[en] Full text:The copolymerization reaction of ρ-(substituted) cyclopropyl styrene's with styrene has been studied. An influence of substituent's on reactivity of ρ-(substituted) cyclopropyl styrene's has been investigated. The copolymerization constant values and Q-e parameters of Alfrey-Praice scheme have been calculated. The parameters of microstructure of copolymers have been determined

[en] Asymmetric hydrosilylation was one of the most effective methods, which provided optically active organosilanes as a synthetically useful intermediate in organic synthesis. One useful transformation is the Tamao-Fleming oxidation, which is an oxidation reaction of carbon[BOND]silicone bond to afford optically active alcohols with retention of configuration. It is demonstrated that a palladium catalyst coordinating with phosphoramidite ligand (S _a,R _c,R _c_,)-L3a from (S)-BINOL and chiral bis((R)-1-ferrocenylethyl) amine shows a high catalytic activity and enantioselectivity up to 97% ee in asymmetric hydrosilylation of styrene and its derivatives. The hydrosilylation of various olefin substrates using these ligands is in progress

[en] An advanced lithographic technology currently under investigation for integrated circuit fabrication having design rules of ≤ 0.20 μm is proximity x-ray lithography. High intensity x-rays produced using either a synchrotron storage ring or laser-produced plasma sources have been shown to meet the requirements for use in x-ray lithography. To offset the cost and space requirements of a synchrotron source, a pulsed laser point source x-ray stepper has been manufactured and is being evaluated at AT ampersand T. Numerous positive and negative tone resist formulations based on conventional and chemical amplification (CA) processes have been investigated. Resist performance criteria include resolving ≤ 0.20 μm line and space pairs in 0.40 μm thick films using an incident x-ray exposure dose of ≤ 20 mJ/cm². Single and multi-component CA resists consisting of 4-t-butoxycarbonyloxystyrene sulfone coplymers have been found to be leading candidates for positive acting x-ray resists. Addition of poly(2-methyl-1-pentene sulfone) to a novolac resin is shown to produce positive tone patterns when exposed to x-radiation. Submicron imaging in this resist is attainable but certain requirements such as having a high contrast x-ray mask are required. Negative CA resists are shown to produce high resolution patterns, but exhibit restricted process latitude when compared to conventional crosslinking negative resists. These resists however at present do not provide the resolution level needed in x-ray lithography. Future changes in the exposure wavelength, improvements in the delivery of the pulsed laser power of the x-ray point source should broaden the candidates of resists compatible with this advanced lithographic technology

[en] Waste expanded polystyrene (EPS) represents a source of valuable chemical products like styrene and other aromatics. The catalytic degradation was carried out in a batch reactor with a mixture of polystyrene (PS) and catalyst at 450 .deg. C for 30 min in case of Mg and at 400 .deg. C for 2 h both for MgO and MgCO_3 catalysts. At optimum degradation conditions, EPS was degraded into 82.20±3.80 wt%, 91.60±0.20 wt% and 81.80±0.53 wt% liquid with Mg, MgO and MgCO_3 catalysts, respectively. The liquid products obtained were separated into different fractions by fractional distillation. The liquid fractions obtained with three catalysts were compared, and characterized using GC-MS. Maximum conversion of EPS into styrene monomer (66.6 wt%) was achieved with Mg catalyst, and an increase in selectivity of compounds was also observed. The major fraction at 145 .deg. C showed the properties of styrene monomer. The results showed that among the catalysts used, Mg was found to be the most effective catalyst for selective conversion into styrene monomer as value added product

[en] Published in summary form only

[en] We report the formation and directed self-assembly of sub-10 nm half-pitch line patterns from lamellar microdomains of a block copolymer hybrid. The hybrid, which is a mixture of poly(styrene-b-ethylene oxide) (PS-b-PEO) and a low molecular weight organosilicate (OS), shows strong segregation between two phases (i.e. PS and PEO+OS) and forms lamellar microdomains of down to approximately 7 nm in half-pitch. Patterns applicable to multifinger device layouts are created by self-assembling the hybrid on topographic pre-patterns with a chemically non-selective surface. With careful design of the guiding topographic pattern geometry, well-controlled lateral placement including bent structures of lamellar microdomains can be obtained by this approach.

[en] New optical writing and electrical erasing devices have been successfully fabricated that exploit the photochromism and electrochromism of viologen. In a preliminary study, both the structures of viologen and device were investigated in detail by UV–vis spectra in order to confirm their effects on the optical writing and electrical erasing performances of corresponding devices. For sandwiched, single and complementary devices based on benzyl viologen (BV ²⁺), only optical writing can be performed, not electrical erasing operations, which indicated these devices cannot realize optical information rewriting. For single and complementary devices based on styrene-functional viologen (V BV ²⁺) and acrylic-functional viologen (ACV ²⁺), optical writing and electrical erasing operations can be reversibly performed and optical information rewriting realized. It is clear that single devices based on V BV²⁺ and ACV²⁺ possess better performance accompanied with contrast without significant degradation and bleaching times and without significant deterioration over 10 repeated writing/erasing cycles. Furthermore, we put forward possible mechanisms for sandwiched, single and complementary devices based on V BV²⁺ and ACV²⁺ for the optical writing and electrical erasing operations. This study provides a new strategy to design optical writing and electrical erasing devices to realize optical information rewriting. (paper)

[en] We have developed a solid phase radioimmunoassay (RIA) system for triiodothyronine (T₃), by immobilizing triiodothyronine antibodies on the inner wall of reaction tubes. The antibody-coated tubes were made via reaction of antibody with glutaraldeyde residue pre coated on the inner wall of the tubes by alkaline self-polimerization. The quality of the coated tubes was tested through its performance in the RIA methodology, by analysing the following RIA parameters: minimum detectable dose (MDD), nonspecific binding (NSB), ''X_50%'', slope of the standard curve, intra and inter-assay precision, accuracy of the method and figure of merit. The serum levels of T₃ in hypothyroid and hyperthyroid patients and the normal values range were determined for the solid phase RIA system. The results are in agreement with found in the literature. (author)

[en] Two types of unsaturated polyester have been prepared according to normal alkyd methods of preparation. In this work the emphasis has been given to the preparation methodology of unsaturated polyesters in styrene. Their molecule weight distributions fall between normal alkyd's i.e. 2500 to 3500. (author)

[en] Tritium-labelled (E)- and (Z)-2,3-dimethyl-2-phenyl oxirane 4, (E)-and (Z)-2-methyl-3-phenyl oxirane 7 and 2,2-dimethyl-3-phenyl oxirane 11 have been prepared by reduction of the corresponding bromoketones with sodium borotritide to the corresponding bromohydrins followed by cyclization to the oxiranes. These oxiranes were successfully used as diagnostic substrates to distinguish between different forms of epoxide hydrolase and glutathione transferase. (author)