COMPOSITIONS AND METHODS FOR IMPROVING MARINE BIODEGRADABILITY OF POLYMERIC COMPOSITIONS

Abstract

The present invention is relative to the use of a composition comprising at least one mineral filler having properties of absorption and/or emission in the far infrared region ranging from wavelength of 2 micrometers to 20 micrometers dispersed in a marine biodegradable polymeric composition for improving marine biodegradability of said marine biodegradable polymeric composition.

Claims

1. A method of improving marine biodegradability of a marine biodegradable polymeric composition comprising dispersing a composition C in the marine biodegradable polymeric composition, wherein the composition C comprises at least one mineral filler M having properties of absorption and/or emission in the far infrared region ranging from wavelength of 2 micrometers to 20 micrometers.

2. The method of claim 1, wherein the marine biodegradable polymeric composition contains a polymer selected from the group consisting of polyamides, polyesters, polysaccharides, polypeptides or proteins, cellulose and polymeric derivatives thereof, cellulose esters and polymeric derivatives thereof, copolymers thereof and blends thereof.

3. The method of claim 2, wherein the polymer is selected from the group consisting of polyhydroxyalkanoates (PHA), polymeric derivatives of cellulose, cellulose acetate polymers, polyglycolic acid, polycaprolactone, copolymers thereof and blends thereof.

4. The method of claim 3, wherein the polymer is a polyhydroxyalkanoate (PHA) selectedfrom the group consisting of poly-3-hydroxybutyrate (PHB or P3HB), poly(3-hydroxypropionate) (PHP or P3HP), polyhydroxyvalerate (PHV), poly(hydroxybutyrate-hydroxyvalerate (PHBV), Poly(3-hydroxyhexanoate) (PHHx), copolymers thereof and blends thereof.

5. The method of claim 1, wherein the marine biodegradable polymeric composition comprises: (a) a polymer selected from the group consisting of polyamide (preferably PA66, PA6, PA 5.6, PA6.10, PA10.10 and PA12), polylactic acid (PLA), poly(butylene succinate) (PBS), poly(butylene adipate-co-terephthalate) (PBAT) and poly(vinyl acetate) copolymers and blends thereof, and (b) an additive A being a composition comprising : (i) at least one carbohydrate-based or starch-based or aromatic-ester modified polymeric material, (ii) optionally a plasticizer, and (iii) optionally water.

6. (canceled)

7. The method of claim 1, wherein the at least one mineral filler M is selected from the group consisting of oxides, sulfates, carbonates, phosphates and silicates.

8. (canceled)

9. The method of claim 7, wherein the composition C comprises at least two mineral fillers M which are different selected from the group consisting of oxides, sulfates, carbonates, phosphates and silicates, at least one mineral filler being a silicate.

10. The method of claim 9, wherein the composition C comprises three mineral fillers M of different types selected from the group consisting of oxides, sulfates, carbonates, phosphates and silicates, at least one mineral filler being a silicate.

11. (canceled)

12. The method of claim 11, wherein the three mineral fillers M of different types are titanium dioxide, barium sulfate and tourmaline.

13. The method of claim 1, wherein the at least one mineral filler M is in the form of particles that have a diameter-average size, measured according to laser diffraction particle size analysis, of less than or equal to 10 micrometers.

14. The method of claim 1, wherein the weight proportion of mineral fillers M relative to the total weight of the marine biodegradable polymeric composition is greater than or equal to 1 percent.

15. The method of claim 1, wherein the weight proportion of the mineral fillers M relative to the total weight of the marine biodegradable polymeric composition is less than or equal to 60 percent.

16. The method of claim 1, wherein the marine biodegradable polymeric composition is in the form of particles or fibers.

17. The method of claim 16, wherein the marine biodegradable polymeric composition is in the form of particles that have a diameter-average size, measured according to laser diffraction particle size analysis, of less than or equal to 800 micrometers.

18. The method of claim 16, wherein the marine biodegradable polymeric composition is in the form of particles that have a substantially spherical shape.

19. (canceled)

20. A marine biodegradable polymeric composition comprising a composition C comprising at least one mineral fillers M of different types having properties of absorption and/or emission in the far infrared region ranging from wavelength of 2 micrometers to 20 micrometers, said composition C being dispersed in said biodegradable polymeric composition, wherein said biodegradable polymeric composition comprises at least one polymer.

