	US 11,834,538 B2
	Anionic graft polymerization onto an existing polymer chain by organometallic base activation
Jason A. Mann, Houston, TX (US)
Assigned to ExxonMobil Chemical Patents Inc., Baytown, TX (US)
Filed by ExxonMobil Chemical Patents Inc., Baytown, TX (US)
Filed on Nov. 22, 2019, as Appl. No. 16/692,864.
Claims priority of provisional application 62/779,252, filed on Dec. 13, 2018.
Prior Publication US 2020/0190241 A1, Jun. 18, 2020
Int. Cl. C08F 257/02 (2006.01); C08F 255/10 (2006.01); C08F 279/00 (2006.01); C08L 71/02 (2006.01); C08F 255/06 (2006.01)

CPC C08F 257/02 (2013.01) [C08F 255/06 (2013.01); C08F 255/10 (2013.01); C08F 279/00 (2013.01); C08L 71/02 (2013.01)]

9 Claims

6. A method for forming a graft copolymer, comprising:

providing a first polymer chain comprising at least a first olefinic monomer comprising isobutylene and a second olefinic monomer bearing a benzylic carbon atom or an allylic carbon atom;

generating a carbanion upon the benzylic carbon atom or the allylic carbon atom;

combining at least one anionically polymerizable monomer with the carbanion upon the first polymer chain; and

growing a second polymer chain from the benzylic carbon atom or the allylic carbon atom of the first polymer chain via anionic polymerization,

wherein the second olefinic monomer comprises a benzylic bromide or a benzylic iodide, and generating the carbanion comprises performing a lithium-halogen exchange reaction, the lithium-halogen exchange reaction being performed by exposing the first polymer chain to an alkyl lithium compound.