MASTERBATCHES OF HIGHLY LOADED AMORPHOUS PHA DISPERSED IN AMORPHOUS OR SEMI-CRYSTALLINE POLYMERS AND PROCESS FOR THEIR PRODUCTION - Patent application

Abstract

The amorphous or semi-crystalline polymer / aPHA composition (masterbatch) has a high loading of aPHA (30-50 wt% of the total composition). A method for making the composition includes feeding two or more portions of aPHA into a blending, mixing or compounding operation. The method includes feeding about 1-15 weight percent (wt%) of the total aPHA into a primary feed hopper of the blending, mixing or compounding equipment and feeding about 30-49 wt% downstream in the process.

Description

[Technical field]

[0001] This application is based on U.S. Provisional Application No. 63 / 325,226, filed March 30, 2022.

[0002] The present disclosure relates to masterbatches of highly filled amorphous polyhydroxyalkanoates (aPHAs) dispersed in amorphous or semi-crystalline polymers for addition as impact modifiers and biodegradation promoters, and methods for making the same. [Background technology]

[0003] Biodegradable plastics are of increasing industrial interest as an alternative or complement to non-biodegradable plastics in a wide range of applications, especially in packaging applications. One class of biodegradable polymers is polyhydroxyalkanoates (PHAs), which are linear aliphatic polyesters that can be produced by many microorganisms as intracellular reserves. Articles made from these polymers are commonly recognized as a food source for soil microorganisms. Thus, there is great interest in the commercial development of these polymers, especially for disposable consumer products. These polymers exhibit good biodegradability and useful physical properties.

[0004] Molecular weight, molecular weight distribution, and long chain branching are the dominant factors affecting the processability and major physical properties of any polymeric composition.

[0005] Polyhydroxyalkanoate (PHA) polymers have very limited thermal stability and undergo chain scission via a beta-elimination mechanism at typical processing temperatures and conditions. This reduces melt strength and melt elasticity, which can lead to undesirable large molecular weight reductions in certain applications. U.S. Patent No. 9,034,989 discloses a method of branching a starting PHA by reacting it with a branching agent and a crosslinking agent to effectively increase the molecular weight and melt strength of the PHA polymer. The entire contents of U.S. Patent No. 9,034,989 are incorporated herein by reference.

[0006] Nos. 9,650,513 and 11,091,632 describe the composition of branched polymer compositions containing PHA and polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), or a combination thereof to improve and / or tailor the physical, chemical, and / or mechanical properties of biodegradable polymers. The entire contents of U.S. Patent Nos. 9,650,513 and 11,091,632 are incorporated herein.

[0007] Blending two or more biopolymers offers a combination of properties not found in a single polymer or copolymer. There are many ways to blend biopolymers. A common method involves using two twin screw extruders (TSEs) to melt two or more biopolymer resins and then sending the molten biopolymer resin blend to a pelletizer for cooling and producing a masterbatch, which is an array of pelletized parts. The TSE motor transmits power to a gearbox / shaft, and the rotating screws impart shear and energy to the workpiece. The TSE utilizes modular barrels and assembles segmented screws on splined shafts, allowing for a wide variety of process system configurations and a wide range of application subdivisions.

[0008] Bio-based plastic materials tend to be more heat and shear sensitive than conventional plastics and usually require blending with modifiers, fillers, additives and other polymers based on the required performance of the final product. Higher melt temperatures and high shear stresses must be managed during the extrusion process to minimize molecular weight degradation and maintain mechanical properties.

[0009] Masterbatches are commonly used to deliver additives to extrusion applications that improve the properties and / or value of polymeric products. Typically, a masterbatch is a concentrate of additives dispersed in a polymer. Typical rubber toughening requires dispersing an elastomeric material in an amorphous or semi-crystalline polymer using high shear. High concentration percentages can be difficult to reach, especially when low melting point components are present in significant concentrations (>30%).

[0010] Amorphous polyhydroxyalkanoates (aPHAs) may be mixed with other polymers to the desired concentration in a compounding or mixing device such as a twin screw extruder. Minimizing the molecular weight (MW) loss associated with this process can be difficult due to the excessive shear required. Also, aPHAs have a very low flow temperature compared to other polymers such as polylactic acid (PLA), and tend to travel to the walls of the extruder and begin to encase the base polymer with a high melting point such as PLA. For these reasons, it has not been easy to induce a phase transition to produce a masterbatch containing high amounts of aPHAs dispersed in a crystalline polymer. Summary of the Invention [Problem to be solved by the invention]

[0011] The inventors have found it difficult to balance the heat load in the extruder while attempting to maintain high aPHA loading and minimize residence time where degradation of the aPHA can occur. Thus, there is a need for improved methods and / or apparatus for producing masterbatches of highly loaded aPHA dispersed in a polymer without molecular weight degradation. [Means for solving the problem]

[0012] One aspect of the present disclosure relates to a method for producing a blend of an amorphous or semi-crystalline polymer and an aPHA (also referred to as a masterbatch or masterbatch composition) having a high loading of aPHA. In one aspect, the aPHA content is about 30-50 wt%, about 35-49 wt%, about 40-48 wt%, about 42-47 wt%, or about 43-46 wt%, based on the total weight of the blend of aPHA and the amorphous or semi-crystalline polymer. The method includes feeding the aPHA in two or more portions into a mixing, blending, or compounding operation. The method is characterized in that about 1-15 weight percent (wt%), about 5-15 wt%, or about 10-15 wt% of aPHA, based on the total aPHA and the total amorphous or semi-crystalline polymer in the masterbatch, is fed to a primary feed (also called "first feed"), and about 30-49 wt%, about 30-45 wt%, or about 35-45 wt% of aPHA, based on the total aPHA and the total amorphous or semi-crystalline polymer in the masterbatch, is fed to a secondary feed (also called "second feed") that is physically separated from the primary feed and located downstream from the primary feed in the process. The weight ratio of aPHA in the first feed to aPHA in the second feed is 1:2-5, 1:2-4, 1:3-4, 1:3.5, 1:4, 1:3, or 1:2. The aPHA in the second feed is fed to the primary feed in a molten state. When aPHA is fed in more than two portions, the second and subsequent portions are fed in a molten state to the primary feed. The weight ratio of aPHA in the first feed to aPHA in the second and subsequent feeds is 1:2-5, 1:2-4, 1:3-4, 1:3.5, 1:4, 1:3, or 1:2. For example, in an exemplary embodiment employing a blending device such as a screw extruder having 10-12 barrels, the primary feed is made in the first barrel, and the second feed is made somewhere between the fifth and eighth barrels.

[0013] According to one aspect of the present disclosure, there is provided a method for making a masterbatch comprising an amorphous or semi-crystalline polymer and an amorphous polyhydroxyalkanoate (aPHA) dispersed in the amorphous or semi-crystalline polymer, the method comprising the steps of:

[0014] providing said amorphous or semi-crystalline polymer and about 1-15 wt % aPHA based on the total aPHA and total amorphous or semi-crystalline polymer in said masterbatch to a primary feed;

[0015] melting said primary feed;

[0016] feeding about 30-49 wt. % of the aPHA, based on the total aPHA and total amorphous or semi-crystalline polymer in said masterbatch, into a secondary feed physically separated from said primary feed and combining said secondary feed with said molten primary feed; and

[0017] and dispersing the aPHA in the secondary feed into the molten primary feed. In an exemplary embodiment, the secondary feed may be a side feed.