21. The marine biodegradable polymeric composition as claimed in claim 20, wherein the mineral fillers M comprises at least three mineral fillers of different types having properties of absorption and/or emission in the far infrared region ranging from wavelength of 2 micrometers to 20 micrometers, two of them being selected from the group consisting of oxides, sulfates, carbonates and phosphates and the third one being a silicate.

22. The marine biodegradable polymeric composition as claimed in claim 20, wherein the polymer is selected from polyhydroxyalkanoate (PHA), polyamide (PA), polyglycolic acid (PGA), polycaprolactone (PCL) or polylactic acid (PLA) copolymers thereof and blends thereof.

23. The marine biodegradable polymeric composition as claimed in claim 20, wherein the marine biodegradable polymeric composition is in the form of particles or fibers.

24. (canceled)

25. (canceled)

26. (canceled)

Description

EXPERIMENTAL PART

Examples

Example 1

1.A – Materials

[0137] The materials used for the preparation of the samples are as follows: [0138] ✔ PHB with the following features: [0139] Origin: commercial: Biocycle®1000 sold by PHB Industrial S.A. [0140] Density (ASTM D792): 1.23 g/cm3 [0141] Melt Flow Index (ASTM D1238): 15.0 g/10min [0142] Melting Point (ASTM D3418): 165-170° C. [0143] Izod Impact Resistance (ASTM D256): 20.4 J/m [0144] Modulus of Elasticity (ASTM D638): 3.07 GPa [0145] Elongation at break (ASTM D638): 2.24 % [0146] Tensile strength (ASTM D638): 32.4 MPa [0147] ✔ PHBV with the following features: [0148] Origin: commercial: ENMAT®Y1000 sold by TianAn [0149] Density (ASTM D792): 1.25 g/cm3 [0150] Melt Flow Rate(190° C.- 2.16 kg) (ASTM1238): < 5.0 g/10min [0151] Melting Point (ASTM D3418): 177° C. [0152] Molecular weight: 450000 [0153] ✔ PLGA with the following features: [0154] Origin: commercial: POLYLACTIC-CO-GLYCOLICACID (PLGA-50:50) sold by Nomisma Healthcare [0155] Molecular ratio of LA/GA by NMR: 1.0 [0156] Viscosity: 0.25 dl/g [0157] ✔ Tourmaline [0158] Origin: commercial from Microservice [0159] Particle size (D50): 0.8 .Math.m [0160] ✔ Barium sulfate [0161] Origin: commercial from Venator [0162] Particle size (D50): 0.8 .Math.m [0163] ✔ Titanium dioxide [0164] Origin: commercial from Venator [0165] Diameter-average particle size of 0.3 .Math.m [0166] Particle size D50: 0.8 .Math.m [0167] ✔ Citric Acid [0168] Origin: commercial from Sigma Aldrich [0169] Role: thermal stabilizer additive [0170] ✔ Kaolin [0171] Origin: commercial from Ouro Branco [0172] Role: FIR additive [0173] ✔ Silica [0174] Origin: commercial from Ouro Branco [0175] Role: FIR additive

1.B Production of Polymeric Compositions According to the Invention

[0176] Polymeric compositions with the following content were produced according to below: [0177] Polymeric composition A 69 wt% of PHB, and 31 wt% of additives: [0178] Tourmaline 15.5 wt%, [0179] Barium Sulfate 10.5 wt%, [0180] Titanium dioxide 4 wt% and [0181] Citric acid 1 wt%. [0182] Polymeric composition B 84 wt% of PHB, and 16 wt% of additives: [0183] Tourmaline 7.75 wt%, [0184] Barium Sulfate 5.25 wt%, [0185] Titanium dioxide 2 wt% and [0186] Citric acid 1 wt%. [0187] Polymeric composition C 69 wt% of PHB, and 31 wt% of additives: [0188] Silica 15 wt%, [0189] Kaolin 15 wt% and [0190] Citric acid 1 wt%. [0191] Polymeric composition D 69 wt% of PHBV, and 31 wt% of additives: [0192] Tourmaline 15.5 wt%, [0193] Barium Sulfate 10.5 wt%, [0194] Titanium dioxide 4 wt% and [0195] Citric acid 1 wt%. [0196] Polymeric composition E 70 wt% of PLGA, and 30 wt% of additives: [0197] Tourmaline 15 wt%, [0198] Barium Sulfate 10 wt%, [0199] Titanium dioxide 5 wt% and

[0200] The polymeric compositions are obtained according to the process described below.

Polymer Drying Condition

[0201] The PHB and PHBV are dried in a Convection Drying Oven at 60° C. for 4 hours.

