STUDY ON LIQUID CRYSTALLINITY OF POLY(N-VINYLCARBAZOLE)

The liquid crystallinity of poly(N-vinylcarbazole) was studied by using powder X-ray diffraction, polarized opticalmicroscopy, and differential scanning calorimetry. The results show that the lower molecular weight fractions of this polymerdo not form a liquid crystalline phase, while the samples of sufficiently high molecular weight do form a mesophase attemperatures above the glass transition. The lowest value of the degree of polymerization for PVK to form a stable liquidcrystalline phase was found to be in the range of 150 to 200, significantly higher than the value of 50 for most conventionalside chain liquid crystaline polymers.     

STUDY ON BINUCLEAR COPPER(I)COMPLEXES III.SYNTHESIS,CHARACTERIZATION AND ELECTROCHEMISTRY OF DICHLORO-TRIS(4-VINYLPYRIDINE)-DICOPPER(I)COMPLEX

Recent years,many novel complexes have been prepared by usinghetero-bidentate ligands.However,complexes with such ligands as 4-vinylpyridinewhich has two different coordinating sites have not been reported,and only a fewcomplexes of Cu(I)have been published~(1-3).The title complex Cu_2(C_5H_4N·CH=CH_2)_3Clwas prepared and characterized by elemental analyses,ICP,IR,and electronicspectra.Its conductivity,oxidation potential and reduction potential weremeasured.     

STUDY ON THE POLING PROPERTIES OF NONLINEAR OPTICAL ACTIVE DERIVATIVE OF POLY (p-HYDROXYSTYRENE):(PS)O-DCV

In this paper, the poling properties of (PS)O-DCV, a derivative of poly (p-hydroxystyrene ), was reported. The investigations showed that the thermochromism correction, which was neglected in the literatures, should be considered in the measurements of order parameter of poled films with electrochromism technique Here, another linear optical method, IR and polarized IR spectra for characterizing of poled films was suggested first time. The bulk second nonlinear optical coefficient d_(33) of poled films could be estimated by measured order parameter semi-qualitatively.     

SYNTHESIS AND CHARACTERIZATION OF POLY(STYRENE-co-4-VINYLPYRIDINE) NEODYMIUM COMPLEX

Poly(styrene-co-4-vinylpyridine)-neodymium complexes(NdCl_3·PS4VPY)with variouscontents of the functional group and neodymium have been prepared and characterized.Theinfrared and X-ray photoelectron spectra indicate that uncoordinated 4-vinylpyridine(4VPY)unitsremain in the NdCl_3·PS4VPY complexes.The catalytic behaviour of NdCl_3·PS4VPY was described briefly.     

STUDY ON THE PHYSICAL CHEMICAL PROPERTIES OF FFA—1 ION EXCHANGE FIBER

The physical and chemical properties of FFA-1 ion exchange fiber have been characterized with IR spectrum,thermal analysis and SEM means.The pH titration curve,swelling rate,mechanical properties,resistance drop of filter layer as well as the dynamic adsorption for SO2 was determined.These experiments provided the essential parameters for the practical application of FFA-1 material in adsorption of toxic gases.     

EFFECTS OF L-PHENYLALANINE ON THE RADIATION SYNTHESIS OF POLY(N,N''''-METHYLENEBISACRYLAMIDE-co-4-VINYLPYRIDINE)(MICRO)GELS

The effects of L-phenylalanine(L-Phe)on the synthesis of poly(N,N'-methylenebisacrylamide-co-4-vinylpyridine) (poly(Bis-co-4-VP))(micro)gels by γ-ray irradiation were studied.The addition of L-Phe could not only decrease the gelation dose(D_g)of the synthesis obviously,but also transform the morphology of copolymer from microgel to gel.In addition,the swelling ability of the(micro)gels was also affected in the presence of L-Phe.The decrease of D_g was ascribed to the effect of pH,while the transformation of the morphology was ascribed to the effect of L-Phe on the stability of the poly(Bis-co-4-VP)microgel.Such an effect was confirmed further as compared with the effects of L-alanine,L-glutamic acid,L-arginine,sulfuric acid and aqueous ammonia.     

CONFORMATIONAL CHARACTERISTICS OF POLY(ACRYLIC ACID) AND POLY(METHACRYLIC ACID)

A full-relaxation optimization of molecule and the Dreiding force field are employed toobtain the geometry parameters and the conformational energy surfaces of meso or racemicdyad of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA). Three differentcarbonyl-bond orientations of side-groups resulted in the differences in depth of potentialwells in their energetic contours for a meso or a racemic dyad. These discrepancies areinterpreted as a result of various fine structures corresponding to grid search conformationsas well as thereby different interactions. The analysis on the most stable conformationsof PMAA confirmed that the ester groups are nearly perpendicular to the plane definedby the two adjacent skeletal bonds but may possibly change their relative orientations tomeet the requirement of lower energy during the conformational state transition. For eachpolyme, two global energy maps of a meso and a racemic dyad were finally constructedfrom the superposition of energy data for the three kinds of side-group orientations by theBoltzmann factors. From an ensemble average, the proposed scheme with three rotationalisomeric states (RIS) allowed us to access the experimentally unperturbed dimensions ofPAA chain via the configurational statistical mechanics. Although the calculation wasbased on the short-range, local interactions, it was interested to note that the experimentalcharacteristic ratios just fell within the range calculated for atactic chains.     

