A PROCESS FOR DEGRADING PLASTIC PRODUCTS

Abstract

The present invention relates to processes for degrading plastic products and their uses. The processes of the invention particularly comprise an amorphization step of a plastic product prior to a depolymerization step. The processes of the invention are particularly useful for degrading a plastic product comprising polyethylene terephthalate and / or polylactic acid. The invention also relates to a method for producing monomers and / or oligomers from a plastic product comprising at least one polyester, in particular polyethylene terephthalate and / or polylactic acid, comprising subjecting the plastic product to both an amorphization step and a depolymerization step.

Description

A PROCESS FOR DEGRADING PLASTIC PRODUCTS The present invention relates to processes for degrading plastic products and their uses. The processes of the invention particularly comprise a buffering step of a plastic product prior to a depolymerization step. The processes of the invention are particularly useful for degrading a plastic product comprising polyethylene terephthalate and / or polylactic acid. The invention also relates to a method for producing monomers and / or oligomers from a plastic product comprising at least one polyester, in particular polyethylene terephthalate and / or polylactic acid, comprising subjecting the plastic product to both a buffering step and a depolymerization step. BACKGROUND Plastics are inexpensive and durable materials that can be used to manufacture a variety of products for a wide range of applications. As a result, plastic production has increased dramatically in recent decades. Furthermore, over 50% of these plastics are used for single-use, disposable applications, such as packaging, agricultural films, disposable consumer goods, or short-lived products that are discarded within a year of manufacture. Due to the durability of the polymers involved, substantial quantities of plastic accumulate in landfills and natural habitats worldwide, creating increasing environmental problems. Even degradable and biodegradable plastics can persist for decades depending on local environmental factors, such as levels of exposure to ultraviolet light, temperature, and the presence of suitable microorganisms. Various solutions have been studied to reduce the environmental and economic impacts related to plastic accumulation, from plastic degradation to plastic recycling, including reprocessing degraded plastic into new plastic material. As an example, in recent years, polyethylene terephthalate (PET), an aromatic polyester produced from terephthalic acid and ethylene glycol, has been widely used in the manufacture of various products for human consumption, such as food and beverage containers (e.g., bottles, conveniently sized soft drinks, bags for food items) or textiles, fabrics, carpets, rugs, etc. Meanwhile, PET is the most recycled plastic in closed-loop systems. Generally, PET waste undergoes successive treatments that lead to recycled PET (PETr). PET waste (mainly bottles) is collected, sorted, baled, shredded, washed, flaked, melted, extruded into pellets, and sold. This recycled PET can then be used to create fabrics for the clothing industry or new packaging, such as bottles or blister packs, etc. However, these plastic recycling processes are only suitable for plastic items containing PET and therefore require extensive pre-sorting. Consequently, these plastic recycling processes lead to degradation applications and are also expensive, meaning that recycled products are generally not competitive compared to virgin plastic. Another potential process for recycling plastic is chemical recycling, which allows for the recovery of the polymer's chemical components. The resulting monomers, after purification, can be used to manufacture plastic articles again or to make other synthetic chemicals. However, so far, this recycling process has only been carried out with sorted or partially sorted polymers and is not efficient with raw plastic products that may comprise a mixture of different polymers. Therefore, there is a need for an improved process to degrade plastic products that does not require preliminary sorting and / or expensive pretreatments and that can be used at an industrial yield. SUMMARY OF THE INVENTION The present invention provides novel methods for degrading plastic products containing polyesters, comprising a plastic product buffering step and a depolymerization step. Advantageously, the buffering step reduces the degree of crystallinity of the polyester in the plastic product, thereby facilitating subsequent depolymerization. By combining buffering and depolymerization, a high level of degradation is achieved without sorting and under industrial conditions. The methods of the invention are particularly useful for degrading plastic products containing polyethylene terephthalate. / CLn / zznz / e / YiAi In this regard, an objective of the invention is to provide a process for degrading a plastic product containing at least one polyester, comprising the steps of: a. Amortize at least partially at least one polyester component of the plastic product; and b. Depolymerize said polyester at least partially amortized from the plastic product. Another objective of the invention is to provide a method for producing monomers and / or oligomers from a plastic product containing at least one polyester, comprising subjecting the plastic product to an abatement step to at least partially abatement one polyester from the plastic product and a subsequent depolymerization step to depolymerize said at least partially abatement polyester from the plastic product. According to the invention, the depolymerization step is a biological depolymerization, in which the plastic product is exposed to a depolymerase. A further objective of the invention is to provide a method for recycling a plastic product comprising at least one polyester, comprising successively subjecting said at least one polyester to abatement and depolymerization, and recovering monomers and / or oligomers. It is also an objective of the invention to provide a method for treating a plastic product comprising at least one polyester, wherein the plastic product is subjected to depolymerization and depolymerization. In a particular embodiment, the amortization stage comprises subjecting the plastic product to a temperature higher than the crystallization temperature (Te), preferably higher than the melting temperature (Tf) of a polyester of the plastic product. Furthermore, the curing step involves subjecting the plastic product to shear stress. In one particular embodiment, the curing step further comprises, after heating, subjecting the plastic product to a temperature below the glass transition temperature (Tv) of said polyester. In one particular embodiment, the process comprises a subsequent biological depolymerization step, in which the plastic product is brought into contact with a depolymerase and / or a microorganism that expresses and excretes a depolymerase. Advantageously, the depolymerase is selected from cutinases, lipases, proteases, carboxylesterases, and esterases, preferably from cutinases and proteases. Therefore, an objective of the invention is to provide a process for degrading a plastic product containing at least one polyester, comprising the steps of: a) To partially amortize at least one polyester of the plastic product by successively subjecting the plastic product to a temperature above the crystallization temperature (Te), preferably above the melting temperature (Tf) of one polyester of the plastic product and to a temperature below the glass transition temperature (Tv) of said polyester; and b) Depolymerize said polyester at least partially depolymerized from the plastic product by bringing the plastic product from step a) into contact with a depolymerase and / or a microorganism that expresses and excretes a depolymerase. Advantageously, the plastic product comprises semicrystalline polyesters, preferably polyethylene terephthalate and / or polylactic acid. An additional objective of the invention is to provide a process for degrading a plastic product containing PET, comprising the steps of: a. At least partially amortize the PET in the plastic product; and b. Depolymerizing the PET of the plastic product, wherein the curing step comprises exposing the plastic product to a temperature equal to or greater than 245°C, preferably between 250°C and 300°C, and then exposing the plastic product to a temperature between 4°C and 65°C, and / or the depolymerization step comprises subjecting the plastic product to a cutinase. These and other aims and embodiments of the invention will become more apparent after the detailed description of the invention, including the preferred embodiments thereof provided in general terms. FIGURE LEGEND / CLn / zznz / e / YiAi Figure 1: Depolymerization of Volvic® bottles before (BV1) and after a buffering step according to the invention (BV2, BV3). The initial rate of enzymatic depolymerization improved 8.2-fold and 9.8-fold for buffered samples BV2 and BV3, respectively, compared to the untreated Volvic® bottle (sample BV1). At the end of the reaction, 88% and 84% of buffered samples BV2 and BV3 were enzymatically degraded, respectively, while only 12% of the crystalline Volvic® sample BV1 was enzymatically degraded. Figure 2: Depolymerization of Volvic® bottles before (BV1) and after a buffering step according to the invention (BV4, BV5, BV6). The initial rate of enzymatic depolymerization improved by 3.6 times, 4.8 times, and 8.4 times for buffered samples BV4, BV5, and BV6, respectively, compared to the untreated Volvic® bottle (sample BV1). At the end of the reaction, 82%, 94%, and 47% of buffered samples BV4, BV5, and BV6 were enzymatically degraded, respectively, while only 12% of the crystalline Volvic® sample BV1 was enzymatically degraded. Figure 3: Depolymerization of milk bottles before (BL1) and after a buffering step according to the invention (BL2, BL3, BL4). The initial rate of enzymatic depolymerization improved 3.2-fold, 4.6-fold, and 10-fold for the buffered samples BL3, BL2, and BL4, respectively, compared to the untreated milk bottle (sample BL1). At the end of the reaction, 86%, 88%, and 89% of the buffered samples BL3, BL2, and BL4 were enzymatically degraded, respectively, while only 33% of the clear milk bottle sample BL1 was enzymatically degraded. Figure 4: Depolymerization of Cristaline™ water bottles before (BC1) and after amortization according to the invention (BC2). At the end of the reaction, 90.5% of the amortized Cristaline™ bottle sample BC2 was enzymatically degraded, while only 18% of the uncured Cristaline™ bottle sample BC1 was enzymatically degraded. DETAILED DESCRIPTION OF THE INVENTION Definitions This disclosure will be best understood by reference to the following definitions. In the context of the invention, the terms "plastic article" or "plastic product" are used interchangeably and refer to any article or product comprising at least one polymer, such as a