Toughening Polylactic Acid With Polyhydroxyalkanoates

• US 20130065046A1
• Filed: 05/17/2011
• Published: 03/14/2013
• Est. Priority Date: 05/17/2010
• Status: Active Grant

• Current Assignee: CJ Cheiljedang Corporation (CJ Group)
• Original Assignee: Cj Research Center Llc (CJ Group)
• Inventors: Krishnaswamy, Rajendra K.
• Granted Patent: US 9,328,239 B2
• Time in Patent Office: Days
• US Class Current: 428/336
• CPC Class Codes: B32B 2307/716 Degradable
• CPC Class Codes: B32B 2307/7163 Biodegradable
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: C08G 63/02 Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
• CPC Class Codes: C08G 63/06 derived from hydroxycarboxylic acids
• CPC Class Codes: C08G 63/08 Lactones or lactides
• CPC Class Codes: C08G 63/912 derived from hydroxycarboxylic acids
• CPC Class Codes: C08J 2367/04 Polyesters derived from hydroxy carboxylic acids, e.g. lactones C08J2367/06 takes precedence
• CPC Class Codes: C08J 2467/04 Polyesters derived from hydroxy carboxylic acids, e.g. lactones C08J2467/06 takes precedence
• CPC Class Codes: C08J 3/00 Processes of treating or compounding macromolecular substances
• CPC Class Codes: C08J 3/20 Compounding polymers with additives, e.g. colouring
• CPC Class Codes: C08K 2003/2206 of calcium, strontium or barium
• CPC Class Codes: C08K 3/01 characterized by their specific function
• CPC Class Codes: C08K 3/013 Fillers, pigments or reinforcing additives
• CPC Class Codes: C08K 3/014 Stabilisers against oxidation, heat, light or ozone
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 3/28 : Nitrogen-containing compounds
• CPC Class Codes: C08K 3/34 : Silicon-containing compounds
• CPC Class Codes: C08K 3/346 : Clay
• CPC Class Codes: C08K 3/36 : Silica
• CPC Class Codes: C08K 5/0016 : Plasticisers
• CPC Class Codes: C08K 5/005 : Stabilisers against oxidation, heat, light, ozone
• CPC Class Codes: C08K 5/0083 : Nucleating agents promoting the crystallisation of the polymer matrix
• CPC Class Codes: C08K 5/14 : Peroxides
• CPC Class Codes: C08L 2201/06 : Biodegradable
• CPC Class Codes: C08L 2203/16 : used for films
• CPC Class Codes: C08L 23/08 : Copolymers of ethene C08L23/16 takes precedence
• CPC Class Codes: C08L 23/0884 : Epoxide containing esters
• CPC Class Codes: C08L 2666/18 : Polyesters or polycarbonates according to C08L67/00 - C08L69/00; Derivatives thereof
• CPC Class Codes: C08L 33/06 : of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
• CPC Class Codes: C08L 33/068 : containing glycidyl groups
• CPC Class Codes: C08L 67/00 : Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain of polyester-amides C08L77/12; of polyester-imides C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 67/02 : Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C08L 67/04 : Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: Y10T 428/265 : 1 mil or less
• CPC Class Codes: Y10T 428/31786 : Of polyester [e.g., alkyd, etc.]

Abstract

Compositions of polymer blends of polylactic acid (PLA) and polyhydroxyalkanoate are described. In certain embodiments, the PHA is a multiphase copolymer blend having one phase a fully amorphous phase with a glass transition temperature of below 20° C. and is between about 5 to about 45% of the total PHA. Methods of making the compositions of the invention are also described. The invention also includes articles, films and laminates comprising the compositions.

Claims

1. A composition comprising a polymer blend of polylactic acid (PLA) and a polyhydroxyalkanoate polymer, copolymer or blend thereof (PHA), wherein the PHA has a T_g between about −

5°

C. and about −

50°

C.

28. The composition of claim 1, wherein the PHA comprises an amorphous rubber phase having 3HB and 4HB with a weight % 4HB of about 25% to about 50% in the PHA composition, and the composition further comprises, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, diethylene glycol dimethacrylate, and one or more additives selected from plasticizers, clarifiers, nucleating agents, thermal or oxidative stabilizers, inorganic fillers, anti-slip agents, compatibilizers and blocking agents.

38. The composition of claim 1, wherein the PHA is a multiphase PHA copolymer of 34-38% P3HB, 22-26% P3HB-4HB copolymer with 8-14% 4HB by weight and 38-42% P3HB-4HB copolymer with 25-33% 4HB by weight, further comprising, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, diethylene glycol dimethacrylate, and one or more additives selected from plasticizers, clarifiers, nucleating agents, thermal or oxidative stabilizers, inorganic fillers, anti-slip agents, compatibilizers and blocking agents.

2. A composition comprising a polymer blend of polylactic acid (PLA) and a polyhydroxyalkanoate polymer, wherein the PHA is a multiphase copolymer blend of PHA, having an amorphous rubber phase with a T_g between about −

15°

C. and about −

40°

C. and is between about 5 weight % to about 45 weight % of the total PHA in the composition.

3. The composition of claim 2, wherein the PHA is a multiphase copolymer blend of PHA, having a rubber phase with a degree of crystallinity between about 0% and about 5%.

