Reaction Analysis of Templated Polymer Systems

Abstract

Templated polymer systems have unique 'trained' binding characteristics that make them of high interest within chromatography, sensors, diagnostic devices, and drug delivery carriers. In this work, a typical highly crosslinked recognitive polymer from the literature was synthesized (poly(methacrylic acid-co-ethylene glycol dimethacrylate) (poly(MAA-co-EGDMA)) imprinted network). Reaction analysis of this system revealed low double bond conversions ((35.0 ± 2.3) %) which indicate the feed composition with a short bi-functional crosslinker are not representative of the final polymer network. Parameters such as monomer-template ratio, crosslinking percentage, crosslinking monomer length, reaction temperature, initiator wt%, solvent wt%, and reaction mechanism were varied to determine effects upon the polymerization and template binding parameters. --Y´Living/controlled¡ polymerization techniques used to synthesize poly(MAA-co-EGDMA) imprinted networks achieved a 63% increase in template binding capacity over imprinting via standard free-radical polymerization methodologies and demonstrated a 85% increase in template affinity at equivalent double bond conversions over imprinting via standard free-radical polymerization. Weakly crosslinked poly(MAA-co-EGDMA) and poly(diethylaminoethyl-methacrylate-co-2-hydroxyethyl-methacrylate-co-polyethylene-glycol200dimethacrlyate) (poly(DEAEM-co-HEMA-co-PEG200DMA) imprinted gels synthesized via ´living/controlled¡ polymerization techniques demonstrate a significant increase in template binding capacity (90% and 89%) over imprinting via conventional free radical polymerization, respectively. Poly(DEAEM-co-HEMA-co-PEG200DMA) gels show a significant decrease in mesh size with the use of ´living/controlled¡ polymerization techniques from 30.3 ± 1.7 to 19.7 ± 2.1 . Template dynamic release studies for poly(DEAEM-co-HEMA-co-PEG200DMA) imprinted gels synthesized via --Y´living/controlled¡ polymerization techniques demonstrate a two fold extended release and a more constant (zero-order) release. Kinetic analysis reveals ´living/controlled¡ reaction mechanisms increase the chemically controlled propagation mechanism during the polymerization thus decreasing the growing chain frustrations within the network potentially providing an optimum environment for the formation of ´tailored¡ macromolecular memory binding sites. The use of ´living/controlled¡ polymerization techniques within templated mediated polymers presented in this dissertation have the potential to significantly enhance the binding parameters and the tailorability of templated polymer networks for sensors, diagnostic devices, and drug delivery carriers.