[0018] In one embodiment, the present disclosure relates to an amorphous or semi-crystalline polymer / aPHA composition (masterbatch) that contains about 30-50 wt%, about 35-49 wt%, about 40-48 wt%, about 42-47 wt%, or about 43-46 wt% aPHA, based on the total weight of the masterbatch composition.

[0019] The amorphous or semi-crystalline polymer may be, but is not limited to, for example, an aliphatic aromatic polyester such as polylactic acid (PLA), polybutylene succinate (PBS), or polybutylene adipate terephthalate (PBAT), a crystalline polyhydroxyalkanoate (PHA), polyethylene succinate (PES), or polycaprolactone (PCL), or a combination thereof.

[0020] The masterbatch compositions can be incorporated to produce polymeric articles in conventional thermoplastic processes, including injection molding, extrusion (blow, cast, oriented film, sheet, profile, etc.), fiber, spunbond, monofilament, thermoforming, blow molding, compression molding, and other thermoplastic processing operations.

[0021] The present disclosure also relates to a method of preparing an amorphous or semi-crystalline polymer product by adding said amorphous or semi-crystalline polymer / amorphous polyhydroxyalkanoate (aPHA) masterbatch to an amorphous or semi-crystalline polymer to obtain a mixture and subjecting said mixture to injection molding, extrusion (blow, cast, oriented film, sheet, profile, etc.), thermoforming, blow molding, compression molding, or other thermoplastic processing operations.

[0022] In one embodiment, the method includes producing a PLA / aPHA masterbatch by splitting aPHA into two or more feeds in a mixing, blending, or compounding operation. The method includes feeding the entire amount of PLA and about 1-15 wt%, about 5-15 wt%, or about 10-15 wt% of the aPHA, based on the total aPHA and PLA in the masterbatch, into a primary feed, melting the primary feed, feeding about 30-49 wt%, about 30-45 wt%, or about 35-45 wt% of the aPHA, based on the total aPHA and PLA in the masterbatch, into a secondary feed physically separated from the primary feed, combining the secondary feed with the molten primary feed, and dispersing the aPHA in the secondary feed into the molten primary feed to obtain a masterbatch containing discrete aPHA particles dispersed in the PLA. The method further includes, if desired, cooling the masterbatch. In one embodiment, the melting is carried out at a temperature range of 155° C. to 220° C., 166° C. to 210° C., or 175° C. to 195° C. In one embodiment, the dispersion is carried out at a temperature lower than the temperature of the melting step, for example, at a temperature range of 140° C. to 180° C., 145° C. to 170° C., or 150° C. to 160° C.

[0023] In one embodiment, the present disclosure relates to a PLA / aPHA composition (masterbatch) containing about 30-50 wt%, about 35-49 wt%, about 40-48 wt%, about 42-47 wt%, or about 43-46 wt% aPHA based on the total weight of the masterbatch composition.

[0024] The PLA / aPHA masterbatch compositions can be incorporated to produce PLA products in conventional thermoplastic processes, including injection molding, extrusion (blow, cast, oriented film, sheet, profile, etc.), fiber, spunbond, monofilament, thermoforming, blow molding, compression molding, and other thermoplastic processing operations.

[0025] In one embodiment, the method includes producing a polybutylene succinate (PBS) / aPHA masterbatch by feeding aPHA in two or more separate portions in a mixing, blending, or compounding operation. The method includes feeding the entire amount of PBS and about 1-15 wt%, about 5-15 wt%, or about 10-15 wt% of the aPHA, based on the total aPHA and PBS in the masterbatch, into a primary feed, melting the primary feed, feeding about 30-49 wt%, about 30-45 wt%, or about 35-45 wt% of the aPHA, based on the total aPHA and PBS in the masterbatch, into a secondary feed physically separated from the primary feed, combining the secondary feed with the molten primary feed, and dispersing the aPHA in the secondary feed into the molten primary feed to obtain a masterbatch containing discrete aPHA particles dispersed in the PBS. The method further includes, if desired, cooling the masterbatch. In one embodiment, the melting is carried out at a temperature range of 140° C. to 200° C., 150° C. to 190° C., or 160° C. to 180° C. In one embodiment, the dispersion is carried out at a temperature lower than the temperature of the melting step, for example, at a temperature range of 130° C. to 180° C., 140° C. to 170° C., or 150° C. to 160° C.

[0026] In one embodiment, the present disclosure relates to a PBS / aPHA composition (masterbatch) containing about 30-50 wt%, about 35-49 wt%, about 40-48 wt%, about 42-47 wt%, or about 43-46 wt% aPHA based on the total amount of the masterbatch composition.

[0027] The PBS / aPHA masterbatch compositions can be incorporated into conventional thermoplastic processes to produce PBS products, including injection molding, extrusion (blow, cast, oriented film, sheet, profile, etc.), fiber, spunbond, monofilament, thermoforming, blow molding, compression molding, and other thermoplastic processing operations.

[0028] In one embodiment, the method includes producing a polybutylene adipate terephthalate (PBAT) / aPHA masterbatch by feeding two or more portions of aPHA in a mixing, blending, or compounding operation, the method includes feeding the entire amount of PBAT and about 1-15 wt%, about 5-15 wt%, or about 10-15 wt% of the aPHA, based on the total aPHA and PBAT in the masterbatch, into a primary feed, melting the primary feed, feeding about 30-49 wt%, about 30-45 wt%, or about 35-45 wt% of the aPHA, based on the total aPHA and PBAT in the masterbatch, into a secondary feed physically separated from the primary feed, combining the secondary feed with the molten primary feed, and dispersing the aPHA in the secondary feed into the molten primary feed to obtain a masterbatch including discrete aPHA particles dispersed in the PBAT. The method further includes cooling the masterbatch, if necessary. In one embodiment, the melting is performed at a temperature in the range of 140° C. to 200° C., 150° C. to 190° C., or 160° C. to 180° C. In one embodiment, the dispersion is performed at a temperature lower than the temperature of the melting step, for example, in the range of 130° C. to 180° C., 140° C. to 170° C., or 150° C. to 160° C.

[0029] In one embodiment, the present disclosure relates to a PBAT / aPHA composition (masterbatch) containing about 30-50 wt%, about 35-49 wt%, about 40-48 wt%, about 42-47 wt%, or about 43-46 wt% aPHA based on the total amount of the masterbatch composition.

[0030] The PBAT / aPHA masterbatch compositions can be incorporated to produce PBAT products in conventional thermoplastic processes, including injection molding, extrusion (blow, cast, oriented film, sheet, profile, etc.), fiber, spunbond, monofilament, thermoforming, blow molding, compression molding, and other thermoplastic processing operations.

