PREPARATION AND CHARACTERIZATION OF cis-,4-POLYBUTADIENE CONTAINING A FRACTION OF trans-1,4-POLYBUTADIENE

Polymerization of butadiene catalysed first with V(acac)_3-Al(i-Bu)_2Cl, then with Co(acac)_3-H_2O-Al(i-Bu)_2Cl has been studied. The polymer obtained was identified to be a new variety of cis-1,4-polybutadiene which contained a fraction of trans-1,4-polybutadiene chemically bonded to the cis-1,4-polybutadiene chains. Its molecular weight and trans-1,4 content can be regulated by varying the catalyst composition and concentration as well as other polymerization conditions. The trans-1,4 fraction, although it presents only in 9—16%, forms a crystalline phase in the matrix at room temperature and facilitates the crystallization of the polymer.     

PREPARATION AND STRUCTURAL CHARACTERIZATION OF A DIMETHYLAMINE-OCCLUDING GALLOARSENATE

<正> A dirnethylamine-occluding galloarsenate,designated as GaAsO4-2,was prepared hydrothermally and determined structurally by single crystal X-ray diffraction technique. The compound crystallizes in nionoclinic space group P21/n with unit cell con-stants:a=18. 011(4),b=10. 466(4),c=19. 035(4)A ,β=113. 97(6)°,V= 3278. 81 A3,Dc =3. 06gcm-3,Z=4. The three-dimensional net of GaAsO4-2 constructed by Ga, As,O and F atoms has three kinds of open channels. One is formed by 10-T (T = Ga or As)rings packed along [010],the other two are formed by zigzag packing of 8-T rings a-long [100]and [001]. The dimethylamine molecules as templates are located inside the 10-T channels with their NH group pointing toward the channel wall.     

SYNTHESIS AND CHARACTERIZATION OF HETEROAROMATIC POLYMERS CONTAINING PYRIDINE MOIETIES

1. INTRODUCTION The new kinds of heteroaromatic polymers have been important topics in polymer science fields since they were developed at 1960s in order to meet demands for heat-resistant plastics for space and military applications. Because heteroaromatic polymers exhibit excellent thermal and chemical stability, outstanding electrical and mechanical properties, good solvent resistance, and dimensional stability, these polymers have found usage as adhesives, coatings, matrix resins, film…     

SYNTHESIS AND CHARACTERIZATION OF SILAZANE OLIGOMER CONTAINING 1,1,3,3,5,5-HEXAMETHYLCYCLOTRISILAZANE

A new silazane oligomer containing cyclotrisilazane was synthesized by KH-catalyzed dehydro-coupling reactionsbetween diphenylsilane and 1,1,3,3,5,5-hexamethylcyclotrisilazane (D_3~N).     

PREPARATION AND CHARACTERIZATION OF A NEW COENZYME B_（12） ANALOGUE CONTAINING 2＇，3＇－ DIDEOXYURIDINE

ＰＲＥＰＡＲＡＴＩＯＮＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦＡＮＥＷＣＯＥＮＺＹＭＥＢ_（１２）ＡＮＡＬＯＧＵＥＣＯＮＴＡＩＮＩＮＧ２＇，３＇－　ＤＩＤＥＯＸＹＵＲＩＤＩＮＥＢａｏＨｕａＺＨＵ；ＨｏｎｇＹＡＮ；ＬａｉＢｉｎＬＵＯ；ＺｅＨｕａＬＩＵ?..     

PREPARATION AND CHARACTERIZATION OF POLYAMIDE 11/CLAY NANOCOMPOSITES

INTRODUCTIONIn recent years, polymer/clay nanocomposites have attracted great interest from researchers since they frequentlyexhibit unexpected hybrid properties synergistically derived from the two components. Compared to their microcounterparts and the pristine polymer matrix, polymer/clay nanocomposites exhibit improved tensile strength andmodulus, decreased thermal expansion coefficient, decreased gas permeability, increased swelling resistance,enhanced ion conductivity, and reduced fl…     

THE PREPARATION AND CHARACTERIZATION OF ZnO-Ag CORE-SHELL ULTRAFINE PARTICLE

ＴＨＥ　ＰＲＥＰＡＲＡＴＩＯＮ　ＡＮＤ　ＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮ　ＯＦ　ＺｎＯ－Ａｇ　ＣＯＲＥ－ＳＨＥＬＬ　ＵＬＴＲＡＦＩＮＥ　ＰＡＲＴＩＣＬＥＴＨＥＰＲＥＰＡＲＡＴＩＯＮＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦＺｎＯ－ＡｇＣＯＲＥ－ＳＨＥ...     

