Preparation and Purification of a Flame-Retardant Polyphenylphosphonate Containing 4,4'-Dihydroxybenzophenone

Abstract

A polyphenylphosphonate containing 4,4'-dihydroxybenzophenone was synthesized as a flame retardant. However, impurities were detected and may compromise its properties and thermal stability. Thus, a purification route based on water and hexane extraction with reflux was proposed. Results showed success in removing impurities, especially P–Cl groups, without damaging the polymer.