Carnegie Mellon University

Dorota Greszta

Krzysztof A Matyjaszewski

Simion Coca

Scott G Gaynor

Jin-Shan Wang

Jianhui Xia

Timothy E Patten

Improved processes for atom (or group) transfer radical polymerization (ATRP) and novel polymers have been developed and are described. In certain embodiments, novel copolymers comprising a least one polymeric branch or polymeric block with a predominantly alternating monomer sequence are described. Novel copolymers comprising a least one polymeric branch or polymeric block with a gradient monomer structure are described. Additionally, novel copolymers comprising a least one polymeric branch or polymeric block with a predominantly periodic monomer sequence are also described. Novel copolymers having a water soluble backbone and at least two hydrophobic polymeric branches grafted to the water soluble backbone are also described.

Processes based on atom (or group) transfer radical polymerization and novel (co)polymers having useful structures and properties

An improved process for free radical polymerization is produced making it possible to control the growth steps of a polymerization to produce homopolymers and copolymers, including block and graft copolymers. The process uses a long half-life radical initiators and compounds which have the structure of formula I

Rate enhancement of nitroxyl radical-mediated polymerization

An improved process for free radical polymerization is produced making it possible to control the growth steps of a polymerization to produce homopolymers and copolymers, including block and graft copolymers. The process uses a long half-life radical initiators and compounds which have the structure of formula I ##STR1## wherein X is a group having at least one carbon atom and is such that the free radical X is capable of polymerizing the unsaturated monomer by free radical polymerization, and the radical functionality resides on the or one of the carbon atoms, R.sup.1, R.sup.2, R.sup.5 and R.sup.6 represent the same or different straight chain or branched substituted or unsubstituted alkyl groups of a chain length sufficient to provide steric hindrance and weakening of the O--X bond, and R.sup.3 and R.sup.4 represent the same or different, straight chain or branched, substituted alkyl groups or R.sup.3 CNCR.sup.4 may be part of a cyclic structure which may have fused with it another saturated or aromatic ring, the cyclic structure or aromatic ring being optionally substituted.

Method for preparation of alkoxyamines from nitroxyl radicals

Improved processes have been developed for atom (or group) transfer radical polymerization (ATRP). In one improvement, the ATRP process involves polymerizing in the presence of a (partially) free radical-deactivating amount of the corresponding reduced or oxidized transition metal compound. In a further improvement, the ATRP process involves polymerizing in a homogeneous system or in the presence of a solubilized initiating/catalytic system. The present invention also concerns end-functional, site-specific functional and telechelic homopolymers and copolymers; block, random, graft, alternating and tapered (or 'gradient') copolymers which may have certain properties or a certain novel structure; star, comb and 'hyperbranched' polymers and copolymers; multi-functional hyperbranched, end-functional polymers; cross-linked polymers and gels; water-soluble polymers and hydrogels (e.g., a copolymer prepared by radical copolymerization of a water-soluble monomer and a divinyl monomer); and an ATRP process using water as a medium.

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Pittsburgh, PA, United States of America

Dorota Greszta