Water Soluble Polyurethane “Star Polymers”

Title: MULTI-ARM HYDROPHILIC URETHANE POLYMERS, METHODS OF MAKING THEM, AND COMPOSITIONS AND PROCESSES EMPLOYING THEM

 Number/Link: US2014/038874

Applicant/Assignee: Stepan

Publication date: 6-02-2014

Gist”: PU star polymers, useful as surfactants, are prepared from a polyhydroxy ‘core’ molecule, a diisocyanate and a surplus of PEG.

Why it is interesting: A low MW ‘core’ molecule with an OH functionality of up to 6 is reacted with a surplus of diisocyanate to form an NCO ended prepolymer. The prepolymer is then reacted with a suplus of a polyethylene glycol (PEG).  Reactants and ratios are chosen such that the average MW of the resulting product is less than about 10,000 and is water soluble or at least water dispersible. In an example trimethylolpropane is reacted with dicyclohexylmethane di-isocyanate (H12MDI) and ‘capped’ with PEG 400,  resulting in a mixture of structures, one of which is shown below.  The star polymers are supposedly useful as surfactants for use in detergents etc..
While these are interesting molecules, I doubt that these stuctures can be controlled finely enough to compete with established surfactants. I might be more interesting to use methoxy PEGs (i.e. monols) instead of PEGs.

Example of a PU star polymer.

Example of a PU star polymer.

Rigid Polyurethane Foam from Modified Polymer Polyols

Title: METHOD FOR PRODUCING RIGID POLYURETHANE FOAMS

 Number/Link: WO2013/024101  (German)

Applicant/Assignee: BASF

Publication date: 21-02-2013

Gist”: Polymer polyols comprising surface-active and reactive SAN particles for improved rigid foams.

Why it is interesting: In this invention polymer polyols are prepared by in-situ co-polymerisation of styrene, acrylonitrile (preferred) and a polyether siloxane surfactant comprising at least one  unsaturated group and at least one hydroxyl group. This will result in a polymer polyol (or “graft polyol”) comprising surface-modified particles, which, when used to prepare rigid foams, will end up predominantly (>50%) in the cell walls rather than in the cell struts. This is new and surprising. The rigid foams should show improved insulation properties and compressive strength.

surface active monomer used in the invention

surface active monomer used in the invention

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