Influence of Polymer Branching Architecture in Bulk Polymers

Influence of Polymer Branching Architecture in Bulk Polymers [Pg.711]

Hyperbranched polymers are compact, highly branched, three-dimensional macromolecules with a high density of end-groups [84]. Their compact structure results in inherently low viscosity, as evidenced by the value of the Mark-Houwink constant a being less than 0.5. Hyperbranched aliphatic polyesters have been applied as toughners for epoxy thermosets without a significant increase in viscosity [Pg.712]

Dendrimers are a relatively new class of highly and regularly branched polymers [Pg.712]

Dense grafting of side chains onto linear backbones, and homopolymerization of macromonomers, are both used to synthesize macromolecular brushes. Steric repulsion of the side chains forces the main chain into an extended wormlike conformation, resulting in liquid-crystalline phases, and lower dynamic shear moduli than linear flexible coils in concentrated solutions [93, 94]. Densely grafted polymeric brushes on sliding surfaces have been found to reduce friction, and therefore have potential for providing biolubrication for artificial implants [95]. [Pg.712]