Methods for annealing block copolymers and articles manufactured therefrom
View Patent ↗Disclosed herein is a block copolymer comprising a first block derived from a vinyl aromatic monomer; where the vinyl aromatic monomer has at least one alkyl substitution on an aromatic ring; a second block derived from a siloxane monomer; where a chi parameter that measures interactions between the first block and the second block is 0.03 to 0.18 at a temperature of 200° C. Disclosed herein is a method comprising polymerizing a vinyl aromatic monomer to form a first block; and polymerizing a second block onto the first block to form a block copolymer; where the second block is derived by polymerizing a siloxane monomer; and where the block copolymer has a chi parameter of 0.03 to 0.18 at a temperature of 200° C.; where the chi parameter is a measure of interactions between the first block and the second block of the copolymer.
1. A block copolymer comprising:
a first block derived from a vinyl aromatic monomer; where the vinyl aromatic monomer has at least one alkyl substitution on an aromatic ring;
a second block derived from a siloxane monomer; where a chi parameter that measures interactions between the first block and the second block is 0.03 to 0.18 at a temperature of 200° C.
2. The block copolymer of claim 1 , where the vinyl aromatic monomer is an alkylstyrene.
3. The block copolymer of claim 2 , where the alkylstyrene is o-methylstyrene, p-methylstyrene, m-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, α-methyl-p-methylstyrene, 2,4-dimethylstyrene, iso-propyl styrene, propyl styrene, butyl styrene, tert-butylstyrene, sec-butylstyrene, isobutylstyrene, 4-tert-butylstyrene, or a combination comprising at least one of the foregoing alkylstyrenes.
4. The block copolymer of claim 1 , where the first block comprises poly(4-tertbutyl styrene) and has a molecular weight of 2,000 to 200,000 grams per mole.
5. The block copolymer of claim 1 , where the siloxane monomer has a structure represented by formula (1)
wherein each R is independently a C 1 -C 10 alkyl, a C 3 -C 10 cycloalkyl, a C 6 -C 14 aryl, a C 7 -C 13 alkylaryl or a C 7 -C 13 arylalkyl and where a degree of polymerization n in the formula (1) is to 5,000.
6. The block copolymer of claim 1 , where the second block comprises polydimethylsiloxane.
7. The block copolymer of claim 1 , where the block copolymer comprises cylindrical and/or lamellar domains and has an interdomain spacing of less than or equal to about 50 nanometers.
8. The block copolymer of claim 1 , where the block copolymer is annealed to a temperature of up to 400° C. for up to 4 hours.
9. The block copolymer of claim 1 , where the block copolymer is annealed to a temperature of 270 to 330° C. for 0.5 minutes to 2 hours.
10. An article formed from the block copolymer of claim 1 .
11. A method comprising:
polymerizing a vinyl aromatic monomer to form a first block, wherein the vinyl aromatic monomer has at least one alkyl substitution on an aromatic ring; and
polymerizing a second block onto the first block to form a block copolymer; where the second block is derived by polymerizing a siloxane monomer; and where the block copolymer has a chi parameter of 0.03 to 0.18 at a temperature of 200° C.; where the chi parameter is a measure of interactions between the first block and the second block of the copolymer.
12. The method of claim 11 , where the first block is anionically polymerized.
13. The method of claim 12 , where the second block is polymerized by condensation polymerization.
14. The method of claim 11 , further comprising disposing the block copolymer on a substrate.
15. The method of claim 11 , further comprising annealing the block copolymer on a substrate; where the annealing is conducted at a temperature of up to 400° C. for up to 4 hours.