Sulfur's role in the flame retardancy of thio-ether–linked hyperbranched polyphosphoesters in epoxy resins

摘要: Abstract Hyperbranched polyphosphoesters are promising multifunctional flame retardants for epoxy resins. These polymers were prepared via thiol-ene polyaddition reactions. While key chemical transformations and modes of actions elucidated, the role sulfur in composition remains an open question. In this study, FR-performance a series phosphorus-based retardant additives with without (thio-ethers or sulfones) their structure compared. The successful synthesis thio-ether sulfone-containing variants is described verified by 1H 31P NMR, also FTIR MALDI-TOF. A decomposition process proposed from pyrolytic evolved gas analysis (TG-FTIR, Py-GC/MS), retardancy effect on resins investigated under conditions fire testing cone calorimeter. presence increased thermal stability introduced added condensed phase action. Likely, radical generation plays flame-retardant mode action, sulfones released incombustible SO2. results highlight multifunctionality hyperbranched polymer, which displays better performance than its low molar mass analogue due to vinyl groups higher monomer groups.