[0031] In one embodiment, the method includes producing a semi-crystalline PHA / aPHA masterbatch by splitting aPHA into two or more feeds in a mixing, blending, or compounding operation, the method includes: feeding the entire amount of semi-crystalline PHA and about 1-15 wt%, about 5-15 wt%, or about 10-15 wt% of the aPHA, based on the total aPHA and semi-crystalline PHA in the masterbatch, into a primary feed, melting the primary feed, feeding about 30-49 wt%, about 30-45 wt%, or about 35-45 wt% of the aPHA, based on the total aPHA and semi-crystalline PHA in the masterbatch, into a secondary feed physically separated from the primary feed, combining the secondary feed with the molten primary feed, and dispersing the aPHA in the secondary feed into the molten primary feed to obtain a masterbatch including discrete aPHA particles dispersed in the semi-crystalline PHA. The method further includes cooling the masterbatch, if necessary. In one embodiment, the melting is performed at a temperature in the range of 140° C. to 200° C., 150° C. to 190° C., or 160° C. to 180° C. In one embodiment, the dispersion is performed at a temperature lower than the temperature of the melting step, for example, in the range of 130° C. to 180° C., 140° C. to 170° C., or 150° C. to 160° C.

[0032] In one embodiment, the present disclosure relates to a semi-crystalline PHA / aPHA composition (masterbatch) containing about 30-50 wt%, about 35-49 wt%, about 40-48 wt%, about 42-47 wt%, or about 43-46 wt% aPHA based on the total amount of the masterbatch composition.

[0033] The semi-crystalline PHA / aPHA masterbatch compositions can be incorporated to produce semi-crystalline PHA products in conventional thermoplastic processes, including injection molding, extrusion (blow, cast, oriented film, sheet, profile, etc.), fiber, spunbond, monofilament, thermoforming, blow molding, compression molding, and other thermoplastic processing operations.

[0034] In the above embodiments, the discrete aPHA particles dispersed in the continuous amorphous or semi-crystalline polymer may have an average diameter of less than 3 μm. In some embodiments, the discrete aPHA particles dispersed in the continuous amorphous or semi-crystalline polymer may have an average diameter of about 0.001 μm to 3 μm, about 0.01 μm to 3 μm, about 0.05 μm to 2 μm, about 0.1 μm to 1 μm, or about 0.001 μm to 2 μm. In some embodiments, the average size of the discrete aPHA particles dispersed in the continuous amorphous or semi-crystalline polymer may be less than 2 μm, less than 1 μm, less than 0.5 μm, less than 0.1 μm, 0.01 to 0.1 μm, 0.02 to 0.09 μm, 0.03 to 0.08 μm, 0.04 to 0.07 μm, or 0.05 to 0.06 μm.

[0035] According to the present disclosure, split feeding of the aPHA allows for high loading of the aPHA in the resulting masterbatch to be achieved while simultaneously maintaining acceptable residence times in the resulting masterbatch (and thus minimizing degradation of the aPHA) and maintaining mechanically acceptable torque. Adding the aPHA entirely or in large amounts outside the above ranges downstream in the process significantly reduces the melt temperature of the carrier polymer, resulting in high viscosity of the carrier polymer and excessive power required by the motor. On the other hand, adding the aPHA entirely or in large amounts outside the above ranges together with the carrier polymer or upstream in the process increases the residence time of the aPHA, resulting in further degradation of the aPHA. Specifically, the present disclosure relates to the following:

[0036] Item 1. A method for producing a masterbatch comprising an amorphous or semi-crystalline polymer and an amorphous polyhydroxyalkanoate (aPHA) dispersed in the amorphous or semi-crystalline polymer by a compounding operation, comprising:

[0037] providing said amorphous or semi-crystalline polymer and about 1-15 wt % aPHA based on the total aPHA and total amorphous or semi-crystalline polymer in said masterbatch to a primary feed;

[0038] melting said primary feed;

[0039] feeding about 30-49 wt. % of the aPHA, based on the total aPHA and total amorphous or semi-crystalline polymer in said masterbatch, into a secondary feed physically separated from said primary feed and combining said secondary feed with said molten primary feed; and

[0040] The method of claim 1, wherein the aPHA in the secondary feed is dispersed into the molten primary feed to obtain a masterbatch comprising discrete aPHA particles dispersed in the amorphous or semi-crystalline polymer.

[0041] Item 2. The method according to Item 1, wherein the masterbatch contains about 30 to 50 wt % of aPHA and about 50 to 70 wt % of the crystalline polymer based on the total amount of the masterbatch.

[0042] Item 3. The method according to item 1, wherein the amorphous or semi-crystalline polymer is selected from the group consisting of polylactic acid (PLA), polybutylene succinate (PBS), aliphatic aromatic polyesters such as polybutylene adipate terephthalate (PBAT), semi-crystalline polyhydroxyalkanoates (PHA), polyethylene succinate (PES), polycaprolactone (PCL), and combinations thereof.

[0043] Item 4. The method according to Item 1, wherein the compounding operation is carried out using a twin-screw extruder.

[0044] Item 5. The method according to Item 1, wherein the melting is carried out at a temperature in the range of 155°C to 220°C.

[0045] Item 6. The method according to Item 1, wherein the dispersion is carried out at a temperature in the range of 140°C to 180°C.

[0046] Item 7. The method according to Item 1, further comprising dispersing the aPHA of the secondary feed in the molten primary feed and cooling the resulting dispersion after the dispersion.

[0047] Item 8. The method of item 1, wherein the discrete aPHA particles have an average diameter of less than 3 μm.

[0048] Item 9. The method according to item 1, wherein the aPHA comprises a poly(3-hydroxybutyrate) (P3HB) copolymer.

[0049] Item 10. The method of item 9, wherein the P3HB copolymer is poly(3-hydroxybutyrate-co-3-hydroxypropionate) (PHB3HP), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (PHB4HB), poly(3-hydroxybutyrate-co-4-hydroxyvalerate) (PHB4HV), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB3HV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHB3HH), or poly(3-hydroxybutyrate-co-5-hydroxyvalerate) (PHB5HV).

[0050] Item 11. The method according to Item 1, wherein the aPHA is a PHA copolymer containing about 50 to 80% by weight of 3-hydroxybutyric acid monomer units and about 20 to 50% by weight of one or more hydroxyalkanoic acid monomer units selected from the group consisting of 3-hydroxybutyric acid, 3-hydroxyhexanoic acid, 3-hydroxyoctanoic acid, 3-hydroxydecanoic acid, 3-hydroxydodecanoic acid, and 4-hydroxybutyric acid.

[0051] Item 12. The method according to Item 1, wherein the aPHA is a PHA copolymer containing about 55 to 75% by weight of 3-hydroxybutyric acid monomer units and about 25 to 45% by weight of one or more hydroxyalkanoic acid monomer units selected from the group consisting of 3-hydroxybutyric acid, 3-hydroxyhexanoic acid, 3-hydroxyoctanoic acid, 3-hydroxydecanoic acid, 3-hydroxydodecanoic acid, and 4-hydroxybutyric acid.

