POLYALKYLENE OXIDE-RUBBER BLOCK COPOLYMERS AND METHODS FOR MAKING THE SAME
In one aspect, the disclosure relates to a block copolymer comprising a first block derived from an alkene and a second block derived from an epoxide. In another aspect, the block copolymer has the structure wherein X is selected from: or any combination thereof; wherein R 1 is selected from H or a C1-C4 aliphatic hydrocarbon chain, wherein R 2 and R 3 are individually selected from H or methyl; wherein n is from about 1800 to about 20,000; and wherein m is from 4 to 2300. Also disclosed herein are rubber compositions including the disclosed block copolymers, tires including the rubber compositions, and methods of making the block copolymers.
1 . A block copolymer comprising a first block derived from an alkene and a second block derived from an epoxide.
2 . The block copolymer of claim 1 , wherein the alkene comprises styrene, butadiene, isoprene, or any combination thereof.
3 . The block copolymer of claim 1 , wherein the second block comprises polypropylene oxide units or polybutylene oxide units.
4 . The block copolymer of claim 1 , wherein the block copolymer has the structure:
wherein X is selected from:
or any combination thereof;
wherein R 1 is selected from H or a C1-C4 aliphatic hydrocarbon chain,
wherein R 2 and R 3 are individually selected from H or methyl;
wherein n is from about 1800 to about 20,000; and
wherein m is from 4 to 2300.
5 . A rubber composition comprising the block copolymer of claim 1 and at least one filler.
6 . A tire comprising the rubber composition of claim 5 .
7 . A method for making a block copolymer comprising a first block derived from an alkene and a second block derived from an epoxide, the method comprising:
(a) polymerizing an alkene to produce a polymerized alkene; and
(b) polymerizing an epoxide in the presence of the polymerized alkene to produce the block copolymer.
8 . The method of claim 7 , wherein polymerizing the alkene in step (a) comprises mixing the alkene with an initiator and a multidentate ligand in a first solvent.
9 . The method of claim 8 , wherein the initiator comprises n-butyllithium, s-butyllithium, t-butyllithium, or any combination thereof.
10 . The method of any one of claim 8 , wherein the multidentate ligand comprises tetramethylethylenediamine (TMEDA), ditetrahydrofurylpropane (DTP), or any combination thereof.
11 . The method of claim 7 , wherein the alkene comprises butadiene, isoprene, styrene, or any combination thereof.
12 . The method of claim 7 , further comprising adding an organoaluminum compound during step (b).
13 . The method of claim 12 , wherein the organoaluminum compound comprises triisobutylaluminum.
14 . The method of claim 7 , wherein the block copolymer is precipitated from a third solvent, pan dried, drum dried, or stripped to recover the block copolymer.
15 . The block copolymer of claim 1 , wherein the first block comprises polybutadiene, polyisoprene, or styrene butadiene rubber.
16 . The block copolymer of claim 1 , wherein the block copolymer has a glass transition temperature (T g ) of from about −90° C. to about −5° C.
17 . The block copolymer of claim 1 , wherein the first block has a molecular weight of from about 2 kDa to about 1,000,000 kDa.
18 . The block copolymer of claim 1 , wherein the block copolymer comprises from about 0.5 wt % to about 10 wt % of the second block.
19 . The block copolymer of claim 1 , wherein the second block has a molecular weight of from about 0.2 kDa to about 2 kDa.
20 . The rubber composition of claim 5 , wherein the at least one filler comprises silica, carbon black, or any combination thereof.