DURABLE POLYHYDROXYALKANOATE COMPOSITIONS

Abstract

A polyhydroxyalkanoate composition, having a an elongation at break (ASTM D648) greater than 3%, an impact resistance (IS0179 1 eA, 23° C., unnotched) greater than 18 KJ/m2 and a flexural modulus of at least 950 MPa, includes at least 25% wt of a polyhydroxyalkanoate component (I); from 5 to 40% wt of one or more thermoplastic polymers as a non-polyhydroxyalkanoate component (II); from 0 to 40% wt of one or more fillers (III); from 0 to 20% wt of one or more plasticizers (IV); and from 0 to 10% wt of one or more additives (V). The polyhydroxyalkanoate composition can be used for the preparation of durable goods that may be labelled as containing more than 20% non-fossil carbon, and for articles prepared therefrom.

Claims

1.-18. (canceled)

19. A polyhydroxyalkanoate composition having an elongation at break (ASTM D638) greater than 3%, an impact resistance (Charpy test; ISO179 1 eU, 23° C., unnotched) greater than 18 KJ/m.sup.2 and a flexural modulus of at least 950 MPa comprising: at least 25% wt of a polyhydroxyalkanoate component (I), comprising one or more hydroxyalkanoate copolymers wherein the content of poly(3-hydroxybutyrate) homopolymer is and less than 5% wt; from 5 to 40% wt of (IIa) a thermoplastic polyurethane which is a block copolymer, and has a hardness lower than 56 Shore D, as measured according to ASTM D2240 in admixture with an acrylic polymer (IIb) with a melting flow index according to ASTM D1238 at 175° C./2.16 kg higher than 0.25 g/10 min and/or a glass transition temperature less than 150° C.; wherein the acrylic polymer (IIb) is either an acrylic block copolymer (IIb1) with a core that is butadiene based and/or acrylic based rubber and that is cross-linked; or an acrylic terpolymer (IIb2) containing glycidyl and/or maleic groups; or a mixture of said acrylic block copolymer or said acrylic terpolymer, comprising no more than 5% wt biodegradable polymers (ASTM D6400); from 0 to 40% wt of one or more fillers (III); from 0 to 20% wt of one or more plasticizers (IV); and from 0 to 10% wt of one or more additives (V), wherein component (I) and (II) together comprise at least 40% wt of the composition, and the % wt of the components is calculated on the total weight of components (I) to (V) of the composition and adds up to 100% wt.

20. The polyhydroxyalkanoate composition as claimed in claim 19, wherein the polyhydroxyalkanoate component (I) comprises one or more copolymers of a 3-hydroxyalkanoate.

21. The polyhydroxyalkanoate composition as claimed in claim 19, wherein the polyhydroxyalkanoate component (I) comprises one or more copolymers of 3-hydroxybutyrate and a 3-hydroxyalkanoate with more than 4 carbon atoms; and/or one or more copolymers of 3-hydroxybutyrate and a 4-hydroxyalkanoate with 4 or more carbon atoms; and/or a terpolymer of 3-hydroxybutyrate and two or more hydroxyalkanoates, preferably a copolymer of 3-hydroxybutyrate and 4-hydroxybutyrate p(3HB-co-4HB), a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate p(3HB-co-3HV), or a copolymer of 3-hydroxybutyrate and 3-hydroxyhexanoate p(3HB-co-3HH) or a copolymer of 3-hydroxybutyrate and 3-hydroxyoctanoate p(3HB-co-3HO).

22. The polyhydroxyalkanoate composition as claimed in claim 19, wherein the thermoplastic polyurethane (IIa) is a block copolymer, preferably having a Melting Point (measured according to ASTM3418) lower than 180° C. and/or a glass transition temperature Tg lower than 40° C. (measured according to ISO 11357) and/or a hardness lower than 56 Shore d (measured according to ASTM D2240).

23. The polyhydroxyalkanoate composition as claimed in claim 22, wherein the thermoplastic polyurethane (IIa) is based on a saturated polyester, preferably based on adipic acid, reacted with an aromatic isocyanate with two or more isocyanate groups, preferably 4,4′-methylenediphenyl diisocyanate (MDI).

