Process for preparing crystallized plga copolymers

Abstract

The present invention relates to a process for the preparation of crystallized poly(lactic-co- glycolic acid), comprising processing a melt of a PLGA copolymer into a PLGA copolymer product and crystallizing the PLGA copolymer in the PLGA copolymer product, wherein one or more nucleating agents are added to the PLGA copolymer or the melt thereof in an amount between 0.1 and 10.0 wt%, based on the total weight of said PLGA copolymer and said nucleating agents. In particular, said one or more nucleating agents is a poly(glycolic acid) homopolymer and, optionally one or more of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, or a sorbitol derivative.

Description

[0001]PROCESS FOR PREPARING CRYSTALLIZED PLGA COPOLYMERS FIELD OF THE INVENTION The present invention relates the field of PLGA copolymer processing. In particular, the present invention relates to a process for the preparation of crystallized PLGA copolymers, in particular for the preparation of products or articles made up of crystallized PLGA copolymers. The present invention provides a process for enhancing the crystallization rate of the PLGA copolymers. BACKGROUND OF THE INVENTION The demand for biodegradable polymers with excellent material properties is rapidly growing. Biodegradable polymers can be used in various applications, from biomedicine, additive technologies, film, fibers, packaging, automotive to agriculture, etc. Poly(lactic-co-glycolic acid), which is herein also referred to as PLGA copolymer, are polymers based on lactide and glycolide monomers. PLGA copolymer typically exhibits properties between polylactic acid and polyglycolic acid, depending on the ratio of the lactide and glycolide monomers in the PLGA copolymer. The homopolymer polyglycolic acid, herein also referred to and abbreviated as PGA, is a fast crystallizable degradable polymer. Processing of PGA is difficult because its melting temperature is close to its degradation temperature. Also, the fast crystallization of a PGA homopolymer limits its use in conversion process, such as extrusion-thermoforming. Compared to polylactic acid, which is herein also referred to as polylactide and abbreviated as PLA, PLGA copolymers degrade faster at milder conditions and provide improved barrier properties towards e.g. oxygen and water. Compared to polyglycolic acid, which is herein also referred to as polyglycolide and abbreviated as PGA, PLGA copolymers are easier to process, because the incorporation of lactide monomers reduces the melting point of the polymer, and can therefore be processed at a lower temperature. This will increase the difference between its processing temperature and degradation temperature and therefore enlarges the processing window. However, it will also reduce the speed of crystallization of PGA. On the one hand, this is beneficial to obtain articles made up of amorphous PLGA / PGA. However, the usage of such articles is limited because of the low glass transition temperature of PGA, which is about 40°C. Above the glass transition temperature, the material becomes soft and sticky. In order to obtain PLGA copolymer based articles which can withstand higher temperatures, the article needs to be semi-crystalline. In general, such articles can be made more economically when the polymer crystallizes quickly during processing, leading to shorter cycle times. Crystallization is thus a particularly important process as it controls the polymer’s structural formation and strongly influences the properties of the final product or final article. There is thus a need in the art to enhance the crystallization behaviour and increase the crystallinity of PLGA copolymers and articles comprising PLGA copolymers. SUMMARY OF THE INVENTION It has now surprisingly been found that some or all of the above drawbacks can be overcome by a process for the preparation of crystallized PLGA copolymer as defined herein, wherein said process comprises the use of a nucleating agent. More in particular, it has surprisingly been found that a PGA homopolymer is a particularly effective nucleating agent or crystallization promotor for the crystallization of crystallizable PLGA copolymers. The present invention presents an improved process for the preparation of crystallized PLGA copolymers which increases crystallization speed of the PLGA copolymer, and provides easier, more fluent and automated processing of the PLGA copolymer into crystallized PLGA copolymer based products. A first aspect of the present invention relates to a process for the preparation of crystallized PLGA copolymer, said process comprising the steps of: (a) providing a crystallizable PLGA copolymer, wherein said PLGA copolymer has a glycolide content of at least 75.0 wt%, based on the total weight of the PLGA copolymer; (b) processing said crystallizable PLGA copolymer, particularly a melt of said PLGA copolymer, into a PLGA copolymer product, and (c) crystallizing the crystallizable PLGA copolymer in the PLGA copolymer product, wherein said method is characterised in that a PGA homopolymer is added as a nucleating agent to said PLGA copolymer or to a melt thereof, in an amount between 0.1 and 10.0 wt%, based on the total weight of said PLGA copolymer and said nucleating agent; and wherein said PGA homopolymer has a number average molecular mass of at least 15,000 g / mol; more in particular wherein said PGA homopolymer has a number average molecular mass of at least 18,000 g / mol, as determined by size exclusion chromatography; and / or wherein said PGA homopolymer has a weight average molecular mass of at least 25,000 g / mol, more in particular wherein said PGA homopolymer has a weight average molecular mass of at least 30,000 g / mol, as determined by size exclusion chromatography; and / or wherein said PGA homopolymer has a z average molecular mass Mzof at least 35,000 g / mol, more in particular a z average molecular mass Mzof at least 40,000 g / mol, even more in particular a z average molecular mass Mzof at least 45,000 g / mol, as determined by size exclusion chromatography. In particular embodiments, the PGA homopolymer has a Mw / Mnratio of equal to or below 3.0, and / or a Mz / Mwratio of equal to or below 5.0. In certain embodiments, the PGA homopolymer is added to said PLGA copolymer or a melt thereof prior to step (b), preferably wherein step (a) comprises (i) dry-blending said PGA homopolymer with said PLGA copolymer, or (ii) compounding said PGA homopolymer with said PLGA copolymer into a nucleated PLGA composition. In particular embodiments, one or more additives selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof is added as a further nucleating agent to said PLGA copolymer or a melt thereof, particularly in an amount between 0.01 wt% and 10 wt% based on the total weight of said PLGA copolymer and the nucleating agents. More in particular, said additive and said PGA homopolymer are added to said PLGA copolymer composition or a melt thereof prior to step (b), preferably wherein step (a) comprises (i) compounding said PGA homopolymer and said one or more additives into a nucleating agent mixture, and blending, such as dry-blending, said nucleating agent mixture with said PLGA copolymer, or (ii) compounding said additive and said PGA homopolymer with said PLGA copolymer into a nucleated PLGA composition. In preferred embodiments, said additive: - is a fatty acid amide, in particular a fatty acid amide selected from the group consisting of a saturated fatty acid bisamide, an unsaturated fatty acid bisamide, a saturated fatty acid monoamide, an unsaturated fatty acid monoamide, an N-alkyl substituted fatty acid monoamide, and any mixtures thereof. More in particular, said fatty acid amide is added in an amount between 100-10000 ppm, preferably in an amount between 100 and 2000 ppm based on the total weight of said PLGA copolymer and the nucleating agents; and / or - is a mineral, particularly wherein the mineral is talc, clay or kaolin. More in particular, the mineral is added in an amount between 0.1 and 10 wt%, preferably in an amount between 0.5 and 5 wt%, based on the total weight of said PLGA copolymer and the nucleating agents. In particular embodiments, step (b) comprises preparing or providing a melt of said PLGA copolymer, and transforming the melt of said PLGA copolymer in a shaped PLGA copolymer. More in particular, said PGA homopolymer or said PGA homopolymer and said additive, preferably a mineral and / or a fatty acid amide, may be compounded with said PLGA copolymer into a nucleated PLGA composition, and subsequently a melt of the nucleated PLGA composition is transformed in a shaped PLGA copolymer product. Alternatively, said PGA homopolymer or said PGA homopolymer and said additive, preferably a mineral and / or a fatty acid amide, may first be compounded into a nucleating agent mixture, which is then dry- blended with said PLGA copolymer, and subsequently a melt of the mixture of the PLGA copolymer and the nucleating agent mixture is transformed in a shaped PLGA copolymer product. In certain embodiments, step (c) is performed at a temperature between 60 °C and 160 °C, particularly at a temperature between 80 °C and 140 °C, such as at a temperature between 60 °C and 140 °C or between 80 °C and 120 °C. In more particular embodiments, a melt of the PLGA copolymer with a temperature between 180 °C and 250 °C, preferably between 200 °C and 240 °C, is introduced in a mold and the solidification and crystallization, in particular step (c), is / are performed at a mold temperature between 60°C and 140 °C, particularly at a mold temperature between 80°C and 120 °C. In certain embodiments, the processing of a melt of the PLGA copolymer is performed by injection molding, wherein the injection molding is performed with a total time in the mold of the PLGA copolymer below 50s, preferably with a total time in the mold below 30s, more preferable with a total time in the mold below 15s, more preferable with a total time in the mold below 10s, most preferably with a total time in the mold below 7s. In particular embodiments, the process according to the present invention is or is part of an injection molding process, an extrusion process, a blow molding process, a 3D printing process, or a thermoforming process. A related aspect of the present invention relates to a crystallized PLGA copolymer product, particularly wherein said crystallized PLGA copolymer product is an injection molded article, a blow molded article, an extrusion molded article, a 3D printed article, a thermoformed article or a fiber, obtainable or obtained by carrying out a process according to the present invention. More in particular, the crystallized PLGA copolymer product according to the present invention comprises (i) a PLGA copolymer having a glycolide content of at least 75.0 wt%; (ii) a PGA homopolymer in an amount between 0.1 and 10.0 wt%, and optionally, an additive selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof, in an amount between 0.01 wt% and 10 wt%, with wt% based on the total weight of said PLGA copolymer, PGA homopolymer and said optional additive(s) wherein said PGA homopolymer has a number average molecular mass of at least 15,000 g / mol; more in particular wherein said PGA homopolymer has a number average molecular mass of at least 18,000 g / mol, as determined by size exclusion chromatography; and / or wherein said PGA homopolymer has a weight average molecular mass of at least 25,000 g / mol, more in particular wherein said PGA homopolymer has a weight average molecular mass of at least 30,000 g / mol, as determined by size exclusion chromatography; and / or wherein said PGA homopolymer has a z average molecular mass Mzof at least 35,000 g / mol, more in particular a z average molecular mass Mzof at least 40,000 g / mol, even more in particular a z average molecular mass Mzof at least 45,000 g / mol, as determined by size exclusion chromatography. A further related aspect of the present invention relates to the use of a PGA homopolymer as a nucleating agent and / or for increasing the crystallization speed of a PLGA copolymer, particularly of a melt of said PLGA copolymer, particularly wherein said PLGA copolymer has a glycolide content of at least 75.0 wt%, based on the total weight of the PLGA copolymer; and wherein said PGA homopolymer is used in an amount between 0.1 and 10.0 wt%, based on the total weight of the PLGA copolymer and the PGA homopolymer, and wherein said PGA homopolymer has a number average molecular mass of at least 15,000 g / mol; more in particular wherein said PGA homopolymer has a number average molecular mass of at least 18,000 g / mol, as determined by size exclusion chromatography; and / or wherein said PGA homopolymer has a weight average molecular mass of at least 25,000 g / mol, more in particular wherein said PGA homopolymer has a weight average molecular mass of at least 30,000 g / mol, as determined by size exclusion chromatography, and / or wherein said PGA homopolymer has a z average molecular mass Mz of at least 35,000 g / mol, more in particular a z average molecular mass Mz of at least 40,000 g / mol, even more in particular a z average molecular mass Mz of at least 45,000 g / mol, as determined by size exclusion chromatography. The independent and dependent claims set out particular and preferred features of the invention. Features from the dependent claims may be combined with features of the independent or other dependent claims as appropriate. DETAILED DESCRIPTION OF THE FIGURES Figure 1 schematically illustrates two possible strategies for processing a mixture of PLGA and one or more nucleating agents into a PLGA article. Figure 1A depicts the processing of a nucleated PLGA compounded composition; figure 1B shows the dry-blending of the PLGA copolymer with a compounded mixture of the nucleating agents, and the subsequent processing of the dry blend. DETAILED DESCRIPTION OF THE INVENTION When describing the invention, the terms used are to be construed in accordance with the following definitions, unless a context dictates otherwise. Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention. Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while certain embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. The terms "comprising", "comprises" and "comprised of" as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements, or method steps. It will be appreciated that the terms "comprising", "comprises" and "comprised of" as used herein comprise the terms "consisting of", "consists" and "consists of". As used in the specification and the appended claims, the singular forms "a", "an," and "the" include plural referents unless the context clearly dictates otherwise. By way of example, "a step" means one step or more than one step. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art. The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g. 1 to 5 can include 1, 2, 3, 4 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). The recitation of endpoints also includes the end point values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein. The term "about" as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of + / -10% or less, preferably + / -5% or less, more preferably + / -1% or less, of and from the specified value, insofar such variations are appropriate to perform in the disclosed invention. It is to be understood that the value to which the modifier "about" refers is itself also specifically, and preferably, disclosed. The terms “wt%,” “vol%”, or “mol%” refers to a weight percentage of a component, a volume percentage of a component, or molar percentage of a component, respectively, based on the total weight, the total volume of material, or total moles, which includes the component. When describing the present invention, the terms used are to be construed in accordance with the definitions specified herein, unless a context dictates otherwise. In the following passages, different aspects and preferred statements (features) and embodiments and uses of this invention are defined in more detail. Each aspect, statement and embodiment of the invention so defined may be combined with any other aspect, statement and / or embodiment unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features or statements indicated as being preferred or advantageous. Hereto, the present invention is in particular captured by any one or any combination of one or more of the below numbered statements and embodiments, with any other aspect and / or embodiment. In general, the present invention provides a process for the preparation of crystallized poly(lactic-co-glycolic acid) (PLGA copolymer), comprising processing a melt of a crystallizable PLGA copolymer into a PLGA copolymer product and crystallizing the PLGA copolymer in the PLGA copolymer product, wherein one or more nucleating agents are added to the PLGA copolymer or a melt thereof, particularly wherein the one or more nucleating agents are selected from the group consisting of a poly(glycolic acid) homopolymer (PGA homopolymer), a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof, more in particular wherein the one or more nucleating agents are selected from the group consisting of a PGA homopolymer, a fatty acid amide, a mineral and mixtures thereof. Statement 1. Process for the preparation of crystallized PLGA copolymer, said process comprising the steps of: (a) providing a crystallizable PLGA copolymer, wherein said PLGA copolymer has a glycolide content of at least 75.0 wt%, based on the total weight of the PLGA copolymer; (b) processing said crystallizable PLGA copolymer, particularly a melt of said PLGA copolymer, into a PLGA copolymer product, and (c) crystallizing the crystallizable PLGA copolymer in the PLGA copolymer product, wherein said method is characterised in that a PGA homopolymer is added as a nucleating agent to said PLGA copolymer or to a melt thereof, in an amount between 0.1 and 10.0 wt%, based on the total weight of said PLGA copolymer and said nucleating agent. Statement 2. Process according to statement 1, wherein said PGA homopolymer has: - a number average molecular mass of at least 15,000 g / mol, such as ranging between 15,000 g / mol and 75,000 g / mol; more in particular wherein said PGA homopolymer has a number average molecular mass of at least 18,000 g / mol, such as ranging between 18,000 g / mol and 70,000 g / mol; even more in particular wherein said PGA homopolymer has a number average molecular mass of at least 19,000 g / mol or at least 20,000 g / mol, such as ranging between 19,000 g / mol and 60,000 g / mol, between 20,000 g / mol and 60,000 g / mol or between 20,000 and 50,000 g / mol, as determined by size exclusion chromatography, particularly as determined by size exclusion chromatography as described in the examples, materials and methodology section; and / or - a weight average molecular mass of at least 25,000 g / mol, such as ranging between 25,000 g / mol and 150,000 g / mol, more in particular wherein said PGA homopolymer has a weight average molecular mass of at least 30,000 g / mol, such as ranging between 30,000 g / mol and 120,000 g / mol or between 30,000 g / mol and 100,000 g / mol, as determined by size exclusion chromatography, particularly as determined by size exclusion chromatography as described in the examples, materials and methodology section; and / or - a z average molecular mass Mz of at least 35,000 g / mol, such as ranging between 35,000 g / mol and 200,000 g / mol, more in particular a z average molecular mass Mz of at least 40,000 g / mol, even more in particular a z average molecular mass Mz of at least 45,000 g / mol or of at least 50,000 g / mol, such as ranging between 50,000 g / mol and 160,000 g / mol, as determined by size exclusion chromatography, particularly as determined by size exclusion chromatography as described in the examples, materials and methodology section. Statement 3. Process according to statement 1 or 2, wherein said PGA homopolymer has: - a molecular mass distribution Mw / Mnof equal to or below 3.0, particularly equal to or below 2.5, more particularly equal to or below 2.0, and / or - a molecular mass distribution Mz / Mwof equal to or below 5.0, particularly equal to or below 4.5, more particularly equal to or below 4.0. Statement 4. Process according to any one of statements 1 to 3, wherein said PGA homopolymer is added to said PLGA copolymer or a melt thereof in an amount between 0.1 and 10.0 wt% or between 1.0 and 10.0 wt%, preferably in an amount between 2.0 and 8.0 wt%, more preferably in an amount between 2.5 and 7.5 wt%, based on the total weight of said PLGA copolymer and said nucleating agent. Statement 5. Process according to any one of statements 1 to 4, wherein the PGA homopolymer is added to said PLGA copolymer or a melt thereof prior to step (b), preferably wherein step (a) comprises (i) dry-blending said PGA homopolymer with said PLGA copolymer, or (ii) compounding said PGA homopolymer with said PLGA copolymer into a nucleated PLGA composition. Statement 6. Process according to any one of statements 1 to 5, wherein an additive selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof is added as a further nucleating agent to said PLGA copolymer or a melt thereof, particularly in an amount between 0.01 wt% and 10 wt% based on the total weight of said PLGA copolymer and the nucleating agents. Statement 7. Process according to statement 6, wherein said PGA homopolymer and said additive are added separately to said PLGA copolymer or the melt thereof. Statement 8. Process according to statement 6, wherein said PGA homopolymer and said additive are added in combination to said PLGA copolymer or the melt thereof. Statement 9Process according to any one of statements 6 to 8, wherein said additive and said PGA homopolymer are added to said PLGA copolymer composition or a melt thereof prior to step (b), preferably wherein step (a) comprises (i) compounding said PGA homopolymer and said additive into a nucleating agent mixture, and dry-blending said nucleating agent mixture with said PLGA copolymer, or (ii) compounding said additive and said PGA homopolymer with said PLGA copolymer into a nucleated PLGA composition. Statement 10. Process according to any one of statements 6 to 9, wherein said additive is a fatty acid amide and is added in an amount between 100-10000 ppm, preferably in an amount between 100 and 2000 ppm based on the total weight of said PLGA copolymer and the nucleating agents. Statement 11. Process according to statement 10, wherein said fatty acid amide is selected from the group consisting of a saturated fatty acid bisamide, an unsaturated fatty acid bisamide, a saturated fatty acid monoamide, an unsaturated fatty acid monoamide, an N-alkyl substituted fatty acid monoamide, and any mixtures thereof. Statement 12. Process according to statement 11, wherein said fatty acid amide is selected from the group of ethylenebis stearamide, ethylenebis caprylic acid amide, ethylenebis capramide, ethylenebis lauramide, ethylenebis myristamide, ethylenebis palmitamide, ethylenebis isostearamide, ethylenebis behenamide, ethylenebis (12-hydroxystearamide), methylenebis caprylic acid amide, methylenebis capramide, methylenebis lauramide, methylenebis myristamide, methylenebis palmitamide, methylenebis stearamide, methylenebis isostearamide, methylenebis behenamide, methylenebis (12- hydroxystearamide), butylenebis stearamide, butylenebis behenamide, hexamethylenebis stearamide, butylenebis (12-hydroxystearamide), hexamethylenebis behenamide, hexamethylenebis (12-hydroxystearamide), and N,N’-distearyl adipamide. Statement 13. Process according to any one of statements 6 to 12, wherein said additive is a mineral and is added in an amount between 0.1 and 10 wt%, preferably in an amount between 0.5 and 5 wt%, based on the total weight of said PLGA copolymer and the nucleating agents. Statement 14. Process according to statement 13, wherein the mineral is talc, clay or kaolin, preferably wherein the mineral is talc. Statement 15. Process according to any one of statements 1 to 14, wherein the PLGA copolymer has a glycolide content between 75.0 wt% and 100 wt%, with 100 wt% excluded, preferably between 75.0 wt% and 99 wt% or between 80.0 and 99.0 wt%, based on the total weight of the PLGA copolymer. Statement 16. Process according to any one of statements 1 to 15, wherein step (b) comprises preparing or providing a melt of said PLGA copolymer, and transforming the melt in a shaped PLGA copolymer product, or a shaped intermediate thereof. Statement 17. Method according to statement 16, wherein said PGA homopolymer or said PGA homopolymer and said additive, preferably a mineral and / or a fatty acid amide, are compounded with said PLGA copolymer into a nucleated PLGA composition and subsequently preparing a melt of the nucleated PLGA composition, and subjecting said melt of the nucleated PLGA composition to a shaping step, particularly wherein a melt of the nucleated PLGA composition is transformed into a shaped PLGA copolymer product, and to a solidification and crystallization step, particularly wherein the shaped PLGA copolymer product is subject to a solidification and crystallization step. Statement 18. Process according to statement 16, wherein said PGA homopolymer or said PGA homopolymer and said additive, preferably a mineral and / or a fatty acid amide, are compounded into a nucleating agent mixture, wherein said nucleating agent mixture is dry- blended with said PLGA copolymer, and wherein a melt of the mixture of the PLGA copolymer and the nucleating agent mixture is subjected to a shaping step, particularly wherein said melt is transformed into a shaped PLGA copolymer product, and to a solidification and crystallization step, particularly wherein the shaped PLGA copolymer product is subject to a solidification and crystallization step. Statement 19. Process according to any one of statements 16 to 18, wherein the solidification or crystallization step, particularly step (c), is / are performed at a temperature between 60 °C and 160 °C, particularly at a temperature between 80 °C and 140 °C. Statement 20. Process according to any of statements 16 to 19, wherein the melt is prepared and subjected to a shaping step at a temperature of the melt of the PLGA copolymer between 180 °C and 250 °C, preferably between 200 °C and 240 °C. Statement 21. Process according to any of statements 16 to 20, wherein a melt of the PLGA copolymer with a temperature between 180 °C and 250 °C, preferably between 200 °C and 240 °C, is introduced in a mold and wherein step (c) is performed at a mold temperature between 60°C and 140 °C, particularly at a mold temperature between 80°C and 120 °C. Statement 22. Process according to any one of statements 16 to 21, wherein step (b) is performed by injection molding, and wherein the injection molding is performed with a total time in the mold of the PLGA copolymer below 50s, preferably with a total time in the mold below 30s, more preferable with a total time in the mold below 15s, more preferable with a total time in the mold below 10s, most preferably with a total time in the mold below 7s. Statement 23. Process according to any one of the previous statements, wherein said process is or is part of an injection molding process, an extrusion process, a blow molding process, a 3D printing process, or a thermoforming process. Statement 24. Process according to any one of the previous statements, wherein said process is a process for increasing the crystallisation rate of a PLGA copolymer; and / or wherein said method is a method for improving and / or optimizing the processing of a melt of a PLGA copolymer. Statement 25. A crystallized PLGA copolymer product, obtainable or obtained by carrying out a process according to any one of