Modeling of Highly Branched Water-Soluble Polymers with Applications to Drug Delivery Model Extensions and Validation.

Reversible addition fragmentation transfer (RAFT) polymerization can be used to produce highly branched polymer approximating the structure of dendrimers, but with less regularity and much less synthetic complexity. This can be accomplished by using a RAFT agent with a polymerizable double bond. Thus, the stoichiometry is fixed, with one branch point (RAFT agent double bond) per chain. Since each of these branch points will also branch, a highly regular highly branched material is formed. If this RAFT chemistry is applied to the monomer N-isopropyl-acrylamide (NIPAAm), the resulting water-soluble polymer has unique applications in drug delivery, due to the hyperbranched nature of the polymer, and also to the lower critical solution temperature exhibited by poly(NIPAAm). In this paper, a previous mathematical model of the RAFT-pNIPAAm system is extended, and validated against experimental polymerization data. [ABSTRACT FROM AUTHOR]