24. The polyhydroxyalkanoate composition as claimed in claim 19, wherein the acrylic polymer (IIb) is a cross-linked butadiene acrylonitrile elastomer, and/or a cross-linked acrylate terpolymer.

25. The polyhydroxyalkanoate composition as claimed in claim 19, wherein the acrylic polymer (IIb) is a cross-linked styrene-acrylate elastomer.

26. The polyhydroxyalkanoate composition as claimed in claim 19, wherein the acrylic polymer (IIb) is a terpolymer of ethylene, an alkyl acrylate or methacrylate, and glycidyl methacrylate or glycidyl acrylate.

27. The polyhydroxyalkanoate composition as claimed in claim 19, wherein a combination of a TPU (IIa) and an acrylic polymer (IIb) is used in relative weight amounts of 3:1 to 1:3, preferably 2:1 to 1:2.

28. The polyhydroxyalkanoate composition as claimed in claim 19, wherein the combination of components (II) is used in an amount of 10 to 35% wt.

29. The polyhydroxyalkanoate composition as claimed in claim 19, wherein component (III) is selected from mineral fillers, synthetic fillers or mixtures thereof, preferably mineral fillers selected from talc, carbonates, silicates (more preferably clays and zeolites), and/or metal oxides (more preferably titanium oxide, zinc oxide, magnesium oxide).

30. The polyhydroxyalkanoate composition as claimed in claim 19, wherein component (IV) is an epoxidized oil, preferably an epoxidized oil of a vegetable source, more preferably epoxidized soybean oil.

31. The polyhydroxyalkanoate composition as claimed in claim 19, wherein component (V) is selected from one or more from the group of additives comprising antioxidants, anti-hydrolysis agents, UV stabilizing agents, pigments and surface modification agents.

32. Use of the composition according to claim 19, for the preparation of durable goods that may be labelled as containing more than 20, preferably more than 40, % wt non-fossil carbon.

33. Articles prepared from a polyhydroxyalkanoate composition as claimed in claim 19.

Description

EXAMPLES

Quick Description of Methods

[0046] Mechanical Properties: [0047] “Elongation at break” (ASTM D638) measures the maximum deformation that a specimen subjected to a force can withstand before breaking down in two pieces. In the present case high values are desirable. [0048] “Strength at break” (ASTM D638) measures the maximum force that a specimen can withstand before breaking down in two pieces. In the present case high values are desirable. [0049] “Flexural Modulus” (ASTM D790) measures the force that is needed to bend a specimen. Either high or low values are desirable, depending on the needs. [0050] “Izod” Resilience/impact resistance test method (ASTM D256) measures the energy that is absorbed before breaking. The more energy is absorbed by the material, the more difficult it will be to fracture the test sample. Tests were performed at 0° C. with specimen that were notched. In case a specimen did not break or only break partially, they are rated “NB” and “RP” respectively. In this case high values are desirable; although RP is even better and NB is better than RP. [0051] “Charpy” Resilience/impact resistance test method (ISO 179 1 eU) measures the same property as the Izod test. In this case the specimens were unnotched and the tests were carried out at the temperatures indicated in the Tables.

[0052] Thermal Properties: [0053] “Vicat” (ASTM D1525) measures the temperature at which a 1 mm.sup.2 flat-ended needle will penetrate 1 mm into a material under a specified load and heating rate. The Vicat softening temperature can be used to compare the heat softening characteristics of different materials. The measurement is carried out with a heating rate of 50° C./hr, and a loading of 10N, unless indicated otherwise. In the present case high values are desirable.

[0054] Aesthetical Properties: [0055] “Gloss 60°” measures the quantity of light reflected by a surface. In the present case high values are better. [0056] “Surface tension” is an indirect measure of the polarity of the surface. In the present case high values are better, because paint/adhesive will be easier to apply.

[0057] Environmental Properties: [0058] “% wt coming from renewable sources” (“Environmental property”) indicates the w/w percentage of ingredients, the carbon of which proceeds from renewable sources (in the specification also referred to as “non-fossil carbon”). In this case applies: the higher, the better.

