Pentaerythritol (PER) is not a standalone flame retardant. It is an essential component in intumescent systems, acting as the primary “char source” or “carbonific agent”.

Flame Retardant Mechanism PER’s role is to provide the “carbon” to build the intumescent char:

1. Char Source: PER is a polyol (it has four -OH groups). In a fire, the acid source (like APP) attacks these -OH groups, catalyzing a dehydration and esterification reaction.

2. Char Formation: This reaction cross-links the PER molecules into a stable, 3D, carbonaceous char “backbone”. This char is then expanded by the gas source (like Melamine) to create the thick, insulating foam.

Key Application Areas

• IFR Systems: A fundamental component of P-N intumescent systems. It is always used synergistically with an acid source (APP) and a gas source (Melamine).

• Applications: These IFR systems are used to make flame-retardant Polypropylene (PP) and are the basis for most intumescent fire-protective coatings.