One-pot Synthesis of 2,5-Disubstituted Oxazoles Using Poly[styrene(iodosodiacetate)]

Disubstituted oxazoles were prepared conveniently by treatment of aromatic -methyl ketones and nitriles with poly[styrene(iodosodiacetate)] in one-pot process.

SYNTHESIS AND CHARACTERIZATION OF POLY{4-[2-(tert-BUTYLDIMETHYLSILOXY)ETHYL]STYRENE}AND ITS HYDROLYSIS DERIVATIVE

The living cationic polymerization of 4-[2-(tert-butyldimethylsiloxy)ethyl]styrene (TBDMES) was studied in methylcyclohexane (MeChx)/methylchloride (MeCl) (50/50 V/V) solvent mixture at -80 degrees C. The initiator 1,1-diphenylethylene (DPE) capped 2-chloro-2,4,4-trimethylpentane (TMPCl) was formed in situ in conjunction with titanium tetrachloride (TiCl(4)). The Lewis acidity of TiCl(4) was decreased by the addition of titanium(IV) isopropoxide (Ti(OiPr)(4)) to accomplish living polymerization of TBDMES. Hydrolysis of poly(TBDMES) in the presence of tetra-butylammonium fluoride yielded poly[4-(2-hydroxyethyl)styrene] (poly(HOES)). FT-IR, NMR and DSC demonstrated the hydrolysis was complete.

Poly[styrene(iodosodiacetate)]:An Efficient Reagent for Regioselective Azido-arylselenylation of Olefins

Poly[styrene(iodosodiacetate)] reacted with diaryl diselenides, followed by sodium azide, giving 1-azido-2-arylselenoalkanes regioselectively. The polymer reagent could be regenerated and reused.

Synthesis of Poly(styrene-co-divinylbenzene)-supported Dichloro Cyanuric Acid

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DETERMINATION OFTHE CRYSTALLINITY IN DIFFERENT TYPE POLY (OXYETHYLENE-STYRENE)BLOCK COPOLYMERS BY X-RAY DIFFRACTION METHOD

By means of the intensity theory of X-ray scattering and the two-phase concept of high polymer, the basic formula of the crystaUinity in block copolymers has been proposed after the corrections of atomic, temperature, absorption, Lorentz and polarization factor. Application of this method to different type poly (oxyethylene-styrene)block copolymers and the same type block copolymers with different EO contents indicates that the crystallinity in poly (oxyethylene-styrene ) block copolymers increases with the increase of the EO content and decreases in the order: PEO-PS-PEO>PEO-PS>PS-PEO-PS.

Poly{[4-(hydroxyl)(tosyloxyl)iodo]styrene} Promoted Halotosyloxylation Reaction of Alkynes

Halotosyloxylation reaction of alkynes with iodine or NBS or NCS was efficiently promoted by the poly{[4-(hydroxyl)(tosoyloxyl)iodo]styrene}.

Safety evaluation of long-term vas occlusion with styrene maleic anhydride and its non-invasive reversal on accessory reproductive organs in langurs

Aim:To evaluate the safety of the long term vas occlusion with styrene maleic anhydride (SMA) and its non-invasive reversal at the level of accessory reproductive glands (ARGs) in langurs.Methods:The morphology of seminal vesicle and ventral prostate was evaluated by light as well as transmission electron microscopy.Serum clinical chemistry and urine albumin were evaluated in an autoanalyzer using reagent kits.Fructose,acid phosphatase and zinc in the seminal plasma were evaluated spectrophotometrically according to the WHO manual.Serum testosterone, prostate specific antigen and sperm antibodies were evaluated by enzyme-linked immunosorbent assays (ELISA) using reagent kits and hematology was estimated according to standard procedures.Results:The morphological features and secretory activity of the seminal vesicle and prostate were normal as evidenced by the presence of well- developed mitochondria,rough endoplasmic reticulum,Golgi bodies,secretory granules and normal nuclear charac- teristics throughout the course of investigation.Serum testosterone and prostate specific antigen remained unaltered and serum antisperm antibodies level presented negative titres.Urine albumin was nil.Total red blood corpuscles (RBC),white blood corpuscles (WBC),hemoglobin (Hb) and red cell indices,serum protein,glucose,cholesterol, creatinine,creatine kinase (CK),serum glutamate oxalate transaminase (SGOT),serum glutamate pyruvate transami- nase (SGPT),lactate dehydrogenase (LDH),bilirubin,urea,triglycerides and high-density lipoprotein (HDL) did not show appreciable changes following vas occlusion and after its non-invasive reversal.Although fructose,acid phos- phatase (ACP) and zinc in the seminal plasma showed a significant reduction following vas occlusion,it could not be related to the morphology of seminal vesicle and prostate.Conclusion:SMA vas occlusion and its non-invasive reversal do not damage the accessory reproductive organs.