plastic sheet, tube, rod, profile, shape, block, fiber, etc. Preferably, the plastic article is a manufactured product, such as rigid or flexible packaging, agricultural films, bags and sacks, disposable or similar articles, carpet scraps, fabric scraps, textile scraps, etc. The plastic article may contain additional substances or additives, such as plasticizers, minerals, organic fillers, or colorants. In the context of the invention, the plastic article may comprise a mixture of additives and / or semicrystalline and / or amorphous polymers. A polymer refers to a chemical compound or mixture of compounds whose structure consists of multiple repeating units (i.e., monomers) linked by covalent chemical bonds. Within the context of the invention, the term polymer includes natural or synthetic polymers, comprising either a single type of repeating unit (i.e., homopolymers) or different types of repeating units (i.e., block copolymers and random copolymers). As an example, synthetic polymers include polymers derived from petroleum oil, such as polyolefins, aliphatic or aromatic polyesters, polyamides, polyurethanes, and polyvinyl chloride. Natural polymers include lignin, polysaccharides such as cellulose, hemicellulose, starch, and polyhydroxyalkanoates, and derivatives thereof. According to the invention, oligomers refer to molecules containing from 2 to approximately 20 monomeric units. For example, oligomers recovered from PET include methyl-2-hydroxyethyl terephthalate (MHET), bis(2-hydroxyethyl) terephthalate (BHET), 2-hydroxyethyl benzoate (HEB), and dimethyl terephthalate (DMT). As another example, lactic acid oligomers can be recovered from PLA. Within the context of the invention, the term "polyester" refers to a polymer containing the ester functional group in its main chain. The ester functional group is characterized by a carbon atom bonded to three other atoms: a single bond to another carbon atom, a double bond to an oxygen atom, and a single bond to another oxygen atom. The single bonded oxygen atom is bonded to another carbon atom. Based on the composition of their main chain, polyesters can be aliphatic, aromatic, or semi-aromatic. A polyester can be a homopolymer or a copolymer. For example, polyethylene terephthalate is a semi-aromatic copolymer composed of two monomers, terephthalic acid and ethylene glycol. In the context of the invention, crystalline polymers or semicrystalline polymers refer to partially crystalline polymers in which crystalline and amorphous regions coexist. The degree of crystallinity of a semicrystalline polymer can be estimated by various analytical methods and typically ranges from 10% to 90%. For example, differential scanning calorimetry (DSC) or X-ray diffraction can be used to determine the degree of crystallinity of polymers. Other techniques, such as small-angle X-ray scattering (DXAP) and infrared spectroscopy, are also suitable for estimating polymer crystallinity with less reliability. In this disclosure, the degrees of crystallinity disclosed correspond to degrees of crystallinity measured using DSC.More specifically, the CBD experiments were performed as follows: a small amount of the sample (several mg) was heated at a constant heating rate from room or sub-room temperature to a high temperature that is higher than the Tf of the polyester. Heat flow data were collected and plotted as a function of temperature. The degree of crystallinity Xc (%) was calculated as: Xc(%) / CLn / zznz / B / YiAi (ΔΗ / - AHc / ) P * A Hf 100% x 100% where AHt is the enthalpy of fusion that can be determined by integrating the endothermic fusion peak, AHct is the cold crystallization enthalpy and is determined by integrating the cold exothermic crystallization peak, p is the weight fraction of polyester in the plastic, and ÁHf,ioo% is the enthalpy of fusion for a completely crystalline polymer and can be found in the literature. As an example, the AHt,ioo% of PET is taken from the literature as 125.5 J / g (Polymer Data Handbook, second edition, edited by James E. Mark, OXFORD, 2009). According to the literature, the AHf,ioo% of PLA is equal to 93 J / g (Fisher EW, Sterzel HJ, Wegner G., Investigation of the structure of solution grown crystals of lactide copolymers by means of chemical reactions, Kolloid Zeitschrift & Zeitschrift für Polymere, 1973, 251, pages 980-990). As used herein, the terms amortization or amortize are used interchangeably to refer to a step that reduces the degree of crystallinity of a given polymer compared to its degree of crystallinity before the amortization step. Preferably, the amortization step allows the crystallinity of a target polymer to be reduced by at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 80%, or 90% compared to its degree of crystallinity before amortization. Advantageously, the amortization step, according to the invention, results in a polymer in the plastic product with a maximum of 30%, preferably a maximum of 25%, more preferably a maximum of 20%, and even more preferably a maximum of 15% crystallinity.Preferably, the amortization stage allows the crystallinity of a target polymer to be reduced by at least 5%, 10%, 20%, 30%, or 40% compared to the degree of crystallinity before the amortization stage, leading to a polymer with a maximum of 25%, preferably a maximum of 20%, and more preferably a maximum of 15% crystallinity. A degradation process in relation to a plastic article refers to a process by which at least one polymer of said plastic article degrades into smaller molecules, such as monomers, oligomers, water and / or carbon dioxide. In the context of the invention, Tv, Te, Tcf, and Tf refer respectively to the glass transition temperature, crystallization temperature, cold crystallization temperature, and melting temperature of a polymer. These temperatures can be estimated using various analytical methods well known to those skilled in the art. For example, Differential Scanning Calorimetry (DSC) or Differential Thermal Analysis (DTA) can be used to determine the Tv, Te, Tcf, and Tf of polymers. In this disclosure, the Tv, Te, Tcf, and Tf of the disclosed polymers correspond to temperatures measured using DSC. Amortization stage The inventors have demonstrated that it is possible to improve the degradability of a plastic product comprising polyesters by subjecting the plastic product to conditions that promote the breakdown of a given polyester before its depolymerization. The breakdown stage allows for at least partial disruption of the crystalline structure of at least one polyester in the plastic product. In one particular embodiment, the amortization stage comprises subjecting the plastic product to a temperature at which the plastic product is in a partially or totally molten state. Therefore, an objective of the invention is to provide a degradation process for a plastic article, wherein the degradation step comprises subjecting the plastic product to a temperature above the crystallization temperature (Te) of a polyester component of the plastic product, preferably to or above the melting temperature (Tf) of said polyester. In particular, the plastic product is subjected to a temperature corresponding to the Tf of a polyester component of the plastic product. Even more preferably, the plastic product is subjected to a temperature corresponding to Tf + 5 at 25°C, preferably Tf + 10 at 25°C, more preferably Tf + 15 at 25°C, such as Tf + 20°C of a polyester component of the plastic product. In another embodiment, the plastic product is subjected to a temperature corresponding to Tf + 25 at 50°C. In another preferred embodiment, the plastic product is subjected to a temperature corresponding to Tf + 50°C or higher. According to the invention, the plastic product may comprise different polyesters. In such an embodiment, the plastic product is advantageously subjected to a temperature equal to or greater than the Te or Tf of the target polyester, i.e., the polyester for which depolymerization is sought. Alternatively, the plastic product is subjected to a temperature equal to or greater than the highest Te or Tf of the polyesters contained within it. This embodiment may lead to the depolymerization of all the polyesters contained in the plastic product. In one particular embodiment, the plastic product further comprises thermoplastic polymers other than a polyester. In such a case, the plastic product may alternatively be subjected to a temperature equal to or greater than Te or above the Tf of the target polyester, or to a temperature above the Te or the highest Tf of the thermoplastic polymers contained in the plastic product. The temperature of the amorphization stage can be adjusted by a specialist depending on the target polyester. Generally speaking, the plastic product will be subjected to heat treatment for a sufficient period of time to achieve amorphization of the target polyester. For example, this duration can range from 10 seconds to several minutes, depending on the temperature and / or the plastic product. In one particular embodiment, the plastic product comprises PET, and the amorphization step comprises subjecting the plastic product to a temperature above 170°C, preferably equal to or above 245°C, and more preferably to a temperature between 250°C and 300°C. Even more preferably, the plastic product comprising PET is subjected to a temperature between 260°C and 280°C. In another embodiment, the plastic product comprising PET is subjected to a temperature of 300°C or higher, preferably between 300°C and 320°C. In another particular embodiment, the plastic product comprises PLA and the amorphization step comprises subjecting the plastic product to a temperature above 110°C and more preferably equal to or greater than 145°C. In another particular embodiment, the plastic product comprises PLLA and the amorphization step comprises subjecting the plastic product to a temperature equal to or greater than 180°C. In another embodiment, the plastic product comprises PLA stereocomplex and the amorphization step comprises subjecting the plastic product to a temperature equal to or greater than 230°C. In a preferred embodiment, the amorphization step comprises subjecting the plastic product to both a shear stress and a temperature above the Te of a polyester of the plastic product, preferably equal to or above the Tf of said polyester. The heating and the shear stress are preferably carried out simultaneously to enhance the amorphization. In one particular embodiment, the amorphization step may further comprise, after heating the plastic product, cooling said plastic product in order to fix the plastic product in the amorphous state. Advantageously, the cooling is carried out immediately after heating. In one particular embodiment, cooling is carried out by subjecting the heated plastic product to a temperature lower than the glass transition temperature (Tv) of a polyester of the plastic product. / CLn / zznz / e / YiAi In another particular embodiment, cooling is achieved by subjecting the heated plastic product to a temperature below the Te of the polyester of the plastic