Functional polyvinylethylene glycols (PVEGs) with pendent vinyl groups were synthesized by Pd/B synergistic catalysts and their structures were characterized by 1 H NMR and FT-IR. The photopolymerization of the obtained PVEGs with multifunctional thiols in the presence of a photoinitiator proceeded smoothly via thiol-ene photo-click reaction to give a series of crosslinked materials by the variation of the molecular weight of PVEGs and a ratio of thiols and enes. The curing behavior was studied by FT-IR and the properties of crosslinked materials were characterized by the test of gel content, swelling ratio, and water absorption. The dynamic mechanical analysis, mechanical properties, thermogravimetry, and surface properties of the crosslinked materials were investigated and the performance of coating for the crosslinked film materials was also characterized. The crosslinked film materials can be further functionalized by post-crosslinking modification through thiol-ene photo-click reaction. Graphical
Background Efficient lead extraction and recovery from wastewater are crucial for advancing sustainable metal recycling and reducing environmental pollution. Method Herein, a chitosan-TMA composite (CSTA) was synthesized via one-step cross-linking of chitosan with trimesic acid, exhibiting superior Pb(II) adsorption selectivity and capacity in aqueous solutions. Significant Findings The experimental results showed that the maximum adsorption capacity of CSTA for Pb(II) reached 98.59 mg/g at the optimal pH value of 6.0, which was much higher than that of unmodified chitosan (17.62 mg/g). Further investigation of the adsorption process revealed that the Pb(II) adsorption behavior on CSTA followed the pseudo-second-order kinetic model, suggesting a predominantly chemisorption-controlled process, and conformed to the Langmuir adsorption isotherm model with a theoretical maximum capacity of 104.17 mg/g at room temperature. Competitive adsorption experiments in a multi-cation solution (containing Zn 2+ , Cu 2+ , Ni 2+ , Co 2+ , Sr 2+ , Cd 2+ , and Ag + , pH 6.0) demonstrated CSTA's exceptional selectivity for lead, achieving a high adsorption capacity of 96.33 mg/g, significantly surpassing that of other metal ions. Combined experimental and characterization analyses revealed that Pb(II) removal primarily occurs via coordination with oxygen atoms from carboxylic acid groups in TMA. This work provides both an effective adsorbent for lead-contaminated wastewater treatment and mechanistic insights for designing biomass-based water purification materials.
Kai Chen,Ruowang Liu,Chao Zou,Qinyi Shao,Yunjun Lan,Xiaoqing Cai,Lanlan Zhai
Linear polyurethane (PU) ionomers were synthesized as solid–solid phase changing materials (PCMs) for thermal energy storage . Poly(ethylene glycol)s (PEGs) with 6000 and 10,000 g/mol number average molecular weight were used as latent heat storage materials, and 4,4-diphenylmethane diisocyanate (MDI), N-methyldiethanolamine (MDEA) and 1,3-Propanesulfonate (PS) were used as supporting materials. The phase change enthalpies of PU ionomers were 142.5 J/g and 152.3 J/g respectively, which were much close to the highest reported value of the branched PUPCM or the cross-linking PUPCM. The results of Fourier transform infrared spectroscopy (FT-IR) and atomic force microscopy (AFM) suggested a high degree of phase separation existed in PU ionomers . And the thermal resistance of PU ionomers was improved by the introduction of ionic groups.
Functional polyvinylethylene glycols (PVEGs) with different central structures were synthesized by Pd/B synergistic catalysts and reacted with isophorone diisocyanate (IPDI) and 2-hydroxyethyl methacrylate(HEMA) to prepared pendent vinyl-functional polyurethane acrylates (VFPUAs). The photopolymerization of the obtained VFPUAs with pentaerythritol tetra(3-mercaptopropionate) (PETMP) in the presence of a photoinitiator proceeded smoothly via thiol-ene photo-click reaction to give a series of crosslinked materials by the variation of the chemical structure of VFPUAs and a ratio of thiols and enes. The curing behavior was studied by FT-IR and the properties of crosslinked materials were characterized by the test of gel content, swelling ratio and water absorption. The dynamic mechanical properties, mechanical properties, thermogravimetry and surface properties of the crosslinked materials were investigated and the performance of coating for the crosslinked film materials was also characterized. The crosslinked film materials can be further functionalized by post-crosslinking modification through thiol-ene photo-click reaction.
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