[0059] Quick Description of Materials:

[0060] In the Experiments the following raw materials were used: [0061] P(3HB-co-3HV) or PHBV, (Enmat™ from TIANAN) [0062] TPU polymer, Laripur™8025, adipate based polyurethane from COIM [0063] Acrylic polymer, Sunigum™ P2100 from ELIOKEM [0064] PLA [0065] PBS, Bionolle™ from SHOWA [0066] Epoxidized Soybean Oil (ESBO), VIKOFLEX™ 7170 from ARKEMA [0067] Triethyl Citrate, Citrofol™ from JUNGBUNZLAUER [0068] Glycerine [0069] Polyadipate, Palamoll™ from BASF [0070] Talc CAS 14807-96-6

Example 1, Comparison with PP

[0071] Table 1 shows a comparison between a PP based composition based on 69.2% wt polypropylene, 0.5% wt antioxidant; 0.8% wt titanium dioxide and 29.5% wt talc and a PHA composition according to the invention, containing 56.5% wt P(3HB-co-3HV), 16.0% wt TPU, 0.5% wt antioxidant, 3.5% wt epoxidized soybean oil and 23.5% wt talc. The table shows that the PHA composition is very similar to the PP based composition, even outperforming the PP based composition in terms of flexural modulus, thermal properties and gloss.

The table here below represents the amounts of the ingredients of the PP-based composition and the PHA-based composition.

TABLE-US-00001 TABLE 1 PP- PHA- based based compo- compo- sition sition Mechanical Strength at ASTM MPa 28 27 properties break D638 Flexural ASTM MPa 3040 3255 modulus D790 Thermal Vicat B ASTM ° C. 93 97 properties D1525 Aesthetical Gloss 60° 36 75 properties Surface mN/m 31 38 Tension Environ- % wt of % wt 0 60 mental ingredients properties with carbon from renew. sources

Example 2, Adverse Effect of PLA

[0072] Table 2 shows the components used in this model experiment. In this case, no plasticizer was present. One composition was made with TPU as component (II), the comparative composition was made used PLA. In Table 3 the effect on the mechanical properties is illustrated. This table clearly shows the adverse effect on both resilience and elongation at break.

TABLE-US-00002 TABLE 2 Entry 1 Entry 2 P(3HB-CO-3HV) 60% 60% TPU 20% PLA 20% Plasticizer — — Talc 20% 20% 100%  100% 

TABLE-US-00003 TABLE 3 Entry 1 Entry 2 Izod test, notched (0° C.) ASTM D256 J/m 30.4 12.9 Charpy test, unnotched ISO179 1eU KJ/m.sup.2 50.4 10.6 (23° C.) Elongation at break ASTM D638 % 7.9 2.3

Example 2, Component (II)

[0073] Table 4 shows a composition containing the pure PHA (comparative) and compositions containing TPU polymer, acrylic polymer or a mixture of polyurethane and acrylic polymers. Table 5 reports measures of physical properties.

[0074] Entry 4, Entry 5 in comparison to Entry 3 show that the presence of the claimed non-HPA component (II), either an acrylic polymer or TPU polymer improve the values of both Resilience and Elongation at break.

[0075] Entry 5 in comparison to Entry 4 shows that the presence of acrylic polymers leads to a higher value of elongation at break than the one exhibited by a composition containing the same amount of TPU. Thus an object made of a material whose composition is Entry 5 will withstand a higher deformation before breaking down than one whose composition is Entry 4.

[0076] Nevertheless a comparison between Entry 4 and Entry 5 shows that the presence of TPU leads to a higher value of Vicat than the one exhibited by a composition containing the same amount of acrylic polymer. Thus an object made of a material whose composition is Entry 4 is more suitable for being used in warm environments than an object whose composition is Entry 5. Entry 6 shows a synergistic effect of the use of both acrylic polymers and TPU when elongation at break value is kept in consideration.