STUDY ON THE MODIFICATION OF POLY (METHYL METHACRYLATE) TRANSPARENT MATERIAL

A kind of transparent plastic material has been prepared with bulk copolymer of MMA-MA containing MA 20 vol% as matrix modified by introducing EtOH during bulk copolymerization to increase the transparency and by copolymerizing together with metallic salts of MA forming ionomer polymer to improve the heat-tolerance and hardness. The effect of the contents of the additives on the heat stability, hardness and transparency of the copolymer has been studied. The optical homogeneity of the copolymer material has also been examined. It has been found that the specific property of transparent material of this kind may be obtained by controlling the amounts of EtOH and metallic salt of MA.     

PROPERTIES OF DILUTE SOLUTIONS OF HYDROPHOBICALLY MODIFIED POLY (4-VINYL PYRIDINE) (POLYSOAPS)

Hydrophobically modified poly(4-vinyl pyridines) by alkyl bromides arekinds of polysoap similar to the surfactant. Properties of dilute solutions were studiedthrough the viscosity measurements in pure water and NaCl solutions. In aqueous solu-tions of polysoaps hydrophobic interaction can be attributed to aggregation of hydrophobicgroups of the polysoap main chains. The hydrophobic groups of polysoap can aggregate toform hydrophobic microdomains (micelles) in aqueous solution. This is a compact confor-mation. The formation of such microdomains is a process of dynamic equilibrium.     

STUDY ON THE SYNTHESIS AND PROPERTIES OF MACRORETICULAR IPN POLYACRYLAMIDE—POLY(VINYL—ETHYLENEDIAMINE)CHELATE SORBENTS

A new series of MR-IPN polyacrylamide—poly(vinyl-ethylenediamine)chelatesorbents were prepared by the reaction of ethylenediamine with MR-IPN matrixes.The newchelate sorbent showed good sorption properties for auric and platinic ions.     

STUOIES ON TRANSITION METAL COMPLEXES OF SCHIFF BASE—OXYGEN—CARRYING PROPERTIES OF THREE COBALT（Ⅱ） COMPLEXES OF N－SALICYLIDENEAMINO ACIDS

ＳＴＵＯＩＥＳＯＮＴＲＡＮＳＩＴＩＯＮＭＥＴＡＬＣＯＭＰＬＥＸＥＳＯＦＳＣＨＩＦＦＢＡＳＥ—ＯＸＹＧＥＮ—ＣＡＲＲＹＩＮＧＰＲＯＰＥＲＴＩＥＳＯＦＴＨＲＥＥＣＯＢＡＬＴ（Ⅱ）ＣＯＭＰＬＥＸＥＳＯＦＮ－ＳＡＬＩＣＹＬＩＤＥＮＥＡＭＩＮＯＡＣＩＤＳＸｉａ...     

STUDY ON AB-CROSSLINKED POLYMERS Ⅰ. THE SYNTHESIS AND MECHANICAL PROPERTIES OF AB-CROSSLINKED POLYMERS BASED. ON PU/PS

The AB-crosslinked polymers (i.e. ABCP) with polystyrene as chain A and vinyl group blocked prepolymers of polyurethanes (PU) as chain B were synthesized and studied. The results of dynamic mechanical spectrometry (DMS) show that the compatibility between the components A and B can be improved greatly through chemical crosslinking during the formation of ABCPs. This effect is especially pronounced when short chain prepolymers is chosen as one of the components. It is apparent that the degree of crosslinking between the two components plays a major role in determining their compatibility. Copolymerizafion of styrene with maleic anhydride in chain A can improve the compatibility and broaden the damping temperature range. Mechanical properties of the sythesized ABCPs were also studied.     

A STUDY ON POLY (ETHYLENE OXIDE)/POLY(VINYL ACETATE)BLENDS

Melt blends of poly(ethylene oxide) (PEO) and poly(vinyl acetate (PVAc) were prepared andstudied by Torsional Pendulum Analysis (TPA) and Fourier Transform Infrared (FTIR). Two glasstransitions were found in these blends. The lower T_g corresponds to the segmental motion in thepure PEO. The dependence of the position and broadness of the higher T_g on composition of theblends indicates that the two components are compatible in the amorphous phase with micro-hetero-geneity. These T_g values observed from mixed PVAc/PEO phase are much higher than that calculatedfrom Fox equation. The comparison of the blends quenched and annealed from melt implies thatPVAc mixed with PEO at the segmental level on molten state and the deviation of T_g values fromFox equation could be due to variation of the blend's composition by crystallization of part of thePEO component. Further indication that the blends are compatible down to the level of chain segments and thatthere are specific interactions between PVAc and PEO molecules comes from the analysis of FTIRspectra of the blends and the solution of PVA in diethylene glycol dimethyl ether.     