the previous statements. Statement 26. A crystallized PLGA copolymer product, comprising - a PLGA copolymer having a glycolide content of at least 75.0 wt%, in particular having a glycolide content between 75.0 wt% and 100 wt%, with 100 wt% excluded, more particularly between 75.0 wt% and 99 wt% or between 80.0 and 99.0 wt%, based on the total weight of the PLGA copolymer; and - a PGA homopolymer in an amount between 0.1 and 10.0 wt%, based on the total weight of said PLGA copolymer and said PGA homopolymer. Statement 27. The crystallized PLGA copolymer product according to statement 26, wherein said PGA homopolymer has: - a number average molecular mass of at least 15,000 g / mol, such as ranging between 15,000 g / mol and 75,000 g / mol; more in particular wherein said PGA homopolymer has a number average molecular mass of at least 18,000 g / mol, such as ranging between 18,000 g / mol and 70,000 g / mol; even more in particular wherein said PGA homopolymer has a number average molecular mass of at least 19,000 g / mol or of at least 20,000 g / mol, such as ranging between 19,000 g / mol and 60,000 g / mol, between 20,000 g / mol and 60,000 g / mol, or between 20,000 and 50,000 g / mol, as determined by size exclusion chromatography, particularly as determined by size exclusion chromatography as described in the examples, materials and methodology section; and / or - a weight average molecular mass of at least 25,000 g / mol, such as ranging between 25,000 g / mol and 150,000 g / mol, more in particular wherein said PGA homopolymer has a weight average molecular mass of at least 30,000 g / mol, such as ranging between 30,000 g / mol and 120,000 g / mol or between 30,000 g / mol and 100,000 g / mol, as determined by size exclusion chromatography, particularly as determined by size exclusion chromatography as described in the examples, materials and methodology section; and / or - a z average molecular mass Mz of at least 35,000 g / mol, such as ranging between 35,000 g / mol and 200,000 g / mol, more in particular a z average molecular mass Mz of at least 40,000 g / mol, even more in particular a z average molecular mass Mz of at least 45,000 g / mol, or of at least 50,000 g / mol, such as ranging between 50,000 g / mol and 160,000 g / mol, as determined by size exclusion chromatography, particularly as determined by size exclusion chromatography as described in the examples, materials and methodology section. Statement 28. The crystallized PLGA copolymer product according to statement 26 or 27, wherein said PGA homopolymer has: - a molecular mass distribution Mw / Mn of equal to or below 3.0, particularly equal to or below 2.5, more particularly equal to or below 2.0, and / or - a molecular mass distribution Mz / Mwof equal to or below 5.0, particularly equal to or below 4.5, more particularly equal to or below 4.0. Statement 29. The crystallized PLGA copolymer product according to any one of statements 26 to 28, comprising a PLGA copolymer having a glycolide content of at least 75.0 wt%, based on the total weight of the PLGA copolymer, a PGA homopolymer in an amount between 0.1 and 10.0 wt%, and an additive selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof in an amount between 0.01 wt% and 10 wt%, with wt% based on the total weight of said PLGA copolymer, PGA homopolymer and said additive(s). Statement 30. The crystallized PLGA copolymer product according to statement 29, wherein - said additive is a fatty acid amide, such as a saturated fatty acid bisamide, an unsaturated fatty acid bisamide, a saturated fatty acid monoamide, an unsaturated fatty acid monoamide, an N-alkyl substituted fatty acid monoamide, and any mixtures thereof, and is present in an amount between 100-10000 ppm, preferably in an amount between 100 and 2000 ppm; and / or - said additive is a mineral, such as talc, kaolin or clay, and is present in an amount between 0.1 and 10 wt%, preferably in an amount between 0.5 and 5 wt%, based on the total weight of said PLGA copolymer, said PGA homopolymer and said additive(s). Statement 31. The crystallized PLGA copolymer product according to any one of statements 26 to 30, wherein said product is an injection molded article, a blow molded article, an extruded article, a 3D printed article, a thermoformed article, or a fiber. Statement 32. A composition, particularly a dry-blended or compounded composition, comprising: - a PLGA copolymer having a glycolide content of at least 75.0 wt%, in particular having a glycolide content between 75.0 wt% and 100 wt%, with 100 wt% excluded, more particularly between 75.0 wt% and 99 wt% or between 80.0 and 99.0 wt%, based on the total weight of the PLGA copolymer; and - a PGA homopolymer in an amount between 0.1 and 10.0 wt%, based on the total weight of said PLGA copolymer and said PGA homopolymer. Statement 33. The composition according to statement 32, wherein said PGA homopolymer has: - a number average molecular mass of at least 15,000 g / mol, such as ranging between 15,000 g / mol and 75,000 g / mol; more in particular wherein said PGA homopolymer has a number average molecular mass of at least 18,000 g / mol, such as ranging between 18,000 g / mol and 70,000 g / mol; even more in particular wherein said PGA homopolymer has a number average molecular mass of at least 19,000 g / mol or into 20,000 g / mol, such as ranging between 19,000 g / mol and 60,000 g / mol, between 20,000 g / mol and 60,000 g / mol or between 20,000 g / mol and 50,000 g / mol, as determined by size exclusion chromatography, particularly as determined by size exclusion chromatography as described in the examples, materials and methodology section; and / or - a weight average molecular mass of at least 25,000 g / mol, such as ranging between 25,000 g / mol and 150,000 g / mol, more in particular wherein said PGA homopolymer has a weight average molecular mass of at least 30,000 g / mol, such as ranging between 30,000 g / mol and 120,000 g / mol or between 30,000 g / mol and 100,000 g / mol, as determined by size exclusion chromatography, particularly as determined by size exclusion chromatography as described in the examples, materials and methodology section; and / or - a z average molecular mass Mzof at least 35,000 g / mol, such as ranging between 35,000 g / mol and 200,000 g / mol, more in particular a z average molecular mass Mzof at least 40,000 g / mol, even more in particular a z average molecular mass Mz of at least 45,000 g / mol, or of at least 50,000 g / mol, such as ranging between 50,000 g / mol and 160,000 g / mol, as determined by size exclusion chromatography, particularly as determined by size exclusion chromatography as described in the examples, materials and methodology section. Statement 34. The composition according to statement 32 or 33, wherein said PGA homopolymer has: - a molecular mass distribution Mw / Mn of equal to or below 3.0, particularly equal to or below 2.5, more particularly equal to or below 2.0, and / or - a molecular mass distribution Mz / Mw of equal to or below 5.0, particularly equal to or below 4.5, more particularly equal to or below 4.0. Statement 35. The composition according to any one of statements 32 to 34, comprising a PLGA copolymer having a glycolide content of at least 75.0 wt%, based on the total weight of the PLGA copolymer, a PGA homopolymer in an amount between 0.1 and 10.0 wt%, and an additive selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof in an amount between 0.01 wt% and 10 wt%, with wt% based on the total weight of said PLGA copolymer, PGA homopolymer and said additive(s). Statement 36. The composition according to statement 35, wherein - said additive is a fatty acid amide, such as a saturated fatty acid bisamide, an unsaturated fatty acid bisamide, a saturated fatty acid monoamide, an unsaturated fatty acid monoamide, an N-alkyl substituted fatty acid monoamide, and any mixtures thereof, and is present in an amount between 100-10000 ppm, preferably in an amount between 100 and 2000 ppm; and / or - said additive is a mineral, such as talc, kaolin or clay, and is present in an amount between 0.1 and 10 wt%, preferably in an amount between 0.5 and 5 wt%, based on the total weight of said PLGA copolymer, said PGA homopolymer and said additive(s). Statement 37. Use of a PGA homopolymer as a nucleating agent and / or for increasing the crystallization speed of a PLGA copolymer, particularly of a melt of said PLGA copolymer, particularly wherein said PLGA copolymer has a glycolide content of at least 75.0 wt%, based on the total weight of the PLGA copolymer; and wherein said PGA homopolymer is used in an amount between 0.1 and 10.0 wt%, based on the total weight of the PLGA copolymer and the PGA homopolymer. Statement 38. Use according to statement 37, wherein said PGA homopolymer has: - a number average molecular mass of at least 15,000 g / mol, such as ranging between 15,000 g / mol and 75,000 g / mol; more in particular wherein said PGA homopolymer has a number average molecular mass of at least 18,000 g / mol, such as ranging between 18,000 g / mol and 70,000 g / mol; even more in particular wherein said PGA homopolymer has a number average molecular mass of at least 19,000 g / mol or at least 20,000 g / mol, such as ranging between 19,000 g / mol and 60,000 g / mol, between 20,000 g / mol and 60,000 g / mol or between 20,000 g / mol and 50,000 g / mol, as determined by size exclusion chromatography; and / or - a weight average molecular mass of at least 25,000 g / mol, such as ranging between 25,000 g / mol and 150,000 g / mol, more in particular wherein said PGA homopolymer has a weight average molecular mass of at least 30,000 g / mol, such as ranging between 30,000 g / mol and 120,000 g / mol or between 30,000 g / mol and 100,000 g / mol, as determined by size exclusion chromatography; and / or - a z average molecular mass Mz of at least 35,000 g / mol, such as ranging between 35,000 g / mol and 200,000 g / mol, more in particular a z average molecular mass Mz of at least 40,000 g / mol, even more in particular a z average molecular mass Mz of at least 45,000 g / mol or of at least 50,000 g / mol, such as ranging between 50,000 g / mol and 160,000 g / mol, as determined by size exclusion chromatography, particularly as determined by size exclusion chromatography as described in the examples, materials and methodology section. Statement 39. Use according to statement 37 or 38, wherein said PGA homopolymer has: - a molecular mass distribution Mw / Mnof equal to or below 3.0, particularly equal to or below 2.5, more particularly equal to or below 2.0, and / or - a molecular mass distribution Mz / Mwof equal to or below 5.0, particularly equal to or below 4.5, more particularly equal to or below 4.0. Statement 40. Use according to any one of statements 37 to 39, wherein the PGA homopolymer in amount between 0.1 and 10.0 wt% is used in combination with an additive selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof in an amount between 0.01 wt% and 10 wt%, with wt% based on the total weight of said PLGA copolymer, PGA homopolymer and said additive(s). Statement 41. Use according to statement 40, wherein - said additive is a fatty acid amide, such as a saturated fatty acid bisamide, an unsaturated fatty acid bisamide, a saturated fatty acid monoamide, an unsaturated fatty acid monoamide, an N-alkyl substituted fatty acid monoamide, and any mixtures thereof, and is present in an amount between 100-10000 ppm, preferably in an amount between 100 and 2000 ppm; and / or - said additive is a mineral, such as talc, kaolin or clay, and is present in an amount between 0.1 and 10 wt%, preferably in an amount between 0.5 and 5 wt%, based on the total weight of said PLGA copolymer, said PGA homopolymer and said additive(s). Statement 42. Use according to statement 40 or 41, wherein said PGA homopolymer and said additive are added separately or are added as a blend to said PLGA copolymer or to the melt thereof. The inventors have surprisingly found that the crystallization of a crystallizable PLGA copolymer can be enhanced by using a specific nucleating agent prior to or during processing of the PLGA copolymer. In its broadest aspect, the present invention provides a process for the preparation of crystallized PLGA copolymer, comprising processing a PLGA copolymer or a melt thereof into a PLGA copolymer product and crystallizing the PLGA copolymer in the PLGA copolymer product, wherein one or more nucleating agents are added to the PLGA copolymer or a melt thereof, particularly wherein the one or more nucleating agents are selected from the group consisting of a PGA homopolymer, a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof. Stated differently, the present invention also relates to a process for increasing the crystallisation rate of a PLGA copolymer; and / or for improving and / or optimizing the processing of a melt of a PLGA copolymer. In a first aspect, the present invention relates to a process for the preparation of crystallized PLGA copolymer, said process comprising the steps of: (a) providing a PLGA copolymer, wherein said PLGA copolymer has a glycolide content of at least 75.0 wt%, based on the total weight of the PLGA copolymer; (b) processing said PLGA copolymer, particularly a melt of said PLGA copolymer, into a PLGA copolymer product, and (c) crystallizing the PLGA copolymer in the PLGA copolymer product, wherein said method is characterised in that a PGA homopolymer is added as a nucleating agent to said PLGA copolymer or to a melt thereof, in an amount between 0.1 and 10.0 wt%, more in particular in an amount between 1.0 and 10.0 wt%, even more in particular in an amount between 2.0 and 8.0 wt%, more preferably in an amount between 2.5 and 7.5 wt%, based on the total weight of said PLGA copolymer and said nucleating agent. The term “PLGA copolymer” as used herein refers to poly(lactic-co-glycolic acid) polymers, i.e. polymers comprising lactide