Copolymers of L-(-)-lactide and epsilon caprolactone

• US 4,057,537 A
• Filed: 01/28/1975
• Issued: 11/08/1977
• Est. Priority Date: 01/28/1975
• Status: Expired due to Term

• Current Assignee: Chevron Research Company (Chevron Corp.)
• Original Assignee: Gulf Oil Corporation (Chevron Corp.)
• Inventors: Sinclair, Richard G.
• Primary Examiner(s): Anderson, Harold D.
• Assistant Examiner(s): Nielsen, E. A.
• Application Number:
  US05/544,788
• Time in Patent Office: 1,015 Days
• Field of Search: 260/78.3 R
• US Class Current: 528/354
• CPC Class Codes: C08G 63/08 Lactones or lactides

Abstract

Copolymers which can be fabricated into films, fibers and structural shapes are prepared by copolymerizing an optically active lactide, i.e., L-(-)-lactide, and epsilon caprolactone in the presence of a tin ester of a carboxylic acid. A copolymer prepared from 75 parts by weight of L-(-)-lactide and 25 parts by weight of epsilon caprolactone is a thermoplastic elastomer. A copolymer prepared from 90 parts by weight of L-(-)-lactide and 10 parts by weight of epsilon caprolactone is a rigid, clear, thermoplastic solid.

Claims

1. A non-gummy, high impact, non-brittle, thermally stable copolymer of an optically active lactide and epsilon caprolactone, said copolymer being obtained by heating a mixture of L-(-)-lactide having a melting point below 100°

C. and epsilon caprolactone at a temperature above the melting point of L-(-)-lactide and below 200°

C. in the presence of a catalyst, said mixture comprising about 75 to about 90 percent by weight of L-(-)-lactide.

6. A thermally stable copolymer in accordance with claim 1 wherein said catalyst is a tin ester of a carboxylic acid containing up to 18 carbon atoms.

2. A non-gummy, high impact, non-brittle thermoplastic elastomer of an optically active lactide and epsilon caprolactone, said elastomer being obtained by heating 75 parts by weight of L-(-)-lactide having a melting point below 100°

C. and 25 parts by weight of epsilon caprolactone at a temperature above the melting point of L-(-)-lactide and below 200°

C. in the presence of a tin ester of a carboxylic acid containing up to 18 carbon atoms.

3. A thermoplastic elastomer in accordance with claim 2 wherein the L-(-)-lactide and epsilon caprolactone are heated at about 135°

to about 145°

C.

4. A rigid, clear, non-gummy, high impact, non-brittle thermoplastic solid of an optically active lactide and epsilon caprolactone, said solid being obtained by heating 90 parts by weight of L-(-)-lactide having a melting point below 100°

C. and 10 parts by weight of epsilon caprolactone at a temperature above the melting point of L-(-)-lactide and below 200°

C. in the presence of a tin ester of a carboxylic acid containing up to 18 carbon atoms.

5. A rigid, clear, thermoplastic solid in accordance with claim 4 wherein the L-(-)-lactide and epsilon caprolactone are heated at about 130°

to about 160°

C.