Hydridosiloxanyl substituted cyclotrisiloxanes, preparation method thereof, and polymeric products derived therefrom
A new class of cyclotrisiloxanes having hydridosiloxanylalkyl substituents on one, two, or three of the ring silicon atoms and a method for their preparation are provided. These compounds undergo living anionic ring-opening polymerization to generate unique polymer structures.
1. A cyclotrisiloxane wherein one, two, or three of the ring silicon atoms has a hydridosiloxanylalkyl substituent, wherein the alkyl group has about 2 to 8 carbon atoms.
2. The cyclotrisiloxane according to claim 1 , wherein at least one of the hydridosiloxanylalkyl substituents is hydridosiloxanylethyl.
3. The cyclotrisiloxane according to claim 2 , having formula (1):
4. The cyclotrisiloxane according to claim 2 , having formula (2):
5. The cyclotrisiloxane according to claim 2 , having formula (3):
6. The cyclotrisiloxane according to claim 1 , wherein at least one of the hydridosiloxanylalkyl substituents has formula (5):
wherein R is an alkyl group having 1 to about 4 carbon atoms, n is an integer of 0 or greater, and R′ is an alkyl group having 2 to about 8 methylene units.
7. The cyclotrisiloxane according to claim 6 , wherein R is methyl, R′ is —CH 2 CH 2 — and n is 0 or 1.
8. The cyclotrisiloxane according to claim 1 , wherein the cyclotrisiloxane has two or three hydridosiloxanylalkyl substituents, and wherein the two or three hydridosiloxanylalkyl substituents may be the same or different.
9. A method of preparing a cyclotrisiloxane wherein one, two, or three of the ring silicon atoms has a hydridosiloxanylalkyl substituent, the method comprising reacting a vinyl-substituted cyclotrisiloxane with a dihydride functional siloxane.
10. The method according to claim 9 , wherein the dihydride functional siloxane is a disiloxane or a trisiloxane.
11. A polymer formed from the living anionic ring opening polymerization of a cyclotrisiloxane according to claim 1 .
12. The polymer according to claim 11 , wherein the polymer has an alpha terminus selected from the group consisting of alkyl, vinyl, hydride, fluorinated alkyl, alkoxyalkyl, and alkoxy(polyalkylenoxy)alkyl.
13. The polymer according to claim 11 , wherein the polymer has an omega terminus selected from the group consisting of methacryloxyalkyl, acrylamidoalkyl, acryloxyalkyl, methacrylaminoalkyl, hydridoalkylsiloxy, vinyl, aminoalkyl, carbinol, and chlorodialkylsiloxy.
14. A block copolymer formed from the living anionic ring opening polymerization of a cyclotrisiloxane according to claim 1 and a second cyclotrisiloxane.
15. The block copolymer according to claim 14 , wherein the second cyclotrisiloxane is hexamethylcyclotrisiloxane or tris(trifluoropropyl)methylcyclotrisiloxane.