Bioinspired flame retardant polymers of Tyrosol

The enzyme catalyzed polymerization of flame retardant (FR) polymers from the renewable resource 2-(4-hydroxyphenyl) ethanol (HPE), commonly known as tyrosol, is presented. The synthesis is environmentally friendly and requires only monomer, peroxidase catalyst, dilute hydrogen peroxide, and deionized water. Phenolic polymers are produced in short, one pot, high yield reactions that require minimal purification. Fourier transform infrared spectroscopy and 1H-NMR analysis suggest the polymers are coupled through the 1, 2, 4, and 5 positions of the phenol ring and through the phenoxy substituent. Thermogravimetric analysis and pyrolysis combustion flow calorimeter show HPE homopolymers exhibit very low heat release rate and total heat release, while copolymerization with phenol increases already high char yields. Gel permeation chromatography reveals the molecular weight of the polymer increases with ethanol cosolvent concentration. The alcohol cosolvent also increases the proportion of oxyphenylene linkages to the detriment of FR properties. Preliminary quantitative structure–activity relationship toxicity modeling predicts the polymers are negative for developmental toxicity and Ames mutagenicity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45394.