Preparation and properties of a single molecule intumescent flame retardant

Melamine salt of pentaerythriol phosphate (MPP), as a new single molecule intumescent flame-retardant, was prepared from pentaerythritol, phosphoric acid, and melamine, and then incorporated into polypropylene (PP) with organic montmorillonite (OMT) to obtain flame retardant PP/MPP/OMT composites. The flammability and combustion behavior of flame retardant PP composites were characterized by using LOI, UL-94 test, and cone calorimeter, respectively. The results showed that the flame retardant properties of the composite containing 29.0 wt% MPP and 1.0 wt% OMT are the best among all the composites. The digital photographs after cone calorimeter test demonstrated that moderate OMT could promote to form the homogenous and compact intumescent char layer.

► MPP is a single molecule intumescent flame-retardant.
► MPP was prepared from pentaerythritol, phosphoric acid, and melamine.
► PP/MPP/OMT composites were prepared based on PP, OMT, and MPP.
► The PP/MPP/OMT composite with 1.0 wt% showed the best flame retardant properties.