Flammability and thermal behavior of polypropylene composites containing dihydrogen phosphate anion‐intercalated layered double hydroxides

Abstract

Dihydrogen phosphate anion‐intercalated layered double hydroxides (M‐LDHs) was prepared by modification of Mg‐Al‐CO32− layered double hydroxides (LDHs) with anion exchange procedure. The structure of the M‐LDHs was characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscope (TEM). Polypropylene (PP)/LDHs and PP/M‐LDHs composites were prepared by melt compounding. The morphology of PP composites was investigated by TEM and XRD, which demonstrated that M‐LDHs could be well dispersed in PP matrix to form a nano‐scale exfoliated structure. Thermogravimetric analysis showed that thermal stability of PP composites was improved by the presence of LDHs and M‐LDHs. The flammability of PP composites was characterized by limited oxygen index, vertical burning test (UL‐94), FTIR, and cone calorimeter test, and the result showed the fire performance were significantly improved after the addition of LDHs and/or M‐LDHs which can remarkably decrease the heat release rate, total heat release, and the fire performance index. It was proposed that the lamellar structure of LDHs can block the heat, dilute the flammable gases and decrease the temperature, while the replaced H2PO4− into LDHs molecules can enhance the charred layer formation during burning procedure. Inductively coupled plasma mass spectrometer analysis showed that most phosphorus remained in the char layer, suggesting the replaced H2PO4− in LDHs molecules mainly function in the condensed phase. POLYM. COMPOS., 36:2230–2237, 2015. © 2014 Society of Plastics Engineers

The flammability of expandable polystyrene foams coated with melamine modified urea formaldehyde resin

“…The fire performance index (FPI) used as a fire resistance parameter is defined as the ratio of TTI to PHRR, which can provide an estimation of both the spread rate and the size of a fire. The higher the FPI value, the smaller the risk of fire . From Table , it can be seen that the FPI increases from 0.011 m 2 s/kW of neat EPS to 0.034 m 2 s/kW of EPS/MUF sample, and further increases to 0.085 m 2 s/kW of EPS/MUF/IFR sample, demonstrating the presence of MUF and/or IFR are effective in improving the fire performance of EPS, which is consistent with LOI and UL‐94 test results.…”

New Alternative to Produce Colored Polymer Nanocomposites: Organophilic Ni/Al and Co/Al Layered Double Hydroxide as Fillers into Low-Density Polyethylene

“…Therefore, these compounds are the most suitable for application as fillers for polymer nanocomposites. [7][8][9][10][11][12][13][14][15] However, research articles about polymer nanocomposites based on polyolefin and layered double hydroxides are still relatively scarce. 16 Layered compounds are characterized by stacked layers (having thickness from one to several atoms), in which the atoms have strong bonds along the crystallographic axes a and b, and are stacked along the c-axis (basal axis).…”

Preparation and Investigation on Morphology, Thermal Stability and Crystallization Behavior of HDPE/EVA/Organo‐Modified Layered Double Hydroxide Nanocomposites

“…B, the FTIR of OLDH after MAPK treatment is changed. The stretching vibration of ‐C‐H‐ is observed at 2,919 and 2,850 cm −1 , the stretching vibration of P = O at 1,216 cm −1 , and the stretching vibration of P‐O‐C at 1,083 cm −1 . In addition, the stretching vibration at 1,355 cm −1 is significantly reduced.…”

“…The type and amount of metal ions on the LDH laminates are both variable so that materials with special nanostructures and functions can be obtained [14]. Generally, the divalent metal ions that form hydrotalcites are Mg 21 , Zn 21 , Ni 21 , Co 21 , Cu 21 , Ga 21 and the trivalent metal ions include Al 31 , Fe 31 , Cr 31 , Sc 31 . Qian et al [15] synthesized redox and red phosphorus as raw materials, and synthesized Mg/Al/Fe-LDH, Ni/Al/Fe-LDH, Cu/Al/Fe-LDH, and Zn/Al/Fe-LDH.…”