP properties are strongly directed by tacticity or the methyl group orientation as related the methyl groups in neighboring monomer units. J. Gracida, J. Alba, J. Cardoso, F. Perez-Guvera, Polymer Degrad- ation and Stability, 83(2), 247 (2004). 6, pp. Should current production and waste management trends continue, landfill plastic waste and that in the natural environment could exceed 12,000 Mt of plastic waste by 2050 [9]. Proteins are polymers of natural origin, consisting of peptide bonds, the result of hydrogen bonds, ionic bonds and cross-links between amines that can originate from plant or animal material [67]. Vegetables. The testing regime must be explicitly described within a protocol of steps that can be collected for various polymers and compared on an equal basis. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. Only time will tell whether these new plastics will and Aneurinibacillus sp. The hydrophobic nature of PET poses a significant barrier to microbial colonization of the polymer surface thus attenuating effective adsorption and access by hydrolytic enzymes to accomplish the polymer degradation [101]. N. B. Nykvist, in Proc. Organic Polymers, Submitted: April 16th, 2019 Reviewed: June 19th, 2019 Published: September 27th, 2019, Total Chapter Downloads on intechopen.com. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. Polym. The biodegradability of polymers depends on several factors. Biodegradability of Polymers. PLA and PCL are biodegradable polymers which can be subjected to various processing techniques such as extrusion, injection molding, compression molding, and solvent casting. Therefore, one chooses to extract the gelatin present in its composition for use. It was then stored as standard clear solution. Another important factor is tacticity. 41. A major trend of ever increasing consumption of plastics has been seen in the areas of industrial and domestic applications. The effects of oxo-biodegradable additives on the photo-oxidation of four types of polyolefin polymers, namely high-density polyethylene (HDPE), low-density PE (LDPE), linear low-density PE (LLDPE), and isotactic polypropylene (itPP) were investigated. During trials, the pressurized system ensures optimal aerobic conditions and prevents undesired anaerobic fermentation. Polymer degradation accomplished under anaerobic conditions produces organic acids, H2O, CO2, and CH4. The parameters monitored are inlet air pressure, environmental chamber temperature, CO2 concentration, temperature, and airflow rate of the exhausted air. 4. material that can be molded. B. Laycock et al. 433, edited by J. E. Glass and G. Swift (ACS Symposium Series, Washington, DC, 1990), p. 149. However, some of these polyesters can also be produced using monomers from renewable resources. Approximately 26% of food waste is generated from the beverage industry, followed by the dairy industry (21%), fruit and vegetables (14.8%), cereals processing (12.9%), preservation of meat products (8%), processing of oils of vegetable and animal origin (3.9%), among others (12.7%) [5]. The materials produced from regenerated cellulose acquire exceptional physical and chemical characteristics, as well as clear benefits for society, especially when minimizing environmental impacts. Both types of polymers are abundant around us. Studies to improve the properties of biopolymers. Our findings were checked (CV < 10%) by means of a cumulative measurement technique, performed simultaneously during a fixed time, and based on acid-base titration, using saturated Ba(OH)2 to trap the evolved carbon dioxide. [38] incorporated the extract of mango leaves to the antioxidant film of chitosan for active food packaging. Each vessel charge included 276g of inoculum (wet weight), which filled about two-thirds of the internal volume, plus 23g of the specimen or reference material (Table 1). D. S. Chahal and W. D. Gray, in Biodeterioration of Materials, edited by A. H. Walters and J. J. Elphick (Elsevier, New York, 1968), p. 584. Polym. The degree of biodegradation is determined from the amount of specimen carbon converted to CO2 by the end of the trial. In addition, it can be seen that the amount of hydrophilic groups is reduced. Polym. Relating to or dealing with shaping or modeling: the. The Y. Otake, T. Kobayashi, J. Appld. [45, 46]. Chem. The results of the second biodegradation trial performed on specimens C (a commercial plastic polymer) and D (polyethylene as negative reference) are shown in Figures 6 and 7. (CRC Press, Boca Raton, FL 1990), p. 515. biocompatibility and are, therefore, a very important class of A. Corti, G. Vallini, A. Pera, et al. S. N. Swain, K. K. Rao, P. L Nayak, J. Appld. Oxygen entrained in the buried materials is initially depleted by aerobic bacteria. Compositionally, these films have been found to be a single microbial species or multiple microbial species with attachment to a range of biotic and abiotic surfaces [34, 35]. To evaluate the biodegradability of biopolymers, different standard methods have been defined [6, 7]. Chem. Biotechnol. The buried strata are generally covered by 3-m-thick layers which prevent oxygen replenishment. They A. L. Pometto, K. E. Johnson, J. Environ. 5, 225 (1978). October 12, 2022 Biodegradable polymers derived from bio- and fossil-based sources have emerged as one feasible alternative to overcome inconveniences associated with the use and disposal of non-biodegradable polymers. This study may serve as basis for further investigations on biopolymer degradation in different composting conditions and environment. M. Shibata, S. Oyamada, J. Appld. among several others. K. Yamane, H. Suzuki, and K. Nisizawa, J. Biochem. The carbamate linkage can be severed by chemical and biological processes [70]. The plastic specimen was milled (<1mm) and thoroughly mixed with the inoculum at the start of trial, ensuring a 1:6, plastic:inoculum weight ratio, on a dry matter basis. This sourcebook, for use with groups of up to 25 young people ages 10 and up, is designed to stimulate a sense of environmental stewardship for the planet through group discussion, role playing, experimentation, demonstration, and simulation. 1,23 (1993). Plastic, and associatively polymers, nowadays seem to have a negative connotation because your brain automatically associates the word 'plastic' with the idea of non-biodegradable plastic waste overflowing in oceans and coastal regions. This research was carried out within the framework of IGAN ECO-POT project, funded by Regione Toscana, Italy (PSR 20072013), and was partially supported by the DFG RTG 1703 Resource Efficiency in Interorganizational Networks.. When considering energy production the anaerobic process produces less energy due to the absence of O2, serving the electron acceptor which is more efficient in comparison to CO2 and SO42 [23]. 6, 900 (1968). poly(butylene adipate-co-terephthalate) (PBAT) is commercially This continuous increase suggests that as material use broadens yearly, the amount of waste will also increase and present waste disposal problems. Polymer biodegradation is a process in which any change in the polymer structure occurs as a result of polymer properties alteration resulting from the transformative action of microbial enzymes, molecular weight reduction, and changes to mechanical strength and surface properties attributable to microbial action. 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