SYNTHESIS OF A NOVEL "MESOGEN-JACKETED LIQUID CRYSTAL POLYMER" BASED ON VINYLTEREPHTHALIC ACID

Poly{2,5-bis[(p-methoxyphenyl)oxycarbonyl]styrene}was successfully synthesized.This new polymer has a structure characteristic of mesogen-jacketed liquid cyrstalline polymers(MJLCPs)and does form a liquid crystal phase above its glass transition.It thus became the starting member of a new series of MJLCPs.The synthesis of the polymer as well as the liquid crystalline properties of the polymer and its monomer was discussed.A brief comparison of the new monomer and polymer with some previously reported counterparts was also included.

A Facile One-pot Synthesis of 2,5-Disubstituted Oxazoles Us-ing Poly[styrene(iodosodiacetate)]

Disubstituted oxazoles were prepared conveniently by treatment of aromatic -methyl ketones and nitriles with poly[styrene(iodosodiacetate)] in a one-pot manner.

High corrosion-resistant silver nanowire/poly(3,4-ethylene dioxythiophene)/poly(styrene sulfonate)@nickel electrode for transparent electromagnetic shielding film

Silver nanowire(AgNW)has become one of the best candidates for flexible transparent electromagnetic(EMI)shielding materials,while the low corrosion resistance of AgNW hinders its application in environments with high content of corrosive substances.Herein,an AgNW/poly(3,4-ethylene dioxythiophene)/poly(styrene sulfonate)(PEDOT:PSS)@nickel electrode was prepared through ultrasonic spray coating and electroplating methods.PEDOT:PSS is sprayed to improve the conductivity of the AgNW network,and a 9.8-16.5 nm Ni layer is deposited on the AgNW/PEDOT:PSS to protect the AgNWs from corrosion.The AgNW/PEDOT:PSS@Ni electrode shows a sheet resistance of 29 U·sq^(-1),a transmittance of 78.18%,an average EMI shielding efficiency of 19.64 dB and excellent corrosion resistance in Na2S solution.The resultant AgNW/PEDOT:PSS@Ni electrode is promisingly used in high corrosion resistance transparent EMI shielding film.

PREPARATION OF SULPHONATE-CONTAINING POLYMER PARTICLES VIA SEMI-CONTINUOUS EMULSION COPOLYMERIZAION OF STYRENE AND SODIUM STYRENE SULPHONATE

Submicron-sized P（St-NaSS） latexes were prepared via a semi-continuous emulsion copolymerization of styrene （St） and sodium styrene sulphonate （NaSS） in the presence of anionic surfactant, in which NaSS aqueous solution and St were separately dropwise charged into the polymerization system at the same time. The hydrodynamic diameter of the latex particles was measured by dynamic light scattering （DSL） method, and the NaSS unit content of the purified copolymer by water extraction was calculated based on the elementary analysis. Results showed that the copolymerization could be performed smoothly with the monomer conversion more than 96% in the absence of crosslinker, and PNaSS homopolymer could be removed from the latex product by water extraction for 28 h. The weight loss in the water extraction tended to decrease and the NaSS unit content of the purified copolymer tended to increase with the increase of monomer feeding time, and both of them increased with the increase of NaSS/St mole ratio in the charge. The introduction of divinyl benzene （DVB） could decrease the weight loss in the water extraction and increase the NaSS unit content of the purified copolymer. When 25/75 mole ratio of NaSS/St and 11 mol% DVB of total NaSS and St were used in the recipe, and the monomer feeding time was 3 h in copolymerization, the NaSS unit content of the purified copolymer reached 7.31 mol%.

