Controlled Free-Radical Polymerization of Phenol Derivatives by Enzyme-Catalyzed Reactions in Organic Solvents

The ability to control the molecular weight and dispersity of poly(p-ethylphenol) was demonstrated. The polymer was synthesized enzymatically in different organic solvents and a water-in-oil microemulsion. Using solubility parameters, the composition of the reaction medium was varied to study effects on the polymer yield, molecular weight, and dispersity. As a result, polymers with low dispersities and molecular weights from 1000 to 3000 could be synthesized in reversed micelles. In comparison, reactions in bulk solvents resulted in a narrow range of molecular weights (281-675). With dimethylformamide as eluent, the effect of LiBr on the molecular aggregation of poly(p-ethylphenol) was studied using gel permeation chromatography. The presence of LiBr (at greater than or equal to 0.35 w/v %) in dimethylformamide resulted in complete dissociation of the aggregation in solution. Poly(p-ethylphenol) was functionalized at hydroxyl positions with palmitoyl and cinnamoyl groups. Structural characterization of the polymers was carried out by super(13)C-NMR, UV, and FTIR spectroscopies.