product. This particular embodiment is particularly suited to PBAT, for example, or to any polyester whose Tv is below 202°C. Alternatively, cooling is achieved by subjecting the heated plastic product to a temperature that is at least 20°C below the Te, preferably at least 30°C, 40°C, or 50°C. In one particular embodiment, cooling is carried out by subjecting the plastic product to room temperature (i.e., 25°C + / - 5°C). In another embodiment, cooling is carried out by subjecting the plastic product to a temperature of approximately 10°C, preferably approximately 5°C. In a particular embodiment, the plastic product is subjected to a cooling temperature after the heating phase, in particular less than 1 minute, preferably less than 30 seconds, more preferably less than 20 seconds, even more preferably less than 10 seconds after the heating phase. As an example, cooling can be achieved by immersing the plastic product in a liquid at a temperature below the vapor temperature (Tv) of a given polyester. For example, the plastic product is immersed in a liquid at room temperature, more preferably below room temperature. More preferably, the plastic article is immersed in a cold liquid, the temperature of which is below 14°C, preferably below 10°C or below 5°C. In one particular embodiment, the plastic product is immersed in cold water, such as water at 5°C or below. Alternatively, cooling can be achieved by immersing the plastic product in cold air. As another example, the plastic item can be cooled using a cooling air system. Alternatively, or in addition, cooling can be carried out using an underwater granulator where the polymer is directly cut using cold water within a thermoregulated water system, granulating the plastic into fine pellets. Specifically, such an underwater granulator can be attached to the extruder head used to heat the plastic product, such as those sold by Gala Industries® or ECON Under Pelletizing / CLn / zznz / e / YiAi System®. Preferably, cooling can be carried out using an underwater microgranulator that produces microgranules or mini-granules smaller than 1 mm. This process advantageously allows the milling stage between depolymerization and depolymerization to be eliminated. More generally, any suitable method can be used to quickly reduce the temperature of the plastic product. According to the invention, the plastic product may comprise different polyesters. In such a case, the plastic product is advantageously subjected to a temperature lower than the Te or Tv of the polyester for which depolymerization is sought. Alternatively, the plastic product is subjected to a temperature lower than the lowest Te or Tv of the polyesters contained in the plastic product. When said polyester has a Tv lower than 0.2°C, the plastic product is advantageously subjected to a temperature lower than ambient temperature, preferably lower than 20°C. When said polyester has a Tv lower than 20°C, the plastic product is advantageously subjected to a temperature lower than ambient temperature, preferably lower than 20°C. In another embodiment, the plastic product further comprises thermoplastic polymers other than polyester. In such an embodiment, the plastic product is subjected, alternatively, to a temperature lower than the Te or Tv of the polyester for which depolymerization is sought, or to a temperature lower than the lowest Te or Tv of the thermoplastic polymers contained in the plastic product. If at least one thermoplastic polymer in the plastic product has a Tv lower than 20°C, the plastic product may be subjected to a temperature lower than ambient temperature, preferably lower than 20°C. In one particular embodiment, the amortization step further comprises adding at least one degradation agent. Examples of degradation agents include, but are not limited to, water, monomers, alcohol, metal alkoxides, plasticizers, etc. Preferably, these degradation agents can be added during the heating phase of the plastic product and / or the shear stress phase of the plastic product. Preferably, the curing step comprises at least the addition of water. Alternatively, or in addition, monomers of a polyester from the plastic product are added during the curing step. Preferably, the monomers are selected from monomers of the target polyester (i.e., the polyester for which depolymerization is intended). In one particular embodiment, PET monomers such as monoethylene glycol and / or terephthalic acid and / or isophthalic acid are added during the curing step of a plastic article comprising PET. In particular, these monomers are added during the heating phase of the plastic article. Preferably, these degradation agents are added at a concentration of less than 20% of the total mass (i.e., plastic product and degradation agents), preferably at a concentration between 0.05% and 10%, more preferably between 0.05% and 5%, before undergoing the amortization stage. In another embodiment, these degradation agents are added at a concentration between 0.1% and 10%, more preferably between 0.1% and 5%, before undergoing the amortization stage. In one particular embodiment, water is added during the heating phase of the plastic article at a concentration greater than 5% of the total mass, preferably between 10% and less than 20%. Alternatively, or in addition, monomers are added during the heating phase of the plastic article at a concentration less than 10% of the total mass, preferably less than 5%, 4%, 3%, 2%, or 1%. In one particular embodiment, the curing stage is carried out using an extruder. The extruder allows a plastic product to be subjected to a given temperature and shear stress, simultaneously or sequentially. It is also possible to add a degradation agent or agents to the extruder, if required. The extruder may also allow for cooling the plastic product. Consequently, the use of an extruder, such as single-screw extruders, multi-screw extruders with a co-rotation or counter-rotation design, planetary roller extruders, dispersive kneaders, pusher single-screw extruders (co-kneaders), mini-extruders, or internal mixers, may be of particular interest for implementing the curing stage.Preferably, an underwater granulator that produces mini granules of less than 1 mm is attached to the extruder head to enable the production of plastic granules of the desired size and to replace the possible grinding stage required before depolymerization. Amortization can also be carried out by implementing any process that allows at least partially breaking the crystalline structure of at least one polyester in the plastic product. Alternatively, the amortization stage can be carried out in a reactor or through atomization of the polyester, or solubilization of the polyester in a solvent, or plasma treatment, or electronic or atomic irradiation, or cryogenic mechanical wear (Schexnaydre et al., 2008) or any technique known to an expert in the field. Depolymerization stage According to the invention, the degradation process comprises, after the amorphization stage, a depolymerization stage. According to a preferred embodiment, the depolymerization stage targets at least one polyester from the preceding amorphization stage. The depolymerization step may comprise chemical depolymerization and / or biological depolymerization, preferably at least biological depolymerization. Accordingly, in one particular embodiment, the degradation process of the invention comprises contacting the plastic product with a depolymerase (i.e., an enzyme). Preferably, the depolymerase is capable of degrading at least one polyester of the plastic product, preferably at least one polyester that has been previously amorphized by the amorphization step. The depolymerase is advantageously selected from the group consisting of a cutinase, a lipase, a protease, a carboxylesterase, a p-nitrobenzylesterase, an esterase, an scl-PHA depolymerase, an mcl-PHA depolymerase, and a PHB depolymerase. In one particular embodiment, the plastic product is brought into contact with at least two different depolymerases. In one particular embodiment, the plastic product comprises PET and the depolymerase is a cutinase, preferably selected from Thermobifida cellulosityca, Thermobifida halotolerans, Thermobifida fusca, Thermobifida alba, Bacillus subtilis, Fusarium solani pisi, Humicola insolens, Sirococcus conigenus, Pseudomaria terrestris, or any functional variant thereof. In another embodiment, the cutinase is selected from a metagenomic library such as the LC-cutinase described in Sulaiman et al., 2012, or any functional variant thereof. In yet another particular embodiment, the depolymerase is a lipase, preferably selected from Ideonella sakaiensis. In another particular embodiment, the depolymerase is a cutinase selected from Humicola insolens, such as the one referenced A0A075B5G4 in Uniprot or any functional variant thereof.In another embodiment, the depolymerase is selected from commercial enzymes such as Novozym 51032 or any functional variant thereof. In a particular embodiment, the plastic product comprises PLLA and the depolymerase is a protease, preferably selected from Amycolatopsis sp., Amycolatopsis orientalis, proteinase K from Tritirachium album, Actinomadura keratinilytica, Laceyella sacchari LP175, Thermus sp. or any commercial enzymes known to degrade PLA such as Savinase®, Esperase®, Everlase® or any functional variant thereof. In another particular embodiment, the plastic product comprises PDLA and the depolymerase is a cutinase or a lipase preferably selected from CLE of Cryptococcus sp., PS Lipase of Burkholderia cepacia, Paenibacillus amylolyticus TB-13, Candida Antarctica, Rhiromucor miehei, Saccharomonospora viris, Cryptococcus magnus or any commercial enzyme known to degrade PLA, such as Savinase®, Esperase®, Everlase® or any functional variant thereof. The enzyme may be in soluble form or in solid form, such as a powder. In particular, it may be bound to cell membranes or lipid vesicles, or to synthetic supports such as glass, plastic, polymers, filters, membranes, for example, in the form of beads, columns, plates, and the like. The enzyme may be in isolated or purified form. Preferably, the enzymes of the invention are expressed, derived, secreted, isolated, or purified from microorganisms. The enzymes may be purified using techniques known in the art and stored using conventional techniques. The enzymes may be further modified to improve, for example, their stability, activity, and / or adsorption onto the polymer. For example, the enzymes are formulated with stabilizing and / or solubilizing components, such as water, glycerol, sorbitol, dextrin, including maltodextrin and / or cyclodextrin, starch, propanediol, salt, etc. ! 