Process Conditions

[0202] The materials of polymeric composition A were mixed and then extruded in a co-rotating twin-screw extruder coupled to a torque rheometer (Thermo Scientific™, model PolyLab™ OS Rheodrive 7/ Extruder HAAKE™ Rheomix OS PTW 16).

[0203] The mixture is processed in the twin-screw extruder according to the following conditions:

TABLE-US-00001 Screw rpm (min.sup.-1) 60 Feeding rate (%) 11 Temperatures (°C) Zone 1 166 Zone 2 168 Zone 3 169 Zone 4 169 Zone 5 170 Zone 6 170

[0204] The extruder cylinder contains co-rotating screws that convey, mix and melt the polymer through 6 extruder heating zones with a gradient of temperature from 166 to 170° C., incorporating the additives to the melt polymer to produce the compound which is forced out for an extrusion die head. The compound is extruded in the form of molten strands, cooled in a water trough, pulled through a water stripper by pull rolls to a helical cutter of the pelletizer and then cut into pellets. Polymeric compositions B, C, and D were processed according to the same conditions of the polymeric composition A.

[0205] Polymeric composition E was processed in the Haake Reomix OS, with roller rotors and following conditions: [0206] Speed: 40 rpm [0207] Temperature: 110° C.

1.C Production of Particles of Polymeric Composition

[0208] The pellets of the polymeric composition obtained in the example 1B were grinded by Cryogenic grinding under the below conditions: [0209] Equipment: Netzsch Fluidized Bed Jet Mill CGS10 [0210] Process condition: [0211] Speed: 16000 rpm [0212] Cryogenic fluid: liquid nitrogen

[0213] Particles of polymeric composition containing 69 wt% of PHB, 30 wt% of mineral fillers (tourmaline, barium sulfate and titanium dioxide) and 1% of citric acid were thus obtained, with particle size (D50) less than 19 micron, with density of 1.53 g/cm3 and shape factor of 0.86.

[0214] The particle size analysis was carried out by a laser diffraction particle size analyser (Mastersizer 2000. Malvern Instruments), the powder being dispersed in ethanol.

[0215] The density of the compound and the particle shape factor was measured according to ASTM D792 and ASTM F1877.

1.D - Marine Biodegradability Tests ASTM D6691-01(2017)

[0216] The particles of the compositions described in 1B with FIR emitting minerals according to the invention were obtained by grinding process described above in 1C, particles of virgin polymer (without FIR additives but same particle size, less than 850 micron, and produced according to same process described above) as comparative example and cellulose particles (without FIR additives but same particle size) as reference were tested according to ASTM D6691-01 (2017) standard method to measure their marine biodegradability. The results are summarized in the table 1 below.

TABLE-US-00002 Absolute biodegradation of polymeric compositions prepared with FIR minerals and samples of virgin polymers. Sample Description Absolute biodegradation in seawater (%) Laboratory Reference cellulose 65.2 PHB Virgin polymer 20.2 PHBV Virgin polymer 10.8 PLGA Virgin polymer 23.5 Composition A PHB+30wt% of FIR1 minerals 38.3 Composition B PHB+15wt% of FIR1 minerals 25.5 Composition C PHB+30wt% of FIR2 minerals 39.4 Composition D PHBV+30wt% of FIR1 minerals 22.3 Composition E PLGA+30wt% of FIR1 minerals 30.5

[0217] The absolute biodegradation results show that when polymeric compositions present FIR minerals the biodegradation of the polymers in marine environment is improved.

Example 2

2.A — Materials

[0218] The materials used for the preparation of the samples are as follows: [0219] ✔ Polyamide 6.6 with the following features. [0220] Origin: commercial: POLYAMIDE 6.6 BRILLIANT produced by [0221] Rhodia Brasil S.A, Solvay Group. [0222] Density (ISO 845 ou 1183): 1.14 g/cm3 [0223] Melting Point (ISO 11357): 265° C. [0224] Izod Impact Resistance (ISO180-2019):150 J/m [0225] Modulus of Elasticity (ISO 527-1:2012 ): 2.93 GPa [0226] Elongation at break (ISO 527-1:2012): 25% [0227] Tensile strength (ISO 527-1:2012): 65 MPa [0228] ✔ Tourmaline [0229] Origin: commercial from Microservice [0230] Particle size (D50): 0.8 .Math.m [0231] ✔ Barium sulfate [0232] Origin: commercial from Venator [0233] Particle size D50: 0.8 .Math.m [0234] ✔ Titanium dioxide [0235] Origin: commercial from Venator [0236] Particle size D50: 0.3 .Math.m [0237] ✔ Polyethylene glycolpolymer, PEG35000, with molecular weight of 35000 g/mol [0238] Origin: Sigma Aldrich [0239] ✔ Ethoxylated/propoxylated block copolymer, Antarox L101 [0240] Origin :Solvay

