Polymerization of lactide
First Claim
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1. A process for polymerizing lactide comprising melting at 100°
- to 220°
C. a lactide and up to 20 mole percent of another lactone of the formula ##STR5## where n is 4 or 5, h, i, k and m are independently 1 or 2, each R is independently selected from H or hydrocarbyl containing up to 12 carbon atoms or substituted hydrocarbyl containing up to 12 carbon atoms with a catalyst of the formula MZ3, wherein M is yttrium or a rare earth metal and one Z is --OCR'"'"'3 where R'"'"' is independently hydrogen, hydrocarbyl or substituted hydrocarbyl, the remaining two Zs are fluoride, chloride, bromide, iodide, carboxylate, tetrasubstituted porphyrinato (-2), betadiketone anions, beta keto ester anions, cyclopentadienide, phenoxide or pentamethylcyclopentadienide, and cooling the resulting polymer.
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Abstract
A process for polymerizing lactide and up to 20 mole percent of another lactone in the absence of solvent at 100° to 220° C. using an yttrium or lanthanide series rare earth metal catalyst.
29 Citations
14 Claims
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1. A process for polymerizing lactide comprising melting at 100°
- to 220°
C. a lactide and up to 20 mole percent of another lactone of the formula ##STR5## where n is 4 or 5, h, i, k and m are independently 1 or 2, each R is independently selected from H or hydrocarbyl containing up to 12 carbon atoms or substituted hydrocarbyl containing up to 12 carbon atoms with a catalyst of the formula MZ3, wherein M is yttrium or a rare earth metal and one Z is --OCR'"'"'3 where R'"'"' is independently hydrogen, hydrocarbyl or substituted hydrocarbyl, the remaining two Zs are fluoride, chloride, bromide, iodide, carboxylate, tetrasubstituted porphyrinato (-2), betadiketone anions, beta keto ester anions, cyclopentadienide, phenoxide or pentamethylcyclopentadienide, and cooling the resulting polymer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
- to 220°
Specification