TABLE-US-00004 TABLE 4 Entry 3 Entry 4 Entry 5 Entry 6 P(3HB-CO-3HV) 100% 70% 70% 70% TPU 30% 15% Acrylic polymer 30% 15% 100% 100%  100%  100% 

TABLE-US-00005 TABLE 5 Entry Entry Entry Entry 3 4 5 6 Izod test, notched ASTM D256 J/m 23.1 34.3 30.1 30.9 (0° C.) Charpy test, unnotched ISO 179 leU kJ/m.sup.2 9.1 121.9 NB NB (23° C.) Elongation at break ASTM D638 % 2.0 7.5 16.3 54.1 Flexural Modulus ASTM D790 MPa 2510 1475 1164 1991 Vicat (50° C./hr; 50N) ASTM D1525 ° C. 132 86 62 74

Example 4, the Selection of Plasticizer

[0077] Table 6 shows compositions containing different plasticizers wherein epoxidized soybean oil is the preferred plasticizer according to the invention. Although glycerine, triethyl citrate and polyadipate are conventional plasticizers, in the current composition they are not preferred. In Table 7 the results are reported.

[0078] Entry 10, Entry 11, Entry 12, Entry 13 show different values of Elongation at break. The highest value is given by Entry 10 where epoxidized soybean oil is used. The use of epoxidized Soybean oil is preferred because represents the best trade-off between the properties of Elongation at Break and resistance to heat softening.

TABLE-US-00006 TABLE 6 Entry 10 Entry 11 Entry 12 Entry 13 P(3HB-CO-3HV) 39% 39% 39% 39% TPU 19% 19% 19% 19% Acrylic polymer 19% 19% 19% 19% Glycerine  5% Epoxidized soybean oil  5% Triethyl citrate  5% Polyadipate  5% Talc 18% 18% 18% 18% 100%  100%  100%  100

TABLE-US-00007 TABLE 7 Entry Entry Entry Entry 10 11 12 13 Izod test, notched ASTM D256 J/m RP RP RP RP (0° C.) Charpy test, unnotched ISO 179 leU kJ/m.sup.2 NB NB NB NB (23° C.) Elongation at break ASTM D638 % 89.3 19.6 12.1 67.2 Flexural Modulus ASTM D790 MPa 978 1030 1280 1050 Vicat (50° C./hr; 10N) ASTM D1525 ° C. 110 106 102 113 Vicat (50° C./hr; 50N) ASTM D1525 ° C. 40.3 45.2 30.0 40.5

Example 5, Amount of Plasticizer

[0079] Table 8 shows compositions according to the invention containing different amounts of epoxidized soybean oil. In Table 9 the results are reported.

[0080] Resilience of Entry 14, Entry 15, and Entry 16 increases with the increased amount of the plasticizer. Flexural modulus decreases with the increase of the amount of plasticizer. Entry 16 is a flexible material that has a high resistance to shocks.

TABLE-US-00008 TABLE 8 Entry 14 Entry 15 Entry 16 PHA 63% 60% 56% TPU 21% 20% 19% Epoxidized soybean oil  5% 11% Talc 16% 15% 14% 100%  100%  100% 

TABLE-US-00009 TABLE 9 Entry Entry Entry 14 15 16 Izod test, notched ASTM D256 J/m 30.6 30.7 38.3 (0°) Charpy test, ISO179 1eU kJ/m.sup.2 41.8 66.8 81.9 unnotched (23°) Charpy test, ISO179 1eU kJ/m.sup.2 34.6 44.8 52.0 unnotched (0° C.) Elongation at break ASTM D638 % 10.9 29.7 14.1 Flexural Modulus ASTM D790 MPa 2928 2157 1611 Vicat (50° C./hr; ASTMD1525 ° C. 96.4 74.5 58.4 50N)

Example 6, Selection of Component (II)

[0081] Table 10 shows compositions containing no non-HPA component (II) or different components (II). In Table 11 the results are reported.

[0082] Entry 7 shows the lowest values of resilience and elongation at break in comparison to both Entry 8 and Entry 9. A comparison between Entry 8 and Entry 9 shows that TPU is more effective (about the twice) in comparison to an aliphatic polyester such as PBS.

