Effect of two‐dimensional zeolitic imidazolate frameworks‐L on flame retardant property of thermoplastic polyurethane elastomers

Abstract

In this study, three kinds of two‐dimensional nanoplates consisting of zinc zeolite imidazole frameworks‐L (Zn‐ZIF‐L), cobalt zeolite imidazole frameworks‐L (Co‐ZIF‐L), and Zinc‐Cobalt hybrid zeolite imidazole frameworks‐L (Zn&Co‐ZIF‐L), were prepared by a green and nonpolluting method. Each of the three nanoplates was added to thermoplastic polyurethane elastomers (TPU) at 3 wt% to investigate their performance in flame retardancy and smoke suppression of TPU. Compared with pure TPU, the limiting oxygen index values of Zn‐ZIF‐L/TPU, Co‐ZIF‐L/TPU, and Zn&Co‐ZIF‐L/TPU increased from 23.2% for pure TPU to 25.3, 26.0, and 25.7%, respectively; the total heat release of these three composite materials decreased by 7.8, 11.4, and 9.3%, their peak heat release rate decreased by 28.8, 42.8, and 43.8% and their peak smoke production rate reduced by 50, 45, and 51.5%, respectively. All three nanoplates showed good flame retardancy and smoke suppression properties. In addition, through thermogravimetric/Fourier transform infrared spectroscopy (TG‐FTIR) analysis of the TPU composite and the X‐ray diffraction analysis of residual char, the specific flame‐retardant mechanisms and smoke suppression mechanisms were explored.

Ultrafast metal corrosion engineering facilitates the construction of CoSx derived from MOFs as enhanced supercapacitor electrodes

“…The stretching vibrations of the imidazole ring led to the emergence of peaks at 747, 987, 1140, 1300, and 1415 cm −1 . 59,60 Additionally, the absorption peak at 1567 cm −1 corresponded to the CN stretching bond of the imidazole ring within ZIF-L. 61 In the spectrum of CoS x @NiFe-S@NF, three new distinct absorption peaks were observed. The presence of Co–S groups in CoS x was represented by the peak at 1064 cm −1 , 62–64 while the peak at 594 cm −1 was indicative of Ni–S groups in NiFe-S. Also, the FTIR spectrum of Co ZIF-L@NiFe-LDH exhibited a distinct absorption peak at 424 cm −1 , corresponding to the Co–N bond in the Co ZIF-L structure.…”

“…The presence of Co–S groups in CoS x was represented by the peak at 1064 cm −1 , 62–64 while the peak at 594 cm −1 was indicative of Ni–S groups in NiFe-S. Also, the FTIR spectrum of Co ZIF-L@NiFe-LDH exhibited a distinct absorption peak at 424 cm −1 , corresponding to the Co–N bond in the Co ZIF-L structure. 59,60 In contrast, this absorption peak was completely absent in the spectrum of CoS x @NiFe-S@NF, indicating the rupture of the Co–N bond after sulfurization (Fig. S4†).…”

“…The stretching vibrations of the imidazole ring led to the emergence of peaks at 747, 987, 1140, 1300, and 1415 cm −1 . 59,60 Additionally, the absorption peak at 1567 cm −1 corresponded to the C]N stretching bond of the imidazole ring within ZIF-L. 61 In the spectrum of CoS x @NiFe-S@NF, three new distinct absorption peaks were observed.…”