1 / CLn / ZZnZ / B / YIAI In another embodiment, the plastic product is brought into contact with a microorganism that expresses and secretes the depolymerase. In the context of the invention, the enzyme can be secreted into the culture medium or onto the cell membrane of the microorganism, where the enzyme may be anchored. This microorganism may naturally synthesize the depolymerase or may be a recombinant microorganism into which a recombinant nucleotide sequence encoding the depolymerase has been inserted, using, for example, a vector. For instance, a nucleotide molecule encoding the depolymerase of interest is inserted into a vector, such as a plasmid, recombinant virus, phage, episome, artificial chromosome, or the like. Those skilled in the art are well-versed in the transformation of the host cell and the appropriate culture conditions for the host. Recombinant microorganisms can be used directly. Alternatively, or in addition, recombinant enzymes can be purified from the culture medium. Any commonly used separation / purification method can be employed for this purpose, such as protein precipitation by salt addition, gel filtration, hydrophobic interaction chromatography, affinity chromatography, or ion-exchange chromatography. In specific embodiments, microorganisms known to synthesize and excrete depolymerases of interest can be used. According to the invention, various microorganisms and / or purified enzymes and / or synthetic enzymes can be used together or sequentially to depolymerize different types of polymers contained in the same plastic article or in different plastic articles. Advantageously, the microorganism of the invention has a modified metabolism to avoid consuming the monomers and / or oligomers obtained from the degraded polymers. For example, the microorganism is a recombinant microorganism in which the enzymes that degrade these monomers and / or oligomers have been suppressed or deactivated. Alternatively, the process of the invention can be carried out in a culture medium containing at least one carbon source usable by the microorganism, such that the microorganism preferentially consumes this carbon source instead of the monomers and / or oligomers. Advantageously, the plastic article is placed in contact with a culture medium containing the microorganisms, glucose or similar as a carbon source, as well as an available nitrogen source, including an organic nitrogen source (e.g., peptone, meat extract, yeast extract, corn steep water) or an inorganic nitrogen source (e.g., ammonium sulfate, ammonium chloride). If necessary, the culture medium may additionally contain inorganic salts (e.g., sodium ion, potassium ion, calcium ion, magnesium ion, sulfate ion, chloride ion, phosphate ion). Furthermore, the medium may also be supplemented with trace components such as vitamins and amino acids. In one particular embodiment, the depolymerase is used under conditions that favor its adsorption onto the plastic article, so that the polymer of the plastic article is depolymerized more efficiently to monomers and / or oligomers. More specifically, the depolymerase may be a mutated enzyme that has an enhanced affinity for the polymer of the plastic particle compared to a wild-type enzyme. Alternatively, the depolymerase may be used with plastic-binding proteins or binding modules that enhance the binding between the depolymerase and the polymer of the plastic article. The time required for the depolymerization of at least one polymer in the plastic article can vary depending on the plastic article and its polymer itself (i.e., the nature and origin of the plastic article, its composition, shape, molecular weight, etc.), the type and quantity of microorganisms / enzymes used, and various process parameters (i.e., temperature, pH, additional agents, etc.). More generally, the temperature is kept below an inactivation temperature, which corresponds to the temperature at which the depolymerase is inactivated and / or the recombinant microorganism no longer synthesizes the depolymerase. In a particular embodiment, the temperature is kept below the Tv of the target polyester to be depolymerized.Advantageously, the pH is adjusted to improve process efficiency according to several factors, including the target polyester, the solubility of the target monomers / oligomers, and / or the development of byproducts during the process. In one particular embodiment, the pH is adjusted to maintain the optimum pH of the depolymerase. A person skilled in the art can easily adapt the process parameters to the plastic articles and / or depolymerases. / CLn / zznz / B / YiAi In one particular embodiment, the plastic product comprises PET, and the process is carried out at a temperature between 20°C and 90°C, preferably between 30°C and 80°C, more preferably between 40°C and 70°C, more preferably between 50°C and 70°C, and even more preferably between 60°C and 70°C. Furthermore, the process is preferably carried out at a pH between 5 and 11, preferably between 7 and 9, more preferably between 7 and 8.5, and even more preferably between 7 and 8. Advantageously, the process is performed by mixing, preferably with stirring, and more preferably with vertical stirring at a rotation speed preferably between 30 rpm and 2000 rpm, in order to promote contact between the depolymerase and the plastic product. In one particular embodiment, the plastic product comprises PLA, and the process is carried out at a temperature between 20°C and 90°C, preferably between 20°C and 60°C, more preferably between 30°C and 55°C, more preferably between 40°C and 50°C, and even more preferably at 45°C. Furthermore, the process is preferably carried out at a pH between 5 and 11, preferably between 7 and 10, more preferably between 8.5 and 9.5, and even more preferably between 8 and 9. In another particular embodiment, the process can be carried out preferably at a pH between 7 and 8. A person skilled in the art can easily adapt the pH to the PLA depolymerase. Advantageously, the process is carried out with stirring, preferably between 30 rpm and 2000 rpm, in order to promote contact between the depolymerase and the plastic product. Additional optional stages In one particular embodiment, the degradation process may include a preliminary depolymerization step, performed before the amortization step. Preferably, after this preliminary depolymerization step, the non-depolymerized polymers are recovered before the amortization step is performed. In a particular embodiment, the degradation process may comprise a pretreatment stage to mechanically and / or physically and / or chemically and / or biologically modify the plastic product, with said pretreatment stage preferably being carried out before the amortization stage and / or before the depolymerization stage. / CLn / zznz / e / YiAi For example, pretreatment can physically alter the structure of the plastic product to increase the surface area of ​​contact between the polymers and enzymes and / or to facilitate the amortization stage. Alternatively, or in addition, pretreatment can reduce the microbial load from waste. In one particular embodiment, the plastic article is transformed into an emulsion or powder, which is added to a liquid medium containing microorganisms and / or enzymes. Alternatively, the plastic article may be mechanically ground, granulated, microgranulated, etc., by cutting, impact, crushing, grinding, fractionation, cryogenic milling, or similar methods, to reduce its size and modify its shape before subjecting it to curing and / or adding it to a liquid medium containing microorganisms and / or enzymes. Mechanical pretreatment may also include ultrasonic treatment, centrifugation, shearing, colliding, high-pressure homogenizing, maceration, or liquefaction using a rotating drum, screw press, disc screen crusher, or piston press. Alternatively or additionally, a heat pretreatment can be applied, using, for example, a microwave. This heat pretreatment allows for the disinfection, pasteurization, or sterilization of the plastic product. In another specific embodiment, the plastic product is chemically pretreated to modify its structure and increase the contact surface area between the polymers and the enzymes. A basic, acidic, or ionic liquid, as well as a solvent, can be used. Ozonation can also be implemented. In one particular embodiment, the plastic article can also be sorted, washed, disinfected, sterilized and / or biologically cleaned before degradation. According to the invention, several pretreatments can be combined. In a preferred embodiment, the PET-containing plastic product undergoes cryogenic grinding, freezer crushing, or cryo-crushing before the depolymerization stage. Preferably, the plastic article is crushed or ground before the depolymerization stage and / or before the depolymerization stage. In particular, the plastic product can be physically transformed into films, flakes, powders, granules, or fibers. Even more preferably, the amorphization stage is carried out using an underwater extruder and granulator leading to microgranules below 1 mm, so that no cryogenic grinding is required before the depolymerization stage. Plastic articles / CLn / zznz / e / YiAi The inventors have developed a degradation process for breaking down plastic articles containing polyesters. The process of the invention can be advantageously used with plastic articles originating from plastic waste collection and / or post-industrial waste. More specifically, the process of the invention can be used to degrade household plastic waste, including plastic bottles, plastic bags and plastic containers, both soft and / or hard plastics, even those contaminated with food residues, surfactants, etc. Alternatively, the process of the invention can be used to degrade plastic fibers, such as fibers originating from fabrics, textiles, and / or industrial waste. More specifically, the process of the invention can be used with PET fibers, such as PET fibers originating from fabrics, textiles, or tires.Interestingly, the process of the invention allows the production of monomers and / or oligomers that can be recovered and / or further reprocessed. Ventajosamente, el proceso de la invención se usa para degradar un producto de plástico que comprende al menos un poliéster seleccionado entre tereftalato de polietileno (PET); tereftalato de politrimetileno (PTT); tereftalato de polibutileno (PBT); tereftalato de ¡sosorbida de polietileno (PEIT); ácido poliláctico (PLA); polyhidroxyalkanoate (PHA) (as poly(3-hidroxybutyrate) (P(3HB) / PHB), poly(3-hidroxyvalerate) (P(3HV) / PHV), poly(3-hidroxyhexanoate) (P(3HHx)), hidroxioctanoate) (P(3HO)), poly(3-hidroxyhexanoate) (P(3HD)), hidroxibutirato-co-3-hidroxivalerato) hidroxibutiratoco-3-hidroxihexanoato) hidroxibutirato-co-5-hidroxihidroxylado) (P(3HB-co-3HV) / PHBV), (P(3HB-co-3HHx) / (PHBHHx)), poli(3poli(3poli(3pol¡(3(PHB5HV), poly(3-hidroxybutyrate-co-3hidroxypropionate) (PHB3HP), polyhidroxybutyrate-co-hidroxioctonoate (PHBO), polyhidroxybutyrate-co-hidroxioctadecanoate (PHBOd), poly(3-hidrox¡but¡rato-co-3hidroxivalerate-co-4-hidroxybutyrate) (P(3HB-co-3HV-co-4HB)));polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), polyethylene furanoate (PEF), polycaprolactone (PCL), poly(ethylene adipate) (PEA), polyethylene naphthalate (PEN), polycyclohexylene dimethylene terephthalate (PCT), poly polyethylene succinate (PES), poly(butylene succinate-co-terephthalate) (PBST), poly(butylene succinate / terephthalate / isophthalate)-co-(lactate) (PBSTIL) y mezclas / combinaciones de estos polímeros.; Preferentemente, el proceso de la invención se usa para degradar un producto de plástico que comprenda al menos un poliéster termoplástico, preferentemente seleccionado entre tereftalato de polietileno (PET); tereftalato de politrimetileno (PTT); tereftalato de polibutileno (PBT); tereftalato de ¡sosorbida de polietileno (PEIT); ácido poliláctico (PLA);polihydroxyalkanoato (PHA) (tal como poli(3-hydroxybut¡rato) (P(3HB) / PHB), poli(3-hydroxyvalerato) (P(3HV) / PHV), pol¡(3hydroxyhexanoato) (P(3HHx)), poli(3-hydroxyoctanoato) (P(3HO)), poli(3hydroxydecanoato) (P(3HD)), poly(3-h¡drox¡butirato-co-3-h¡drox¡valerato) (P(3HB-co3HV) / PHBV), poly(3-hidrox¡butirato-co-3-hidrox¡hexanoato) (P(3HB-co3HHx) / (PHBHHx)), poly(3-hydroxybutyrato-co-5-hidrox¡valerato) (PHB5HV), poly(3-hidrox¡butirato-co-3-hidrox¡hexanoato) (PHB3HP), polihydroxybutirato-cohydroxyoctonoato (PHBO), polihydroxybutirato-co-hydroxyoctadecanoato (PHBOd), poly(3-hydroxybut¡rato-co-3-hidrox¡v¡nato-co-4-h¡droxibut¡rato) P(3HB-co-3HV-co4HB)));polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), polyethylene furanoate (PEF), polycaprolactone (PCL), poly(ethylene adipate) (PEA), polyethylene naphthalate (PEN), polycyclohexylene dimethylene terephthalate (PCT), poly polyethylene succinate (PES), poly(butylene succinate-co-terephthalate) (PBST), poly(butylene succinate / terephthalate / isophthalate)-co-(lactate) (PBSTIL) y mezclas / combinaciones de estos polímeros.; In a particular implementation, the process of the invention is used to degrade plastic fibers that include at least polyester and preferably at least PET or PLA. In one particular embodiment, the plastic product comprises at least two different polymers, such as at least two polyesters. More generally, the plastic products targeted by the process of the invention may comprise different types of polymers, including synthetic polymers, polymers derived from petrochemicals, or polymers of bio-based origin. As an example, the plastic product comprises at least one polyester and further comprises polymers other than a polyester, such as polyamides, polyolefins, or vinyl polymers (such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, ethylene vinyl acetate, ethylene vinyl alcohol, or polyvinyl alcohol), rubber, wood or wood compounds such as lignin, cellulose, or hemicellulose, and starch, and derivatives thereof.As another example, the plastic product may comprise at least one polyester and may further comprise an additional component such as metallic compounds (such as aluminum, aluminum oxide, titanium, titanium oxide, nickel or chromium), mineral compounds (such as silica or silicon dioxide, glass or mica), glass compounds, natural or synthetic fibers (such as carbon fibers, flax fibers, hemp fibers, wood fibers, paper fibers, straw fibers, jute fibers, cotton fibers, viscose fibers, glass fibers, metallic fibers, aramid fibers, boron fibers or ceramic fibers), paper and derivatives thereof. In a preferred embodiment of the invention, the plastic product comprises aromatic polyesters, such as polyethylene terephthalate and / or polytrimethylene terephthalate. Advantageously, the plastic product comprises or is made of PET, preferably semicrystalline PET. In the context of the invention, the terms polyethylene terephthalate or polyethylene terephthalate polymer, also abbreviated as PET or PETE, are used interchangeably and refer to a thermoplastic polymer resin of the polyester family, produced from monoethylene glycol (MEG) monomers and dimethyl terephthalate (DMT) or purified terephthalic acid (PTA). PET can exist in both amorphous and semicrystalline states. In the context of the invention, PET homopolymers and copolymers are also included.Examples of copolymers include glycol-modified polyethylene terephthalate (PETG), in which cyclohexane dimethanol is added to the main polymer structure instead of ethylene glycol, or isophthalic acid-modified polyethylene terephthalate, in which isophthalic acid replaces part of the linkage of terephthalate units, or biaxially oriented PET (BOPET) or oriented PET (OPET), etc. In another embodiment, the plastic product comprises aliphatic polyester, such as PLA and, more particularly, semicrystalline PLA. According to the invention, the terms polylactic acid or polylactic acid polymer, also abbreviated as PLA, are used interchangeably and refer to a thermoplastic polymeric resin of the polyester family, produced from lactic acid monomers (D-lactic acid or L-lactic acid). PLA can exist in both amorphous and semicrystalline states. In the context of the invention, homopolymers, copolymers, or stereocomplexes of PLA are also included, such as poly(L-lactic acid) (PLLA), poly(D-lactic acid) (PDLA), poly(D,L-lactic acid) (PDLLA), or PLA stereocomplex (scPLA). Therefore, an objective of the invention is to provide a process for degrading a plastic product containing at least one polyester, comprising the steps of: a. Amortize at least partially at least one polyester component of the plastic product; and b. Depolymerize said polyester at least partially amortized from the plastic product. Another objective of the invention is to provide a method for producing monomers and / or oligomers from a plastic product comprising at least one polyester, which includes subjecting the plastic product to a depolymerization step to at least partially depolymerize one polyester of the plastic product, and a depolymerization step of said polyester of the plastic product, wherein the depolymerization step comprises exposing the plastic product to a depolymerase. According to the invention, the depolymerase is advantageously selected from the group consisting of a cutinase, a lipase, a protease, a carboxylesterase, a p-nitrobenzylesterase, an esterase, an scl-PHA depolymerase, an mcl-PHA depolymerase, and a PHB depolymerase. A particular objective of the invention is to provide a process for degrading a plastic product containing PET, comprising the steps of: a. At least partially amortizing the PET of the plastic product by subjecting the plastic product to a temperature above 170°C, preferably above 185°C, more preferably above 200°C, even more preferably above 220°C, 240°C, 245°C, 250°C, 255°C, 260°C, 265°C; and then subjecting the plastic product to a temperature below 80°C, preferably below 65°C, more preferably below 102°C; / CLn / zznz / e / YiAi b. Depolymerize the PET of the plastic product by bringing the plastic product into contact with a depolymerase, preferably a cutinase. Another particular objective of the invention is to provide a process for degrading a plastic product containing PLA, comprising the steps of: a. At least partially depolymerize the PLA of the plastic product by subjecting the plastic product to a temperature above 110°C, preferably above 160°C, more preferably above 170°C; and then subjecting the plastic product to a temperature below 85°C, preferably below 55°C, more preferably below 10°C; and b. Depolymerize the PLA of the plastic product by contacting the plastic product with a depolymerase, preferably a protease. Therefore, an objective of the invention is to provide a method for producing terephthalic acid and / or ethylene glycol and / or methyl-2-hydroxyethyl terephthalate (MHET) and / or bis(2-hydroxyethyl) terephthalate (BHET) and / or 2-hydroxyethyl benzoate (HEB) and / or dimethyl terephthalate (DMT), from a plastic product comprising PET, wherein the plastic product is subjected to an amorphization step to at least partially amorphize the PET of the plastic product and a depolymerization step of the PET of the plastic product, wherein the depolymerization step comprises exposing the plastic product to a cutinase. Therefore, another objective of the invention is to provide a method for producing lactic acid from a plastic product comprising PLA, wherein the plastic product is subjected to an amorphization step to at least partially amorphize the PLA of the plastic product and to a depolymerization step of the PLA of the plastic product, wherein the depolymerization step comprises exposing the plastic product to a protease. Another objective of the invention is to provide a process for degrading a plastic article, further comprising a purification step for the monomers and / or oligomers resulting from the depolymerization step. The monomers and / or oligomers resulting from the depolymerization can be recovered sequentially or continuously. A single type of monomer and / or oligomer, or several different types of monomers and / or oligomers, can be recovered, depending on the starting polymers and / or plastic articles. An additional objective of the invention is to provide a method for recycling a plastic product comprising at least one polyester, comprising successively subjecting said at least one polyester to depolymerization and depolymerization, and recovering monomers and / or oligomers. The recovered monomers and / or oligomers can be purified using any suitable purification method and conditioned into a repolymerizable form. Examples of purification methods include extraction, aqueous solution separation, selective steam condensation, filtration and concentration of the medium after bioprocessing, separation, distillation, vacuum evaporation, extraction, electrodialysis, adsorption, ion exchange, precipitation, crystallization, concentration and dehydration, acid addition precipitation, nanofiltration, acid catalyst treatment, semi-continuous or continuous distillation, solvent extraction, evaporative concentration, evaporative crystallization, liquid / liquid extraction, hydrogenation, azeotropic distillation, adsorption, column chromatography, simple vacuum distillation, microfiltration, centrifugation, and ultrafiltration, either alone or in combination. In particular, the invention provides a degradation process for a plastic product comprising PET in which the preferred recovered monomers are selected from monoethylene glycol and terephthalic acid, and the preferred oligomers are selected from methyl-2-hydroxyethyl terephthalate (MHET), bis(2-hydroxyethyl) terephthalate (BHET), 2-hydroxyethyl benzoate (HEB), and dimethyl terephthalate (DMT). In particular, the invention provides a degradation process for a plastic product comprising PLA in which the preferred recovered monomers are selected from lactic acid, in particular D-lactic acid or L-lactic acid. In a preferred embodiment, the repolymerizable monomers and / or oligomers can then be reused to synthesize polymers, preferably polyesters. Advantageously, polymers of the same type are repolymerized. However, it is possible to mix the recovered monomers and / or oligomers with other monomers and / or oligomers to synthesize new copolymers. Initiators can be added to the monomer / oligomer solution / CLn / zznz / e / YiAi to promote the polymerization reaction. A person skilled in the art can easily adapt the process parameters to the monomers / oligomers and polymers to be synthesized. In addition, or as an alternative, a recovery step