and glycolide monomers. In certain embodiments, the PLGA is produced by melt ring opening polymerization of a mixture of a lactide and glycolide in the presence of a conventional catalyst, as known to the skilled person. In accordance with the present invention, the PLGA copolymer applied in the present process is a crystallizable PLGA copolymer. Crystallized PLGA copolymers can be identified via e.g. DSC measurements by the presence of a melting endotherm and a melting temperature. In particular, a crystallizable PLGA copolymer is a PLGA copolymer that exhibits a DSC melting endotherm after being subject to an isothermal holding treatment for 8 hrs at 100°C. A “melt of the PLGA copolymer” or a “PLGA melt” as used herein refers to a PLGA copolymer, as defined herein, which is in a molten state. A crystallizable PLGA copolymer has a glycolide content of at least 75.0 wt%, based on the total weight of the PLGA copolymer. More in particular, the PLGA copolymer in accordance with the present invention has a glycolide content between 75.0 wt% and 100 wt%, with 100 wt% excluded, preferably between 75.0 wt% and 99.0 wt% or between 80.0 and 99.0 wt%, more preferably between 85.0 and 98.0 wt% or between 90.0 and 95.0 wt%, based on the total weight of the PLGA copolymer. The determination of the glycolide content in PLGA polymers is known to the skilled person. The glycolide content may be determined by hydrolyzing the PLGA polymer by methanolic potassium hydroxide and transesterification of the hydrolysis products to their corresponding methyl ester. The methyl esters are subsequently separated and quantified by gas chromatography using a polar column, using internal standards for calibration. The PLGA copolymer in accordance with the present invention may have a melt flow index (MFI) ranging between 1 and 500 g / 10 min, measured at 230 °C and 2.16 kg, particularly determined according to ISO 1133-1 (2011). As used herein, the term “PGA homopolymer”, also referred to as PGA, polyglycolide or polyglycolic acid, refers to a polymer of glycolide monomers. In certain embodiments, the PGA homopolymer has a melt flow index (MFI) ranging between 1 and 500 g / 10 min, particularly ranging between 1 and 100 g / 10 min, measured at 230 °C and 2.16 kg, particularly determined according to ISO 1133-1 (2011). The molecular mass (Mn(number average molecular mass), Mw(weight average molecular mass), Mz(z average molecular mass) and molecular mass (weight) distributions Mw / Mn(also referred to as the polydispersity index or PDI), Mz / Mw, and Mz / Mnwere determined by size exclusion chromatography (SEC). It is understood that prior to the size exclusion chromatography, the PGA homopolymer is first converted into an amorphous state, such as by quenching a melt of the PGA homopolymer in a water bath. The number average (Mn), weight average (Mw) and z average (Mz) molecular mass are defined by the following expressions and are determined from the calculated Mi: Here Ni and Wi are the number and weight, respectively, of molecules having molecular mass Mi. The third representation in each case (farthest right) defines how one obtains these averages from SEC chromatograms. hi is the height (from baseline) of the SEC curve at the ith elution fraction and Mi is the molecular weight of species eluting at this increment. In particular embodiments, the PGA homopolymer has: - a number average molecular mass Mn of at least 15,000 g / mol, such as ranging between 15,000 g / mol and 75,000 g / mol; more in particular wherein said PGA homopolymer has a number average molecular mass Mn of at least 18,000 g / mol, such as ranging between 18,000 g / mol and 70,000 g / mol; even more in particular wherein said PGA homopolymer has a number average molecular mass Mn of at least 19,000 g / mol or of at least 20,000 g / mol, such as ranging between 19,000 g / mol and 60,000 g / mol, between 20,000 g / mol and 60,000 g / mol, or between 20,000 g / mol and 50,000 g / mol, as determined by size exclusion chromatography, and / or - a weight average molecular mass Mwof at least 25,000 g / mol, such as ranging between 25,000 g / mol and 150,000 g / mol, more in particular wherein said PGA homopolymer has a weight average molecular mass Mwof at least 30,000 g / mol, such as ranging between 30,000 g / mol and 120,000 g / mol or between 30,000 g / mol and 100,000 g / mol, as determined by size exclusion chromatography, and / or - a z average molecular mass Mzof at least 35,000 g / mol, such as ranging between 35,000 g / mol and 200,000 g / mol, more in particular wherein said PGA homopolymer has a z average molecular mass Mzof at least 40,000 g / mol; even more in particular wherein said PGA homopolymer has a z average molecular mass Mzof at least 45,000 g / mol or of at least 50,000 g / mol, such as ranging between 50,000 g / mol and 160,000 g / mol, as determined by size exclusion chromatography. In particular embodiments, the PGA homopolymer has - a molecular mass distribution Mw / Mnor Mw / Mnratio of equal to or below 3.0, such as ranging between 1 and 3.0, particularly equal to or below 2.5, more particularly equal to or below 2.0, and / or - a molecular mass distribution Mz / Mw or Mz / Mw ratio of equal to or below 5.0, such as ranging between 1 and 5.0, particularly equal to or below 4.5, more particularly equal to or below 4.0. In certain embodiments, the PGA homopolymer is not halogenated. Addition of PGA, particularly PGA as described herein, has been shown to be most effective in improving / increasing the crystallization speed of a PLGA copolymer. However, other additives, particularly in combination with PGA, have been shown to improve / increase the crystallization speed of a PLGA copolymer as well. Accordingly, in particular embodiments of the process according to the present invention, the process comprises the steps of: (a) providing a PLGA copolymer as defined herein, particularly wherein said PLGA copolymer has a glycolide content of at least 75.0 wt%, based on the total weight of the PLGA copolymer; (b) processing said PLGA copolymer, particularly a melt of said PLGA copolymer, into a PLGA copolymer product, and (c) crystallizing the PLGA copolymer in the PLGA copolymer product, wherein said method is characterised in that a PGA homopolymer and one or more additives are added as nucleating agents to said PLGA copolymer or to a melt thereof, wherein the one or more additives are selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof. The one or more additives are typically added in an amount between 0.01 wt% and 10 wt% based on the total weight of said PLGA copolymer and the nucleating agents. In particular embodiments, said additive is a fatty acid amide. The term “fatty acid amide” as used herein means an amide comprising in its structure at least one aliphatic hydrocarbon chain of at least 4 carbon atoms, such as from 4 to 28 carbon atoms, which may be saturated or unsaturated. More in particular, the fatty acid amide is selected from the group consisting of a saturated fatty acid bisamide, an unsaturated fatty acid bisamide, a saturated fatty acid monoamide, an unsaturated fatty acid monoamide, an N-alkyl substituted fatty acid monoamide, and any mixtures thereof. The term “fatty acid bisamide” as used herein refers to a component having two amide bonds in one molecule, such as a saturated fatty acid bisamide, or an unsaturated fatty acid bisamide. The term “fatty acid monoamide” as used herein refers to an amide comprising in its structure one aliphatic hydrocarbon of at least 4 carbon atoms, and preferably from 4 to 28 carbon atoms which may be saturated, i.e. a “saturated fatty acid monoamide”, or unsaturated, i.e. a “unsaturated fatty acid monoamide”. The term “N-alkyl substituted fatty acid monoamide” as used herein refers to a fatty acid monoamide, as defined herein (such as a saturated fatty acid monoamide or an unsaturated fatty acid monoamide) wherein one amide hydrogen of said fatty acid monoamide is substituted with an alkyl group. Particular examples of the fatty acid amide as envisaged herein include ethylenebis stearamide, ethylenebis caprylic acid amide, ethylenebis capramide, ethylenebis lauramide, ethylenebis myristamide, ethylenebis palmitamide, ethylenebis isostearamide, ethylenebis behenamide, ethylenebis (12-hydroxystearamide), methylenebis caprylic acid amide, methylenebis capramide, methylenebis lauramide, methylenebis myristamide, methylenebis palmitamide, methylenebis stearamide, methylenebis isostearamide, methylenebis behenamide, methylenebis (12-hydroxystearamide), butylenebis stearamide, butylenebis behenamide, hexamethylenebis stearamide, butylenebis (12-hydroxystearamide), hexamethylenebis behenamide, hexamethylenebis (12-hydroxystearamide), and N,N’- distearyl adipamide. The fatty acid amide as envisaged herein, either as a single component or as a mixture of a plurality of components, is typically added in an amount between 100 and 10000 ppm (i.e. between 0.01 and 1 wt%), preferably in an amount between 100 and 2000 ppm (i.e. between 0.01 and 0.2 wt%), based on the total weight of the PLGA copolymer and the nucleating agents. In particular embodiments, said additive is a mineral and is added in an amount between 0.1 and 10 wt%, preferably in an amount between 0.5 and 5 wt% or in an amount between 0.5 and 2.5 wt%, based on the total weight of said PLGA copolymer and the nucleating agents. In particular embodiments, the mineral is talc, clay or kaolin. A particularly preferred mineral is talc. More in particular, the talc has a particle size distribution with a median diameter (D50 value) between 4.5 and 7 µm, more in particular between 5.0 and 6.0 µm, and with a D95 value of 10 to 20 µm, more in particular between 12 and 15 µm, as determined by laser diffraction, in particular as determined according to ISO 13320-1 (2009). In particularly preferred embodiments, the process according to the present invention is characterized in that a PGA homopolymer as defined herein, and a fatty acid amide as defined herein and / or a mineral, particularly talc as defined herein, are added as nucleating agents to said PLGA copolymer or to a melt thereof, wherein these nucleating agents are added in a total amount below 15 wt%, particularly in a total amount below 10 wt%; wherein the PGA homopolymer is added in an amount between 2.0 and 8.0 wt%, more preferably in an amount between 2.5 and 7.5 wt%; wherein the fatty acid amide is added in an amount between 100 and 2000 ppm and / or wherein the mineral, preferably talc, is added in an amount between 0.5 and 5 wt% or between 0.5 and 2.5 wt%, based on the total weight of said PLGA copolymer and the nucleating agents. It is understood that the PGA homopolymer and the one or more additives may be added separately or in combination to the PLGA copolymer or the melt thereof. In certain embodiments, the nucleating agents, in particular PGA, and, optionally, the one or more additives, are compounded with the PLGA copolymer, thereby obtaining a nucleated PLGA composition, which is subsequently processed into a PLGA copolymer product or article. Compounding may be performed by any means suitable for this purpose. For instance, compounding of the PLGA copolymer and the nucleating agents may be performed on a twin- screw extruder. Typically, the PLGA copolymer and the PGA are in molten state inside the twin screw extruder. In certain embodiments, PGA and the other nucleating agents when present, may be blended, particularly dry-blended, with the PLGA copolymer. More in particular, PGA is first compounded with the other nucleating agents, such as a fatty acid amide and / or a mineral, thereby obtaining a nucleating agent mixture, and said nucleating agent mixture is subsequently blended, particularly dry-blended, with the PLGA copolymer and the thus obtained blend is then processed into a PLGA copolymer product or article. The PGA may also be added in molten form to the PLGA copolymer, particularly to a melt of the PLGA copolymer. In accordance with the present invention, the PLGA copolymer, particularly a composition comprising the PLGA copolymer and the one or more nucleating agents as envisaged herein, is processed into a PLGA copolymer product or article. Such processing generally comprises: - a melting step, wherein the PLGA copolymer is transformed in a molten state; - a shaping step, wherein the PLGA copolymer melt is transformed into a shaped product, or stated differently, wherein the melt of the PLGA copolymer is transformed or shaped into a PLGA product or article with a defined 3D structure; and - a solidification and crystallization step or shape retention step, for retaining the shape of the PLGA product or article. It is understood that some overlap between these different steps is possible. More in particular, in the shaping step, the melt may flow or be forced into a mold to create a 3D shape; it may flow or be forced through a die or orifice, typically to form a shape with a constant 2D cross-sectional geometry; or it may flow or be forced onto a surface – typically to form a sheet or sheetlike shape. In some processes, the shaping step may comprise an initial shaping step, such as to obtain an intermediate PLGA copolymer product or article, e.g. a preform or a sheet, which is followed by a further deformation or shaping step into the final PLGA copolymer product or article. The processing technique for transforming the PLGA copolymer into a crystallized PLGA based product as envisaged herein is not particularly limiting. Advantageously, conventional plastic processing techniques may be used, such as for instance injection molding, extrusion, blow molding, or thermoforming. In particular embodiments, the PLGA copolymer, in particular the composition comprising the PLGA copolymer and the one or more nucleating agents as envisaged herein, may be subjected to a melt-based processing technique, wherein the PLGA copolymer composition