Regulation of Thermal Degradation and Char Evolution of Polypropylene by Core–Shell MF@β‐CD and Amino‐Modified Attapulgite

ABSTRACT In this work, a core–shell flame retardant (MF@β‐CD) was prepared by coating β‐cyclodextrin (β‐CD) with melamine‐formaldehyde (MF) resin through in situ polymerization. Amino‐functionalized attapulgite (ATP‐NH 2 ) was also prepared via silane modification. MF@β‐CD and ATP‐NH 2 were incorporated with piperazine pyrophosphate (PAPP) to fabricate flame‐retardant PP composites through melt blending. The incorporation of MF@β‐CD and ATP‐NH 2 improved the fire performance and thermal stability of PP composites. The PP composite containing the MF@β‐CD/ATP‐NH 2 system exhibited a limiting oxygen index (LOI) of 33.8% and achieved a UL‐94 V‐0 rating. Compared with neat PP, the peak heat release rate and total smoke production decreased by 91.9% and 87.7%, respectively. Thermal analysis and char characterization suggested that the MF@β‐CD/ATP‐NH 2 system promoted the formation of a more continuous and stable char layer during combustion. The MF shell contributed to improved interfacial compatibility between β‐CD and the PP matrix, while ATP‐NH 2 helped maintain the integrity of the char structure. This work provides a feasible approach for improving the fire safety and condensed‐phase stability of PP using bio‐based flame‐retardant components.