SYNTHESIS AND CHARACTERIZATION OF PHENOTHIAZINE-BASED PPV-TYPE COPOLYMERS CONTAINING FLUORENE AND THIOPHENE MOIETIES

1. INTRODUCTION Since the first report of efficient polymer light emitting diode (PLED) in 1990, conjugated polymers have intrigued great interests because of substantial promise for electro-optical applications [1,2]. It is essential to develop novel str…     

PREPARATION AND MAGNETIC PROPERTIES OF POLYMERIC COMPLEXES CONTAINING 1,10-PHENANTHROLINE

A series of polymeric complexes were prepared from Fe~(2 ),Co~(2 ) or Ni~(2 ) and poly(Schiff base)(DAPcIPA), which was obtained by polycondensation of 5,6-diamino-1,10-phenanthroline(DAP)with isophthalaldehyde(IPA).The structures of the polymer and the polymeric complexes were characterized by IR,~1H-NMR and elemental analysis.The magnetic behavior of these complexes was measured as a function of magnetic field strength(0-3.98×10~6 A/m)at 5 K and as a function of temperature(5-300 K)at a magnetic field strength of 2.39×10~6 A/m.Experimental results show that DAPcIPA-Ni~(2 ),DAPcIPA-Co~(2 ) are soft ferromagnets while DAPcIPA-Fe~(2 ) exhibits features of an antiferromagnet.     

PREPARATION AND SURFACE PROPERTIES OF ACRYLIC COPOLYMERS CONTAINING FLUORINATED MONOMERS

A series of copolymers comprising butylmethacrylate, styrene, butylacrylate, hydroxypropyl acrylate and perfluoroalkyl methacrylate were synthesized by the free radical polymerization using BPO as an initiator. The surface property of the copolymer films was subsequently characterized. The contact angle measurements and energy dispersive analysis of X-ray （EDAX） show that the length and content of perfluoroalkyl side chains in the copolymers are crucial for the preparation of the film with low surface energy. At a given content of fluorinated monomers in the copolymers, the longer the perfluoroalkyl side chain, the larger the water contact angle of the copolymer films will be. On the other hand, the higher the content of fluorinated monomers, the lower the surface energy is. The water contact angle increases with the increase of the fluorinated monomer content and reaches a plateau at 3 wt% of fluorinated monomer content.     

CHARACTERIZATION AND PROPERTIES OF URUSHIOL POLYMER CONTAINING BORON-NITROGEN COORDINATE BOND

Urushiol polymer containing B--N bond (PUBN) was synthesized with urushiol-boronpolymer and diethylene triamine. Its structure was characterized by XPS, IR, UV, HPLC,DTA-TG and elemental analysis. The physico-mechanical and anticorrosive propertiesof the polymer were also investigated. The results show that the coating of PUBN canbe hardened in 2h at room temperaure and its film has excellent physico-mechanicalproperties and good anticorrosive properties.     

PREPARATION AND CHARACTERIZATION OF PVDF-HFP MICROPOROUS MEMBRANE BY TEMPLATE METHOD

Porous poly（vinylidene fluoride-co-hexafluoropropylene） （PVDF-HFP） membranes were successfully prepared using dibutyl phthalate （DBP）, polyvinylpyrrolidone （PVP-K30）, polyethylene glycol 200 （PEG200） as templates. SEM was used to examine the morphology of the PVDF-HFP porous membranes. It was found that these membranes have an asymmetric structure and the blends of PVDF-HFP/DBP formed nanoporous membranes, whereas the blends of PVDF- HFP/PVP-K30 formed ＂sponge-like＂ and microporous membranes. Moreover, the average pore size and porosity was about 0.3 μm and 48.7%, respectively. The crystallinity, thermal stability and mechanical strength of membranes were characterized by XRD, DSC, TGA and stress-strain tests. The results showed that the membranes are a crystals with excellent thermal stability. It was an effective way to regulate pore size and morphology of the PVDF-HFP membranes.     

PREPARATION OF ULTRAFINE PARTICLE IRON-CARBONIDE CATALYST AND CHARACTERIZATION OF ITS CATALYTICAL BEHAVIOR

Studies on ultrafine particle catalyst have attracted many researchers' attention by its large surfacearea,higher activity and selectivity.Based on the mechanism of α-Fe and Fe_xC_y as the catalyticalactive species this paper reports for the first time the preparation method of Fe_3C ultrafine parti-cle catalyst,from highly dispersed amorphous Fe powder and free carbon.The Fe powder and free car-bon,prepared by laser pyrolysis technique,was then treated by washing and heating at high tempera-ture protected with N_2.The catalyst prepared under different experimental conditions wascharacterazed by means of XRD,electronic diffraction and TEM.It shows that the crystlline grain sizeis in a range of 1-4nm and composed of Fe_3C and α-Fe.It has been found that the ultrafine particleiron-carbonide catalyst exhibited much higher activity and selectivity to light olefins.At the standardatmosphere and 380℃ reaction temperature,the conversion of CO reached a maximum of 80%.     

