Organic modified kaolinite-urea intercalation complex (KUIC) was prepared using dimethyl sulfoxide (DMSO) as the precursor of kaolinite intercalation. Its structure was characterized by Fourier transform infrared (FTIR) and X-ray diffraction (XRD). Subsequently, as a synergistic agent, KUIC was combined with flame retardant ammonium polyphosphate (APP) to improve the flame retardant and smoke suppression performance of unsaturated polyester (UP) resin. A cone calorimeter (CONE) was used to study its flame retardancy and smoke suppression, and a scanning electron microscope (SEM) and thermogravimetry (TG) were used to study the micro morphology of the char and flame retardant mechanism. The results show that 12 phr of APP and 3 phr of KUIC were doped into UP to obtain a 28.0% limiting oxygen index (LOI) value. Compared with UP, the heat release rate and smoke production of UP/APP/KUIC composites were greatly decreased. Meanwhile, KUIC indeed enhanced the mechanical properties of UP.
Imogolite nanotubes (INTs) were synthesized from tetraethoxysilane,
aluminum nitrate nonahydrate, and ammonia solution by the method of
Arancibia-Miranda, and their dispersion was modified by 1-butyl-3-methylimidazolium
hexafluorophosphate ([BMIM]PF6) to obtain ionic liquid
(IL)-functionalized INTs (INTs-PF6-ILs). Then, the flame
retardant INTs-PF6-ILs was complexed with ammonium polyphosphate
(APP) and applied to unsaturated polyester resin (UPR). The limiting
oxygen index value and the UL-94 level of the UPR/APP/INTs-PF6-ILs composites reached 28 and V-0, respectively. The residual
carbon of the composites in thermogravimetric analysis increased by
19.47%, compared with that of pure UPR. The cone calorimeter test
result showed that the peak of heat release rate and total heat rate
values of the UPR/APP/INTs-PF6-ILs composites were lowered
by 41 and 34% than those of the pure UPR, respectively. The effect
of heat combustion and the maximum mass loss rate of UPR/APP/INTs-PF6-ILs composites were also greatly decreased. There were no
holes or folds observed on the surface of the UPR/APP/INTs-PF6-ILs composites’ residual carbon in scanning electron
microscopy images. The intact residual carbon could have effectively
insulated the heat and oxygen to improve the flame retardant performance.
Ionic liquid functionalized imogolite nanotubes (INTs-PF6-ILs) were introduced into the epoxy resin (EP)/ammonium polyphosphate (APP) system to investigate the flame retardant performance and thermal properties using the limiting oxygen index (LOI) test, the UL-94 test, and the cone calorimeter test (CCT). The results suggested that a synergistic effect exists between INTs-PF6-ILs and APP on the char formation and anti-dripping behavior of EP composites. For the EP/APP, an UL-94 V-1 rating was obtained for the loading of 4 wt% APP. However, the composites containing 3.7 wt% APP and 0.3 wt% INTs-PF6-ILs could pass the UL-94 V-0 rating without dripping behavior. In addition, compared with the EP/APP composite, the fire performance index (FPI) value and fire spread index (FSI) value of EP/APP/INTs-PF6-ILs composites were remarkably reduced by 11.4% and 21.1%, respectively. Moreover, the char formed by EP/APP composites was intumescent, but of poor quality. In contrast, the char for EP/APP/INTs-PF6-ILs was strong and compact. Therefore, it can resist the erosion due to heat and gas formation and protect the inside of the matrix. This was the main reason for the good flame retardant property of EP/APP/INTs-PF6-ILs composites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.