In this study, for the first time cross-linking of linear aliphatic diamine-based main-chain polybenzoxazine (MCPBz) electrospun nanofibers were accomplished by two-step approach consisting of photo and thermal curing. Initially, two novel MCPBz resins which comprise of a benzophenone unit in the polymer main-chain were synthesized and uniform MCPBz nanofibers were produced by electrospinning. ...

Two optically active (100% enantiomeric excess) isomers (13a and 13b) of ofloxacin (1) [(•})ofloxacin; DL-8280; (•} )-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl1 -piperazinyl)-7-oxo-7Hpyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid] and their fluoromethyl derivatives (14a and 14b) were prepared via their optically active intermediates resolved by use of high-performance liquid chromatography...

N,N-bis(2-hydroxybenzyl)alkylamines, benzoxazine dimers, are the major product produced from benzoxazine monomers on mono-functional phenol by the one step ring opening reaction. Due to the metal responsive property of benzoxazine dimers, in this present work, N,N-bis(5-methyl-2-hydroxybenzyl)methylamine (MMD), N,N-bis (5-ethyl-2-hydroxybenzyl)methylamine (EMD), and N,N-bis(5-methoxy-2-hydroxyb...

A benzoxazine containing a vinyl group (P-4va) was prepared by the reaction of phenol, 4-vinylaniline, and paraformaldehyde. A differential scanning calorimetry (DSC) study revealed that ring-opening polymerization of the benzoxazine and chain polymerization of the vinyl group occurred in the same temperature range. When 2,2'-azobisisobutyronitrile was added as a radical initiator to P-4va, how...

We studied the mechanism of volatile-induced surface porosity formation during the resin transfer molding (RTM) of aerospace composites using a blended benzoxazine/epoxy resin, and identified reduction strategies based on material and processing parameters. The influence of viscosity and pressure on resin volatilization were determined. Then, in situ data was collected during molding using a la...

The novel bisphthalonitrile containing benzoxazine (BPNBZ) has been synthesized using bisphenol-A, 4-aminophenoxylphthalonitrile and paraformaldehyde. The structure of the monomer was supported by FTIR spectroscopy, 1H-NMR, and 13C-NMR spectra, which have exhibited that the reactive benzoxazine ring and cyano groups exist in molecular structure of BPNBZ. The cure reaction of BPNBZ was monitored...

Nonvolatile terpenoid phytoalexins occur throughout the plant kingdom, but until recently were not known constituents of chemical defense in maize (Zea mays). We describe a novel family of ubiquitous maize sesquiterpenoid phytoalexins, termed zealexins, which were discovered through characterization of Fusarium graminearum-induced responses. Zealexins accumulate to levels greater than 800 μg g⁻...

R,S-alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor up-modulators of the benzamide type ("ampakines") have previously been shown to enhance excitatory synaptic transmission in vivo and in vitro and AMPA receptor currents in excised patches. The present study analyzed the effects of an ampakine (CX614; 2H,3H, 6aH-pyrrolidino[2",1"-3',2']1,3-oxazino[6',5'-5,4]benz o[e]1, ...

Using a hydrolysis condensation of triethoxysilane to prepare a synthetic benzoxazine-bridged bis(triethoxysilane) compound (BS), a series of benzoxazine-bridged polysilsesquioxanes precursors were prepared with different degrees of hydrolysis condensation. Ring-opening thermal homopolymerization of the benzoxazine rings in these precursors was employed to obtain several organic–inorganic hybri...