Method for manufacturing stable polylactide

• US 20090247710A1
• Filed: 03/30/2009
• Published: 10/01/2009
• Est. Priority Date: 03/31/2008
• Status: Abandoned Application

• Current Assignee: Purac Biochem BV (Corbion NV)
• Original Assignee: Purac Biochem BV (Corbion NV)
• Inventors: De Vos, Siebe Cornelis
• Application Number:
  US12/385,058
• Publication Number:
  US 20090247710A1
• Time in Patent Office: Days
• US Class Current: 525/450
• CPC Class Codes: C08G 63/823 for the preparation of polylactones or polylactides
• CPC Class Codes: C08G 63/912 derived from hydroxycarboxylic acids

Abstract

The present invention pertains to a process for manufacturing polylactide comprising the steps of combining lactide with a polymerization catalyst, subjecting the mixture to polymerization conditions to form polylactide in the liquid state, adding an organic peroxide, subjecting the liquid polylactide to a devolatilisation step, and allowing the polylactide to solidify.

Claims

1. A process for manufacturing polylactide comprising the steps of combining lactide with a polymerisation catalyst, subjecting the mixture to polymerization conditions to form polylactide in the liquid state, adding an organic peroxide, subjecting the liquid polylactide to a devolatilisation step, and allowing the polylactide to solidify.

2. A process according to claim 1, wherein the catalyst is a catalyst of the formula

(M)(X1, X2 . . . Xm)n  

 

(I)

where M is selected from metals of Group 2, 4, 8, 9, 10, 12, 13, 14, and 15 of the Periodic Table of Elements, (X1, X2 . . . Xm) are independently selected from the group of alkyls, aryls, oxides, carboxylates, halides, alkoxides, alkylesters, m is an integer ranging from 1 to 6, and n is an integer ranging from 0 to 6, wherein the values for m and n depend on the oxidation state of the metal ion.

3. A process according to claim 2 wherein M is a metal ion in its lowest oxidation state, where the metal ion also possesses a higher oxidation state

4. A process according to claim 3 wherein M is selected from Sn(II), Pb(II), Sb(III), Bi(III), and Ti(II).

5. A process according to claim 1 wherein the catalyst is used in an amount of at least 5 ppm, calculated as metal and at most 1300 ppm, calculated as metal.

6. A process according to claim 1, which is carried out in the substantial absence of added phosphorus-containing compounds.

7. A process according to claim 1 wherein the polymerisation is carried out in the substantial absence of added co-catalyst.

8. A process according to claim 1 wherein the peroxide is such that at least 80% of the peroxide decomposes between 1 and 60 seconds at a temperature of 150-220°

C.