Polydiorganosiloxane-polycarbonate block copolymers
View Patent ↗Disclosed herein are polydiorganosiloxane-polycarbonate block copolymers having desirable optical properties, and methods of making such block copolymers. Also disclosed herein are analytical methods for evaluating hydroxyaryl end-capped polydialkylsiloxane monomers.
1. A process for preparing a polydiorganosiloxane-polycarbonate block copolymer, the process comprising:
(a) providing a composition comprising hydroxyaryl end-capped polydiorganosiloxane monomers having the following formula (Ia):
wherein: each R is independently a C 1 -C 13 monovalent organic group;
each X is independently a C 2 -C 4 alkylenyl group;
each R′ is independently selected from the group consisting of halo, cyano, nitro, C 1 -C 8 alkyl, C 1 -C 8 alkoxy, C 1 -C 8 thioalkoxy, C 2 -C 8 alkenyl, C 2 -C 8 alkenyloxy, C 3 -C 8 cycloalkyl, C 3 -C 8 cycloalkyloxy, C 6 -C 10 aryl, C 6 -C 10 aryloxy, C 7 -C 12 arylalkyl, and C 7 -C 12 arylalkoxy;
each m is independently 0, 1, 2, 3 or 4; and
n is about 2 to about 200;
wherein the composition has a polydispersity index (Mw/Mn) of less than 2.2, as measured by size exclusion chromatography with ultraviolet (UV) and refractive index (RI) detection; and
wherein the composition has a % low molecular weight fraction of less than 15%; and
(b) reacting the composition with a carbonate precursor and a dihydroxy monomer of formula (ia): HO—R 1 —OH (ia)
wherein R 1 comprises an aliphatic, alicyclic, or aromatic group, or any combination thereof;
to form the polydiorganosiloxane-polycarbonate block copolymer.
2. A process for preparing a polydiorganosiloxane-polycarbonate block copolymer, the process comprising:
(a) providing a composition comprising hydroxyaryl end-capped polydiorganosiloxane monomers having the following formula (Ia):
wherein: each R is independently a C 1 -C 13 monovalent organic group;
each X is independently a C 2 -C 4 alkylenyl group;
each R′ is independently selected from the group consisting of halo, cyano, nitro, C 1 -C 8 alkyl, C 1 -C 8 alkoxy, C 1 -C 8 thioalkoxy, C 2 -C 8 alkenyl, C 2 -C 8 alkenyloxy, C 3 -C 8 cycloalkyl, C 3 -C 8 cycloalkyloxy, C 6 -C 10 aryl, C 6 -C 10 aryloxy, C 7 -C 12 arylalkyl, and C 7 -C 12 arylalkoxy;
each m is independently 0, 1, 2, 3 or 4; and
n is about 2 to about 200;
wherein the composition has a polydispersity index (Mw/Mn) of less than 2.3, as measured by size exclusion chromatography with ultraviolet (UV) and refractive index (RI) detection; and
wherein the composition has a % low molecular weight fraction of less than 15%; and
(b) reacting the composition with a carbonate precursor and a dihydroxy monomer of formula (ia): HO—R 1 —OH (ia)
wherein R 1 comprises an aliphatic, alicyclic, or aromatic group, or any combination thereof;
to form the polydiorganosiloxane-polycarbonate block copolymer.
3. The process of claim 2 , wherein the polydiorganosiloxane is present in the polydiorganosiloxane-polycarbonate block copolymer in an amount of about 2 wt % to about 25 wt % based on the total weight of the polydiorganosiloxane-polycarbonate block copolymer.
4. The process of claim 2 , wherein a molded article made from the polydiorganosiloxane-polycarbonate block copolymer has a % haze of less than 1.5 at 3.15 mm thickness.
5. The process of claim 2 , wherein a molded article made from the polydiorganosiloxane-polycarbonate block copolymer has a Db of less than 4.5 at 3.15 mm thickness.
6. The process of claim 2 , wherein n is about 30 to about 200.
7. The process of claim 6 , wherein the composition has % high molecular weight fraction of less than 28%.
8. The process of claim 2 , wherein the monomer of formula (Ia) is formula (Ib), formula (Ic), or formula (Id):
9. The process of claim 2 , wherein the composition has a polydispersity index of less than 2.0.
10. The process of claim 2 , wherein the composition has a % low molecular weight fraction of less than 14%.
11. The process of claim 2 , wherein the composition has % high molecular weight fraction of less than 26%.
12. The process of claim 2 , wherein the compound of formula (ia) has the following formula (IIa):
HO-A 1 -Y-A 2 -OH (IIa)
wherein each of A 1 and A 2 comprises a monocyclic divalent arylene group, and Y is a bridging group comprising one or two member atoms.
13. The process of claim 12 , wherein the compound of formula (IIa) has the following formula:
14. The process of claim 2 , wherein the block copolymer comprises one block having the formula (Ie):
and at least one block having the formula (IIb):
wherein m is about 10 to about 45.
15. The process of claim 2 , wherein the polydiorganosiloxane is present in the polydiorganosiloxane-polycarbonate block copolymer in an amount of about 2 wt % to about 8 wt % based on the total weight of the polydiorganosiloxane-polycarbonate block copolymer.
16. The process of claim 2 , wherein a molded article made from the polydiorganosiloxane-polycarbonate block copolymer has a % haze of less than 1.0.
17. The process of claim 2 , wherein a molded article made from the polydiorganosiloxane-polycarbonate block copolymer has a Db of less than 4.0 at 3.15 mm thickness.
18. The process of claim 2 , wherein a % haze of a molded article made from the polydiorganosiloxane-polycarbonate block copolymer satisfies the following equation: haze =−2.39 +0.0525(% low molecular weight fraction)+0.127(% high molecular weight fraction).
19. The process of claim 2 , wherein a Db of a molded article made from the polydiorganosiloxane-polycarbonate block copolymer satisfies the following equation: Db =−2.83 +0.165(% low molecular weight fraction) +0.191(% high molecular weight fraction).
20. The process of claim 2 , wherein a 2.5 mm plaque made from the polydiorganosiloxane-polycarbonate block copolymer has a dL* value of less than or equal to −0.1, wherein the dL* value is calculated by substracting a measured L* value from a L* reference value.