[0052] Item 13. A masterbatch composition produced by the method according to Item 1, comprising a continuous amorphous or semi-crystalline polymer and a discrete amorphous polyhydroxyalkanoate (aPHA) dispersed in the continuous amorphous or semi-crystalline polymer, the aPHA being present in an amount of about 30 to 50 wt % based on the total weight of the masterbatch composition.

[0053] Item 14. The masterbatch composition according to item 13, wherein the amorphous or semi-crystalline polymer is selected from the group consisting of polylactic acid (PLA), polybutylene succinate (PBS), aliphatic aromatic polyesters such as polybutylene adipate terephthalate (PBAT), semi-crystalline polyhydroxyalkanoates (PHA), polyethylene succinate (PES), polycaprolactone (PCL), and combinations thereof.

[0054] Item 15. The masterbatch composition according to Item 13, comprising 40 wt% or more and less than 50 wt% of aPHA based on the total weight of the masterbatch composition.

[0055] Item 16. The masterbatch composition according to item 13, wherein the average diameter of the discrete aPHA particles is less than 3 μm.

[0056] Item 17. The masterbatch composition according to item 13, wherein the aPHA comprises a poly(3-hydroxybutyrate) (P3HB) copolymer.

[0057] Item 18. The master batch composition according to Item 13, wherein the aPHA is a PHA copolymer containing about 50 to 80% by weight of 3-hydroxybutyric acid monomer units and about 20 to 50% by weight of one or more hydroxyalkanoic acid monomer units selected from the group consisting of 3-hydroxybutyric acid, 3-hydroxyhexanoic acid, 3-hydroxyoctanoic acid, 3-hydroxydecanoic acid, 3-hydroxydodecanoic acid, and 4-hydroxybutyric acid.

[0058] Item 19. A method for preparing an amorphous or semi-crystalline polymer product by adding the amorphous or semi-crystalline polymer / amorphous polyhydroxyalkanoate (aPHA) masterbatch composition according to item 13 to an amorphous or semi-crystalline polymer to obtain a mixture, and subjecting the mixture to injection molding, extrusion, thermoforming, blow molding or compression molding. Effect of the Invention

[0059] According to the present disclosure, split feed of the aPHA allows one to simultaneously achieve high loadings of aPHA in the resulting masterbatch while maintaining acceptable residence times in the resulting masterbatch (and thus, minimizing degradation of the aPHA) and maintaining mechanically acceptable torque. [Brief description of the drawings]

[0060] [Figure 1] FIG. 2 is a schematic diagram of a twin screw extruder illustrating an exemplary split feed of an aPHA of an embodiment.

[0061] [Diagram 2] SEM image of freeze-fractured PLA / aPHA masterbatch showing discrete aPHA particles (1) dispersed in continuous PLA (2). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0062] Polyhydroxyalkanoates (PHAs)

[0063] Polyhydroxyalkanoates are biopolyesters that are biosynthesized by a wide range of bacteria in nature, genetically modified bacteria, and genetically modified plant crops. These polymers are biodegradable thermoplastic materials and are produced from renewable resources, making them available for a wide range of industrial applications. Microbial strains useful for the production of PHAs include Alcaligenes eutrophus (renamed Ralstonia eutropha), Alcaligenes latus, Azotobacter, Aeromonas, Comomonas, Hydrophobic bacteria, and genetically modified organisms including genetically modified bacteria (e.g., Pseudomonas, Ralstonia, Escherichia coli).

[0064] Generally, PHAs are formed by the enzymatic polymerization of one or more monomeric units within living cells, with over 100 different types of monomers being incorporated into PHA polymers (Steinbuchel and Valentin, 1995, FEMS Microbiol. Lett. 128; 219-228.). The monomer units incorporated into PHA include 2-hydroxybutyric acid, lactic acid, glycolic acid, 3-hydroxybutyric acid (hereinafter referred to as 3HB), 3-hydroxypropionic acid (hereinafter referred to as 3HP), 3-hydroxyvaleric acid (hereinafter referred to as 3HV), 3-hydroxyhexanoic acid (hereinafter referred to as 3HH), 3-hydroxyheptanoic acid (hereinafter referred to as 3HHep), 3-hydroxyoctanoic acid (hereinafter referred to as 3HO), 3-hydroxynonanoic acid (hereinafter referred to as 3HN), 3-hydroxydecanoic acid (hereinafter referred to as 3HD), 3-hydroxydodecanoic acid (hereinafter referred to as 3HDd), 4-hydroxybutyric acid (hereinafter referred to as 4HB), 4-hydroxyvaleric acid (hereinafter referred to as 4HV), 5-hydroxyvaleric acid (hereinafter referred to as 5HV), and 6-hydroxyhexanoic acid (hereinafter referred to as 6HH). The 3 hydroxy acid monomers incorporated into the PHA are either the (D) or the (R)-isomers of 3 hydroxy acids, with the exception of 3HP, which does not have a chiral center.

[0065] In some embodiments, the PHA is a homopolymer (all monomer units are the same). Examples of PHA homopolymers include poly(3-hydroxyalkanoates) (e.g., poly(3-hydroxypropionate) (hereinafter referred to as P3HP), poly(3-hydroxybutyrate) (hereinafter referred to as P3HB), poly(3-hydroxyvalerate) (hereinafter referred to as P3HV), etc.), poly(4-hydroxyalkanoates) (e.g., poly(4-hydroxybutyrate) (hereinafter referred to as P4HB), poly(4-hydroxyvalerate) (hereinafter referred to as P4HV), etc.), and poly(5-hydroxyalkanoates) (e.g., poly(5-hydroxyvalerate) (hereinafter referred to as P5HV), etc.).

[0066] In one embodiment, the PHA is a copolymer (containing two or more different monomer units) in which different monomers are randomly distributed. Examples of PHA copolymers include poly(3-hydroxybutyrate-co-3-hydroxypropionate) (hereinafter referred to as PHB3HP), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (hereinafter referred to as P3HB4HB), poly(3-hydroxybutyrate-co-4-hydroxyvalerate) (hereinafter referred to as P3HB4HV), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (hereinafter referred to as P3HB3HV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (hereinafter referred to as P3HB3HH), and poly(3-hydroxybutyrate-co-5-hydroxyvalerate) (hereinafter referred to as P3HB5HV). In the PHA copolymer, a wide range of material properties is achieved by selecting the type of monomer and controlling the ratio of the monomer units. Although a PHA copolymer having two different monomer units is exemplified, the PHA may have more than two different monomer units (e.g., three, four, five, or six different monomer units). Examples of PHA having four different monomer units include PHB-co-3HH-co-3HO-co-3HD and PHB-co-3-HO-co-3HD-co-3HDd (these PHA copolymers are hereinafter referred to as PHB3HX). The PHB3HX typically has three or more monomer units and contains 3HB monomers at about 70% by weight or more, preferably about 85% by weight or more, and most preferably more than about 90% by weight of the total monomers, for example, about 92, 93, 94, 95, or 96% by weight of the copolymer. Furthermore, HX contains one or more monomers selected from 3HH, 3HO, 3HD, and 3HDd.

