Polycarbonate block copolymers and methods thereof
AssigneeSaudi Aramco Technologies Company
InventorsScott D. Allen, Dibyendu Debnath
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Abstract
The present disclosure relates to block copolymers comprising, and methods of making thereof, a polycarbonate chain linked to a hydrophilic polymer. Such block copolymers may have the formula B-A-B, where A is a polycarbonate or polyethercarbonate chain and B is a polyether. Provided methods are useful in reducing the amount of waste generated from the synthesis of polycarbonates and provide improved thermal stability and high primary hydroxyl content. Provided block copolymers also have utility as additives in enhanced oil recovery methods, and foam polymer applications.
Claims15
A method of making a block copolymer composition of the formula B-A-B, comprising the steps of:
- i) copolymerizing epoxide and carbon dioxide in the presence of a chain transfer agent and a first catalyst to provide a first polymer A;
- and
- ii) homopolymerizing epoxide on the chain ends of the first polymer A by addition of a second catalyst to provide a second polymer, B-A-B,
- wherein the first catalyst is a metal salen complex.
Dependencies are inferred from the claim text.