PREPARATION AND CHARACTERIZATION OF A HIGH TEMPERATURE WATER-GAS SHIFT CATALYST

ＰＲＥＰＡＲＡＴＩＯＮＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦＡＨＩＧＨＴＥＭＰＥＲＡＴＵＲＥＷＡＴＥＲ┐ＧＡＳＳＨＩＦＴＣＡＴＡＬＹＳＴＺｈｏｕＬｉｎｇｐｉｎｇ＊，ＧｕｏＹｉｑｕｎ，ＳｕＹｕｎｌａｉ，ＷａｎｇＷｅｎｘｉａｎｇ（Ｄｅｐａｒｔｍｅｎｔ...     

PREPARATION AND CHARACTERIZATION OF AC_（60） CHARGE－TRANSFER COMPLEX：COBALTOCENE FULLERIDE

ＰＲＥＰＡＲＡＴＩＯＮＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦＡＣ_（６０）ＣＨＡＲＧＥ－ＴＲＡＮＳＦＥＲＣＯＭＰＬＥＸ：ＣＯＢＡＬＴＯＣＥＮＥＦＵＬＬＥＲＩＤＥ￥ＷｅｉＺＨＡＮＧ；ＺｈｏｎｇＺｈｉＷＵ；ＨｏｎｇＺＨＵ；ＷｅｉＣｈｕａｎｇＴＡＯ；Ｌ?..     

PREPARATION AND CHARACTERIZATION OF ION EXCHANGE MEMBRANES BASED ON POLYVINYLIDENE FLUORIDE

A new ion exchange membrane based on polyvinylidene fluoride (PVDF) and sulfonated poly(styrenedivinylbenzene) was prepared by in-situ polymerization. The incorporation of sulfonic groups into the polyvinylidene fluoride composite membrane was confirmed by infrared spectroscopy (IR), ion exchange capacity (IEC) and energy dispersive X-ray analysis (EDAX). Area resistance, IEC and water uptake of the treated membrane were evaluated. When area resistance in NaCl aqueous solution at 25℃, IEC is as high as 2.43 millimoles per gram of the wet membrane. The hydrophilicity of PVDF membrane is also significantly improved after treatment. When 60% of crosslinked membrane was sulfonated at 80℃ for 6 h, water uptake of the treated membrane can attain 64.7%.     

THE PREPARATION AND CHARACTERIZATION OFSm／NiMODELPLANARCATALYSTS

ＴＨＥＰＲＥＰＡＲＡＴＩＯＮＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦＳｍ／ＮｉＭＯＤＥＬＰＬＡＮＡＲＣＡＴＡＬＹＳＴＳ＊ＹａｏＬｉｊｕｎ，ＳｈｅｎｇＳｈｉｓｈａｎ，ＺｈｕＸｉａｏｌｅｉ，ＸｉｏｎｇＧｕｏｘｉｎｇ（ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏｒｙ...     

PREPARATION, CHARACTERIZATION AND ELECTROCHEMICAL PROPERTIES OF POLYPYRROLE-POLYSTYRENE SULFONIC ACID COMPOSITE FILM

Polypyrrole-polystyrene sulfonic acid (PPy-PSSA) composite films have been electrosynthesized in an aqueous solution of PSSA. The electro-active films exhibit cation exchange during the redox process. Infrared, Raman and energy-dispersive spectroscopic results demonstrated that the polyanion of PSS^- is co-deposited into the PPy matrix and couldn‘t be stripped from the film extensively by dedoping. The doping level together with dipolaron content of the PPy-PSSA composite film increases during electrochemical polymerization process. SEM images revealed that the composite film has smooth and compact morphology and AFM pictures suggested that PPy chains are possibly grown perpendicular to the electrode surface. TGA tests indicated that the composite films has much better thermal stability than that of pure PPy.Furthermore, electrochemical studies showed that the relaxation process at certain holding potential has great effect on the shape of the cyclic voltammetric curves of PPy-PSSA composite film. The composite film exhibits cation and anion exchange during the redox process after undergoing the relaxation step. It is more difficult for divalent anion to enter the polymer matrix than a univalent ion, and a large cation such as (CH3CH2CH2CH2)4N^ cannot be involved in the ion exchange process.