for the non-depolymerized polymers is performed after the depolymerization step. Specifically, these polymers may consist of the crystalline portion of the polyester originally subjected to the depolymerization step and / or different polymers that make up the plastic article. Examples of recovery methods include filtration, microfiltration, separation, solvent extraction, solvent solubilization and evaporation, liquid-liquid extraction, decantation, and centrifugation. The following examples will disclose additional aspects and advantages of the invention, which are to be considered illustrative and do not limit the scope of this application. The following is a description of the present invention, including preferred embodiments provided in general terms. The present invention is further exemplified in the disclosure provided under the heading “Examples” below, which provides experimental data supporting the invention and means of implementing the invention. EXAMPLES Example 1 - Degradation process of a plastic product containing PET: Volvic® bottles A) Amortization stage Volvic® water bottles were collected after use. The caps and adhesive labels were removed. The bottles were then ground into flakes using a Delta Tech Rapid 150 granulator. A first sample (BV1) was collected. The initial degree of crystallinity (Xc) of the flakes was estimated using a Mettler Toledo DSC 3 with a heating rate of 102°C / min. The measured initial crystallinity was 26%. The different temperatures that characterize BV1 were also measured: Glass transition temperature - Tv = 672C, Cold crystallization temperature - Tcf = 1342C Melting point - Tf = 2502C. / CLn / zznz / e / YiAi The amortization stage was carried out using a Leistritz ZSE 18 MAXX twin screw extruder, comprising nine successive heating zones (Z1 - Z9) in which the temperature can be independently controlled and regulated, and a head (Z10). In the first embodiment, Volvic® BV1 bottle flakes were introduced into the main hopper (before Z1). The temperature profile along the screw is described in Table 1. The screw rotation speed was 30 rpm. / CLn / zznz / e / YiAi Table 1: Temperature profile of the extruder used for BV2 and BV3 Zone Z1 Z2 Z3 Z4 Z5 Z6 Z7 Z8 Z9 Z10 (head) TSC 170 eC 230 eC 250 SC 260 eC 270 eC 270 eC 270 eC 260 eC 250 eC 250 eC The molten polymer reached the screw head (Z10), which comprised a die plate with a 3.5 mm hole, and was immediately immersed in a 2 m long cold water bath filled with a mixture of water and crushed ice. The resulting bath temperature was approximately 5°C. The resulting extruded product was granulated into fine solid granules <3 mm and a BV2 sample was collected. The degree of crystallinity of BV2, measured by CDB, was 9%. In a second embodiment, the amorphization stage, as previously disclosed (using the same extruder parameters and cooling conditions), was carried out in BV1, with the addition of water. More specifically, 10% water by total weight was added directly to the Volvic® bottle flakes, which were then mixed before being introduced into the main hopper (before Z1). The resulting extruded product was granulated to form fine solid granules <3 mm and a BV3 sample was collected. The degree of crystallinity of BV3, as measured by CDB, was 11%. In a third embodiment, the amorphization step was carried out in BV1 using the same extruder, the same temperature profile shown in Table 1, and the same cooling conditions, but at a different speed of 60 rpm. The resulting extruded product was granulated to form fine solid granules <3 mm, and a BV4 sample was collected. The degree of crystallinity of BV4, measured by CDB, was 12%. In a fourth embodiment, the debonding stage was carried out in BV1 using the same extruder, the same temperature profile shown in Table 1, the same cooling conditions, a speed of 60 rpm, and the addition of 10% water by weight to the flakes. The resulting extruded product was granulated to form fine solid granules <3 mm, and a BV5 sample was collected. The degree of crystallinity of BV5, measured by CDB, was approximately 12%. In a fifth embodiment, the amortization stage was carried out in BV1 using the same extruder, the same temperature profile shown in Table 1, the same cooling conditions, a speed of 60 rpm, and the addition of 1% EG by weight to the flakes. The resulting extruded product was granulated to form fine solid granules <3 mm, and a BV6 sample was collected. The degree of crystallinity of BV6, measured by CDB, was 16%. B) Depolymerization stage a) Enzymatic depolymerization of samples BV1, BV2 and BV3: The subsequent depolymerization, in BV1, BV2 and BV3, was performed with an LCcutinase produced from recombinant expression in Escherichia coli (Sulaiman et al., Appl. Environ. Microbio., March 2012). For each sample BV1, BV2 and BV3, 100mg of samples were weighed respectively and introduced into a dialysis tube. One milliliter of LC-cutinase at 0.1 mg / ml in 0.1 M potassium phosphate at pH 8 was added to the dialysis tube before sealing it. The dialysis tube was then placed in a glass bottle containing 49 ml of 0.1 M potassium phosphate buffer, pH 8. Depolymerization was initiated by incubating each sample at 70°C and 150 rpm in a Max Q 4450 incubator (Thermo Fisher Scientific, Inc. Waltham, MA, USA). Regularly sampled 150 mL aliquots of buffer were taken. If necessary, the samples were diluted in 0.1 M potassium phosphate buffer, pH 8. Then, 150 mL of methanol and 6.5 mL of 6N HCl were added to 150 mL of sample. After mixing and filtering through a 0.45 µm syringe filter, the samples were analyzed by ultra-high-performance liquid chromatography (UHPLC) to monitor the release of terephthalic acid (TA), MHET, and BHET. The chromatography system used was an Ultimate 3000 UHPLC system (Thermo Fisher Scientific, Inc., Waltham, MA, USA) that included a pump module, an autosampler, a column oven thermostated at 25°C, and a UV detector at 240 nm. The column used was a Discovery® HS C18 HPLC column (150 x 4.6 mm, 5 µm, equipped with a pre-column, Supelco, Bellefonte, USA). The eluents were 10 mM H₂SO₄ (eluent A), ultrapure water (eluent B), and methanol (eluent C). TA, MHET and BHET were separated using a MeOH gradient in water to 1 mM H2SO4. The injection was 20 pl of sample.TA, MHET and BHET were measured according to standard curves prepared from commercial TA and BHET and MHET synthesized in the laboratory under the same conditions as the samples. The percentage of hydrolysis of Volvic® bottle samples BV1, BV2, and BV3 was calculated based on the molar concentration ratio at a given time (TA + MHET + BHET) versus the total amount of TA contained in the initial sample. The depolymerization results are shown in Figure 1. The initial rates of enzymatic depolymerization of the amortized samples BV2 and BV3 improved 8.2 and 9.8 times, respectively, compared to the initial hydrolysis rate of untransformed BV1. At the end of the reaction, 88% and 84% of the amortized samples BV2 and BV3, respectively, were degraded by the enzyme, while only 12% of BV1 was enzymatically degraded. b) Enzymatic depolymerization of samples BV4, BV5 and BV6 The same sample depolymerization procedures (depolymerase used, pH, Te, agitation, etc.) and degradation analysis as described for samples BV1, BV2, and BV3 were applied to samples BV4, BV5, and BV6. Only the temperature during the depolymerization stage was different, i.e., 65°C instead of 70°C. The percentage of hydrolysis of the Volvic® bottle samples BV1, BV4, BV5, and BV6 was calculated, as described above. The depolymerization results are shown in Figure 2. The initial rates of enzymatic depolymerization of the amortized samples BV4, BV5, and BV6 improved by 3.6 times, 4.8 times, and 8.4 times, respectively, compared to the initial hydrolysis rate of the non-amortized sample BV1. At the end of the reaction, 82%, 94%, and 47% of the amortized samples BV4, BV5, and BV6 were enzymatically degraded, respectively, while only 12% of the crystalline Volvic® sample BV1 was enzymatically degraded. c) Enzymatic depolymerization of samples BV1 and BV5 using HiC cutinase Subsequent depolymerization, in BV1 and BV5, was performed with HiC cutinase (Humicola insolens cutinase accession number A0A075B5G4 in Uniprot) produced from recombinant expression in Yarrowia lipolitica. A synthetic gene optimized for expression in Yarrowia lipolitica and encoding a mature 194-amino-acid HiC sequence was obtained from Genscript. This sequence was cloned into the JMP62UraTef vector downstream of the sequence encoding the signal peptide and prodomain (33 N-terminal amino acids) of lipase 2 from Yarrowia lipolitica (accession number Q9P8F7). The vector is a derivative of a previously described vector (Nicaud et al. (2002) FEMS Yeast Res 2 (3): 371-379). This vector contains the Y. lipolitica TEF promoter and the scissile selection marker URA3ex, which are flanked by loxP sites and a Zeta fragment that serves as a homologous integration site. The vectors were verified by DNA sequencing (GATC Biotechy). The vector was digested using Notl, generating linear DNA with Zeta sequences at both ends, and purified. The linear DNA fragment was introduced into the Y. lipolitica JMY1212 Zeta docking platform (Bordes et al. (2007) J Microbiol Methods 70 (3): 493-502) using the lithium acetate method (Duquesne et al. (2012) Methods Mol Biol 861: 301-312). The enzymes were grown in YT2D5 medium (1% w / v yeast extract, 2% w / v tryptone, 5% w / v glucose, and 100 mM phosphate buffer, pH 6.8) for 48 h. The culture was harvested, and the supernatant was collected. The culture supernatant was filtered at 0.2 pm and concentrated using an Amicon Ultra dialysis tube with a 3 kDa cutoff point. The HiC concentration in the concentrated extract was then estimated using the Bradford method. For each of the BV1 and BV5 samples, 100 mg of samples were weighed respectively and introduced into a dialysis tube. One milliliter of HiC cutinase at 0.65 mg / ml in 0.1 M potassium phosphate at pH 8 was added to the dialysis tube before sealing it. The dialysis tube was then placed in a glass bottle containing 49 ml of 0.1 M potassium phosphate buffer at pH 8. Depolymerization was initiated by incubating each sample at 60°C and 150 rpm in a Max Q 4450 incubator (Thermo Fisher Scientific, Inc., Waltham, MA, USA). The same sample degradation analysis procedures were applied as described in a) and b). The percentage of hydrolysis of the Volvic® bottle samples BV1 and BV5 was calculated as described above. After 70 hours of reaction, the BV5 sample showed a degradation rate 173% higher than the BV1 sample. Example 2 - Degradation process of a plastic product containing PET: opaque milk bottles A) Extrusion amorphization of PET flakes from opaque milk bottles Páturages™ Opaque Páturages™ milk bottles were collected and washed after use. The caps and adhesive labels were removed. The bottles were then ground into flakes using a Delta Tech Rapid 150 granulator. A sample of the resulting flakes was micronized using a Mili ZM 200 Ultra Centrifugal system to a fine powder <500 µm in size. This first sample