Preparation and characterization of cyclodextrin microencapsulated ammonium polyphosphate and its application in flame retardant polypropylene

Abstract A novel microencapsulated ammonium polyphosphate (MAPP) with shell of crosslinked β‐cyclodextrin (HDI‐CD) was prepared. The HDI‐CD shell had a fibrous structure and covered with good completeness on the APP core, and a solid chemical bonding was found between the APP core and HDI‐CD shell. The microcapsules were more hydrophobic than the pristine APP. When compounded within polypropylene (PP), the MAPP exhibited good compatibility and dispersibility. The combustion testing results showed that the novel all‐in‐one intumescent flame retardant had efficient flame retardancy for PP materials.