In the present study, friction and wear behaviors of Si3N4-hBN(Hexagonal boron nitride) ceramic composites against polyether-etherketone in artificial seawater were investigated, sliding speed was varied from 0.52 to 1.73 m/s study effect. It found that coefficients rates decreased with increase for Si3N4-hBN (with hBN content ranging 5% 20%) PEEK(Polyether-ether-ketone); pairs represented an u...

Solar photochemistry was proved to be efficient for the nucleophilic substitution of alkoxy groups by amines in alkoxynitrobenzenes. The results of the sun-induced photochemical substitution were comparable to the outcome of the same reaction under irradiation by a low-pressure mercury lamp. Using 4’-nitrobenzo-15-crown-5 as a starting material we obtained a polyether amino alcohol a precursor ...

phores with ruminant growth promoting properties, we have previously reportcd the structure of antibiotic M1396032), the行rst tetronic acidcontainillg polyether. We now wish to describe antibiotic M144255, a monocarboxylic acid type ionophore from a strain of Streptomyces griseus. It has a high affinity fbr divalent cations especially zinc, for which reason it was given the trivial name, zincoph...

A new polyether antibiotic, abierixin, was found in the mycelium of a culture broth of nigericin-producing Streptomyces albus NRRL B-1865. Abierixin was extracted with organic solvents and purified by column chromatography and HPLC. The structure of abierixin was determined by FAB/MS/MS and CI/MS/MS and 1H and 13C NMR spectrometries. Abierixin exhibited weak antimicrobial and ionophorous activi...

Antibiotic DE-3936 was isolated from the fermentation broth of a streptomycete No. 9735-1, which is identified as a strain of Streptomyces hygroscopicus. The antibiotic is a hydrophobic compound having the molecular formula of of C44H75O14Na and is active against Gram-positive bacteria, mycobacteria, mycoplasma and protozoa, especially coccidia. Its chemical and biological properties indicate ...

Polyester diol PCL and PBA, polyether PTMG polycarbonate PCDL were used as components of WPU soft segment, respectively. Polyether PTMG-WPU has the worst hydrolytic property highest thermal stability. The maximum degradation rate temperature Tmax is 407.8 °C, water contact angle reaches 89.5 °. Traditional polyester PCL-WPU shows strongest hydrolysis performance, smallest angle, only 71.7 °, ab...

Blending with a hydrogen-bonding supramolecular polymer is shown to be a successful novel strategy to induce microphase-separation in the melt of a Pluronic polyether block copolymer. The supramolecular polymer is a polybutadiene derivative with urea-urethane end caps. Microphase separation is analysed using small-angle X-ray scattering and its influence on the macroscopic rheological propertie...

The choice of the anion has a surprisingly strong effect on the incorporation of CO2 into the polymer obtained during the zinc-catalysed copolymerisation of CO2 and cyclohexene oxide. The product span ranges from polyethercarbonates, where short polyether sequences alternate with carbonate linkages, to polycarbonates with a strictly alternating sequence of the repeating units. Herein, we report...