was designated BL1. The initial degree of crystallinity (Xc) of the BL1 powder was estimated using a Mettler Toledo DSC 3 with a heating rate of 10°C / min. The measured initial crystallinity was 27%. The different temperatures that characterize BL1 were also measured: Tv = 66°C, Tcf = 120°C, and Tf = 244°C. The amorphization stage was performed using the same Leistritz ZSE 18 MAXX twin-screw extruder, as described in Example 1. In the first embodiment, milk bottle flakes were introduced into the main hopper (before zone Z1). Temperatures were increased to 270°C in Z5, Z6, and Z7 to obtain molten PET at the die head (see Table 1). The screw rotation speed was set at 30 rpm. The molten polymer reached the screw head (Z10), which comprised a die plate with a 3.5 mm orifice, and was immediately immersed in a 2 m long cold water bath filled with a mixture of water and crushed ice. The resulting bath temperature was approximately 5 °C. The extruded product was granulated into fine solid granules <3 mm and micronized using a Milli ZM 200 Ultra Centrifugal system to a fine powder <500 µm. This sample was designated BL2. The degree of crystallinity of BL2, as measured by CDB, was less than 1%. In a second embodiment, the demolding stage was performed on milk bottle flakes using the same extruder, temperature profile as shown in Table 1, and cooling conditions, but at a speed of 60 rpm. The resulting extruded product was granulated into fine solid granules <3 mm and micronized using a Milli ZM 200 Ultra Centrifugal system to a fine powder <500 µm. This sample was designated BL3. The degree of crystallinity of BL3, as measured by CDB, was 4%. In a third embodiment, the previously disclosed amortization stage was performed on milk bottle flakes with the same temperature profile as in Table 2, at a speed of 60 rpm, with the addition of water. More specifically, 20 wt% water based on the total weight was added directly to the flakes, which were then mixed before being introduced into the main hopper (before Z1). The same cooling conditions as in the first embodiment were used. The resulting extruded product was granulated into fine solid granules <3 mm, and a sample was collected and micronized using a Milli ZM 200 Ultra Centrifugal system to a fine powder <500 µm. This sample was designated sample BL4. The degree of crystallinity of BL4, as measured by CDB, was 1%. B) Depolymerization of amortized milk bottles using a cutinase Subsequent depolymerization, in BL1, BL2, BL3 and BL4, was performed with an LC-cutinase produced from recombinant expression in Escherichia coli (Sulaiman et al., Appl Environ Microbio / ., March 2012), using the same material and method described in Example 1. The hydrolysis of milk bottle samples BL1, BL2, BL3, and BL4 was calculated based on the released TA, MHET, and BHET as described above in Example 1. The depolymerization results are shown in Figure 3. The initial rate of enzymatic depolymerization improved 3.2-fold, 4.6-fold, and 10-fold for the amortized samples BL3, BL2, and BL4, respectively, compared to the micronized milk bottle (sample BL1). At the end of the reaction, 86%, 88%, and 89% of the amortized samples BL3, BL2, and BL4 were degraded by the enzyme, respectively, while only 33% of the clear milk bottle sample BL1 was enzymatically degraded. A further depolymerization was performed, in BL1 and BL4, with HiC cutinase produced from recombinant expression in Yarrowia politica using the same material and method, the same degradation analysis and sample degradation procedures set out in Example 1B)c). The percentage of hydrolysis of the Páturaqes™ BL1 and BL4 opaque milk bottle samples was calculated, as described above. After 70 hours of reaction, the amorphized sample BL4 showed a degradation rate 152% higher than sample BL1. Example 3 - Degradation process of a plastic product containing PET: Cristaline™ water bottles A) Amortization by extrusion of PET flakes from Cristaline™ water bottles Cristaline™ water bottles were collected after use. The caps and adhesive labels were removed. The bottles were then ground into flakes using a Delta Tech Rapid 150 granulator. A sample of the flakes was micronized using a Milli ZM 200 Ultra Centrifugal system to a fine powder <500 µm in size; this sample was designated BC1. The initial degree of crystallinity (Xc) of the BC1 powder was estimated using a Mettler Toledo DSC 3 with a heating rate of 10 sC / min. The measured initial crystallinity was 33%. The different temperatures that characterize BC1 were also measured: Tv = 70.5°C, Tcf = 128°C, Tf = 242°C. The amortization stage was performed using the same Leistritz ZSE 18 MAXX twin-screw extruder as described in Examples 1 and 2. Cristaline™ bottle flakes were fed into the main hopper (before zone Z1). Temperatures were increased to 270°C in Z5, Z6, and Z7 to obtain molten PET at the die head (see Table 1). The screw rotation speed was set at 30 rpm. The molten polymer reached the screw head (Z10), which comprised a die plate with a 3.5 mm orifice, and was immediately immersed in a 2 m long cold water bath filled with a mixture of water and crushed ice. The resulting bath temperature was approximately 5 °C. The extruded product was granulated into fine solid granules <3 mm and designated. A sample of the resulting granules was micronized using a Milli ZM 200 Ultra Centrifugal system to a fine powder <500 µm; this sample was designated BC2. The degree of crystallinity of the micronized BC2 sample was 2.7%. B) Enzymatic depolymerization of used Crystalline™ water bottles in a reactor Two Minibio 500 bioreactors (Applikon Biotechnology BV, Delft, The Netherlands) were started with 10 g of either BC1 or BC2 samples and 100 mL of 10 mM pH 8 potassium phosphate buffer containing 10 mg of LC-cutinase. Agitation was set to 250 rpm using a marine propeller. The bioreactors were thermostated at 65°C by immersing them in an external water bath. The pH was adjusted to 8 by adding 3 M KOH. The different parameters (pH, temperature, agitation, base addition) were controlled using BioXpert V2.95 software. Aliquots of the reaction mixture were regularly sampled and prepared according to Example 1 for measurement. The percentage of hydrolysis of the Crystalline™ BC1 and BC2 bottle samples was calculated based on TA, MHET and BHET released as described above in Example 1. The depolymerization results are shown in Figure 4. At the end of the reaction, 90.5% of the Cristaline™ bottle sample BC2 was degraded by the enzyme, while only 18% of the Cristaline™ bottle sample BC1 was enzymatically degraded. Further depolymerization, in BC1 and BC2, was performed with HiC cutinase produced from recombinant expression in Yarrowia lipolitica using the same material and method, the same depolymerization analysis procedures and sample degradation described in Example 1B) c). The percentage of hydrolysis of the Cristaline™ BC1 and BC2 bottle samples was calculated, as described above. After 70 hours of reaction, the BC2 sample showed a degradation rate 570% higher than the BC1 sample. Example 4 - Degradation process of a plastic product containing PLA: BioWare buckets / CLn / zznz / e / YiAi A) Amortization by extrusion of PLA flakes from BioWare buckets Bioware cuvettes were collected and then ground into flakes using a Delta Tech Rapid 150 granulator. This first sample was designated BC1. The initial degree of crystallinity (Xc) of the flakes was estimated using a Mettler Toledo DSC 3 with a heating rate of 102°C / min. The measured initial crystallinity was 24.2%. The different temperatures that characterize BC1 were also measured: Tv = 642C, Tcf = 1132C, Tf = 1482C. The amortization stage was performed using the same Leistritz ZSE 18 MAXX twin-screw extruder from Example 1, but with a different temperature profile (see Table 2 below). In the first implementation, BioWare BC1 tray flakes were introduced into the main hopper (before zone Z1). The screw rotation speed was 60 rpm. / CLn / zznz / e / YiAi Table 2: Temperature profile of the extruder used for BC2, BC3 Zone Z1 Z2 Z3 Z4 Z5 Z6 77 Z8 Z9 Z10 (head) T2C 180 2C 180 SC 180 2C 180 SC 170 2C 170 2C 170 2C 170 2C 170 2C 170 2C The molten polymer reached the screw head (Z10), which comprised a die plate with a 3.5 mm hole, and was immediately immersed in a 2 m long cold water bath filled with a mixture of water and crushed ice. The resulting bath temperature was approximately 5°C. The resulting extruded product was granulated into fine solid granules <3 mm and designated sample BC2. The degree of crystallinity of the buffered sample BC2 was 2%. In a second embodiment, the amortization stage described above (using the same extruder parameters and cooling conditions) was carried out in BC1, with the addition of 10% water by total weight to the Bioware bucket flakes. The mixture was then blended before being introduced into the main hopper (before Z1). The resulting extruded product was granulated into fine solid granules <3 mm and a BC3 sample was collected. The degree of crystallinity of BC3, as measured by CDB, was 7%. B) Enzymatic depolymerization of amortized BioWare PLA trays BC1, BC2, and BC3 were immersed in liquid nitrogen and micronized using a Mili ZM 200 Ultra Centrifugal System to a fine powder <500 µm. Then, 100 mg of each micronized sample was weighed and placed into a dialysis tube. Three milliliters of Savinase® 16L diluted 1 / 100 in 0.1 M Tris buffer, pH 9.5, were added to the dialysis tube before sealing it. The dialysis tube was then placed in a plastic bottle containing 50 milliliters of 0.1 M Tris buffer, pH 9.5. Depolymerization was initiated by incubating each sample at 45°C and 150 rpm in an Infors HT Multitron Pro incubation shaker. Regularly sampled 1 ml aliquots of buffer were taken and filtered through a 0.22 µL syringe filter. The samples were analyzed by high-performance liquid chromatography (HPLC) using an Aminex HPX-87H column to monitor the release of lactic acid (LA) and lactic acid dimer (DP2).The chromatography system used was an Ultimate 3000 UHPLC system (Thermo Fisher Scientific, Inc., Waltham, MA, USA) that included a pump module, an autosampler, a column oven thermostated at 50°C, and a UV detector at 220 nm. The eluent was 5 mM H₂SO₄. The injection volume was 20 µL of sample. Liquid activity (LA) was measured according to standard curves prepared from commercial LA. DP₂ was measured in equivalent LA, applying a factor of 0.8 to the LA standard curve. The hydrolysis of BioWare cuvettes BC1, BC2, and BC3 was calculated based on the LA and LA dimer released. Depolymerization results are shown in Table 3 below. Table 3: Depolymerization rate of BioWare PLA cuvettes before / CLn / zznz / e / YiAi (BC1) and after amortization according to the invention (BC2 and BC3) after 7 h of reaction Samples Degree of crystallinity Degradation rate after 7 hours Degradation rate at baseline 100 compared to BC1 BC1 24% 34% 100 BC2 2% 44% 129 BC3 7% 41% 121 After seven hours, 44% and 41% of the amortized samples BC2 and BC3, respectively, were degraded by the enzyme, while only 34% of BC1 was enzymatically degraded.