is heated to a fluid or molten state and is then forced into a mold or through a cavity to be adapted into a specific shape. For instance, the PLGA copolymer, in particular the composition comprising the PLGA copolymer and the one or more nucleating agents as envisaged herein, may be subject to injection molding, or extrusion. In certain embodiments, a nucleated PLGA composition as defined herein is converted to a molten state, and the corresponding melt is subject to a shaping step and crystallization step as envisaged herein. In certain other embodiments, a dry-blend of the PLGA copolymer with the PGA or the nucleating agent mixture as defined herein is converted to a molten state, and the corresponding melt is subject to a shaping step and crystallization step as envisaged herein. It is understood that such techniques may performed in an automated manner. In particular embodiments, the temperature of the PLGA copolymer melt subject to the shaping step ranges between 180 °C and 250 °C, preferably between 190 °C and 240 °C, even more preferably between 200 °C and 240 °C, such as between 220 °C and 235 °C. Advantageously, the speed of crystallization seems particularly enhanced at lower melt temperatures. In particular embodiments, the shaping step comprises introducing a melt of the PLGA copolymer, or a melt of the composition comprising the PLGA copolymer and the one or more nucleating agents into a mold, and subsequently allowing the PLGA copolymer to solidify and crystallize in the mold. Advantageously, the enhanced PLGA crystallization as demonstrated herein allows to reduce the cycle time, i.e. the time required to mold a single product, typically comprising the injection time, the holding time, the cooling time, the time needed to remove the molded product and the time needed to open and close the mold. More in particular, the enhanced crystallization allows to reduce the total time in the mold, particularly the sum of the mold holding time and the mold cooling time: the enhanced crystallization leads to a faster increase in rigidity of the molded PLGA copolymer, thus allowing for a quicker release of the molded product from the mold. Advantageously, for instance when performing the melt processing by injection molding, the total time in the mold of the PLGA copolymer is below 50s, such as between 2s and 50s, preferably is below 30s, even more preferably below 15s or even below 10s. In particular embodiments, the PLGA copolymer melt has a temperature and is introduced in the mold at a temperature ranging between 180 °C and 250 °C, preferably between 190 °C and 240 °C, even more preferably between 200 °C and 240 °C, such as between 220 °C and 235 °C. Advantageously, the speed of crystallization seems particularly enhanced at lower melt temperatures. In particular embodiments, the solidification and crystallization step is performed at a mold temperature or crystallization temperature between 60 °C and 160 °C or between 60 °C and 140 °C, particularly at a mold temperature or crystallization temperature between 80 °C and 140 °C or between 80 °C and 120 °C.. In other particular embodiments, the PLGA copolymer, in particular the composition comprising the PLGA copolymer and the one or more nucleating agents as envisaged herein, may be transformed in a specific shape by 3D printing, as understood by the skilled person, for instance, wherein a 3D object is created from a melt by additive processes. In further particular embodiments, the PLGA copolymer, in particular the composition comprising the PLGA copolymer and the one or more nucleating agents as envisaged herein, may be transformed in a specific shape by thermoforming. In this manufacturing process, a melt of the PLGA copolymer, in particular a melt of the composition comprising the PLGA copolymer and the one or more nucleating agents as envisaged herein, is first transformed in a sheet, which is softened, typically by applying heat, and subsequently shaping the softened sheet into a product or article by bending or stretching the softened sheet into or onto a mold, wherein the shaped product is allowed to harden Typically, a planar substrate with an extension in the x-y plane and only its planar thickness in the z-direction, is pressed such that the formed object also has an additional formed extension in the z-direction. In further particular embodiments, the PLGA copolymer, in particular the composition comprising the PLGA copolymer and the one or more nucleating agents as envisaged herein may be transformed in a specific shape by blow molding, wherein a melt of the PLGA copolymer, in particular a melt of the composition comprising the PLGA copolymer and the one or more nucleating agents as envisaged herein, is first transformed in a preform, which is softened, typically by applying heat, and subsequently shaping the softened sheet into a product or article by blowing air into the softened preform so that it conforms to a mold, wherein the shaped product is allowed to harden. A further aspect of the present invention relates to a crystallized PLGA copolymer product or article, obtainable or obtained by carrying out a process according to the present invention, in particular by carrying out a process according to any embodiment of a process according to the present invention. In particular embodiments, the crystallized PLGA copolymer product or article is an injection molded product or article, a blow molded product or article, an extruded product or article, a 3D printed product or article or a thermoformed product or article. More in particular, the crystallized PLGA copolymer product or article comprises (i) a PLGA copolymer as defined herein, particularly in an amount of at least 75wt%, at least 80 wt% or even at least 90 wt%, particularly a PLGA copolymer having a glycolide content of at least 75.0 wt% or between 75.0 wt% and 100 wt%, with 100 wt% excluded, more particularly between 75.0 wt% and 99 wt% or between 80.0 and 99.0 wt%, based on the total weight of the PLGA copolymer; and (ii) a PGA homopolymer in an amount between 0.1 and 10.0 wt%, and, optionally, one or more additives selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof in an amount between 0.01 wt% and 10 wt%, with wt% based on the total weight of said PLGA copolymer, PGA homopolymer and said additive(s). Even more in particular, the crystallized PLGA copolymer product or article comprises (i) a PLGA copolymer as defined herein, particularly in an amount of at least 75wt%, at least 80 wt% or even at least 90 wt%; and (ii) a PGA homopolymer in an amount between 0.1 and 10.0 wt%, and a fatty acid amide as defined herein in an amount between 100-10000 ppm, preferably in an amount between 100 and 2000 ppm and / or a mineral as defined herein in an amount between 0.5 and 5.0 wt%, with wt% based on the total weight of said PLGA copolymer, PGA homopolymer and said additive(s). A further aspect of the present invention relates to a composition, particularly a dry-blended or compounded composition, for producing a crystallized PLGA product or article, wherein the composition comprises (i) a PLGA copolymer as defined herein, particularly in an amount of at least 75wt%, at least 80 wt% or even at least 90 wt%, particularly a PLGA copolymer having a glycolide content of at least 75.0 wt% or between 75.0 wt% and 100 wt%, with 100 wt% excluded, more particularly between 75.0 wt% and 99 wt% or between 80.0 and 99.0 wt%, based on the total weight of the PLGA copolymer; and (ii) a PGA homopolymer in an amount between 0.1 and 10.0 wt%, and, optionally, one or more additives selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof in an amount between 0.01 wt% and 10 wt%, with wt% based on the total weight of said PLGA copolymer, PGA homopolymer and said additive(s). More in particular, the composition for producing a crystallized PLGA product or article comprises (i) a PLGA copolymer as defined herein, particularly in an amount of at least 75wt%, at least 80 wt% or even at least 90 wt%; and (ii) a PGA homopolymer in an amount between 0.1 and 10.0 wt%, and a fatty acid amide as defined herein in an amount between 100-10000 ppm, preferably in an amount between 100 and 2000 ppm and / or a mineral as defined herein in an amount between 0.5 and 5.0 wt%, with wt% based on the total weight of said PLGA copolymer, PGA homopolymer and said additive(s). A further aspect of the present invention relates to the use of a PGA homopolymer as defined herein as a nucleating agent for crystallizing a PLGA copolymer as defined elsewhere herein and / or for increasing the crystallization speed of a PLGA copolymer as defined herein, particularly of a melt of said PLGA copolymer as defined herein. In particular, the PGA homopolymer as defined elsewhere herein is added in amount between 0.1 and 10.0 wt%, based on the total weight of PLGA copolymer and PGA homopolymer. In particular embodiments, the PGA homopolymer as defined elsewhere herein is used in combination with one or more additives selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof, more in particular is used in combination with a fatty acid amide as defined herein, such as a saturated fatty acid bisamide, an unsaturated fatty acid bisamide, a saturated fatty acid monoamide, an unsaturated fatty acid monoamide, an N-alkyl substituted fatty acid monoamide, and / or in combination with a mineral, such as talc, kaolin or clay. The following examples serve to merely illustrate the invention and should not be construed as limiting its scope in any way. While the invention has been shown in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes and modifications without departing from the scope of the invention. EXAMPLES Materials and methodology Crystallizable PLGA polymer The crystallizable PLGA copolymer used in the following examples has a glycolide content of 93.2 wt% (based on the total weight of the polymer). Its melting point is 211 °C, its glass transition temperature is 42°C, and its melt flow index (MFI) at 230°C is 72 g / 10 min (load: 2.16 kg). The PLGA copolymer was produced by melt ring opening polymerization of a mixture of lactide and glycolide in the presence of a conventional catalyst. The molecular weight is controlled via the addition of a specific amount of a conventional initiator. After achieving the desired molecular weight, the conventional catalyst is deactivated by adding a deactivation additive and the excess of monomer is removed under vacuum. The glycolide content in the PLGA polymer is calculated as follows. First, 0.5g of the PLGA polymer is hydrolyzed by methanolic potassium hydroxide and the resulting monomers are (trans)esterified to their corresponding methyl ester. The methyl esters are separated using a Thermo Scientific TRACE 1300 Gas Chromatograph and a polar column. Quantification is performed using an internal standard method and resulting chromatograms are analyzed with Chromeleon 7.4 software. The thermal properties glass transition temperature (Tg) and melting temperature (Tm) were analysed with a NETZSCH DSC 3500 Sirius differential scanning calorimeter (DSC) calibrated with indium as standard.10-20mg of the PLGA specimen is heated in a Concavus aluminum pan + lidding under Nitrogen using with the following program: 1) 1st heat from 20°C to 250°C at a rate of 10°C / minute; 2) Isothermal for 3 minutes; 3) Cool from 250°C to 20°C at a rate of 10°C / minute; 4) Isothermal for 3 minutes; 5) 2nd Heat from 20 to 250°C at a rate of 10°C. The glass transition temperature is calculated from the 2nd heat cycle using Proteus Analysis software. The melt flow index [(MFI(230°C; 2.16 kg)] is prepared according to ISO 1133-1 (2011) as follows. Prior to the measurement, the samples are pre-dried in a Motan MDE40 desiccant hot air dryer for a minimum of 4 hours at 90°C. The MFI is measured on a calibrated Karg Meltflow Basic equipment, which is equilibrated at the set temperature for at least 15 minutes.4-5g sample is loaded in the cylinder and molten for 5 minutes at 230°C, with the piston loaded and the nozzle closed. After 5 minutes a weight of 2.16kg is placed on the piston and the nozzle opened. The Karg equipment will cut off first extrudate (=waste) and the following extrudate is collected until a next cut off. The last extrudate is also waste. The collected extrudate is weighted and the MFR is calculated using the Karg Software. The PGA homopolymer The PGA homopolymer used in the following examples was obtained from PJIM Polymer Scientific Co. It had the following molecular mass: Mn: 20kg / mol; Mw: 35kg / mol; Mz: 56kg / mol; PDI (Mw / Mn): 1.71. Prior to determining the molecular mass (weight), the PGA was converted to an amorphous state. To this end, the crystalline PGA homopolymer was first extruded in molten state and quenched in a water bath to obtain amorphous pellets. Absolute molecular mass (weight) parameter Mn (number average molecular mass), Mw (weight average molecular mass), Mz and polydispersity index PDI (Mw / Mn) and Mz / Mn on amorphous PGA samples were determined by size exclusion chromatography (SEC) (gel permeation chromatography or GPC), using a Viscotek GPC Mx VE2001 system with 1,1,1,3,3,3-Hexafluoro-2-propanol (hexafluoroisopropanol or HFiP) and 0.02M CF3COOK as solvent at a flow rate of 0.7mL / min. Size exclusion columns were two PSS PFG analytical linear columns (M, 300 x 8.00 mm, 7 µm) in series, and were calibrated with polymers of known molecular mass. 20-25 mg of sample was weighed in a 20 ml crimp cap vials and 17 gram HFiP, was added. The suspension was shaken for at least 16 hours at room temperature. After 16 hours 1 ml of the sample was filtered through a PVDF 0.45µm filter, transferred to a 2 ml vial and injected. The melt flow index [(MFI(230°C; 2.16 kg)] is prepared according to ISO 1133-1 (2011) as mentioned above. Other PGA homopolymers from PJIM Polymer Scientific Co. for use as a nucleating agent for PLGA copolymers according to the