Preparation and Properties of Autocatalytic Biobased Waterborne Polyol from Rosin Based Epoxy Resin

Due to the complex heterogeneous film forming process of two-component waterborne polyurethane (2K-WPU), the crosslinking reaction rate of 2K-WPU cannot meet the demand of efficient application in coatings. In order to improve the crosslinking reaction rate of 2K-WPU, a waterborne polyol containing tertiary amine groups was synthesized from rosin based epoxy resin and secondary amine compound, and then autocatalytic 2K-WPU was prepared by crosslinking the rosin based waterborne amino polyol with polyisocyanate. The structure of the polyol from rosin based epoxy resin was characterized with Fourier infrared (FT-IR) and nuclear magnetic resonance (NMR). The crosslinking kinetics and the crosslinked product of the rosin based waterborne amino polyol were also compared with a commercial acrylic polyol. It was shown from the results that the crosslinking reaction rate of the rosin based waterborne amino polyol was faster than that of the commercial acrylic polyol, which indicated the tertiary amine groups chemically bonded in the rosin based polyols could autocatalyze the crosslinking reaction of 2K-WPUs with catalysts free. The film of the rosin based waterborne amino polyol had excellent impact strength, adhesion, flexibility, hardness, gloss, fullness and solvent resistance, showing a good application prospect in the field of waterborne coatings.

Cationic ring-opening polymerization of a five membered cyclic dithiocarbonate having a tertiary amine moiety

A dibenzylamine derived cyclic dithiocarbonate (1) undergoes ring-opening polymerization due to the greater reactivity of exocyclic sulfur compared to the tertiary amine with methyl triflate.

Asymmetric Synthesis of 2,3-Dihydrofurans via Squaramide Catalyzed Michael-Alkylation Reaction

Asymmetric Catalysis, Dihydrofuran, Michael-Alkylation Reaction, Tertiary Amine-Squaramide, Organocatalysis, α-Bromonitroalkene

Cobalt-Tertiary-Amine-Mediated Peroxy-Trifluoromethylation and Halodifluoromethylation of Alkenes with CF2XBr (X = F, Cl, Br) and tert-Butylhydroperoxide

An efficient cobalt-tertiary-amine-mediated peroxy-trifluoromethylation and halodifluoromethylation of alkenes with simple and inexpensive CF2XBr (X = F, Cl, Br) has been described. This method demonstrated broad substrate scope and good to high yields with the tolerance of mono-, di-, and trisubstituted alkenes with both electron-donating and electron-withdrawing groups. The protocol provides an efficient access to various β-peroxyl trifluoromethyl/halodifluoromethyl derivatives. Further transformation of these type of compounds to other useful molecules, such as ketene aminal, α-trifluoromethyl ketone, and gem-difluoroalkene demonstrated the utility of this methodology.

Aliphatic Quaternary Ammonium Functionalized Nanogels for Gene Delivery

Gene therapy is a promising treatment for hereditary diseases, as well as acquired genetic diseases, including cancer. Facing the complicated physiological and pathological environment in vivo, developing efficient non-viral gene vectors is needed for their clinical application. Here, poly(N-isopropylacrylamide) (p(NIPAM)) nanogels are presented with either protonatable tertiary amine groups or permanently charged quaternized ammonium groups to achieve DNA complexation ability. In addition, a quaternary ammonium-functionalized nanogel was further provided with an aliphatic moiety using 1-bromododecane to add a membrane-interacting structure to ultimately facilitate intracellular release of the genetic material. The ability of the tertiary amine-, quaternized ammonium-, and aliphatic quaternized ammonium-functionalized p(NIPAM) nanogels (i.e., NGs, NGs-MI, and NGs-BDD, respectively) to mediate gene transfection was evaluated by fluorescence microscopy and flow cytometry. It is observed that NGs-BDD/pDNA complexes exhibit efficient gene loading, gene protection ability, and intracellular uptake similar to that of NGs-MI/pDNA complexes. However, only the NGs-BDD/pDNA complexes show a notable gene transfer efficiency, which can be ascribed to their ability to mediate DNA escape from endosomes. We conclude that NGs-BDD displays a cationic lipid-like behavior that facilitates endosomal escape by perturbing the endosomal/lysosomal membrane. These findings demonstrate that the presence of aliphatic chains within the nanogel is instrumental in accomplishing gene delivery, which provides a rationale for the further development of nanogel-based gene delivery systems.