Boronated (co)polystyrene: monomer reactivity ratios, thermal behavior and flammability

Chemical modification based on incorporation of flame retardants (FR) into the polymer backbone was used in order to reduce polystyrene flammability. Boronated styrenes such as 4-vinylphenylboronic acid (StB(OH)(2)) and 6-methyl-2-(4-vinylphenyl)-1,3,6,2-dioxazaborocane-4,8-dione (StBcyclo) were applied as reactive FR. Homo- and copolymers of boronated styrenes and styrene (St) were synthesized with different feed ratios using free radical polymerization. It yielded in series of (co)polymers with various amounts of StB(OH)(2) and StBcyclo (5-20% mol/mol of St). Copolymer compositions were determined by H-1 NMR. The relative reactivity ratios of system St-StBcyclo were determined by applying the Jaacks method. Glass transition temperature and thermal stability of obtained (co)polymers were determined from DSC and TGA analysis, respectively. The pyrolysis combustion flow calorimeter was applied as a tool for assessing the flammability of the synthesized (co)polymers. Copyright (c) 2014 John Wiley & Sons, Ltd.