Controlled polymer synthesis in homogeneous and heterogeneous processes

Abstract

Research in polymer synthesis can be oriented toward method or structure. This review is intended to document both approaches. Recent examples from our own work as well as future prospectives will be presented. A general concern is to work out the impact from organic and supramolecular chemistry. Examples of method oriented work are (i) a unique polycondensation via carbon sulfur-bond formation providing hybrid structures of, e.g., polyphenylenesulfide and polyaniline; (ii) a triazoline additive establishing a novel self-regulation process in controlled radical polymerization; (iii) a metallocene catalyzed polyolefin synthesis which is performed by using “smart”, reversibly cross-linked polymer resins as support; and (iv) hydrogen-bonded aggregates suggesting new emulsifiers for emulsion polymerization thus leading to functional nanoparticles. Examples of structure oriented work are (i) rod-coil block copolymers (1D case) as a “covalently bound combination” of rigid and flexible segments whereby a key synthetic concern is the chemical modification and quantitative end-functionalization of polyphenylene chains; (ii) discs (2D case) as molecularly defined graphite subunits which are obtained via a remarkably mild intramolecular cyclodehydrogenation; and (iii) dendrimers (3D case) as shape-persistent nanoparticles whose high degree of structural precision results from a new cycloaddition-deprotection protocol.