[0067] Amorphous PHA can be produced by known methods, such as the processes described in U.S. Patent No. 6,228,934 and U.S. Patent Application Publication No. 2013 / 0225761, the entire contents of which are incorporated herein by reference. In one embodiment, the aPHA may be an aPHA copolymer comprising about 50-80 wt%, preferably about 55-75 wt% or about 60-70 wt% 3-hydroxybutyric acid monomer units, and about 20-50 wt%, preferably about 25-45 wt% or about 30-40 wt% one or more hydroxyalkanoic acid monomer units selected from the group consisting of 3-hydroxybutyric acid, 3-hydroxyhexanoic acid, 3-hydroxyoctanoic acid, 3-hydroxydecanoic acid, 3-hydroxydodecanoic acid, and 4-hydroxybutyric acid. In one embodiment, the aPHA may be an aPHA copolymer containing about 50 to 80% by weight, preferably about 55 to 75% by weight or about 60 to 70% by weight, of 3-hydroxybutyric acid monomer units and about 20 to 50% by weight, preferably about 25 to 45% by weight or about 30 to 40% by weight of 4-hydroxybutyric acid.

[0068] Illustrative examples of commercially available aPHAs include PHA copolymers such as P3HB4HB, which contain 30% or more 4HB. Depending on the 4HB content, P3HB4HB can have a semi-crystalline structure (1-20 or 5-15 wt% 4HB) or an amorphous PHA (20-50 wt% 4HB). A 100% 3HB homopolymer (P3HB) is crystalline, brittle, and highly heat-resistant. Amorphous PHA is highly flexible and tough, but has low heat resistance.

[0069] Molecular weight of PHA

[0070] The physical and rheological properties of polymeric materials depend on the molecular weight and distribution of the polymers. "Molecular weight" is calculated in a variety of ways. Unless otherwise specified, "molecular weight" refers to the weight average molecular weight.

[0071] The "number average molecular weight" (Mn) represents the arithmetic mean of the distribution, and is the sum of the molecular weights of each fraction multiplied by its molar fraction (ΣNiMi / ΣNi).

[0072] The "weight average molecular weight" (Mw) is the sum of the molecular weights of each fraction multiplied by its weight fraction (ΣNiMi2 / ΣNiMi). Mw is generally equal to or greater than Mn.

[0073] The molecular weight is determined by techniques such as gel permeation chromatography (GPC). In this methodology, polystyrene standards are used. The PHA has a polystyrene-equivalent weight average molecular weight (unit: Dalton) of about 500 or more, about 10,000 or more, or about 50,000 or more, and less than about 2,000,000, less than about 1,000,000, less than about 1,500,000, and less than about 800,000. In one embodiment, the PHA generally has a weight average molecular weight in the range of about 100,000 to 700,000. For example, the molecular weight range of the PHB and type 1 PHB copolymer used in this application is about 400,000 to 1,500,000 daltons as determined by the GPC method, and the molecular weight range of the type 2 PHB copolymer used in this application is about 100,000 to 1,500,000 daltons.

[0074] The method according to the embodiment allows the molecular weight of the aPHA to be minimized. According to an exemplary embodiment of the process of the present disclosure, the molecular weight of the aPHA in the masterbatch is maintained substantially the same as the initial aPHA. In some exemplary embodiments, the molecular weight of the aPHA in the masterbatch can be at least 90% of the molecular weight of the starting PHA in the primary feed or the secondary feed. In some exemplary embodiments, the molecular weight of the aPHA in the masterbatch can be at least 95% of the molecular weight of the starting PHA in the primary feed or the secondary feed. In some exemplary embodiments, the molecular weight of the aPHA in the masterbatch can be at least 96% of the molecular weight of the starting PHA in the primary feed or the secondary feed. In some exemplary embodiments, the molecular weight of the aPHA in the masterbatch can be at least 97% of the molecular weight of the starting PHA in the primary feed or the secondary feed. In some exemplary embodiments, the molecular weight of the aPHA in the masterbatch can be at least 98% of the molecular weight of the starting PHA in the primary feed or the secondary feed. In some exemplary embodiments, the molecular weight of the aPHA in the masterbatch can be within at least 99% of the molecular weight of the starting PHA in the primary or secondary feed.

[0075] Additives

[0076] In one embodiment, various additives are added to the PHA, including antioxidants, pigments, UV stabilizers, fillers, plasticizers, nucleating agents, and radical scavengers.

[0077] Additives include plasticizers (e.g., to increase the flexibility of the thermoplastic composition), antioxidants (e.g., to protect the thermoplastic composition from degradation by ozone and oxygen), UV stabilizers (e.g., to provide weatherability), lubricants (e.g., to reduce friction), pigments (e.g., to provide color to the thermoplastic composition), flame retardants, fillers, reinforcing agents, mold release agents, and antistatic agents. It is within the skill of one of ordinary skill in the art to determine whether to include additives in a thermoplastic composition, and if so, which additives and how much to include.

[0078] In poly(3-hydroxybutyric acid) compositions, for example, plasticizers are often used to change the glass transition temperature and modulus of the composition, but surfactants may also be used. Also, for example, lubricants may be used in injection molding applications. The plasticizers, surfactants, and lubricants may all be included in the overall composition.

[0079] In another embodiment, the composition includes one or more plasticizers, which may be used alone or in combination with one another.

[0080] In some embodiments, the compositions and methods of the present disclosure may optionally include one or more surfactants. Such surfactants are commonly used for dust removal, lubrication, surface tension reduction, and / or densification. Such surfactants include, but are not limited to, mineral oil, castor oil, soybean oil, and the like. Mineral oil-based surfactants include DRAKE 1000 series available from Penreco (Dickinson, Tex., USA). TM 34 is listed. MAXSPERSE TM W-6000 and W-3000 solid surfactants are available from Chemax Polymer Additives, Inc. (Piedmont, SC, USA). Nonionic surfactants with HLB values ​​of about 2 to 16 can be used, such as TWEEN TM -20, TWEEN TM -65, SPAN TM -40, SPAN TM -85, etc.

[0081] One or more lubricants may also be added to the compositions and methods of the present invention. Lubricants are typically used to reduce adhesion to metal surfaces during heat treatment, and include combinations of polyethylene, paraffin oil, paraffin wax, metal stearates, and the like. Other lubricants include stearic acid, amide wax, ester wax, metal carboxylates, carboxylic acids, and the like. Typically, the lubricants are added in the range of about 0.1 to 1 weight percent in the polymer, and typically about 0.7 to 0.8 weight percent of the compound. Solid lubricants are heated and melted before or during the blending process.

