ENDCAPPED POLYCARBONATES, METHODS OF MANUFACTURE, AND ARTICLES FORMED THEREFROM

1 . An endcapped polycarbonate comprising thioether carbonyl endcaps of the formula

wherein L is a C 1-12 aliphatic or aromatic linking group, and R is a C 1-20 alkyl, C 6-18 aryl, or C 7-24 arylalkylene.

2 . The endcapped polycarbonate of claim 1 , wherein the thioether carbonyl endcaps are of the formula

or a combination thereof, wherein R is a C 1-20 alkyl, C 6-18 aryl, or C 7-24 arylalkylene, and b is 1 to 5.

3 . The endcapped polycarbonate of claim 1 , wherein the thioether carbonyl endcaps are of the formula

or a combination thereof.

4 . The endcapped polycarbonate of claim 1 ,

wherein the thioether carbonyl endcaps are present in an amount effective to provide 3 to 80 parts per million by weight of added sulfur, based on the total parts by weight of the endcapped polycarbonate; or

having a total sulfur content of 3 to 150 parts per million by weight, based on the total parts by weight of the endcapped polycarbonate;

or both.

5 . The endcapped polycarbonate of claim 1 , wherein the polycarbonate is a homopolycarbonate, a copolycarbonate, a poly(ester-carbonate), a poly(carbonate-siloxane), a poly(ester-carbonate-siloxane), or a combination thereof.

6 . The endcapped polycarbonate of claim 1 , wherein the polycarbonate comprises:

0 to 95 mole percent, of low heat aromatic dihydroxy monomer groups; and

5 to 100 mole percent of high heat aromatic dihydroxy monomer groups.

7 . The endcapped polycarbonate of claim 6 , wherein the low heat aromatic dihydroxy monomer groups are bisphenol A groups, and the high heat aromatic dihydroxy monomer groups are of the formula

or a combination thereof, wherein R 4 is methyl or phenyl, each R 2 is methyl, and g is 1 to 4.

8 . The endcapped polycarbonate of claim 1 , wherein, as compared to the same polycarbonate without the thioether carbonyl endcaps, the endcapped polycarbonate has at least one of lower yellowness index, lower yellowness index after heat aging, or less plate-out after molding.

9 . The endcapped polycarbonate of claim 1 , wherein a molded sample of the endcapped polycarbonate has at least one of

a haze of less than 10% as measured according to ASTM D1003-00, Procedure B, illuminant C, on a spectrophotometer, at a thickness of 3.2 mm; or

a visible transmission of greater than or equal to 70% as determined according to ASTM D1003-00, Procedure A, using D65 illumination, 10 degrees observer, at a thickness of 3.2 mm.

10 . A method for the manufacture of the endcapped polycarbonate of claim 1 , the method comprising reacting a thioether carbonyl endcapping agent of the formula:

during manufacturing of the polycarbonate from a bisphenol,

wherein G is a leaving group, L is a C 1-12 aliphatic or aromatic linking group, and R is a C 1-20 alkyl, C 6-18 aryl, or C 7-24 arylalkylene.

11 . The method of claim 10 , wherein the manufacturing is by interfacial polymerization, and G is a hydroxy group, a salt of a hydroxy group, or a halide.

12 . The method of claim 10 , wherein the manufacturing is in the melt, and G is a hydroxy group or a salt of a hydroxy group.

13 . The method of claim 10 , comprising combining the thioether carbonyl endcapping agent with the bisphenol, wherein the combining is: during manufacturing of the bisphenol, during dissolution of the bisphenol before manufacturing the polycarbonate, at the same time that the bisphenol is added to a reaction mixture to form the polycarbonate, during phosgenation to form the polycarbonate, before shipping the bisphenol, or before storing the bisphenol.

14 . (canceled)

15 . An article comprising the endcapped polycarbonate of claim 1 .

16 . The article of claim 15 , wherein the article is a molded article, an extruded layer, or an extruded fiber.

17 . The article of claim 15 , wherein the article is a lens that is optionally hardcoated.

18 . The article of claim 15 , prepared by injection molding or extruding the endcapped polycarbonate.

19 . The endcapped polycarbonate of claim 7 , wherein the high heat aromatic dihydroxy monomer groups are of the formula

or a combination thereof.

20 . The endcapped polycarbonate of claim 1 ,

wherein the thioether carbonyl endcaps are present in an amount effective to provide 3 to 70 parts per million by weight of added sulfur, based on the total parts by weight of the endcapped polycarbonate; or

having a total sulfur content of 3 to 100 parts per million by weight, based on the total parts by weight of the endcapped polycarbonate;

or both.

21 . The endcapped polycarbonate of claim 6 , wherein the polycarbonate comprises:

5 to 90 mole percent of the low heat aromatic dihydroxy monomer groups; and

10 to 95 mole percent of the high heat aromatic dihydroxy monomer groups.