Biodegradable polymer compositions

• US 8,981,002 B2
• Filed: 03/19/2010
• Issued: 03/17/2015
• Est. Priority Date: 03/19/2009
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Cernohous, Jeffrey Jacob, Van Gorden, Garrett Scott
• Primary Examiner(s): Stanley, Jane L
• Application Number:
  US13/256,336
• Publication Number:
  US 20120101198A1
• Time in Patent Office: 1,824 Days
• Field of Search: 524/8, 524/599, 524/612, 524/702
• US Class Current: 524/599
• CPC Class Codes: C08G 2261/132 branched or hyperbranched
• CPC Class Codes: C08G 63/08 Lactones or lactides
• CPC Class Codes: C08G 83/005 Hyperbranched macromolecules
• CPC Class Codes: C08K 5/0033 Additives activating the degradation of the macromolecular compound
• CPC Class Codes: C08K 5/0066 Flame-proofing or flame-retarding additives
• CPC Class Codes: C08K 5/10 Esters; Ether-esters
• CPC Class Codes: C08K 5/14 Peroxides
• CPC Class Codes: C08K 5/34928 Salts
• CPC Class Codes: C08K 5/49 Phosphorus-containing compounds C08K5/0091 takes precedence
• CPC Class Codes: C08K 5/5205 Salts of P-acids with N-bases
• CPC Class Codes: C08L 101/005 Dendritic macromolecules
• CPC Class Codes: C08L 101/16 the macromolecular compounds being biodegradable

Abstract

Hyper-branched biodegradable polymers are produced by melt processing biodegradable polymers with a branching agent at temperatures that promote free radical reactions between the biodegradable polymer and the branching agent. The biodegradable compositions have an excellent balance of mechanical properties and are suitable for flame retardant applications.

Claims

1. A composition comprising a melt processable, hyper-branched polymer derived from a biodegradable polyester polymer and a branching agent wherein the branching agent is an organic compound that contains at least two ethylenically unsaturated sites per molecule, wherein the hyper-branched polymer is produced by melt processing said biodegradable polymer with the branching agent at temperatures that promote free radical reactions between the biodegradable polyester polymer and the branching agent.

2. The composition according to claim 1, wherein the melt processable, hyper-branched polymer is also derived from a free radical initiator.

3. The composition according to claim 1, wherein the branching agent is a multifunctional acrylate or methacrylate compound.

4. The composition according to claim 3, wherein the multifunctional acrylate or methacrylate compounds are selected from the group consisting of 1,6-hexanediol dimethacrylate, 1,6-hexanediol diacrylate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, trimethylol propane triacrylate, trimethylol propane trimethacrylate, glycerol trimethacrylate, glycerol triacrylate, glycerol dimethacrylate, glycerol diacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, and pentaerythritol tetramethacrylate.

5. The composition according to claim 1, wherein the hyper-branched polymer has a rating of HB on the UL 94 horizontal flame retardant test.

6. The composition according to claim 1, further comprising a flame retardant additive.

7. The composition according to claim 6, wherein the flame retardant additive composition is a phosphorus based compound.

8. The composition according to claim 7, wherein the flame retardant additive composition is melamine polyphosphate.

9. The composition according to claim 7, wherein the composition exhibits self-extinguishing properties under UL 94 test procedures.

10. The composition according to claim 6, wherein the composition has a rating of V2, V1 or V0 on the UL 94 vertical flame retardant test.

11. The composition according to claim 6, wherein the composition has one or more of an unnotched impact strength greater than 200 joules/meter under ASTM D256 and flexural modulus of greater than 3000 megapascals under ASTM D790.

12. The composition according to claim 1, wherein the composition has one or more of an unnotched impact strength greater than 265 joules/meter under ASTM D256 and flexural modulus of greater than 2300 megapascals under ASTM D790.

13. The composition according to claim 1, wherein the biodegradable polyester polymer is selected from the group consisting of polysaccharide, peptide, aliphatic polyester, polyamino acid, polyvinyl alcohol, polyamide, polyalkylene glycol, and copolymers thereof.

14. The composition according to claim 1, wherein the biodegradable polyester polymer is selected from the group consisting of polylactic acid, poly-L-lactic acid (PLLA), and random copolymers of L-lactic acid and D-lactic acid, and derivatives thereof.

15. A method comprising melt processing a biodegradable polyester polymer and a branching agent to form a melt proces sable, hyper-branched polymer by a free radical hemolysis reaction.

16. The method according to claim 15, further comprising forming an article by melt processing the melt processable, hyper-branched polymer.

17. The method according to claim 16, wherein the article includes molded architectural products, forms, automotive parts, building components, household articles, or electronic hard goods.

18. A process comprising extruding, injection molding, blow molding, rotomolding, or batch mixing a melt-processable hyper-branched polymer wherein the polymer is derived from a free radical hemolysis reaction between a biodegradable polyester polymer and a branching agent, wherein the branching agent is an organic compound that contains at least two ethylenically unsaturated sites per molecule at temperatures that promote free radical reactions between the biodegradable polyester polymer and the branching agent.

19. A composition comprising a melt processable, hyper-branched polymer derived from a biodegradable polyester polymer and a branching agent wherein the branching agent is a multifunctional acrylate or methacrylate compound and wherein the hyper-branched polymer is produced by melt processing said biodegradable polymer with the branching agent at temperatures that promote free radical reactions between the biodegradable polyester polymer and the branching agent.