[0082] Nucleating Agent

[0083] For example, an optional nucleating agent is added to the PHA to aid in crystallization.Nucleating agents for various polymers include metal compounds including simple substances and composite oxides, such as carbon black, calcium carbonate, synthetic silicic acid, salts, silica, zinc white, clay, kaolin, magnesium carbonate, mica, talc, quartz powder, diatomaceous earth, dolomite powder, titanium oxide, zinc oxide, antimony oxide, barium sulfate, calcium sulfate, alumina, calcium silicate, metal salts of organic phosphoric acid, and boron nitride; low molecular weight organic compounds having a metal carboxylate group, such as octylic acid, toluic acid, heptanoic acid, pelargonic acid, lauric acid, myristic acid, and palmitic acid. metal salts of acrylic acid, stearic acid, behenic acid, cerotic acid, montanic acid, melissic acid, benzoic acid, p-tert-butylbenzoic acid, terephthalic acid, terephthalic acid methyl monomethyl ester, isophthalic acid, isophthalic acid methyl monomethyl ester, and the like; metal salts of polymeric organic compounds having metal carboxylate groups, such as carboxyl group-containing polyethylene obtained by oxidation of polyethylene and carboxyl group-containing polypropylene obtained by oxidation of polypropylene; metal salts of olefins such as ethylene, propylene, butene-1, and acrylic acid or methacrylic acid; copolymers of styrene and acrylic acid; copolymers of styrene and acrylic acid or methacrylic acid; copolymers of olefins and maleic anhydride; copolymers of styrene and maleic anhydride; polymeric organic compounds having a branch at the 3-position carbon atom of α-olefins and having 5 or more carbon atoms, for example, vinylcycloalkanes such as 3,3-dimethylbutene-1, 3-methylbutene-1, 3-methylpentene-1, 3-methylhexene-1, and 3,5,5-trimethylhexene-1; polyalkylene glycols such as vinylcyclopentane, vinylcyclohexane, and vinylnorbornane; Examples of the monomers include polyethylene glycol, polypropylene glycol, poly(glycolic acid), cellulose, cellulose ester, cellulose ether, phosphoric acid or phosphorous acid, sorbitol derivatives such as diphenyl phosphoric acid, diphenyl phosphoric acid ester, metal salts of bis(4-tert-butylphenyl)phosphate, and methylene bis-(2,4-tert-butylphenyl)phosphate, bis(p-methylbenzylidene)sorbitol, bis(p-ethylbenzylidene)sorbitol, thioglycolic anhydride, and p-toluenesulfonic acid and metal salts thereof.The nucleating agents may be used alone or in combination with each other. In certain embodiments, the nucleating agent is cyanuric acid. In some embodiments, the nucleating agent may be other polymers (e.g., polymeric nucleating agents such as PHB).

[0084] In certain embodiments, the nucleating agent is selected from cyanuric acid, carbon black, mica talc, silica, boron nitride, clay, calcium carbonate, synthetic silicic acid and its salts, metal salts of organophosphates, and kaolin. In certain embodiments, the nucleating agent is cyanuric acid.

[0085] In various embodiments, when the nucleating agent is dispersed in a liquid carrier, the liquid carrier may be dispersed in a plasticizer, such as a citric acid compound or an adipic acid compound (e.g., acetyl citrate tributyrate (CITROFLEX TM A4, Vertellus, NC), dibutoxyethoxyethyl adipate (DBEEA), surfactants (e.g., TRITON TM X-100, TWEEN TM -20, TWEEN TM -65, SPAN TM -40, SPAN TM -85), a lubricant, or a volatile liquid (e.g., chloroform, heptane, pentane), an organic liquid, or water.

[0086] In another embodiment, the nucleating agent is aluminum hydroxydiphosphate or a compound containing a nitrogen-containing heteroaromatic ring, the nitrogen-containing heteroaromatic ring being pyridine, pyrimidine, pyrazine, pyridazine, triazine, or imidazole.

[0087] In the film application of the compositions and methods described herein, antiblock master batches are also added. A suitable example is a slip antiblock master batch mixture of erucamide (about 20% by weight), diatomaceous earth (about 5% by weight), Nucleant master batch (about 3% by weight) pelletized into PHA (about 62% by weight). Others are known to those skilled in the art of polymer processing.

[0088] Masterbatch manufacturing process and equipment

[0089] The masterbatch composition may be prepared by a process called "compounding". The compounding combines mixing and blending techniques during the heat treatment to ensure uniformity, homogeneity and dispersibility in the final dispersion. Such compounding may be carried out by extruders such as single screw extruders, twin screw extruders or multi-screw extruders of both co-rotating and counter-rotating designs, dispersion kneaders, reciprocating single screw extruders (co-kneaders), etc.

[0090] In one embodiment, the extruder used to prepare the masterbatch composition is a multi-screw extruder, preferably a twin-screw extruder, more preferably a co-rotating twin-screw extruder. In a particular embodiment, the extruder further comprises a static mixer after the screw. In another embodiment, the extruder uses a die with holes, such as a two-hole die.

[0091] In one embodiment, the residence time of the mixture in the extruder is 5 seconds to 3 minutes, preferably less than 2 minutes, more preferably less than 1 minute. When the masterbatch includes a polymer having a melting temperature of less than 180° C., the residence time of the mixture in the extruder is preferably less than 2 minutes.

[0092] One of ordinary skill in the art can readily adjust the extruder characteristics (e.g., screw length, diameter, etc.) and residence time to suit the type of aPHA polymer, amorphous or semi-crystalline polymer, additives, and masterbatch composition of interest.

[0093] In one embodiment, a masterbatch of about 30-50 wt% aPHA is prepared in an amorphous or semi-crystalline polymer such as PLA, PBS, PBAT, PES, PCL, semi-crystalline PHA, etc. Since the amorphous or semi-crystalline polymer needs to remain as a continuous phase, the masterbatch is first melted and then the final product is 50 wt% or more.

[0094] The masterbatch approach reduces the overall thermal history of the final product being manufactured. Typically, virgin polymer is mixed in-line (as opposed to "in-line") at the final conversion step, reducing the overall thermal history and allowing for a higher final MW and melt strength during processing.

[0095] Masterbatches give end users the flexibility to easily vary the amount of additive used depending on the application, all in one product.

[0096] Masterbatches can reduce overall costs compared to full solutions.

[0097] In one embodiment, the masterbatch is made by a twin screw extruder. A twin screw extruder is a machine consisting of two meshing co-rotating screws mounted on splined shafts in a closed barrel. The screws are clamped and self-wiping, eliminating stagnation zones along the entire length of the process section. Co-rotating intermeshing twin screw extruders have a modular barrel and screw design. By combining barrel modules and screw elements that correspond to different processing tasks (i.e. downstream addition of fillers and fibers, degassing, etc.) side-by-side, the extruder can be adapted for a variety of processes.

[0098] The amorphous or semi-crystalline polymer is usually melted first in the front zone (barrel) of the extruder. This is important to ensure that the amorphous or semi-crystalline polymer is the continuous phase. Generally, aPHA has a very low or no melting point. The aPHA is fed downstream using a side stuff feeder, as feeding into the primary feed hopper would entrap the amorphous or semi-crystalline polymer and melt or soften it, preventing it from melting properly. It is important to split the aPHA feed for thermal equilibrium, but feed the bulk downstream so that the amorphous or semi-crystalline polymer is the continuous phase.

[0099] The method includes feeding two or more portions of aPHA into a twin-screw extrusion operation, feeding the entire amount of semi-crystalline PHA and about 1-15 wt%, about 5-15 wt%, or about 10-15 wt% of the aPHA, based on the total aPHA and semi-crystalline PHA in the masterbatch, into a primary feed, melting the primary feed, feeding about 30-49 wt%, about 30-45 wt%, or about 35-45 wt% of the aPHA, based on the total aPHA and semi-crystalline PHA in the masterbatch, into a secondary feed physically separated from the primary feed, combining the secondary feed with the molten primary feed, and dispersing the aPHA in the secondary feed into the molten primary feed to obtain a masterbatch containing discrete aPHA particles dispersed in the semi-crystalline PHA. The method further includes, if necessary, cooling the masterbatch.

