Regulating Effect of Exfoliated Clay on Intumescent Char Structure and Flame Retardancy of Polypropylene Composites

• Published in: Industrial & engineering chemistry research Vol. 55; no. 20; pp. 5892 - 5901
• Main Authors: Hu, Yapeng, Wang, Xiangmei, Li, Juan
• Format: Journal Article
• Language: English
• Published: American Chemical Society 25.05.2016
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.6b00480

An exfoliated montmorillonite (E-MMT) was prepared by introducing Ni2+ and melamine formaldehyde into layers of MMT. The E-MMT was applied to regulate the flame retardant properties of polypropylene (PP)/intumescent flame retardant (IFR) composites. The IFR used consists of ammonium polyphosphate (APP) and a charring agent, 1,3,5-triazine-2,4,6-trimorpholinyl (TTM). The results revealed that the E-MMT has good synergistic effect on flame retardancy of PP/IFR composites. The PP composites with 16 wt % IFR and 3 wt % E-MMT can pass the UL94 V-0 test. Moreover, the E-MMT not only improves the char residues of IFR and PP/IFR blend but also changes the micromorphology of char, turning the compact surface char produced by PP/IFR into microporous char. This microporous char is so good for isolating heat and mass between PP and the outside that a better flame retardant property is obtained.