Thermally stable polycarbonates, thermoplastic compositions thereof, and articles formed therefrom

1. A polycarbonate comprising repeating structural carbonate units of the formula (H-1):

in which R h is a radical having the formula (H-2):

wherein each of R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 , R 20 , R 21 , R 22 , R 23 , R 24 , R 25 , R 26 , R 27 , and R 28 is independently a hydrogen, a C 1 -C 6 alkyl group, or a halogen substituted C 1 -C 6 alkyl group; and further comprising repeating structural carbonate units of the formula (A-4):

wherein the polycarbonate has a weight average molecular weight (Mw) of from about 15,000 to about 100,000.

2. The polycarbonate of claim 1 , wherein the repeating structural carbonate units having a formula (H-3):

3. The polycarbonate of claim 1 , further comprising repeating structural carbonate units of the formula (A-1):

wherein each of A 1 and A 2 is a monocyclic divalent aryl radical and Y 1 is a bridging radical having one or two atoms that separate A 1 from A 2 .

4. The polycarbonate of claim 1 , further comprising repeating structural carbonate units of the formula (A-2):

wherein R a and R b each represent a halogen atom or a monovalent hydrocarbon group and may be the same or different; p and q are each independently integers or 0 to 4; and X a represents one of the groups of formula (5):

wherein R c and R d each independently represent a hydrogen atom or a monovalent linear or cyclic hydrocarbon group and R e is a divalent hydrocarbon group.

5. A polycarbonate comprising from about 0.1 wt % to about 40 wt % repeating structural carbonate units of the formula (H-1):

wherein the repeating structural carbonate units of the formula (H-1) comprise a formula (H-3) unit:

and

from about 60 wt % to about 99.9 wt % repeating structural carbonate units of the formula (A-1):

wherein each of A 1 and A 2 is a monocyclic divalent aryl radical and Y 1 is a bridging radical having one or two atoms that separate A 1 from A 2 , and wherein the repeating structural carbonate units of the formula (A-1) comprises a formula (A-3) unit, a formula (A-4) unit, or mixture thereof:

wherein the polycarbonate has a weight average molecular weight (Mw) of from about 15,000 to about 100,000.

6. The polycarbonate of claim 5 , wherein the repeating structural carbonate units of formula (A-1) comprise repeating structural carbonate units of the formula (A-3):

7. The polycarbonate of claim 5 , wherein the repeating structural carbonate units of formula (A-1) comprise repeating structural carbonate units of the formula (A-4):

8. The polycarbonate of claim 3 , which comprises:

from about 0.1 wt % to about 40 wt % of repeating structural carbonate units of the formula (H-1); and

from about 60 wt % to about 99.9 wt % of repeating structural carbonate units of the formula (A-4).

9. The polycarbonate of claim 5 , which comprises:

from about 2 wt % to about 20 wt % of repeating structural carbonate units of the formula (H-1); and

from about 80 wt % to about 98 wt % of repeating structural carbonate units of the formula (A-1).

10. The polycarbonate of claim 9 , which comprises:

from about 3 wt % to about 10 wt % of repeating structural carbonate units of the formula (H-1); and

from about 90 wt % to about 97 wt % of repeating structural carbonate units of the formula (A-1).

11. The polycarbonate of claim 8 , wherein the repeating structural carbonate units of the formula (H-1) comprise a formula (H-3) unit:

12. The polycarbonate of claim 5 , wherein the polyester repeating units have a formula (6):

wherein D is a divalent radical derived from a dihydroxy compound selected from the group consisting of a C 2-10 alkylene radical, a C 6-20 alicyclic radical, a C 6-20 aromatic radical and a polyoxyalkylene radical in which the alkylene groups contain 2 to 6 carbon atoms; and T is a divalent radical derived from a dicarboxylic acid selected from the group consisting of a C 2-10 alkylene radical, a C 6-20 alicyclic radical, a C 6-20 alkyl aromatic radical, and a C 6-20 aromatic radical.

13. The polycarbonate of claim 5 , which comprises a copolymer of polysiloxane-polycarbonate.

14. The polycarbonate of claim 1 , in which the formula (H-1) unit is derived from a dihydroxy compound of formula (H-4):

15. The polycarbonate of claim 2 , in which the formula (H-3) unit is derived from a dihydroxy compound of formula (H-5):

16. The polycarbonate of claim 2 , in which the formula (H-3) unit is derived from a bischloroformate compound of formula (H-6):

17. A thermoplastic composition, which includes a polycarbonate comprising from about 0.1 wt % to about 40 wt % repeating structural carbonate units of the formula (H-1):

wherein the repeating structural carbonate units of the formula (H-1) comprise a formula (H-3) unit:

and

from about 60 wt % to about 99.9 wt % repeating structural carbonate units of the formula (A-1):

wherein each of A 1 and A 2 is a monocyclic divalent aryl radical and Y 1 is a bridging radical having one or two atoms that separate A 1 from A 2 , and wherein the repeating structural carbonate units of the formula (A-1) comprises a formula (A-3) unit, a formula (A-4) unit, or mixture thereof:

wherein the polycarbonate has a weight average molecular weight (Mw) of from about 15,000 to about 100,000.

18. The thermoplastic composition of claim 17 , further comprising one or more additives selected from the group consisting of hydrolysis stabilizer, impact modifier, filler/reinforcing agent, visual effect enhancer, antioxidant, heat stabilizer, light stabilizer, ultraviolet light absorber, plasticizer, mold release agent, lubricant, antistatic agent, pigment, dye, flame retardant, processing aid, radiation stabilizer, and anti-drip agent.

19. A thermally stable article made from the thermoplastic composition of claim 17 .

20. The polycarbonate of claim 1 , wherein the polyester repeating units have a formula (6):

wherein D is a divalent radical derived from a dihydroxy compound selected from the group consisting of a C 2-10 alkylene radical, a C 6-20 alicyclic radical, a C 6-20 aromatic radical and a polyoxyalkylene radical in which the alkylene groups contain 2 to 6 carbon atoms; and T is a divalent radical derived from a dicarboxylic acid selected from the group consisting of a C 2-10 alkylene radical, a C 6-20 alicyclic radical, a C 6-20 alkyl aromatic radical, and a C 6-20 aromatic radical.