Flame Retardant Polyester: Reactive and Additive
topic
FR polyester types: (1) Reactive FR: phosphorus comonomer (phosphonate ester, DOPO derivative) incorporated in polymer backbone during polymerisation — permanent, not extractable, LOI raised to 28–32; (2) Additive FR: phosphorus-based masterbatch (ammonium polyphosphate, red phosphorus encapsulated) compounded into melt — potential bloom/migration; (3) FR coating: backcoating with phosphorus/nitrogen intumescent system — fabric weight penalty, durability limited to 25 washes. Halogen-free FR required for most EU applications (REACH, EN 14878).
Role
FR polyester differentiates reactive vs. additive flame retardancy strategies — a fundamental dichotomy applicable across polymer classes. Its importance for regulatory compliance and understanding the phosphorus gas/condensed phase FR mechanism makes it a core industrial chemistry topic.