Synthesis of a Fully Biobased Polyfunctional Vinyl Oligomer and Their UV Cured Films Prepared via Thiol-ene Coupling

In this paper,a fully bio-based vinyl oligomer with high functionalities was successfully prepared from rapeseed oil by three modification steps:epoxidation of rapeseed oil,solvent-free and catalyst-free ring opening by 10-undecylenic acid followed by esterification with 10-undecenoyl chloride.Then,the renewable polymers were prepared by photo-polymerization of these modified vegetable oils with typical thiol monomers:pentaerythritol tetrakis(3-mercaptopropionate),pentaerythritol tris(3-mercaptopropionate)and 1,2-ethanedithiol.The synthesis of the vinyl oligomer was monitored by nuclear magnetic resonance and Fourier-transform infrared spectroscopy.The average number of the carbon-carbon double bonds of the resulting vinyl oligomer is high to be 7.2.The kinetic of thiol-ene photo-polymerization of vegetable oil-based vinyl oligomer was studied by FTIR-ATR analyses.In addition,the thermo-physical properties,thermal stability and solvent resistance of these UV cured films were characterized.The polymers from 1,2-ethanedithiol exhibit higher gel content,storage modulus and glass transition temperature than those from other thiol monomers due to the high crosslinking densities of the resulting polymers.All polymers show excellent thermal stability up to 290oC.The resulting polymers exhibit thermo-physical properties,excellent water resistance and thermals stability,which is promising to find application in coatings and adhesives.

Performance of different macrophytes in the decontamination of and electricity generation from swine wastewater via an integrated constructed wetland-microbial fuel cell process

Plants constitute a major element of constructed wetlands(CWs).In this study,a coupled system comprising an integrated vertical flow CW(IVCW) and a microbial fuel cell(MFC) for swine wastewater tre atment was developed to research the effects of macrophytes commonly employed in CWs,Canna indica,Acorus calamus,and Ipomoea aquatica,on decontamination and electricity production in the system.Because of the different root types and amounts of oxygen released by the roots,the rates of chemical oxygen demand(COD) and ammonium nitrogen(NH4^+-N) removal from the swine wastewater differed as well.In the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,the COD removal rates were 80.20%,88.07%,84.70%,and 82.20%,respectively,and the NH4+-N removal rates were 49.96%,75.02%,70.25%,and 68.47%,respectively.The decontamination capability of the Canna indica system was better than those of the other systems.The average output voltages were 520±42,715±20,660±27,and 752±26 mV for the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,respectively,and the maximum power densities were 0.2230,0.4136,0.3614,and0.4964 W/m^3,respectively.Ipomoea aquatica had the largest effect on bioelectricity generation promotion.In addition,electrochemically active bacteria,Geobacter and Desulfuromonas,were detected in the anodic biofilm by high-throughput sequencing analysis,and Comamonas(Proteobacteria),which is widely found in MFCs,was also detected in the anodic biofilm.These results confirmed the important role of plants in IVCW-MFCs.

Investigation on Self-healing Property of Epoxy Resins Based on Disulfide Dynamic Links

Self-healing polymers based on dynamic crosslinkers have drawn rapidly increasing interest over the last decade.Here,a self-healable epoxy network with exchangeable disulfide bonds was synthesized by polymerizing two epoxies with an aromatic amine containing a disulfide bond.The bisphenol A diglycidyl ether(DGEBA)and poly(ethylene glycol)diglycidyl ether(DER736)were used as rigid and soft components,respectively.The crosslinking densities of studied polymers decreased with the increasing amount of DER736,resulting in the lower glassy temperature and weaker mechanical strength.The dynamic covalent network character of disulfide bond and its low active energy were also investigated through stress relaxation experiments at various temperatures.The self-healing performance of healable epoxy resins with varied flexibility was measured by tensile tests.The tensile strength of a full-cut sample was restored to 84%(13 MPa)of the initial values(16 MPa)at moderate temperature.Its healed fracture strain was up to 505%.Moreover,the effect of healing time and temperature on the self-healing properties was also studied.A model was proposed to investigate the self-repairing efficiency evolution with healing time,suggesting that hydrogen bonds mainly contributed to the initial sticking or interfacial adhesion while disulfide links and chain interdiffusion assisted time dependent reformation of networks to restore the original mechanical strength.

Ni(II)-Catalyzed intermolecular selective Heck-type arylation of unactivated alkenes with arylboronic acids

The Ni(II)-catalyzed intermolecular arylation of unactivated alkenes with arylboronic acids has been disclosed for the first time.This alkene arylation exhibits excellent E/Z selectivity and regioselectivity(γ-selectivity)to provide the correspondingγ-aryl substitutedβ,γ-unsaturated carboxylic acid derivatives with E-selectivity.A Heck-type mechanism is proposed,wherein the 8-aminoquinoline auxiliary group takes the crucial role of the alkenes in the insertion/β-H elimination steps.