Increased work function in PEDOT:PSS film under ultraviolet irradiation

An increase of work function （0.3 eV） is achieved by irradiating poly（3,4-ethylenedioxythiophene）：poly（styrene sul- fonate） （PEDOT：PSS） film in vacuum with 254-nm ultraviolet （UV） light. The mechanism for such an improvement is investigated by photoelectron yield spectroscopy, X-ray photo electron energy spectrum, and field emission technique. Sur- face oxidation and composition change are found as the reasons for work function increase. The UV-treated PEDOT：PSS film is used as the hole injection layer in a hole-only device. Hole injection is improved by UV-treated PEDOT：PSS film without baring the enlargement of film resistance. Our result demonstrates that UV treatment is more suitable for modifying the injection barrier than UV ozone exposure.

Improvement of Environment Stability of an i-Line Chemically Amplified Photoresist

An i-Line chemically amplified(ICA)thick film positive resist is reported in this paper.The impact of process conditions on photoresist performance was investigated.Pre-apply bake temperature and post exposure bake temperature affect acid diffusion and deblocking reactions,thus playing an integral role in defining the resist profile.Both pre-apply bake delay and post exposure delay(PED)affect critical dimension(CD)variation,but PED is more sensitive to contact with airborne contaminants.Different polymers and different photo-acid generators(PAG)are also illustrated in this work.By optimizing the structure and concentration of key components,an ICA resist with good environment stability and excellent lithographic performance was demonstrated.

Synthesis of a New Polymer-supported Reagent──Poly{[4- hydroxy(tosyloxy)iodo]styrene} and Its Application to the Synthesis of 2-Amino-4-arylthiazoles

A new polymer-supported reagent--poly{[4-hydroxy(tosyloxy)iodo]styrene} has good reactivity in the formation of 2-amino-4-arylthiazoles, and the procedure of regeneration and cycle are also described.

In situ grazing-incidence small-angle X-ray scattering observation of block-copolymer templated formation of magnetic nanodot arrays and their magnetic properties

The fabrication of bit-patterned media （BPM） is crucial for new types of hard disk drives. The development of methods for the production of BPM is progressing rapidly. Conventional lithography reaches the limit regarding lateral resolution, and new routes are needed. In this study, we mainly focus on the dependence of the size and shape of magnetic nanodots on the Ar＋-ion etching duration, using silica dots as masks. Two-dimensional （2D） arrays of magnetic nanostructures are created using silica-filled diblock-copolymer micelles as templates. After the self-assembly of the micelles into 2D hexagonal arrays, the polymer shell is removed, and the SiO2 cores are utilized to transform the morphology into a （Co/Pt）2-multilayer via ion etching under normal incidence. The number of preparation steps is kept as low as possible to simplify the formation of the nanostructure arrays. High-resolution in situ grazing-incidence small-angle X-ray scattering （GISAXS） investigations are performed during the Ar＋-ion etching to monitor and control the fabrication process. The in situ investigation provides information on how the etching conditions can be improved for further ex situ experiments. The GISAXS patterns are compared with simulations. We observe that the dots change in shape from cylindrical to conical during the etching process. The magnetic behavior is studied by utilizing the magneto-optic Kerr effect. The Co/Pt dots exhibit different magnetic behaviors depending on their size, interparticle distance, and etching time. They show ferromagnetism with an easy axis of magnetization perpendicular to the film. A systematic dependence of the coercivitv on the dot size is observed.