[0100] An exemplary apparatus that may be employed to produce a masterbatch according to one embodiment is shown in FIG.

[0101] Referring to FIG. 1, as an example, a twin screw extruder 4 includes a feeder 1 for introducing the entire amorphous or semi-crystalline polymer, a feeder 2 for introducing a portion of the aPHA, a primary feeder that is a primary feed heated to a molten state, and a secondary feeder 3 for introducing the remaining aPHA into the primary feed. The extruder includes a side feeder 5, as well as cooling elements such as a vacuum vent 6 and an underwater pelletizer 7. Through the primary feeder, a mixture of the amorphous or semi-crystalline polymer and the aPHA in the first feed is added to the extruder as a primary feed. The primary feed is then heated to melt. The melting temperature of the mixture is about 155°C to 220°C, about 165°C to 210°C, about 175°C to 200°C, or about 180°C to 190°C. The aPHA in the second feed is added to the molten primary feed (molten mixture of amorphous or semi-crystalline polymer and aPHA in the first feed) through a secondary feeder physically separated from the primary feeder and dispersed in the molten primary feed. The dispersion temperature is about 140°C to 180°C, about 145°C to 175°C, about 150°C to 170°C, or about 155°C to 165°C. The dispersed mixture may then be cooled to a temperature of about 140°C or less, about 130°C or less, about 120°C or less, about 110°C or less, or about 100°C or less. The twin screw extruder can be operated at about 200 to 400 rpm, about 225 to 375 rpm, about 250 to 350 rpm, or about 275 to 325 rpm.

[0102] For different amorphous or semi-crystalline polymers, the heating profile can be set appropriately within the above ranges depending on their molecular weight and / or melting point.

[0103] The method produces an amorphous or semi-crystalline polymer / aPHA composition (masterbatch) that contains about 30-50 wt%, about 35-49 wt%, about 40-48 wt%, about 42-47 wt%, or about 43-46 wt% aPHA based on the total weight of the masterbatch composition.

[0104] The amorphous or semi-crystalline polymer may be, but is not limited to, an aliphatic aromatic polyester such as PLA, PBS, or PBAT, PES, PCL, semi-crystalline PHA, or a combination thereof. Commercially available aliphatic aromatic polyesters such as PLA, PBS, or PBAT, PES, PCL, semi-crystalline PHA, etc. may be suitably used.

[0105] Application of Masterbatch

[0106] The amorphous or semi-crystalline polymer / aPHA masterbatch compositions can be incorporated to produce polymeric articles in conventional thermoplastic processes, including injection molding, extrusion (blow, cast, oriented film, sheet, profile, etc.), fiber, spunbond, monofilament, thermoforming, blow molding, compression molding, and other thermoplastic processing operations.

[0107] In making useful products, the amorphous or semi-crystalline polymer / aPHA masterbatch is processed near the glass transition temperature (Tg) or crystalline melting point of the amorphous or semi-crystalline polymer to minimize molecular weight degradation. Additives are selected to be stable at these temperatures. The molten polymeric composition is processed into the desired shape and then cooled to set the shape and, if necessary, induce crystallization. Such shapes include, but are not limited to, fibers, filaments, films, sheets, rods, tubes, and bottles. Such processing can be accomplished using any of the known techniques, such as extrusion, injection molding, compression molding, blowing, blow molding (e.g., blown film, foam blow), calendaring, rotational molding, casting (e.g., cast sheet, cast film), and thermoforming.

[0108] The masterbatches are used to make a variety of useful products, such as automotive, consumer durables, construction, electronics, medical, packaging, etc. The polymeric compositions are used in a wide variety of applications, such as, for example, films (e.g., packaging films including food packaging films, agricultural films, mulch films, fertilizer coatings, shopping bags, erosion control, hay wrap, slit films, food packaging, pallet packaging, protective packaging for automobiles and appliances, etc.), golf tees, caps and closures, agricultural supports, paper and board coatings (e.g., cups, cardboard, plates, boxes, etc.), thermoformed articles (e.g., trays, food containers, lids, yogurt pots, cup lids, flower pots, noodle bowls, molded articles, etc.), housings (e.g., for electronic devices, e.g., cell phones, PDA cases, music player cases, computer cases, etc.), bags (e.g. garbage bags, shopping bags, food bags, compost bags, etc.), hygiene products (e.g. diapers, sanitary products, incontinence products, disposable wipes, etc.), coatings for pellet products (e.g. fertilizer pellets, herbicides, insecticides, seeds, etc.), injection molded articles (writing instruments, tableware, disc cases, etc.), solution and spun fibers, meltblown fibers and nonwovens (yarns, lint, wipes, stuffing, disposable absorbent articles), blow molded articles (deep containers, bottles, etc.), foam molded articles (cups, bowls, plates, packaging, etc.), fishing nets, cosmetic containers, 3D printing filaments, etc.

[0109] Thermoforming is a process that uses thermoplastic films or sheets. The polymeric composition is processed into a film or sheet. The sheet of polymer is then placed in an oven where it is heated. Once softened enough to be molded, it is transferred to a mold and shaped.

[0110] The molded articles include a wide variety of product types, such as disposable spoons, forks, knives, buckets, bowls, lids, cup lids, yogurt cups, other containers, bottles, bottle-like containers, and the like.

[0111] Like thermoforming, blow molding is used to make deep drawn objects such as bottles that have deep interiors.

[0112] The masterbatch described herein is provided in a suitable form that is easy to apply depending on the purpose, for example, the masterbatch is pelletized and then used to produce films, coatings, molded articles, etc., or is used to produce films, coatings, molded articles, etc.

[0113] The specific examples shown below are merely examples and do not limit the contents of the present disclosure. It is understood that a person skilled in the art can fully utilize the present invention based on the description of this specification without any special description. All documents cited in this specification are incorporated herein by reference in their entirety. Mode of the invention Working Example

[0114] The following examples further illustrate the present invention in detail, but are not intended to limit the scope of the present invention.

[0115] Example 1

[0116] A 27 mm MAXX Leistritz co-rotating twin screw extruder was used to prepare aPHA / PLA blend (masterbatch) with minimal MW reduction of the aPHA using the heating profile shown in the table below and downstream cooling.

[0117] [Table 1]

[0118] UWG: Underwater Pelletizer

[0119] PLA (available from Natureworks, 4032D TM ) 550g and aPHA (available from CJ Biomaterials, Inc., PHACT TMA mixture of PLA and aPHA (A1000P) was fed in the primary feed (here barrel #1). The mixture contained 15 wt% aPHA based on 1000 g total aPHA and total PLA. 30 wt% aPHA based on total aPHA and total PLA was fed into the molten mixture of PLA and aPHA in the secondary feed (here barrel #6). A series of mixing elements were designed to shear and disperse the aPHA into micron-sized domains. The residence time of the mixture in the extruder was approximately 1 minute. The extruder was operated at 300 rpm, and the aPHA was well dispersed in the master as shown in Figure 2.

