Process for the preparation of hydrophobic/hydrophile AB block copolymers
AssigneeForschungszentrum Julich GmbH
InventorsJürgen Allgaier, Lutz Willner, Dieter Richter
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Abstract
The invention relates to a process for the preparation of hydrophobic-hydrophilic AB block copolymers wherein block A consists of the monomer unit a, which is conjugated diene, and block B consists of the monomer unit b, which is epoxide, and the invention also relates to the AB block copolymer synthesized by the preparation process, as well as to micellar systems made from the AB block copolymer. According to the invention, the AB block copolymer is synthesized in two steps, whereby the first step is the preparation of block A in a nonpolar solvent and the second step is the preparation of block B in a polar solvent.
Claims24
Process for the preparation of hydrophobic-hydrophilic AB-block copolymer by anionic polymerization, wherein:
- monomer units a of block A comprise a conjugated diene and monomer units b of block B comprise an epoxide, wherein block A is formed in a first reaction step in a non-polar solvent, and block B is formed in a second reaction step in a polar solvent, and, to conclude the first reaction step,
- 1. the epoxide and
- 2. a proton-donator
- are introduced and the polymerization of block B proceeds with the aid of an alkali metal initiator other than a lithium initiator
- and wherein the copolymer produced does not exhibit any branching caused by side chains.
Process for the preparation of a hydrophobic-hydrophilic AB-block copolymer, comprising:
- anionically polymerizing monomer units a′, wherein units a′ comprise conjugated diene, in a first reaction step in a non-polar solvent which dissolves the conjugated diene, to obtain block A with still-active chain ends;
- in a subsequent reaction step, grafting onto the still-active chain ends of block A a monomer unit b′, said unit b′ being an epoxide, and treating said block A with a proton donor to obtain a functionalized polymer A having at least one OH group;
- separating the resulting functionalized polymer A from said non-polar solvent, and dissolving the functionalized polymer A in a polar solvent which also dissolves an alkali metal organyl;
- and
- adding an alkali metal organyl, alkali metal hydride, or elemental alkali metal to said polar solvent, to initiate the formation of block B and the grafting of block B onto block A to obtain the hydrophobic-hydrophilic AB-block copolymer.
Process for the preparation of a hydrophobic-hydrophilic block copolymer having a block A that is soluble in non-polar solvent and a block B that is soluble in polar solvent, comprising:
- block A is produced in a first reaction step in a non-polar solvent,
- separating the resulting functionalized polymer A from said non-polar solvent and dissolving the functionalized polymer A in a polar solvent and
- block B is produced in a second reaction step in said polar solvent.
Process for the preparation of a hydrophobic-hydrophilic block copolymer having a block A that is soluble in non-polar solvent and a block B that is soluble in polar solvent, comprising:
- block A is produced in a first reaction step in a non-polar solvent, and block B is produced in a second reaction step in a polar solvent and wherein the copolymer produced does not exhibit any branching caused by side chains.
Dependencies are inferred from the claim text.