Abstract In this paper, four novel kinds of triazine-trione based tri-imidazole derivatives (IM-TT, 2MI-TT, 2EI-TT and EMI-TT) were synthesized through the addition reaction between triglycidyl isocyanurate (TGIC) and imidazole (IM), 2-methylimidazole (2MI), 2-ethylimidazole (2EI) and 2-ethyl-4-methylimidazole (EMI), respectively. The triazine-trione based tri-imidazole derivatives were blended with epoxy resin and the reactivity, thermal latency and thermal property were investigated. The results on curing behaviors indicated that the curing exothermic peaks of the blends with triazine-trione based tri-imidazole derivatives shifted to higher temperatures compared with those with commercial imidazoles. The curing exothermic peak temperatures (T p s) of the synthesized tri-imidazole derivatives were increased by 23–32 ℃ compared with the unmodified imidazoles. In addition, Rheological behavior results indicated that the EP blends with tri-imidazole derivatives also exhibited excellent storage stability which was as long as 38 days under room temperature. Last but not the least, the EP blends with triazine-trione based tri-imidazole derivatives also exhibited high glass transition temperatures due to introducing of triazine-trione structures with high crosslinking density. The glass transition temperatures (T g s) of the prepared thermosets ranged from 128 to 152 ℃. The triazine-trione based tri-imidazole derivatives provide a way to prepare latency epoxy resin with high high glass transition temperature and long storage stability.
Article Highlights
Four novel kinds of triazine-trione based tri-imidazole derivatives were synthesized.
The EP cured with the tri-imidazole derivatives displayed great thermostability.
The EP cured with the tri-imidazole derivatives exhibited long storage stability.
In order to enhance the properties of polymer anion-exchange membranes (AEMs), a class of side-chain-type poly (arylene ether sulfone)s containing tri-imidazole cations in pendant phenoxyphenyl spacer (i.e., Im-PES-xx) were designed and prepared by polymer grafting reaction. Based on these imidazole functionalized polymers, a series of new AEMs were successfully prepared by their solution coating and ion exchange. The obtained membranes exhibited good alkaline stability with the retention of ion-exchange capacity in the range of 78.5%–83.3% after immersion in 4 M NaOH solution at 80 °C for 336 h. The membranes also had high hydroxide conductivity with the values of 34.1–70.5 mS cm −1 at 80 °C. Meanwhile, these membranes possessed good dimensional stability, and their swelling ratio was in the range of 2.5%–7.0% at 80 °C. The incorporation of the dense and local imidazole cations in the side chains for AEMs plays an important role for their properties.
Jiaqing Huang,Xiaoyong Xia,Jiajia Li,Liang Liu,Chunyue Xu,Jinkai Qiu,Cheng Lian,Qingfeng Xu,Jianmei Lu
The extraction of TcO 4 - from nuclear wastewater via adsorption-based methods is recognized as a highly promising strategy but confronted with significant challenges due to the harsh conditions often encountered, such as highly acidic or alkaline environments, elevated ionic strengths, and intense radiation fields. In this work, we have designed and synthesized a triazine-tri-imidazole based cationic covalent organic polymer, CTFT, with covalent triazine frameworks (CTF) as the structural building blocks and tri-imidazole-based (TIB) units as the connecting motifs. This highly conjugated polymer successfully overcomes the aforementioned challenges and exhibits remarkable ReO 4 - (a non-radioactive substitute to TcO 4 - ) uptake capabilities across five critical performance metrics simultaneously: ultrafast adsorption kinetics (equilibrium reached within 0.5 min), exceptional resistance to strong acids and bases (4 M HNO 3 and 4 M NaOH), high selectivity towards ReO 4 - (80.5 %, 5000 × over SO 4 2- ), superior radiation resistance (400 kGy γ-rays), and outstanding recyclability (20 cycles, 95.6 % retention). Additionally, CTFT achieves a high ReO 4 - removal efficiency in simulated Hanford waste (85.3 %, 10 g/L). Experimental and theoretical calculation results demonstrate that strong electrostatic interactions and affinity exist between imidazolium cation and ReO 4 - . This finding provides a potential design strategy for developing polymers with high durability in the field of nuclear environmental remediation.
危险品化学品经营许可证（带存储）