[0120] FIG. 2 shows an SEM image of the freeze-fractured PLA / aPHA masterbatch, showing discrete aPHA particles (1) dispersed in the PLA (2).

[0121] While the subject matter described herein has been described above in the form of examples, the disclosed subject matter is not limited to the above examples, and various modifications and equivalents are encompassed within the spirit and scope of the appended independent claims.

[0122] All numerical ranges, amounts, values, proportions, percentages, etc. described in this specification and the appended claims are applicable even if the numerical values, amounts, values, proportions, percentages, etc. described in this specification are not explicitly accompanied by the word "about."

[0123] Accordingly, unless otherwise indicated, the numerical parameters set forth in the foregoing description and attached claims are approximations that may vary in order to obtain the desired properties of the present invention, and should at least be construed as applying ordinary rounding techniques to the reported number of significant digits and not as an attempt to apply doctrine.

[0124] Even though numerical ranges and parameters describing the broad scope of the present invention, the numerical values ​​are described as precisely as possible. However, any numerical value necessarily contains errors resulting from the standard deviation found in each underlying measurement. Furthermore, when numerical ranges are described herein, these ranges encompass (or may include) the range endpoints described. When mass percent is used herein, the reported numerical values ​​are based on total weight.

[0125] Additionally, any numerical range described herein is intended to include all subranges contained within that range. For example, the range "1 to 10" is intended to include all subranges between 1 and 10, i.e., subranges with a minimum value of 1 or more and a maximum value of 10 or less. As used herein, the terms "one," "a," "one," and the like are intended to include "at least one" or "one or more," unless otherwise specified.

Claims

1. 1. A method for making a masterbatch comprising an amorphous or semi-crystalline polymer and an amorphous polyhydroxyalkanoate (aPHA) dispersed in the amorphous or semi-crystalline polymer by a compounding operation comprising: feeding the amorphous or semi-crystalline polymer and about 1-15 wt. % of the aPHA, based on the total aPHA and amorphous or semi-crystalline polymer in the masterbatch, into a primary feed; melting the primary feed; feeding about 30-49 wt. % of the aPHA, based on the total aPHA and amorphous or semi-crystalline polymer in the masterbatch, into a secondary feed physically separated from the primary feed; combining the secondary feed with the molten primary feed; and dispersing the aPHA in the secondary feed into the molten primary feed, thereby obtaining a masterbatch comprising discrete aPHA particles dispersed in the amorphous or semi-crystalline polymer.

2. 10. The method of claim 1, wherein the masterbatch comprises about 30-50 wt % aPHA and about 50-70 wt % of the amorphous or semi-crystalline polymer, based on the total weight of the masterbatch.

3. 2. The method of claim 1, wherein the amorphous or semi-crystalline polymer is selected from the group consisting of polylactic acid (PLA), polybutylene succinate (PBS), polybutylene adipate terephthalate (PBAT), polyethylene succinate (PES), polycaprolactone (PCL), semi-crystalline polyhydroxyalkanoates (PHAs), and combinations thereof.

4. The method of claim 1 , wherein the compounding operation is carried out in a twin screw extruder.

5. The method of claim 1, wherein the melting is carried out at a temperature range of 155°C to 220°C.

6. The method of claim 1, wherein the dispersion is carried out at a temperature range of 140°C to 180°C.

7. 10. The method of claim 1, further comprising cooling the dispersion of the aPHA of the secondary feed in the molten primary feed after said dispersion.

8. The method of claim 1 , wherein the discrete aPHA particles have an average diameter of less than 3 μm.

9. The method of claim 1 , wherein the aPHA comprises a poly(3-hydroxybutyrate) (P3HB) copolymer.

10. 10. The method of claim 9, wherein the P3HB copolymer is poly(3-hydroxybutyrate-co-3-hydroxypropionate) (PHB3HP), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (PHB4HB), poly(3-hydroxybutyrate-co-4-hydroxyvalerate) (PHB4HV), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB3HV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHB3HH), or poly(3-hydroxybutyrate-co-5-hydroxyvalerate) (PHB5HV).

11. 2. The method of claim 1, wherein the aPHA is a PHA copolymer comprising about 50-80% by weight of 3-hydroxybutyric acid monomer units and about 20-50% by weight of one or more hydroxyalkanoic acid monomer units selected from the group consisting of 3-hydroxybutyric acid, 3-hydroxyhexanoic acid, 3-hydroxyoctanoic acid, 3-hydroxydecanoic acid, 3-hydroxydodecanoic acid, and 4-hydroxybutyric acid.

12. 2. The method of claim 1, wherein the aPHA is a PHA copolymer comprising about 55-75% by weight of 3-hydroxybutyric acid monomer units and about 25-45% by weight of one or more hydroxyalkanoic acid monomer units selected from the group consisting of 3-hydroxybutyric acid, 3-hydroxyhexanoic acid, 3-hydroxyoctanoic acid, 3-hydroxydecanoic acid, 3-hydroxydodecanoic acid, and 4-hydroxybutyric acid.

13. 13. A masterbatch composition produced by the method of claim 1, comprising a continuous amorphous or semi-crystalline polymer and a discrete amorphous polyhydroxyalkanoate (aPHA) dispersed in said continuous amorphous or semi-crystalline polymer, said aPHA comprising about 30-50 wt % based on the total weight of said masterbatch composition.

14. 14. The masterbatch composition of claim 13, wherein the crystalline polymer is selected from the group consisting of polylactic acid (PLA), polybutylene succinate (PBS), polybutylene adipate terephthalate (PBAT), polyethylene succinate (PES), polycaprolactone (PCL), semi-crystalline polyhydroxyalkanoates (PHAs), and combinations thereof.

15. 14. The masterbatch composition of claim 13 comprising from 40 wt% to less than 50 wt% aPHA, based on the total weight of the masterbatch composition.

16. 14. The masterbatch composition of claim 13, wherein the discrete aPHA particles have an average size of less than 3 μm.

17. 14. The masterbatch composition of claim 13, wherein the aPHA comprises poly(3-hydroxybutyrate) (P3HB) copolymer.

18. 14. The master batch composition of claim 13, wherein the aPHA is an aPHA copolymer comprising about 50-80% by weight 3-hydroxybutyric acid monomer units and about 20-50% by weight one or more hydroxyalkanoic acid monomer units selected from the group consisting of 3-hydroxybutyric acid, 3-hydroxyhexanoic acid, 3-hydroxyoctanoic acid, 3-hydroxydecanoic acid, 3-hydroxydodecanoic acid, and 4-hydroxybutyric acid.

19. 14. A method for preparing an amorphous or semi-crystalline polymer product by adding the amorphous or semi-crystalline polymer / amorphous polyhydroxyalkanoate (aPHA) masterbatch composition of claim 13 to a crystalline polymer to obtain a mixture and subjecting said mixture to injection molding, extrusion, thermoforming, blow molding or compression molding.

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