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Co‐microencapsulation of ammonium polyphosphate and aluminum hydroxide in halogen‐free and intumescent flame retarding polypropylene
Author(s) -
Zheng Zaihang,
Sun Huimin,
Li Wenjie,
Zhong Shuangling,
Yan Juntao,
Cui Xuejun,
Wang Hongyan
Publication year - 2014
Publication title -
polymer composites
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.577
H-Index - 82
eISSN - 1548-0569
pISSN - 0272-8397
DOI - 10.1002/pc.22715
Subject(s) - ammonium polyphosphate , intumescent , materials science , limiting oxygen index , cone calorimeter , fire retardant , polypropylene , thermogravimetric analysis , pentaerythritol , charring , chemical engineering , composite material , nuclear chemistry , char , polymer chemistry , combustion , organic chemistry , chemistry , engineering
In this article, co‐microencapsulated ammonium polyphosphate (APP) and aluminum hydroxide (ATH) [M(A&A)] was prepared by using 4,4'‐diphenylmethane diisocyanate (MDI) and melamine (MEL) via in situ surface polymerization method. The chemical composition of M(A&A) was confirmed by Fourier transform‐infrared spectra (FT‐IR). Thermal behavior and surface morphology of M(A&A) were systematically analyzed by thermogravimetric analysis (TGA) and scanning electron microscope (SEM), respectively. Water solubility tests indicate that water solubility of M(A&A) decreases greatly than un‐microencapsulated ones. Besides, flame retardant properties of polypropylene (PP) compositing with M(A&A) were investigated by limiting oxygen index (LOI), vertical burning tests (UL‐94) and cone calorimeter. The results demonstrate the LOI value of PP composites is improved after combining with co‐microencapsulated flame retardants. Compared with PP/A&A, the peak heat release rate of PP/M(A&A) decreases from 210 to 120 kW/m 2 at the same flame retardant loading level. Moreover, in order to investigate the flame retardant mechanism, the char residue of PP composites after combustion was studied by optical photos, X‐ray photoelectron spectroscopy (XPS) spectra and FT‐IR. POLYM. COMPOS., 35:715–729, 2014. © 2013 Society of Plastics Engineers