present application include: Name MFI, Mn Mw Mz PDI Mz / Mn (230C / 2,16kg [g / mol] [g / mol] [g / mol] (g / 10min) Vytal J116 8 37,000 74,000 138,000 2.01 3.77 Vytal J226 52 29,000 48,000 81,000 1.68 2.81 Sample preparation Table 1 lists the additives and formulations for making nucleated PLGA copolymer compositions, i.e. compounded compositions comprising the crystallizable PLGA copolymer and one or more of the nucleating agents. Table 2 lists the composition of the reference samples, in particular PGA and PLLA homopolymers. The PLGA copolymer was from TotalEnergies-Corbion. The PGA homopolymer (PGA) was obtained from PJIM Polymer Scientific Co., Ltd. Luzenac Talc A10XC (“Talc”) was from Imerys. N,N’-ethylenebis (stearamide) (“EBS”; CAS number 110-30-5) was from Sigma-Aldrich. Luminy® PLLA L105 was from TotalEnergies-Corbion. Table 1. Materials for making nucleated PLGA copolymer compounded compositions. Composition is expressed on wt% based on the total weight of the composition. Raw material Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 PLGA 100 wt% 95 wt% 99 wt% 99.9 wt% 94 wt% 93.9 wt% copolymer PGA - 5 wt% - - 5 wt% 5 wt% Talc - - 1 wt% - 1 wt% 1 wt% EBS - - - 0.125 wt% - 0.125 wt% Table 2. Composition of reference samples PGA and PLLA. Raw material Sample 7 Sample 8 PGA homopolymer 100 wt% - Luminy PLLA L105 - 100 wt% The compounding was performed on a Brabender DSE25x48D twin screw extruder at a screw speed of 250 rpm. Unless specified otherwise, the nucleating additives were dry blended with the PLGA copolymer. The PLGA copolymer and the PGA homopolymer were pre-dried in a desiccant hot air dryer at 85°C for a minimum of 6 hours. The Luzenac A10X C talc and EBS were used directly from the packaging. The particle size distribution of the talc powder was determined by laser diffraction, according to ISO 13320-1 (2009), and a median diameter (D50) of 5.4 µm and D95 of 12.2 µm was measured. The compounding conditions comprised the following set of temperature conditions: T1, 200 °C; T2, 215 °C; T3, 230 °C; T4, 230 °C; T5, 230 °C; T6, 225 °C; T7, 210 °C; T8, 190 °C; T9, 180 °C and T10, 180°C. Table 3 further details additional process conditions of the preparation of samples 1-6. Table 3. Compounding conditions for making nucleated PLGA copolymer compounded compositions. Processing Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 conditions Tm (°C) 183 182 183 183 183 184 Pressure (bar) 11.8-12.3 14.5-15 15.7-16.2 14.7-15.2 18.5-19 18.8-19.3 Torque (Nm) 70-75 70-80 70-80 65-75 70-80 75-80 The resulting compounded compositions were dried and crystallized at 100 °C in a desiccant hot air dryer and evaluated by DSC using two methods, i.e. an isothermal DSC method, where the isothermal temperatures were varied from 90 to 150°C, and a non-isothermal DSC method, in which the cooling rates were varied from 5 to 30K / min, as further detailed below. Example 1 – Isothermal DSC study Equipment: DSC Apparatus: NETZSCH DSC 3500 Sirius Cooling device: NETZSCH Intracooler IC70 Sample pan: Concavus pan Al, pierced lid Sample weight: 10 – 20 mg For each isothermal temperature, a new sample was used to prevent bias because of degradation. The DSC program comprised the following sequence of steps: - Step 1: Heat 10K / min to 220 °C (in section B below) and 250°C (in section A+B below); - Step 2: Isothermal for 3 minutes; - Step 3: Cool 200K / min to 90°C, 110°C, 130°C and 150°C (Isothermal temperature). This cool rate was set in the method, but could not be achieved due to equipment limitations. The actual cool rate was monitored. At the start of the cooling phase, the cool rate is a (device maximum) 85K / min, which levels off when reaching the desired isothermal temperature. - Step 4: Isothermal for 30 minutes; - Step 5: Cool to 0°C; - Step 6: Isothermal for 3 minutes; - Step 7: Heat 10K / min to 250°C. A / In a first series of experiments of the isothermal DSC study, the samples are all heated during the first heating phase to 250°C and subsequently cooled down to the desired isothermal crystallization temperature, where it is maintained for 30 minutes. The crystallization parameters during the isothermal phase (as determined by DSC) for the different samples are summarized in Table 4. The PLLA reference sample (sample 8) did not show crystallization at these conditions. It is considered the slowest crystallizable polymer of all polymers tested and is not shown in Table 4. Table 4. DSC data of the crystallization during the isothermal phase. Tc, (a) Tc peak, (b t, € t t (d) € (f) set onse , 50% t1 / 2 ΔHc Sample # ) actual (°C) (°C) (min) (min) (min) (J / g) 150 150 34.6 42.6 8 37.3 1 130 131 31 34 3 25.2 110 111 30.2 33.3 3.1 8.6 90 90 38.2 44.8 6.6 8.1 150 159 27.4 28.2 0.8 42.4 130 146 27.4 27.7 0.3 21.3 2 110 133 27.1 27.6 0.5 29.5 90 124 27.2 27.6 0.4 51.6 150 150 30.7 33.9 3.2 38.3 130 134 29 30.3 1.3 48 3 110 121 28.2 29.3 1.1 39.1 90 102 28.6 29.5 0.9 17.3 150 152 29.6 31.6 2 47.9 130 136 29.1 29.8 0.7 52.4 4 110 128 27.8 28.2 0.4 36.3 90 110 28.4 28.4 8.8 150 159 27.4 28.1 0.7 43.3 130 146 27.3 27.6 0.3 22.5 5 110 133 27.2 27.5 0.3 31.6 90 125 27.2 27.6 0.4 51.6 150 159 27.4 28.1 0.7 41.2 130 146 27.3 27.7 0.4 21.3 6 110 133 27.1 27.5 0.4 31.4 90 124 27.2 27.6 0.4 51.8 150 164 26.7 26.9 0.2 30.8 130 156 26.7 26.9 0.2 52 7 110 158 26.7 26.9 0.2 62.3 90 156 26.7 27 0.3 65 (a): set isothermal (crystallization) temperature; (b): peak temperature of crystallization; (c): DSC time at which crystallization starts; (d) DSC time at which the crystallization proceeded by 50%; €: time required to achieve 50% crystallinity, determined as t,50% - t,onset; (f): crystallization enthalpy developed during the isothermal phase. When considering the isothermal phase of the study, compared to the crystallizable PLGA reference (non-nucleated, sample 1), all nucleated samples 2-6 crystallize faster. Samples 2, 5 and 6 show a very similar crystallization performance, which indicates that the PGA nucleating agent in these compositions dominates the crystallization behaviour. The faster crystallization is inter alia demonstrated by the actual crystallization temperature (Tc peak, actual) vs the set (isothermal) temperature (Tc, set), and by the crystallization half times of the different (nucleated) polymers: the shorter the crystallization half times, the faster the polymer crystallizes. Based on these results it can be concluded that: - the PGA reference sample (7) crystallizes fastest. The crystallization peak temperature is much higher than the set temperature, indicating that the polymer is already crystallized before the isothermal temperature has been reached; - Sample 1, comprising the PLGA copolymer without any nucleating additives, clearly crystallizes at all the isothermal crystallization temperatures and it is confirmed to be a crystallizable PLGA copolymer; - PGA improves the crystallization speed of a crystallizable PLGA most effectively of the different nucleating additives tested, as indicated by the lower crystallization half time (t1 / 2) of the PGA nucleated PLGA copolymer vs the crystallization half time of the EBS and talc nucleated PLGA copolymer; - EBS and Talc also improve the crystallization speed of a crystallizable PLGA matrix, as these nucleating additives also exhibited a lower crystallization half time than the non- nucleated sample; - When a combination of various nucleating agents is used, PGA dominates the crystallization behavior. B / In a second series of experiments in the isothermal DSC study, the samples are all heated during the first heating phase to 220 °C or 250 °C and subsequently cooled down to 130 °C as the desired isothermal crystallization temperature, where it is maintained for 30 minutes. The results indicate that with a lower melting temperature the speed of crystallization increases. Example 2 – non-isothermal DSC study The study was performed on the same DSC equipment as in Example 1. For each cool rate a new sample is used to prevent bias because of degradation. The DSC program contained the following sequence of steps: - Step 1: Heat 10K / min to 250°C - Step 2: Isothermal for 3 minutes - Step3: Cool with 5 -10- 20- 30 K / min (Cool rate) to 0°C - Step 4: Isothermal for 3 minutes - Step 5: Heat 10K / min to 250°C. The crystallization enthalpy developed at different cooling rates is a measure for the speed of crystallization. In Table 5, the crystallization parameters during the cooling phase (as determined by DSC) for the different samples are summarized. ΔHc represents the crystallization enthalpy developed during the cooling phase; Tc is the (peak) crystallization temperature during cooling phase. The PLA reference (sample 8) only show a minor ability to crystallize at the slowest cool rates. It is considered the slowest crystallizable polymer of all polymers tested and is not shown in Table 5. Table 5. DSC data of the crystallization during the cooling phase at different cooling rates of the non-isothermal DSC study. Sample # cool rate (K / min) ΔHc (J / g) Tc (°C) 5 33.9 114 10 6.9 109 1 20 0 30 0 5 60.6 167 10 60.1 158 2 20 61.1 147 30 58.5 138 5 61.2 152 10 56.7 127 3 20 26.5 106 30 0 5 55.8 133 10 53.8 129 4 20 52.3 120 30 50.2 113 5 60.3 168 5 10 60.1 159 20 58.8 148 30 57.9 139 5 60.6 168 10 60.2 159 6 20 59.4 148 30 57.9 138 5 71.3 187 10 73.3 181 7 20 73.1 173 30 68.1 166 Table 4 shows that the PLGA reference sample without a nucleating additive (sample 1) is able to crystallize to some extend when cooled from the melt at a cooling speed of 5 K / min. However, the ability to crystallize decreases with increasing cooling rate is reduced, and at a cool rate of 20K / min the sample does not crystallize anymore. The addition of talc (sample 3) improves the ability to crystallize, however at a cool rate of 30K / min also this sample does not crystallize anymore. The addition of EBS and PGA (samples 2, 4, 5 & 6) shows a significant improvement in the ability of the PLGA polymer to crystallize, and the cool rate has a minimum impact on the crystallization behavior. A similar behavior is seen for the PGA homopolymer reference (sample 7). It can further be seen that, due to the incorporation of lactide monomer the total amount of crystallization enthalpy is somewhat reduced compared to a homopolymer PGA. Example 3 – Injection molding study – evaluating nucleated PLGA compounded compositions Injection molding of samples 1 to 6 was performed to study the effect of the nucleating agents, identified in the DSC study, on the cycle time in an injection molding process. The aim was to obtain crystalline tensile specimens in the shortest possible cycle time. In general, crystallization of a polymer during injection molding is a function of (1) design & thickness of the product; (2) mold temperature; (3) Mold residence time (variable, controlled by the cooling time (tcooling) and holding time (tholding); and (4) composition (variable). Variables 1 & 2 are kept constant during the experiments. More in particular, the test was performed with a 2mm thick tensile bar and at a mold temperature of 120 °C (temperature of the condition unit was 123 °C). As mentioned, the mold residence time was adjusted by changing the holding and cooling time. The composition of the samples 1 to 6 are listed in Table 1 above. The injection molding of nucleated PLGA was performed with a Sumitomo Demag IntElect2 75 / 420-250, with a screw diameter of 18 mm. The processing conditions are as follows: Tz,1: 30°C; Tz,2: 210°C; Tz,3: 235°C; Tz,4: 215°C; Tz,5: 215°C; Thotrunner: 215°C (temperature of melt); Tmold: 123°C (crystallization temperature); Phold: 400 bar; screw speed: 200 rpm; specimen: 2mm thick tensile bar The results are presented in Table 5. If the tensile bars crystallize during the time they are in the mold, their stiffness increases at the set mold temperature to a level the process can run in automatic mode, indicated by the letter “Y” in Table 5. If the tensile bars do not or insufficiently crystallize, these are still very flexible at the set mold temperature and will therefore not eject from the mold and needs to be removed manually. It is than impossible to run the process in automatic mode. This is represented by the letter “N” in Table 5. Table 5. Results of the injection molding with nucleated PLGA comprising different nucleating agents (N: not able to run in automatic mode; Y: able to run in automatic mode) ttotal moldtholdingtcoolingSample Sample Sample Sample Sample Sample time 1 2 3 4 5 6 (s) (s) (s) 15 35 50 N Y Y Y Y Y 15 20 35 N Y Y Y Y Y 15 10 25 N N Y N Y Y 10 8 18 N N N N N Y 3 7 10 N N N N N N Under the conditions of the experiment, it was not possible to run the injection molding in automated mode with sample 1, i.e. the non-nucleated PLGA copolymer. These results thus show the effectiveness of using a nucleated PLGA compound to reduce the cycle time for a crystallized molded article. All of the used additives accelerated the crystallization of the tensile bar for cycle times at least down to 35s. The best results (running in automatic mode at shortest possible cycle times) were obtained with a combination of PGA, talc and EBS as nucleating agents. Example 4 – Injection molding study: dry blending PLGA and PGA Another nucleating approach was studied by dry blending a PGA homopolymer to a crystallizable PLGA during injection molding. The crystallization behavior was studied at 2 mold temperatures, 75 and 120°C. The injection molding was performed with a Sumitomo Demag IntElect275 / 420-250, with a screw diameter of 18 mm. The processing conditions are as follows: Tz,1: 30°C; Tz,2: 210°C; Tz,3: 235°C; Tz,4: 215°C; Tz,5: 215°C; Thotrunner: 235°C (temperature of melt); Tmold: 75 °C or 120 °C (crystallization temperature); Phold: 400 bar; screw speed: 200 rpm; specimen: 2mm thick tensile bar Table 6 shows the effectiveness of dry blending a PGA homopolymer to a crystallizable PLGA copolymer on the crystallization behavior. Sample A is the