National Research Council of Canada

Jacques Roovers

Michael D Guiver

Bogdan Comanita

Paul M Toporowski

Lin-Lin Zhou

Fei Wang

A silane or carbosilane dendrimer is modified with bridge moieties and polymer arms attached to the bridges to form hybrid dendrimer-star polymers. The bridge moieties are attached via Si&mdash;C bonds to the silane or dendrimer. The bridge has one or more reactive groups to which polymer arms are attached. Selected reactive groups on the bridge may serve as initiator sites for in situ polymerization of the arms. The polymer arms are of the polyether, polysulfide or polyester type. These arms may have functional groups which allow further modification and attachments. For this type of star polymer, the bridge has been found to increase resistance to hydrolysis at the silane- or dendrimer-arm junction. These star polymers are useful e.g. as viscosity modifiers, component in molding resins, water solubilizer for hydrophobic molecules, surfactants and as carriers for drugs, prodrugs and other biological agents.

Hybrid silane dendrimer-star polymers

Bromomethyl derivatives of polyaryl ether ketones are obtained by brominating methyl derivatives of the ketones preferably with elemental bromine, optionally under UV light. The bromomethyl derivatives are useful as intermediates for further functionalization of the aromatic polyether ketones. The functionalized derivatives, depending on the substituent, exhibit different properties than the basic polymer, for example increased hydrophilicity and solubility.

Functionalized polyaryletherketones

A carbosilane-based hybrid star polymer having a carbosilane core of large size and addition polymer chains emanating from the core, is described. The carbosilane core is formed from a central silane nucleus and built up by repeated alternating hydrosilylation of reactive vinylic sites followed by vinylation of silicon halide reactive sites. The core is reacted with living addition prepolymers to form the hybrid star polymer. The minimum core size to give the desired properties corresponds to that having at least about 48 reactive silicon halide sites on the periphery. These highly regular hybrid star polymers have unique solution and gelling agent properties and form highly structured and rigid gels, and also act as viscosity modifiers. The large carbosilane core having either vinyl or silicon halide reactive sites can be used as a reactive intermediate.

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Gloucester, Canada

Jacques Roovers