Claims

1. A process for degrading a plastic product comprising at least one semicrystalline thermoplastic polyester, comprising the steps of: a) at least partially depolymerizing said at least one semicrystalline thermoplastic polyester from the plastic product by heating the plastic product to a temperature above the crystallization temperature (Te) of said semicrystalline thermoplastic polyester, and further cooling the plastic product to a temperature below the glass transition temperature (Tv) of said semicrystalline thermoplastic polyester, and b) depolymerizing said at least partially depolymerized polyester from the plastic product into monomers and / or oligomers.

2. The process of claim 1, wherein the amortization step of said polyester is carried out by heating the plastic product above the melting temperature (Tf) of said at least one semicrystalline thermoplastic polyester and further cooling the plastic product to a temperature below the glass transition temperature (Tv) of said semicrystalline thermoplastic polyester.

3. The process of any one of claims 1 to 2, wherein the amortization step further comprises adding at least one degradation agent, selected from the group consisting of water, monomers of a polyester of the plastic product, metal alkoxides, alcohol and plasticizers.

4. The process of claim 1, wherein the amortization stage is carried out by using an extruder.

5. The process of claim 4, wherein the extruder is a single screw extruder.

6. The process of claim 1, wherein the plastic product is a plastic fiber derived from fabrics, textiles and / or industrial waste. 11 / CLn / zznz / e / YiAi 7. The process of claim 1, wherein the amorphization step leads to a partially amorphized polyester with at most 30% crystallinity.

8. The process of claim 1, wherein the depolymerization step comprises chemical depolymerization.

9. The process of claim 1, wherein the depolymerization step is carried out by contacting the plastic product with a depolymerase capable of depolymerizing said polyester at least partially depolymerized into monomers and / or oligomers.

10. The process of claim 1, further comprising recovering oligomers and / or monomers resulting from the depolymerization of said polyester at least partially amortized from the plastic product.

11. The process of claim 10, wherein the recovered oligomers and / or monomers are further purified.

12. The process of claim 1, comprising a pretreatment step to modify the plastic product mechanically and / or physically and / or chemically and / or biologically, performed before the amorphization step.

13. El proceso de la reivindicación 1, en el que el producto de plástico comprende poliésteres semicristalinos, preferentemente seleccionados entre tereftalato de polietileno (PET), tereftalato de politrimetileno (PTT), tereftalato de polibutileno (PBT), tereftalato de ¡sosorbida de polietileno (PEIT); ácido poliláctico (PLA); polyhydroxy alkanoate (PHA), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), polyethylene furanoate (PEF), polycaprolactona (PCL), poly(ethylene adipate) (PEA), polybutylene succinate terephthalate (PBST), polybutylene succinate polyethylene (PES), poly(succinate / terephthalate / butylene isophthalate)-co-(lactate) (PBSTIL) and mixtures / combinations of these materials. 11 / CLn / zznz / e / YiAi 14. The process of claim 13, wherein the depolymerization step is carried out by contacting the plastic product with a depolymerase selected from the group consisting of cutinases, proteases, lipases, carboxylesterases and esterases.

15. The process of claim 1, wherein the plastic product comprises at least PET, and the curing step comprises heating the plastic product to a temperature above 220 2C, then cooling the plastic product to a temperature below 80 2C.

16. The process of claim 1, wherein the plastic product comprises at least PET, and the depolymerization step comprises contacting the plastic product with a cutinase.

17. The process of claim 15, wherein the depolymerization step comprises contacting the plastic product with a cutinase.

18. A method for producing monomers and / or oligomers from a plastic product containing at least one semicrystalline thermoplastic polyester, comprising subjecting the plastic product to an abatement step to at least partially abatement said semicrystalline thermoplastic polyester from the plastic product, wherein the abatement step comprises heating the plastic product to a temperature above the crystallization temperature (Te) of said semicrystalline thermoplastic polyester and further cooling the product to a temperature below the glass transition temperature (Tv) of said semicrystalline thermoplastic polyester, and a depolymerization step to depolymerize said at least partially abatement polyester from the plastic product.

19. The method of claim 18, wherein the plastic product comprises polyethylene terephthalate, and the depolymerization step comprises exposing the plastic product to a cutinase. 11 / CLn / zznz / e / YiAi 20. A process for degrading a plastic product comprising at least one semicrystalline thermoplastic polyester that has been previously buffered by heating the plastic product to a temperature above the crystallization temperature (Te) of said semicrystalline thermoplastic polyester and cooling the plastic product to a temperature below the glass transition temperature (Tv) of said semicrystalline thermoplastic polyester, comprising contacting said buffered plastic product with a depolymerase capable of degrading said previously buffered polyester.

21. The process of claim 4, wherein the extruder is a multi-screw extruder.

22. The process of claim 1, wherein the plastic product comprises at least PET, the curing step comprises heating the plastic product to a temperature above 170 °C, then cooling the plastic product to a temperature below 65 °C, and wherein the depolymerization step comprises contacting the plastic product with a cutinase.

23. The process of claim 1, wherein the plastic product comprises at least PET, the curing step comprises heating the plastic product to a temperature above 240 °C, then cooling the plastic product to a temperature below 65 °C, and wherein the depolymerization step comprises contacting the plastic product with a cutinase.

24. The process of claim 1, wherein the plastic product comprises at least PET, the curing step comprises heating the plastic product to a temperature above 250 °C, then cooling the plastic product to a temperature below 65 °C, and wherein the depolymerization step comprises contacting the plastic product with a cutinase.

25. The process of claim 1, wherein the plastic product comprises at least PLA, the curing step comprises heating the plastic product to a temperature above 145 °C, then cooling the plastic product to a temperature below 55 °C, and wherein the depolymerization step comprises contacting the plastic product with a protease.

26. The process of claim 1, wherein the plastic product comprises at least PLA, the amorphization step comprises heating the plastic product to a temperature above 160 °C, then cooling the plastic product to a temperature below 55 °C, and wherein the depolymerization step comprises contacting the plastic product with a protease.