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Title:
BLOCK COPOLYMERS
Document Type and Number:
WIPO Patent Application WO2004069888
Kind Code:
A3
Abstract:
Block copolymers comprise a core block formed of hydrophilic monomers and have pendant zwitterionic groups, and at least two terminal blocks, comprising stimulus-responsive groups. The core block has a degree of polymerisation of at least 100, whilst the terminal blocks have an average degree of polymerisation of at least 20. A solution of polymer in a liquid may be caused to change its characteristics, for instance rheology, upon being subjected to a stimulus such as a change in temperature or pH. Examples comprise core blocks formed of 2-methacryloyloxyethyl-2'-trimethylammonium ethylphosphate inner salt (MPC) and terminal blocks formed of 2-(diisopropylamino)ethyl methacrylate. Upon changing the pH from around 2 to around 8, an aqueous solution of the block copolymer gels, the solution becoming mobile again upon lowering the pH. The effect is due to deprotonation of a quaternary ammonium pendant ion to form a non-ionised group and subsequent protonation to form an ionised group. This changes the hydrophilicity of the terminal blocks and allowing formation of a network of micellar structures when the pendant groups are not ionised and relatively hydrophobic and associated in micelles.

Inventors:
LEWIS ANDREW LENNARD (GB)
ARMES STEVEN PETER (GB)
MA YINGHUA (GB)
Application Number:
PCT/GB2004/000449
Publication Date:
March 24, 2005
Filing Date:
February 05, 2004
Export Citation:
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Assignee:
BIOCOMPATIBLES UK LTD (GB)
LEWIS ANDREW LENNARD (GB)
ARMES STEVEN PETER (GB)
MA YINGHUA (GB)
International Classes:
A61K9/107; C08F293/00; C08L53/00; (IPC1-7): C08F293/00; C08L53/00
Domestic Patent References:
WO2002028929A12002-04-11
WO2003074026A12003-09-12
WO2003074090A22003-09-12
WO2000071660A12000-11-30
WO2001027209A12001-04-19
WO2001009208A12001-02-08
WO2001001957A12001-01-11
Foreign References:
US6395800B12002-05-28
US5441841A1995-08-15
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