Department Lecture Series
Thursday January 31, 9:45 am, Smith 331

Synthesis of Hyperbranched Polyacrylates by an Inimer Approach

All of the "hyperbranched poly(meth)acrylates" synthesized to date by self-condensing vinyl polymerization (SCVP) of an inimer (initiator-monomer) incorporate the alkyl ester into the polymer backbone upon branching, and leave an alkyl ester side chain functionalized with an initiator fragment at incomplete branching. These polymers are therefore not analogs of any specific linear poly(meth)acrylate, whose properties could be compared to determine architectural effects. We will present a route to synthesize inimers that polymerize by atom transfer radical polymerization to produce polymers with an ester group attached to every other carbon along the polymer backbone, with a non-functionalized alkyl ester attached as a free side chain. The ester group can be aliphatic or non-aliphatic, linear or branched, mesogenic or non-mesogenic, chiral or achiral, and hydrocarbon or non-hydrocarbon. The resulting hyperbranched poly(meth)acrylates are so similar chemically to the corresponding linear poly(meth)acrylates that it is challenging to quantify the degree of branching spectroscopically. Nevertheless, a number of various solution, solid-state, and melt properties support a hyperbranched architecture.