Phosphorous-phosphorous synergistic effect on flame retardancy, mechanically reinforce and hydrolytic resistance for PC/ABS blends

The pursuit of highly efficient phosphorous flame retardants for polymer-matrix composites is of great sense in industrial and academic community. In the contribution, a phosphorous-phosphorous (P-P) synergy between structurally well-defined phosphonium sulfonates (PhS) and triphenyl phosphate (TPP) or bisphenol A bis (diphenyl phosphate) (BDP) was specifically revealed in PC/ABS alloy. Compared with TPP and BDP loadings of respective 14 wt% and 12 wt% to pass UL-94 V-0, the mere 8 wt% FRs was required via an exceptional synergy of 2% allyl-substituted PhS and 6 wt% TPP (or BDP). In parallel, the studied P-P synergy reduced heat release rate and total heat release significantly. Deep mechanism analysis by solid NMR and Py/GC-MS unveiled a concurrent optimization of condensed-phase and vapor-phase effect. Additionally, the multifunctional reinforcement of tensile property, thermal resistance and hydrolytic resistance was sysmatically investigated. In perspective, the P-P synergy between structurally tailored PhSs and phosphates exploits a pathway for highly efficiently fire-safe polymers.