non-nucleated PLGA copolymer (comparative example); samples B and C are a mixture of PLGA and 5wt% or 10 wt% PGA, respectively. Table 6. Results of the injection molding of PLGA dry blended with a PGA homopolymer (N: not able to run in automatic mode; Y: able to run in automatic mode) ttotal moldTmold tholding tcooling time Sample A Sample B Sample C (°C) (s) (s) (s) 15 35 50 N N N 15 20 35 N N N 75 15 10 25 N N N 10 8 18 N N N 3 7 10 N N N 15 35 50 N Y Y 15 20 35 N Y Y 120 15 10 25 N Y Y 10 8 18 N Y Y 3 7 10 N Y Y The results show that, under the conditions of the experiment, a mold temperature of 120°C was required to be able to obtain crystalline products which were sufficiently rigid so that the injection molding process could run in automated mode. The non-nucleated PLGA copolymer crystallizes too slow to be able running the injection molding process in an automatic mode, even with the longest residence time in the mold. The crystallization is enhanced by dry blending a PGA homopolymer into the PLGA copolymer. In the presence of PGA, both at a 5wt% and 10 wt% concentration, the injection molding process could run in automatic mode even at the shortest cycle times tested. Example 5 – Injection molding study: dry blending vs nucleated PLGA compounds The PLGA copolymer was nucleated (i.e. mixed with one or more nucleating agents) by two different methods, as schematically represented in Figure 1: A / (pre-)compounding the nucleating agents (PGA, talc and EBS) in the PLGA copolymer, thereby obtaining a nucleated PLGA compounded composition. In this strategy, a nucleated PLGA compounded composition with the same formulation as Sample 6 (Example 1) was prepared by compounding the nucleating agents and the PLGA copolymer on a Brabender DSE25x48D twin screw extruder, essentially as described above in Example 1. The nucleated PLGA compounded composition was subsequently subject to an injection molding process. B / preparing a (pre-)compounded nucleating agent mixture, comprising PGA, talc and EBS, and dry blending the nucleating agent mixture into the PLGA copolymer. In this strategy, a nucleating agent mixture consisting of 81.6 wt% PGA, 16.3 wt% talc and 2 wt% EBS was compounded on a on a Brabender DSE25x48D twin screw extruder. During injection molding, 6.1% of the nucleating agent mixture was dry blended with the PLGA copolymer, thereby obtaining the same composition as the nucleated PLGA compounded composition of strategy A. The effect of the injection molding melt temperature (225°C (=TIM,1) and 240°C (=TIM,2) and mold temperature (25, 80,100 and 120°C) on the cycle time was evaluated. The cycle time was adapted by changing the holding and cooling times. The process was considered to run stable if it was possible to run in an automatic mode. The sample codes are shown in Table 7 below. The injection molding was performed with a Sumitomo Demag IntElect275 / 420-250, with a screw diameter of 18 mm. The processing conditions are as follows: For the TIM,1 samples: Tz,1: 30°C; Tz,2: 210°C; Tz,3: 235°C; Tz,4: 225°C; Tz,5: 225°C; Thotrunner: 225°C (temperature of melt); Tmold: 80 °C, 100 °C, or 120 °C (crystallization temperature). As a comparative example, a mold temperature of 25°C was also used; Phold: 400 bar; screw speed: 200 rpm; specimen: 2mm thick tensile bar For the TIM,2samples: Tz,1: 30°C; Tz,2: 210°C; Tz,3: 235°C; Tz,4: 240°C; Tz,5: 240°C; Thotrunner: 240°C (temperature of melt); Tmold: 100 °C; Phold: 400 bar; screw speed: 200 rpm; specimen: 2mm thick tensile bar The results are represented in Table 7. If the tensile bars crystallize during the time they are in the mold, the process can run in automatic mode, indicated by the letter “Y” in Table 7. If the tensile bars do not or insufficiently crystallize, it is than impossible to run the process in automatic mode, as indicated by the letter “N” in Table 7. Table 7. Injection molding parameters and their effect on injection molding cycle time TIM,1 TIM,2 ttotal mold Tmold tholding tcooling time Strategy A Strategy B Strategy A Strategy B (°C) (s) (s) (s) Y Y 15 35 50 (IM1-25-A) (IM1-25-B) 15 20 35 Y Y 15 10 25 Y Y 25 10 8 18 Y Y 3 7 10 N Y 1 6 7 N N 1 5 6 N N Y Y 15 35 50 (IM1-80-A) (IM1-80-B) 15 20 35 Y Y 80 15 10 25 N Y 10 8 18 N Y 3 7 10 N N 1 6 7 N N 1 5 6 N N Y Y Y Y 15 35 50 (IM1-100- (IM1-100- (IM2-100- (IM2-100- A) B) A) B) 15 20 35 Y Y Y Y 100 15 10 25 Y Y Y Y 10 8 18 Y Y Y Y 3 7 10 N Y N N 1 6 7 N Y N N 1 5 6 N Y N N Y Y 15 35 50 (IM1-120- (IM1-120- A) B) 15 20 35 Y Y 120 15 10 25 Y Y 10 8 18 Y Y 3 7 10 Y Y 1 6 7 N Y 1 5 6 N Y The following conclusions can be drawn: - Adding nucleating additives aids the crystallization of the PLGA copolymer, resulting in a shorter cycle time compared to a non-nucleated PLGA copolymer (see sample A (comparative example) in Example 4). - The dry blending method wherein a (compounded) nucleating mixture is blended with PLGA during injection molding seems somewhat more effective than using a nucleated compounded PLGA composition, exhibiting the fastest cycle time at all mold temperatures. - The cycle time of the dry blended specimens seem to show a dependency on the injection molding temperature. The fastest cycle time is achieved at the lowest injection molding temperatures. - When injection molding a dry blend of PLGA and the nucleating mixutre at a moderate temperature (ca 225 °C) and a mold temperature of 100 or 120°C, the cycle time is even more favorable over molding at 25°C. This indicates that at those conditions the crystallization process is faster than cooling down the polymer below 40°C in a cold mold. Example 6 – Comparative example - Injection molding study of PLLA with PGA homopolymer PLA is considered a slow crystallizable polymer and needs to be nucleated to obtain acceptable cycle times in e.g. injection molding processes. A PGA homopolymer was evaluated if it could be an effective nucleating agent for heat resistant PLA based applications compared to standard, known nucleation agents used for such applications. To this end, PGA nucleated compounded compositions were made and the effectiveness of the nucleating agent were evaluated in an injection molding process and compared to a PLLA sample comprising talc and PDLA as nucleating agents. An effective nucleation additive would decrease the required cycle time for obtaining a crystallized product or specimen. PLL PLLA L130 and PDLA D070 were from TotalEnergies-Corbion. PGA homopolymer was obtained from PJIM Polymer Scientific Co., Ltd. Luzenac Talc A10XC (“Talc”) was from Imerys. The compositions of the samples are shown in Table 9. Table 9. Materials for making nucleated PLA compositions. Composition is expressed on wt% based on the total weight of the composition. Raw material Sample i Sample ii Sample iii Sample iv Sample v PLLA L130 90 99 97.5 95 92.5 PDLA D070 5 PGA 1 2.5 5 7.5 Talc 5 The compounding was performed on a Brabender DSE25x48D twin screw extruder at a screw speed of 250 rpm. The compounding conditions comprised the following set of temperature conditions: T1 (hopper), 220 °C; T2, 230 °C; T3, 230 °C; T4, 230 °C; T5, 230 °C; T6, 230 °C; T7, 210 °C; T8, 200 °C; T9, 200 °C and T10 (die), 200°C. Table 10 further details additional process conditions of the preparation of samples ii-v. Table 10. Compounding conditions for making PGA nucleated PLLA compounded compositions. Processing Sample ii Sample iii Sample iv Sample v conditions Tm (°C) 199 199 199 200 Pressure (bar) 3.5 5 5.8 5.5 Torque (Nm) 49 58 59 60 Throughput (kg / hr) 5.3 6.2 6.1 6.1 The injection molding of the nucleated PLLA samples i-v was performed with a Sumitomo Demag IntElect275 / 420-250, with a screw diameter of 18 mm. The processing conditions are as follows: Tz,1: 30°C; Tz,2: 160°C; Tz,3: 195°C; Tz,4: 195°C; Tz,5: 195°C; Thotrunner: 195°C; Tmold: 103°C; Phold: 250 bar; screw speed: 200 rpm; specimen: 2mm tensile bar The time in the mold, required to crystallize the PGA nucleated PLLA compounds, was evaluated by changing the holding and cooling times. The mold temperature was set to 103°C, which is known to be the optimal temperature for crystallizing PLA. The results are shown in Table 11. If the tensile bars crystallize during the time they are in the mold, their stiffness increases at the set mold temperature to a level the process can run in automatic mode, indicated by the letter “Y” in Table Z. If it is not possible to run the process in automatic mode due to insufficient crystallization, it is represented by the letter “N”. Table 11. Results of the injection molding of the PLLA samples (N: not able to run in automatic mode; Y: able to run in automatic mode) ttotal moldtholding tcooling PLA Sample Sample Sample Sample Sample time L130 i ii iii iv v (s) (s) (s) 15 35 50 Y Y Y Y Y Y 15 20 35 N Y N N N N 15 10 25 N Y N N N N 10 8 18 N Y N N N N 3 7 10 N N N N N N These results show clearly that adding PGA with the aim to accelerate the crystallization process of a PLLA matrix and reduce the cycle time, is not effective. Indeed, the crystallization and injection molding behaviour of the PGA nucleated PLA was the same as that of the non- nucleated PLA, with the injection molding process only being able to run in automatic mode at the longest cycle time. In contrast, the PLA sample comprising talc and PDLA was able to run in automatic mode at much shorter cycle times, demonstrating that talc and PDLA are effective nucleation additives for PLA. Example 7 – Comparative example – DSC study of PLLA with PGA homopolymer As mentioned in Example 6, PLA is considered a slow crystallizable polymer and needs to be nucleated. A DSC study was set up to complement the results of example 6 and to verify whether or not the PGA homopolymer used in examples 1-6 could be an effective nucleating agent or accelerator for the crystallization of PLA. PLLA L130 and PDLA D070 was from TotalEnergies-Corbion (“Luminy”). PGA homopolymer was from PJIM Polymer Scientific Co. Luzenac Talc A10XC (“Talc”) was from Imerys. The compositions of the reference sample REF, comparative samples CE 1 – CE 4 (comprising PGA), and sample CE 5 (comprising talc and PDLA as known nucleation additives) are shown in Table 12. Table 12. Compounding conditions for making PGA nucleated PLLA compounded compositions. Raw material REF CE 1 CE 2 CE 3 CE 4 CE 5 PLLA 100 wt% 99 wt% 97.5 wt% 95 wt% 92.5 wt% 90 wt% PGA - 1 wt% 2.5 wt% 5 wt% 7.5 wt% - Talc - - - - - 5 wt% PDLA - - - - - 5 wt% The PLLA and the different additives were first compounded using a Brabender DSE25x48D twin screw extruder at a screw speed of 250 rpm. Unless specified otherwise, the nucleating additives were dry blended with PLLA. The compounding conditions comprised the following set of temperature conditions: T1, 170 °C; T2, 190 °C; T3, 210 °C; T4, 220 °C; T5, 230 °C; T6, 230 °C; T7, 210 °C; T8, 200 °C; T9, 190 °C and T10 (= Tdie), 180°C. The pressure at the die was about 13 bar (about 9 bar for sample CE 5). The study was performed on the same DSC equipment as in Example 1. The DSC program was based on the DSC studies in EP446852 and comprised the following sequence of steps: - Step 1: Heat 40K / min, from 25 °C to 190 °C; - Step 2: Isothermal for 3 minutes; - Step 3: Cool 10K / min, from 190 °C to 25 °C. The results are summarized in Table 13. Table 13. DSC data of REF and samples CE 1 – CE 5. Heating Cooling Sample ΔHc(J / g) Tc(°C) ΔHc(J / g) Tc(°C) REF 41.3 137.8 / / CE 1 40.4 143.1 / / CE 2 36.8 146.1 / / CE 3 37.7 143.9 / / CE 4 38.4 142.4 / / CE 5 35.5 118.9 28.2 109.5 The addition of known nucleating additives for PLLA (PDLA and talc) (sample CE 5) results in a shift of the crystallization peak towards lower temperatures in the heating curve. The addition of PGA to PLLA (samples CE 1-4) shows an opposite effect and shifts the crystallization peak towards higher temperatures in the heating curve. The addition of known nucleating additives for PLLA (PDLA and talc) accelerates the crystallization during cooling, which is clearly shown as a crystallization peak at 109.5°C. There is no crystallization shown during cooling for neither the PLLA reference (REF) and PLLA comprising PGA (CE 1-4). These DSC results confirm the results obtained in example 6 and demonstrate that the PGA as envisaged in the present application is not a useful nucleating agent for PLLA. * * * * * In conclusion, the main findings of examples 1-7 can be summarized as follows. Both the isothermal and the non-isothermal DSC study showed that the speed of crystallization of a crystallizable PLGA copolymer can be accelerated by the use of a different range of nucleating agents. It was shown that talc, EBS and a PGA homopolymer are good nucleating agents of which the PGA homopolymer is surprisingly the most effective. Indeed, PGA is unable to accelerate the crystallisation of PLA. The speed of crystallization is further enhanced when the polymer is molten at a lower melt temperature. The injection molding study confirmed the effectiveness of the nucleating agents to enhance the PLGA crystallization and consequently reduce the cycle time. A reduced cycle time improves the option to use crystallisable PLGA copolymers more economically. The injection molding study also showed two possible ways of accelerating the crystallization of a crystallizable PLGA copolymer: 1. Compounding nucleating additives into a crystallizable PLGA copolymer in a first step and forming articles from such a compounded composition in a second step by melt processing, such as by injection molding; 2. using a dry blend of a crystallizable PLGA copolymer and a PGA homopolymer or a compounded nucleating agent mixture comprising PGA homopolymer and other nucleating additives, for making articles by melt processing such as by injection molding. Such articles could find its use where heat resistance is required in combination with e.g. high barrier properties or which needs to be compostable at "home" conditions. Typical applications could be coffee capsules, food trays, etc.

