A novel tandem catalysis system consisted of salicylaldiminato binuclear/mononuclear titanium and 2,6-bis(imino)pyridyl iron complexes was developed to catalyze ethylene in-situ copolymerization. Linear low-density polyethylene (LLDPE) with varying molecular weight and branching degree was successfully prepared with ethylene as the sole monomer feed. The polymerization conditions, including the reaction temperature, the Fi/Ti molar ratio, and the structures of bi- or mononuclear Ti complexes were found to greatly influence the catalytic performances and the properties of obtained polymers. The polymers were characterized by differential scanning calorimetry (DSC), high temperature gel permeation chromatography (GPC) and high temperature ¹³C NMR spectroscopy, and found to contain ethyl, butyl, as well as some longer branches. The binuclear titanium complexes demonstrated excellent catalytic activity (up to 8.95 × 10⁶ g/molTi·h·atm) and showed a strong positive comonomer effect when combined with the bisiminopyridyl Fe complex. The branching degree can be tuned from 2.53 to 22.89/1000C by changing the reaction conditions or using different copolymerization pre-catalysts. The melting points, crystallinity and molecular weights of the products can also be modified accordingly. The binuclear complex Ti²L₁ with methylthio sidearm showed higher capability for comonomer incorporation and produced polymers with higher branching degree and much higher molecular weight compared with the mononuclear analogue.

Agricultural byproducts have excellent potential for pollutant remediation due to their low-cost and environmental sustainability. Konjac flying powder (KFP) is a fine particulate byproduct of the production of konjac glucomannan, accounting for 30–40 wt% of the total raw materials. In this work, KFP was modified by free radical grafting copolymerization with acrylic acid, methacrylic acid and N,N′-methylene bis(acrylamide). The lightly crosslinked product demonstrated excellent adsorption performance for heavy metals, with the maximum adsorption capacity for Cd(II), Pb(II) and Cu(II) reaching 635 mg g⁻¹, 812 mg g⁻¹, and 855 mg g⁻¹, respectively, under optimized conditions. The adsorption isotherm of heavy metal ions fitted well with the Langmuir model. Moreover, the adsorption performance was nearly unchanged after several adsorption–desorption cycles, suggesting that polymeric derivation of KFP has great potential for the remediation of heavy metal pollution.