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Catalytically synergistic effects of novel LaMnO 3 composite metal oxide in intumescent flame‐retardant polypropylene system
Author(s) -
Sheng Yan,
Chen Yinghong,
Bai Yuanzhang
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.22908
Subject(s) - intumescent , materials science , fire retardant , polypropylene , char , composite number , composite material , ammonium polyphosphate , thermal stability , chemical engineering , catalysis , polymer chemistry , organic chemistry , pyrolysis , chemistry , engineering
The newly prepared LaMnO 3 was introduced as a novel perovskite composite metal oxide catalyst for the first time to improve the flame retardancy of flame‐retarded (FR) polypropylene with intumescent flame‐retardant (IFR) system consisting of ammonium polyphosphate (APP), pentaerythritol (PER), and melamine (MA). The synergistic effects of LaMnO 3 catalyst on the performance of IFR PP composites as well as the corresponding catalytically synergistic FR mechanism were investigated. The experimental results show that the incorporated LaMnO 3 catalyst plays an excellently catalytic and synergistic part in improvement of the flame retardancy of FR PP system. Compared with FR system without LaMnO 3 , the incorporation of only 0.5 wt% LaMnO 3 into PP FR system could obviously improve the UL‐94 level from failure to V‐0 rating and decrease the micro‐scale calorimetry parameters peak heat release rate and heat release capacity. The remarkable improvement in flammability can be ascribed to the catalytic carbonization effect of LaMnO 3 on the intumescent flame retardant PP system. The incorporation of appropriate amount of LaMnO 3 , on one hand, could improve the thermal stability of FR PP material, and on the other hand, could also act as nuclei to induce formation of the continuous, compact and smooth condensed phase intumescent charred layer with radialized spherulite‐like structure. As a result, the char yield and also the quality of the formed condensed phase charred layers are correspondingly enhanced remarkably, which is beneficial to improvement of the FR properties. POLYM. COMPOS., 35:2390–2400, 2014. © 2014 Society of Plastics Engineers