2.B Production of a Polymeric Composition According to the Invention

[0241] Polymeric compositions with the following content were produced according to below: [0242] Composition F 95 wt% of PA66 and 5 wt% of additive [0243] Biosphere 201 5 wt%. [0244] Composition G 65 wt% of PA66, and 35 wt% of additives: [0245] Tourmaline 15.5 wt%, [0246] Barium Sulfate 10.5 wt%, [0247] titanium dioxide 4 wt% [0248] Biosphere 201, 5 wt%

[0249] PA66 was dried in a Convection Drying Oven at 80° C. for 6 hours. The materials (PA66 and additives) were mixed and then extruded in a co-rotating twin-screw extruder SHJ20. The mixture (PA66 and additives) was processed in the twin-screw extruder according to the following conditions:

TABLE-US-00003 Screw rpm (min.sup.-1) 460 Feeding rate (%) 10 Temperatures (°C) Zone 1 271 Zone 2 276 Zone 3 281 Zone 4 281 Zone 5 284 Zone 6 270

[0250] The extruder cylinder contains co-rotating screws that convey, mix and melt the polymer through 6 extruder heating zones with a gradient of temperature from 270 to 284° C., incorporating the additives to the melt polymer to produce the compound which is forced out for an extrusion die head.

[0251] The compound is extruded in the form of molten strands, cooled in a water trough, pulled through a water stripper by pull rolls to a helical cutter of the pelletizer and then cut into pellets.

2.C Production of Particles of Polymeric Composition

[0252] Equipment: Co-rotating twin-screw coupled to Thermo Scientific Torque Rheometer - model Polylab OS Rheodrive 7 / HAAKE Rheomex OS Extruder PTW16, L/D 16 mm.

[0253] Process condition:

[0254] The pellets produced as described in example 2.B were mixed with compatibilizing agent Antarox L101 (10 wt%) and PEG 35000 and processed in a twin-screw extruder (Co-rotating twin-screw Coupled to Thermo Scientific Torque Rheometer - model Polylab OS Rheodrive 7 / HAAKE Rheomex OS Extruder PTW16, L/D 16 mm). The temperature profile of the various zones during the process varied from 250° C. to 270° C. rotating at 250 rpm. The compound is extruded and cooled in water. Part of the compound is solubilized in water and the spherical particles are separated by sieving and dried.

[0255] Particles of polymeric composition containing 68 wt% of PA66, 30 wt% of mineral fillers (tourmaline, barium sulfate and titanium dioxide) and 2 wt% of Biosphere 201 were thus obtained, with particle size (D50) less than 28 micron, with density of 1.45 g/cm.sup.3 and shape factor of 0.98.

[0256] Particle size analysis was carried out by a laser diffraction particle size analyser (Mastersizer 2000. Malvern Instruments), the powder being dispersed in ethanol.

2.D - Marine Biodegradability Tests ASTM D6691-01(2017)

[0257] The particles of the compositions described in 2B with Biosphere 201 and FIR emitting minerals according to the invention were obtained by process described above in 2C, particles of virgin polymer (without FIR or Biosphere 201 additives but same particle size, less than 28 micron, and produced according to same process described above) as comparative example and cellulose particles (without FIR additives but same particle size) as reference were tested according to ASTM D6691-01 (2009) standard method to measure their marine biodegradability. The results are summarized in the table 2 below.

TABLE-US-00004 Absolute biodegradation of polyamide compositions. Sample Description Description Absolute biodegradation in seawater (%) Laboratory Reference cellulose 65.2 Polyamide 66 Virgin polymer 2.8 Composition F PA66 + 5 wt% of Biosphere 201 22.6 Composition G PA66 + 5 wt% of Biosphere201+30 wt% of FIR minerals 35.2

[0258] The absolute biodegradation showed that when polyamide additivated with Biospere 201 compositions present FIR minerals, the biodegradation of the polymers in marine environment is improved.

[0259] Therefore, surprisingly, it has been found that the use of the above claimed mineral fillers in a marine biodegradable polymeric composition allows an improved in the marine biodegradability of the resulting polymeric composition.