Absorbable copolylactides and their use

A process for preparing a copolylactide, comprising polymerizing racemic lactide with an E-caprolactone comonomer, at a molar ratio of lactide to comonomer of 84:16, 85:15 or 86:14, in the presence of tin(II) di(ethylhexanoate) as an initiator, at a molar ratio of initiator to lactide/comonomer of 1:30,000 to 1:50,000, and in the presence of an n-alkanol cocatalyst, where the molar ratio of cocatalyst to lactide/comonomer is 1:200 to 1:600, at a temperature not exceeding 165° C.

A process for controlling the molecular weight distribution Mw/Mn of a copolymer comprising polymerized units of racemic lactide and at least one comonomer of ε-caprolactone, comprising polymerizing racemic lactide with an ε-caprolactone comonomer, at a molar ratio of lactide to comonomer of 84:16, 85:15 or 86:14, in the presence of tin(II) di(ethylhexanoate) as an initiator, at a molar ratio of initiator to lactide/comonomer of 1:30,000 to 1:50,000, and in the presence of an n-alkanol cocatalyst, where the molar ratio of cocatalyst to lactide/comonomer is 1:200 to 1:600, at a temperature not exceeding 165° C., whereby Mw/Mn is 1.2 to 2.0.

A flexible, transparent copolylactide comprising polymerized units of racemic lactide and a comonomer of ε-caprolactone, δ-valerolactone, 1,4dioxan-2-one, 1,3-dioxane-2-one or mixtures thereof, having a glass transition temperature of 33 to 37° C., a number average molecular weight Mn of 15,000 to 50,000 and a polydispersity Pn of 1.4 to 1.7.

A process for preparing a copolylactide, comprising polymerizing racemic lactide with an ε-caprolactone, δ-valerolactone, 1,4-dioxan-2-one or 1,3-dioxan-2-one comonomer, or a mixture thereof, at a molar ratio of lactide to comonomer of 90-80:10-20, in the presence of tin(II) di(ethylhexanoate) as an initiator, at a molar ratio of initiator to lactide/comonomer of 1:30,000 to 1:50,000, and in the presence of an n-alkanol, an oligoethylene glycol monomethyl ether or a polyol cocatalyst, where the molar ratio of cocatalyst to lactide/comonomer is 1:200 to 1:600, at a temperature not exceeding 165° C.

A process for controlling the molecular weight distribution Mw/Mn of a copolymer comprising polymerized units of racemic lactide and at least one comonomer of ε-caprolactone, δ-valerolactone, 1,4-dioxan-2-one, 1,3-dioxan-2-one or a mixture thereof, comprising polymerizing racemic lactide with an ε-caprolactone, δ-valerolactone, 1,4-dioxan-2-one or 1,3-dioxan-2-one, comonomer, or a mixture thereof, at a molar ratio of lactide to comonomer of 90-80:10-20, in the presence of tin(II) di(ethylhexanoate) as an initiator, at a molar ratio of initiator to lactide/comonomer of 1:30,000 to 1:50,000, and in the presence of an n-alkanol, an oligoethylene glycol monomethyl ether or a polyol cocatalyst, where the molar ratio of cocatalyst to lactide/comonomer is 1:200 to 1:600, at a temperature not exceeding 165° C., whereby Mw/Mn is 1.2 to 2.0.

A flexible, transparent copolylactide comprising polymerized units of racemic lactide and a comonomer of 1,4-dioxan-2-one, 1,3-dioxane-2-one or mixtures thereof, having a glass transition temperature of 30 to 43° C., a number average molecular weight Mn of 15,000 to 50,000 and a polydispersity Pn of 1.2 to 2.0.

A process for preparing a copolylactide, comprising polymerizing racemic lactide with an 1,4-dioxan-2-one or 1,3-dioxan-2-one comonomer, or a mixture thereof, at a molar ratio of lactide to comonomer of 90-80:10-20, in the presence of tin(II) di(ethylhexanoate) as an initiator, at a molar ratio of initiator to lactide/comonomer of 1:30,000 to 1:50,000, and in the presence of an n-alkanol, an oligoethylene glycol monomethyl ether or a polyol cocatalyst, where the molar ratio of cocatalyst to lactide/comonomer is 1:200 to 1:600, at a temperature not exceeding 165° C.

A process for controlling the molecular weight distribution Mw/Mn of a copolymer comprising polymerized units of racemic lactide and at least one comonomer of 1,4-dioxan-2-one, 1,3-dioxan-2-one or a mixture thereof, comprising polymerizing racemic lactide with an ε-caprolactone, δ-valerolactone, 1,4-dioxan-2-one or 1,3-dioxan-2-one, comonomer, or a mixture thereof, at a molar ratio of lactide to comonomer of 90-80:10-20, in the presence of tin(II) di(ethylhexanoate) as an initiator, at a molar ratio of initiator to lactide/comonomer of 1:30,000 to 1:50,000, and in the presence of an n-alkanol, an oligoethylene glycol monomethyl ether or a polyol cocatalyst, where the molar ratio of cocatalyst to lactide/comonomer is 1:200 to 1:600, at a temperature not exceeding 165° C., whereby Mw/Mn is 1.2 to 2.0.