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A high performance of catalyst material for delaying polyurethane (PU) polymerization at room temperature and rapid PU polymerization at preferred temperature still remains a great challenge because of adverse activation. Herein, N-heterocyclic carbene (NHC)-FeCl3 complex catalyst is developed and optimized to control the PU polymerization. The effects of PU polymerization degree and reaction kinetic is remarkably altered by the NHC-FeCl3 catalyst. It is found that the as-synthesized NHC-FeCl3 shows efficient catalytic activity as very low viscosity changes in room temperature and fast curing (3 h) at 60 °C, which proves considerable catalytic activity than the commercial catalyst and none-catalyst system. Based on DSC measurement, an increase in reaction rate is observed to PU polymerization with NHC-FeCl3. The PU polymerization reaction has excellently initiated at 60 °C by NHC-FeCl3 catalyst, where NHC act as Lewis acid and interacts with polyol, and FeCl3 reacts with isocyanate by electrophilic reaction.

An advanced organometallic catalyst based on N-heterocyclic carbene (NHC) coordinated FeCl3 has been synthesized and used to control the reaction rate in polyurethane (PUR) polymerization. The imidazolium (Im)-based NHC was functionalized on the surface of the supporting material of bead-type chloromethyl polystyrene (PS) resin. The PS-Im–FeCl3 catalyst was synthesized through the coordination reaction between Im and FeCl3. The successful formation, functional groups, structure, and geometry of the PS-Im–FeCl3 catalysts were confirmed by Fourier transform infrared and X-ray photoelectron spectroscopy techniques. A thin layer of Im was observed to be coated uniformly on the PS bead surface and FeCl3 nanoparticles were observed to cover the coating layer homogeneously, as determined by field-emission scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy measurements. The PUR polymerization reaction was investigated through viscosity measurements and non-isothermal activation energy calculations by differential scanning calorimetry analysis. Based on the viscosity measurements, delayed PUR polymerization was achieved using the PS-Im–FeCl3 catalyst system. The highest viscosity (6000 cP) was achieved without any catalyst, with triphenylene bismuth, and with the PS-Im–FeCl3 catalyst after 23, 5, and 25 h of reaction time, respectively. Furthermore, the calculated activation energies (Ea) were 27.92 and 36.35 kJ mol−1 for the no-catalyst and the PS-Im–FeCl3 systems, respectively. Thus, the viscosity measurements and DSC analyses confirm that the PS-Im–FeCl3 catalyst considerably increases the PUR reaction time. The Im–FeCl3 catalyst supported by CMPS can control the reaction rate in PUR synthesis because of its high activity. Thus, the PS-Im–FeCl3 catalyst can be used as a curing retardant in the PUR industry.

adix ranunculus temate saponins (RRTS), one of the main constituents extracted from the popular traditional Chinese medicine Radix Ranunculi ternati, has been reported to have various biological activities including anti-cancer effect. The aim of this study is to investigate the effect of RRTS on the cell proliferation and apoptosis in human gastric adenocarcinoma SGC-7901 cells. The data showed that exposure to RRTS for 24 h produced cytotoxic effects on SGC- 7901 cells in a dose-dependent manner (with an IC50 value of 21.22±2.76 μg/mL), which was accompanied by apoptosis induction (from 2.18±0.89% (control) to 63.72±13.16% (100 μg/mL)). Both the extrinsic or death receptor pathway and the intrinsic or mitochondrial pathway were involved in RRTS-induced apoptosis in SGC-7901 cells. Furthermore, apoptotic signaling induced by RRTS was amplified by cross-link between the two pathways via the signal-integrating protein Bid. In conclusion, our findings contribute to better understanding the molecular mechanism of RRTS’ effect on gastric cancer cells and form the basis of the therapeutic development of RRTS in treating gastric cancer in the future.