4. The composition of claim 2, wherein the multiphase copolymer blend of PHA comprises three phases.

5. The composition of claim 2, wherein the composition further comprises a branching agent.

6. The composition of claim 5, wherein the branching agent is selected from:

dicumyl peroxide, t-amyl-2-ethylhexyl peroxycarbonate, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-amyl peroxy)hexane, 2,5-bis(t-butylperoxy)-2,5-dimethylhexane, 2,5-dimethyl-di(t-butylperoxy)hexyne-3, di-t-butyl peroxide, benzoyl peroxide, di-t-amyl peroxide, t-butyl cumyl peroxide, n-butyl-4,4-bis(t-butylperoxy)valerate, 1,1-di(t-butylperoxy)-3,3,5-trimethyl-cyclohexane, 1,1-di(t-butylperoxy)cyclohexane, 1,1-di(t-amylperoxy)-cyclohexane, 2,2-di(t-butylperoxy)butane, ethyl-3,3-di(t-butylperoxy)butyrate, 2,2-di(t-amylperoxy)propane, ethyl-3,3-di(t-amylperoxy)butyrate, t-butylperoxy-acetate, t-amylperoxyacetate, t-butylperoxybenzoate, t-amylperoxybenzoate, and di-t-butyldiperoxyphthalate or combinations thereof.

7. The composition of claim 5, wherein the concentration of branching agent is between about 0.001% to about 0.5% by weight of the blend composition.

8. The composition of claim 5, wherein the composition further comprises a co-agent for reacting with the polymer blend composition.

9. The composition of claim 8, wherein the co-agent is diallyl phthalate, pentaerythritol tetraacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, diethylene glycol dimethacrylate, bis(2-methacryloxyethyl)phosphate, or combinations thereof.

10. The composition of claim 8, wherein the co-agent is pentaerythritol triacrylate or diethylene glycol dimethacrylate.

11. The composition of claim 8, wherein the co-agent is an epoxy-functional styrene-acrylic polymer, an epoxy-functional acrylic copolymer, an epoxy-functional polyolefin copolymer, an oligomer comprising a glycidyl group with an epoxy functional side chain, an epoxy-functional poly(ethylene-glycidyl methacrylate-co-methacrylate), or an epoxidized oil or combinations thereof.

12. The composition of claim 5, further comprising a nucleating agent such as carbon black, cyanuric acid, uracil, thymine, mica talc, silica, boron nitride, barium nitride, clay, calcium carbonate, synthesized silicic acid and salts, metal salts of organophosphates, and kaolin or combination there of.

13. The composition of claim 2, wherein the PHA comprises an amorphous rubber phase having 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB) with a weight % 4HB of about 25% to about 50% in the PHA composition.

14. The composition of claim 2, wherein the PHA comprises an amorphous rubber phase having 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB) with a weight % 4HB of about 25% to about 40 in the PHA composition.

15. The composition of claim 2, wherein the PHA comprises an amorphous rubber phase having 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB) with a weight % 4HB of about 25% to about 35% in the PHA composition.

16. The composition of claim 2, wherein the PHA comprises an amorphous rubber phase having 3-hydroxybutyrate (3HB) and 3-hydroxyhexanoate (3HH) with a weight % 3HH of about 25% to about 50% in the PHA composition.

17. The composition of claim 2, wherein the PHA comprises an amorphous rubber phase having 3-hydroxybutyrate (3HB) and 5-hydroxyvalerate (5HV) with a weight % of 5HV of about 25% to about 60% in the PHA composition.

18. The composition of claim 2, wherein the PHA comprises an amorphous rubber phase 3-hydroxybutyrate (3HB) and 3-hydroxyoctoate (HO) with a weight % of HO of about 15% to about 60% in the PHA composition.

19. The composition of claim 2, wherein the PHA comprises an amorphous rubber phase having no melting point.

20. The composition of claim 2, wherein the amount of PHA in the polymer composition is about 1% to about 50% by weight of the total composition.

21. The composition of claim 2, wherein the amount of PHA in the polymer composition is about 10% to about 40% by weight of the total composition.

22. The composition of claim 2, wherein the amount of PHA in the polymer composition is about 20% to about 30% by weight of the total composition.

23. The composition of claim 2, wherein the weight average molecular weight of the rubber phase or amorphous rubber phase is between about 100,000 to about 600,000 daltons.

24. The composition of claim 2, further comprising one or more additives.

25. The composition of claim 24, wherein the additive is selected from plasticizers, clarifiers, nucleating agents, thermal or oxidative stabilizers, inorganic fillers, anti-slip agents, compatibilizers, blocking agents or a combination thereof.

26. The composition of claim 25, wherein the compatibilizer is maleic anhydride.

27. The composition of claim 2, further comprising a dendritic or hyperbranched polyester.

29. A multilayer laminate comprising at least one film layer comprising the composition of claim 2.

30. The multilayer laminate of claim 29, wherein the film has a thickness of about 1 to about 2 microns.

31. An article made with the laminate of claim 30.

32. A method of preparing a polylactic acid (PLA)/polyhydroxyalkanoate (PHA) polymer blend composition, comprising

melt blending the composition of claim 2, thereby forming a polymer composition of PLA and PHA.

33. A method of preparing a polylactic acid (PLA)/polyhydroxy-alkanoate (PHA) blend polymer composition, comprising melt reacting a composition of claim 2, wherein one phase of the PHA copolymer blend is a fully amorphous phase with a T_g below 20°

C. and is between 5-45% of the total PHA, thereby forming a branched polymer composition of PLA and PHA with improved tensile toughness and elongation.

34. A film comprising the composition of claim 2.

35. An article comprising the composition of claim 2.

36. The article of claim 35, wherein the article having about 31% to about 58% greater tensile elongation with about 21 to about 35% greater tensile toughness than a corresponding polymer article consisting only of PLA polymer.

37. The film of claim 34, wherein the film has increased tensile elongation and toughness according ASTM D822 relative to a corresponding PLA/PBSA polymer blend film.