Novel styrene polymers functionalized with phosphorus–nitrogen containing molecules: Synthesis and properties

A phosphorus and nitrogen-containing compound with high phosphorus content, AC2NP2, was firstly synthesized by the Kabachnik–Fields reaction and followed by esterification with acryloyl chloride. The synthesized comonomer was then incorporated into different amounts of polystyrene via radical solution polymerization. The copolymers were well characterized using Fourier transform infrared (FTIR), UV/vis spectrophotometer, nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), microscale combustion calorimeter (MCC) and LOI. The results showed that the AC2NP2 was easily incorporated into the backbone of polystyrene, and the copolymers prepared have high transparency. The glass transition temperature (Tg) of the copolymers was decreased with increasing the AC2NP2 content, due to the introduction of much more flexible molecular chain. The TGA results revealed that the introduction of AC2NP2 units slightly decreased the initial decomposition temperatures, but significantly improved the thermal stability of copolymers at high temperature regions under both nitrogen and air atmosphere. Furthermore, all the copolymers exhibited much lower flammability as compared with virgin polystyrene.