TABLE-US-00010 TABLE 10 Entry Entry Entry 7 8 9 P(3HB-CO-3HV) 80% 60% 60% TPU 20% PBS 20% Talc 20% 20% 20% 100%  100%  100% 

TABLE-US-00011 TABLE 11 Entry Entry Entry 7 8 9 Izod test, notched ASTM D256 J/m 13.1 30.5 17.1 (0° C.) Charpy test, ISO179 1eU KJ/m.sup.2 8.9 50.4 23.3 unnotched (23° C.) Elongation at ASTM D638 % 1.9 7.9 3.1 break Flexural Modulus ASTM D790 MPa 4742 2931 3857 Vicat (50° ASTM D1525 ° C. 130 88.2 87.9 C./hr; 50N)

Example 7, Compositions According to the Invention

[0083] Three compositions were made according to the preferred embodiment of the invention. All showed excellent properties.

TABLE-US-00012 TABLE 12 1 2 3 PHBV 55.0%  74.3%  73.1%  TPU 25.0%  3.2% Acrylic polymer 4.5% 3.3% Antioxidant 0.2% 0.2% 0.3% Titanium oxide 0.4% 2.2% 0.4% Zinc oxide 0.1% 0.2% Talc 14.3%  14.3%  12.0%  Epoxidized soybean oil 5.0% 4.5% 7.5% 100%  100%  100% 

TABLE-US-00013 TABLE 13 1 2 3 Melt flow index ASTM D1238 g/10 9.6 13.2 11.0 (180° C./2.16 kg) min Charpy test, ISO179 1eU KJ/m2 103.9 27.3 35.2 unnotched (23° C.) Izod test, notched ASTM D256 J/m 36.9 27.5 26.3 (0° C.) Elongation at ASTM D638 % 9.30 4.08 4.46 break Flexural Modulus ASTM D790 MPa 2560 2700 3108 Vicat (50 C./hr; ASTM D1525 ° C. 70 81.5 92.3 50N) Weight % 60.0 78.8 80.6 percentage of ingredients coming from renewable sources

Example 8, Comparison with Core-Shell Type Copolymer

[0084] In order to show the effectiveness of the compositions according to the present invention in comparison to a composition comprising a core-shell type acrylic rubber thermoplastic polymer three compositions were prepared. In Entry 17 no thermoplastic polymer was added. In Entry 18 the same acrylic polymer as added in experiment 2 of Example 7 was added, and in Entry 19 a core-shell graft copolymer comprising an acrylic rubber as the core layer and a vinyl monomer-derived polymer as the shell layer (Kane Ace M-410, from Kaneka) was added. The compositions are recorded in Table 14.

[0085] The elongation at break and impact resistance were determined. The results are shown in Table 15.

TABLE-US-00014 TABLE 14 Entry 17 Entry 18 Entry 19 PHBV 83.2% 58.9% 58.9% Acrylic polymer 24.3% M-410 24.3% Talc 15.3% 15.3% 15.3% Epoxidized soybean oil  1.4%  1.4%  1.4%  100%  100%  100%

TABLE-US-00015 TABLE 15 Entry Entry Entry 17 18 19 Elongation at ASTM % 1.7 7.3 2.8 break D638 Charpy test, ISO179 KJ/m.sup.2 9.6 39.5 21.4 unnotched (23° C.) 1eU Charpy test, ISO179 KJ/m.sup.2 7.7 20.0 13.6 unnotched (0° C.) 1eU

[0086] The results clearly show that composition according to the invention performs better than the other two compositions.

Example 9, Comparison with Mixture of Two PHAs

[0087] In order to show the effectiveness of the compositions according to the present invention containing a mixture of PHAs a composition was prepared as indicated in Table 16. The performance thereof was tested. The results of the tests are shown in Table 17.

TABLE-US-00016 TABLE 16 P(3HB-CO-3HV) 35.0% P(3HB-CO-3HH) 20.0% TPU 19.0% Acrylic polymer Antioxidant  0.2% Titanium oxide  0.6% Talc 18.2% Epoxidized soybean oil  7.0%  100%

TABLE-US-00017 TABLE 17 Melt flow index (180° C./2.16 kg) ASTM D1238 g/10 min 7.9 Charpy test, unnotched (23° C.) ISO179 1eU KJ/m2 NB Izod test, notched (0° C.) ASTM D256 J/m 32.5 Elongation at break ASTM D638 % 55.6 Flexural Modulus ASTM D790 MPa 1450 Vicat (50 C./hr; 50N) ASTM D1525 ° C. 49 Weight percentage of ingredients % 62.0 with carbon coming from renewable sources