Micellar core-shell-type acrylic-polyurethane hybrid materials with self-polishing property

Abstract

Marine fouling can be a serious problem in the shipping industry, since it increases the surface roughness of the hull and hence its frictional resistance to its movement through water. Antifouling paint can be defined as preventing the attachment of marine organisms onto surfaces. However, the most commonly used antifouling coating which is the tributyltin-based self-polishing copolymer causes the severe pollution of marine environment. Ammonium salt-based paints include tertiary amines as biocides which have effective biocidal and biodegradable properties without accumulation in the sea environment. However, ammonium salt-based coatings were too sensitive to seawater and became swollen. In this study, polyurethane-acrylic copolymers were synthesized by radical polymerization. These hybrid materials were found to form core–shell structures in aqueous media. Synthesis and properties of copolymers were investigated by Fourier transform-infrared spectrometer, proton-nuclear magnetic resonance, transmission electron microscopy, and dynamic light scattering. The polishing rate of self-polishing copolymer was determined from the reduction in dry film thickness after artificial seawater immersion under a dynamic condition.     

Anwendung nuklearer Verfahren in der ungarischen Tonerdeindustrie

Der Beitrag gibt einen zusammenfassenden Überblick über die in der ungarischen Tonerdeindustric verwendeten nuklearen Versuchsmethoden.

Anhand von Beispielen werden die an Betriebsapparaturen durchgeführten Durchlauf- und Verteiungsmessungen sowie die unter Laborbedingungen vorgenommenen reaktionskinetischen Untersuchungen, die auf die Klärung verschiedener Prozesse der Tonerdeherstellung gerichlet waren, veranschaulicht.

Weiterhin werden analytische Anwendungen der Neutronenaktivierungs- und Röntgenfluoreszenzmethode sowie Meß- und Regelungseinrichtungen, die auf der Strahlenabsorption beruhen, bekanntgemacht.     

“Titration” polymerization of monovinylacetylene

A polymer consisting of a saturated carbon backbone with pendent acetylenic groups was prepared from monovinylacetylene. A titration was performed between the monomer and tertiary butyllithium, its lithiating agent. The charge transfer complex formed between the solvent THF and the tertiary butyllithium was used as an indicator of the unreacted butyllithium. Hence, a stoichiometric quantity of tertiary butyllithium was added dropwise to a solution of monovinylacetylene in THF to form lithiovinylacetylene. The addition of a slight excess of butyllithium led to the polymerization of the lithiated monomer. The obtained polymer was reprotonated and characterized. This polymerization was evaluated as a possible route to synthesize poly(vinylacetylene) with processable molecular weights, for its application as a potential carbon fiber precursor. © 1996 John Wiley & Sons, Inc.     

SYNTHESIS OF MONOSUBSTITUTED PENTAKIS(2,6-DIETHYLPHENYLISO CYANIDE)- COBALT(I) COMPLEXES WITH BIDENTATE TERTIARY PHOSPHINE LIGANDS. I. MONOMETALLIC COMPLEXES

Abstract

Reaction of [Co(CNC₆H₃Et₂-2,6)5]BF₄ with bidentate phosphines leads to monosubstituted Co(I) complexes, [Co(CNC₆H₃Et₂-2,6)₄(L-L)]BF4, where L-L = Ph₂P(CH₂)n PPh₂, n = 1-4,6; Ph₂PCH₂-CH₂AsPh₂, Ph₂PC₆H₄PPh₂-p, Ph₂PCH[dbnd]CHPPh₂-trans. Reaction conditions are such that disubstitution would be possible, but bidentate bridging to form bimetallic complexes is not favoured. Comparison of v([sbnd]N°C) IR, electronic spectra, and molar conductivities with values for [Co(CNC₆H₃Et₂-2,6)4L]X, where X = ClO₄, BF₄; L = monodentate triarylphosphine; indicates that these new complexes must also be five-coordinate Co(I) complexes, in which the potentially bidentate phosphine ligands are coordinated through only one P atom. Structures are approximately trigonal bipyramidal in solution and the solid state, with the phosphine ligand occupying an axial position.     

浊点萃取技术的应用

浊点萃取是近年发展起来的一种新兴的萃取技术。重点阐述了浊点萃取在环境样品、生物样品和食品工业分析中的应用,总结了浊点萃取技术的优点,指出了存在的问题,探讨了该技术的发展前景。     

Highly sensitive determination of haloperidol in human serum by capillary gas chromatography using a surface ionization detector

A method has been developed for highly sensitive determination of haloperidol in human serum involving a simple extraction procedure followed by gas chromatographic separation. Target components were separated from the extracting solvents with a Van den Berg type solventless sample injector before introduction Into a DB-1 capillary separation column. A surface ionization detector (SID), which has highly selective sensitivity for Substituted amines, was employed for quantitation using bromperidol as an internal standard. Chloroform proved to be the best extracting solvent, yielding a quantitative detection limit of 5 ng/ml (S/N = 2). Comparison of the response to target compounds obtained by the SID, FTD (flame thermionic detector), and FID (flame ionization detector) showed the SID to be superior.     

One-pot synthesis of 4-substituted 4-alkoxy-1,4-dihydro-3,1-benzoxazine-2-thiones by the reaction of 2-isothiocyanatobenzoates with organolithiums

An efficient one-pot procedure for the preparation of 4-substituted 4-alkoxy-1,4-dihydro-3,1-benzoxazine-2-thiones from 2-isothiocyanatobenzoates has been developed. Thus, 2-isothiocyanatobenzoates were reacted with organolithiums including lithium enolates of acetates and tertiary acetamides in THF at −78 °C to give the desired products in generally good yields.     

One-pot approach for the synthesis of 2-aryl benzothiazoles via a two-component coupling of gem-dibromomethylarenes and o-aminothiophenols

One-pot synthesis of 2-aryl benzothiazoles from gem-dibromomethylarenes using 2-aminoarylthiols is described. Benzothiazoles were obtained in high chemical yields under mild conditions. This transformation would facilitate synthesis by short reaction times, large-scale synthesis, easy and quick isolation of the products, which are the main advantages of this procedure.     

关于工业产品生产许可证管理的探讨

对工业产品生产许可证管理方面存在的一些问题进行了探讨。经分析认为,在做好实地核查及证后监管的前提下,生产许可证制度的关键在于宣贯和相关细节的明确上。