Claims

CLAIMS 1. Process for the preparation of crystallized PLGA copolymer, said process comprising the steps of: (a) providing a crystallizable PLGA copolymer, wherein said PLGA copolymer has a glycolide content of at least 75.0 wt%, in particular having a glycolide content between 75.0 wt% and 100 wt%, with 100 wt% excluded, more particularly between 75.0 wt% and 99 wt% or between 80.0 and 99.0 wt%, based on the total weight of the PLGA copolymer; (b) processing said crystallizable PLGA copolymer, particularly a melt of said PLGA copolymer, into a PLGA copolymer product, and (c) crystallizing the crystallizable PLGA copolymer in the PLGA copolymer product, wherein said method is characterised in that a PGA homopolymer is added as a nucleating agent to said PLGA copolymer or to a melt thereof, in an amount between 0.1 and 10.0 wt%, based on the total weight of said PLGA copolymer and said nucleating agent; and wherein said PGA homopolymer has a number average molecular mass Mnof at least 15,000 g / mol, as determined by size exclusion chromatography; and / or wherein said PGA homopolymer has a weight average molecular mass Mw of at least 25,000 g / mol, as determined by size exclusion chromatography; and / or wherein said PGA homopolymer has a z average molecular mass Mzof at least 35,000 g / mol, as determined by size exclusion chromatography.

2. Process according to claim 1, wherein said PGA homopolymer has a number average molecular mass Mnof at least 18,000 g / mol, as determined by size exclusion chromatography; and / or wherein said PGA homopolymer has a weight average molecular mass Mwof at least 30,000 g / mol, as determined by size exclusion chromatography; and / or a z average molecular mass Mzof at least 45,000 g / mol, as determined by size exclusion chromatography.

3. Process according to claim 1 or 2, wherein said PGA homopolymer has a molecular mass distribution Mw / Mnof equal to or below 3.0, and / or a molecular mass distribution Mz / Mwof equal to or below 5.

0.

4. Process according to any one of claims 1 to 3, wherein the PGA homopolymer is added to said PLGA copolymer or a melt thereof prior to step (b), preferably wherein step (a) comprises (i) dry-blending said PGA homopolymer with said PLGA copolymer, or (ii) compounding said PGA homopolymer with said PLGA copolymer into a nucleated PLGA composition.

5. Process according to any one of claims 1 to 4, wherein an additive selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof is added as a further nucleating agent to said PLGA copolymer or a melt thereof, particularly in an amount between 0.01 wt% and 10 wt% based on the total weight of said PLGA copolymer and the nucleating agents.

6. Process according to claim 5, wherein said additive and said PGA homopolymer are added to said PLGA copolymer composition or a melt thereof prior to step (b), preferably wherein step (a) comprises (i) compounding said PGA homopolymer and said additive into a nucleating agent mixture, and dry-blending said nucleating agent mixture with said PLGA copolymer, or (ii) compounding said additive and said PGA homopolymer with said PLGA copolymer into a nucleated PLGA composition.

7. Process according to claim 5 or 6, wherein said additive is a fatty acid amide and is added in an amount between 100-10000 ppm, preferably in an amount between 100 and 2000 ppm based on the total weight of said PLGA copolymer and the nucleating agents, particularly wherein said fatty acid amide is selected from the group consisting of a saturated fatty acid bisamide, an unsaturated fatty acid bisamide, a saturated fatty acid monoamide, an unsaturated fatty acid monoamide, an N-alkyl substituted fatty acid monoamide, and any mixtures thereof.

8. Process according to claim 5 or 6, wherein said additive is a mineral, particularly wherein the mineral is talc, clay or kaolin, and is added in an amount between 0.1 and 10 wt%, preferably in an amount between 0.5 and 5 wt%, based on the total weight of said PLGA copolymer and the nucleating agents.

9. Process according to any one of claims 1 to 8, wherein step (b) comprises preparing or providing a melt of said PLGA copolymer, and transforming the melt in a shaped PLGA copolymer product.

10. Process according to claim 9, wherein said PGA homopolymer or said PGA homopolymer and said additive, preferably a mineral and / or a fatty acid amide, are compounded with said PLGA copolymer into a nucleated PLGA composition and subsequently transforming a melt of the nucleated PLGA composition in a shaped PLGA copolymer product; or wherein said PGA homopolymer or said PGA homopolymer and said additive, preferably a mineral and / or a fatty acid amide, are compounded into a nucleating agent mixture and dry- blended said nucleating agent mixture with said PLGA copolymer prior to transforming a meltof the mixture of the PLGA copolymer and the nucleating agent mixture in a shaped PLGA copolymer product.

11. Process according to claim 9 or 10, wherein step (c) is performed at a temperature between 60 °C and 140 °C, particularly at a temperature between 80 °C and 120 °C; particularly wherein a melt of the PLGA copolymer with a temperature between 180 °C and 250 °C, preferably between 200 °C and 240 °C, is introduced in a mold and wherein step (c) is performed at a mold temperature between 60°C and 140 °C, particularly at a mold temperature between 80°C and 120 °C.

12. Process according to any one of claims 9 to 11, wherein the processing of a melt of the PLGA copolymer is performed by injection molding, and wherein the injection molding is performed with a total time in the mold of the PLGA copolymer below 50s, preferably with a total time in the mold below 30s, more preferable with a total time in the mold below 15s, more preferable with a total time in the mold below 10s, most preferably with a total time in the mold below 7s.

13. Process according to any one of claims 1 to 12, wherein the process is or is part of an injection molding process, an extrusion process, a blow molding process, a 3D printing process, or a thermoforming process.

14. A crystallized PLGA copolymer product, particularly wherein said crystallized PLGA copolymer product is an injection molded article, a blow molded article, an extrusion molded article, a 3D printed article or a thermoformed article, obtainable or obtained by carrying out a process according to any one of claims 1 to 13.

15. A crystallized PLGA copolymer product according to claim 14, comprising - a PLGA copolymer having a glycolide content of at least 75.0 wt%, in particular having a glycolide content between 75.0 wt% and 100 wt%, with 100 wt% excluded, more particularly between 75.0 wt% and 99 wt% or between 80.0 and 99.0 wt%, based on the total weight of the PLGA copolymer; - a PGA homopolymer in an amount between 0.1 and 10.0 wt%, and optionally, an additive selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof, in an amount between 0.01 wt% and 10 wt%, with wt% based on the total weight of said PLGA copolymer, PGA homopolymer and said optional additive(s) and wherein said PGA homopolymer has a number average molecular mass Mn of at least 15,000 g / mol, as determined by size exclusion chromatography; and / or wherein said PGA homopolymer has a weight average molecular mass Mw of at least 25,000 g / mol, asdetermined by size exclusion chromatography, and a z average molecular mass Mzof at least 35,000 g / mol.

16. The crystallized PLGA copolymer product according to claim 15, wherein said PGA homopolymer has a number average molecular mass Mnof at least 18,000 g / mol, as determined by size exclusion chromatography; and / or a weight average molecular mass Mwof at least 30,000 g / mol, as determined by size exclusion chromatography, and / or a z average molecular mass Mzof at least 35,000 g / mol.

17. The crystallized PLGA copolymer product according to any one of claims 14 to 16, wherein said PGA homopolymer has a molecular mass distribution Mw / Mnof equal to or below 3.0, and / or a molecular mass distribution Mz / Mwof equal to or below 5.

0.

18. Use of a PGA homopolymer as a nucleating agent and / or for increasing the crystallization speed of a PLGA copolymer, particularly of a melt of said PLGA copolymer, particularly wherein said PLGA copolymer has a glycolide content of at least 75.0 wt%, based on the total weight of the PLGA copolymer; and wherein said PGA homopolymer is used in an amount between 0.1 and 10.0 wt%, based on the total weight of the PLGA copolymer and the PGA homopolymer and wherein said PGA homopolymer has a number average molecular mass Mn of at least 15,000 g / mol; and / or a weight average molecular mass Mw of at least 25,000 g / mol, and / or a z-average molecular mass Mz of at least 35,000 g / mol, as determined by size exclusion chromatography.

19. Use according to claim 18, wherein said PGA homopolymer has a number average molecular mass Mn of at least 18,000 g / mol, and / or a weight average molecular mass Mw of at least 30,000 g / mol, and / or a z-average molecular mass Mz of at least 45,000 g / mol.

20. Use according to claim 18 or 19, wherein said PGA homopolymer has a molecular mass distribution Mw / Mn of equal to or below 3.0 and / or a molecular mass distribution Mz / Mw of equal to or below 5.

0.

21. Use according to any one of claims 18 to 20, wherein the PGA homopolymer in amount between 0.1 and 10.0 wt% is used in combination with an additive selected from the group consisting of a fatty acid amide, a mineral, an adipate, a polyethylene glycol, an epoxidized oil, a citrate ester, an aromatic sulphonate derivative, a sorbitol derivative, and mixtures thereof in an amount between 0.01 wt% and 10 wt%, with wt% based on the total weight of said PLGA copolymer, PGA homopolymer and said additive(s).

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