STUDY ON FLUORESCENCE BEHAVIOUR OF EU~(3+) CONTAINING POLY(METHYL METHACRYLATE)

Fluorimetry has been used to characterize ionomers synthesized by copolymerization ofmethyl mehacrylate, methacrylic acid and europium methacrylate (EMA). Under excita-tion of UV light at 375 nm no seif-quenching was found in fluorescence of EMA containingionomers at 615nm within the concentration range of 1.6×10~(-2) to 11.49×10~(-2) mol%.This means that the distance between two Eu~(3+) ions is larger than 5nm. In the sameconcentration range seif-quenching took place in europium octanoate (EOA) containingpoly(methyl methacrylate) in which EOA was doped as an additive.     

INVESTIGATIONS ON VINYLENE CARBONATE Ⅰ. PREPARATION AND PROPERTIES OF POLY-(VINYLENEC ARBONATE)

Bulk polymerization of vinylene carbonate using t-butylperoxypivalate at 40℃gave colourless, high molecular weight poly(vinylene carbonate) (PVCA). Solutions of PVCA in acetone and DMF are not stable at 25℃and this degradation was studied. From measurements in DMF with unfractionated PVCA a Mark-Houwink equation was obtained:     

METAL COMPLEXES OF POLYCYCLIC TERTIARY AMINES. PART VI. PREPARATION AND CRYSTAL STRUCTURE OF HEXAMETHYLENETETRAMINE-SILVER(I) BROMIDE (1/4)

<正> C6H12N4Br4Ag4,Mr = 891.31, orthorhombic, Pnma, a = 8.778(2),b = 9.80.5(2), c = 16.906(3) A, V = 1455.1(4) A3, Z = 4, Dx = 4.069, Dm (displacement of H2O) = 4.03 g cm-3 , A(Mo-Ka) = 161.3 cm-1 , F(OOO) = 1615.77,T = 295°, final R = 0.052 arid Rw = 0.062 for 1472 observed reflections.All four lone pairs of each (CH2)6N4 molecule serve as ligand sites in a polymeric framework comprising octahedral AgBr5N, tetrahedral AgBr3N, and tetragonal pyramidal AgBr4N coordination polyhedra. The Ag-N and Ag-Br bond lengths lie in the ranges 2.366(12)-2.454(12) and 2.640(2)-3.178(2) A, respectively.     

STUDY ON THE STRUCTURE AND PROPERTIES OF 4-(2-PYRIDYLAZO)-RESORCINOL(PAR) AND ITS DERIVATIVES

The dissociation constants of the reagents were determined spectrophotometrically, the existential patterns of PAR in aqueousalcohol solution were studied by quantumchemical method, and the color reactions between these reagents and Nickel(Ⅱ) were investigated.     

RAMAN SPECTROSCOPIC STUDY ON THE CHAIN CONFORMATION OF ELECTROSYNTHESIZED POLY(ρ-PHENYLENE)FILMS

Poly(ρ-phenylene)(PPP)films have been electrochemically deposited on mirrorlike stainless steel(SS)electrode surfaces by direct oxidation of benzene in boron trifluoride diethyl etherate(BFEE)solutions at a constant applied potential of 1.7 V(versus Ag/AgCl).The chain conformations of as-grown PPP films have been studied by Raman spectroscopy.The results demonstrated that high synthesis temperature favors the formation of planar PPP,and the conformation of planar PPP can be changed into torsional PPP by cooling treatment.     

STUDIES ON COMPLEXES OF RARE EARTHS WITH CROWN ETHERS(Ⅳ)SYNTHESIS AND CHARACTERIZATION OF THE COMPLEXES OF RARE EARTH NITRATES WITH 4''''-BROMO-5''''-NITROBENZO-15-CROWN-5

Six new solid complexes of macrocyclic polyether ligand 4′-bromo-5′-nitrobenzo-15-crown-5(L)withUivalent rare earth nitrates having composition of RE(NO_3)_3·L·mCH_3CN·nH_2O(RE=L_a--Nd,m=n=0,RE=Sm,Bu,m=0.1,n=1,4)have been synthesized in acetonitrile or acetone.All the isolated complexes have been char-acterized by elementary analysis,IR and UV spectra,differential thermal and thermogravimetric analysis,X-ray powderdiffraction analysis,molar conductance and measurementa of solubility in some general solventa.It shows thatcoordination number of the rare earth cation in the complexes of La,Ce,Pr and Nd nitrate is eleven.     

ESR SPECTRA STUDY OF COPPER(Ⅱ) COORDINATION COMPLEXES OF PYRIDI

The ESR spectra of powdered samples of Cu(Ⅱ) complexes with pyridine and its sixhomologues and pyrrol, aniline, as well as their solutions are measured at 77K in this paper.The electronic levels of these complexes are calculated from the ESR spectral parameters.It is found that the non-pyridine ligands of complexes which can be substituted by pyridinemolecules of solvent in solution of pyridine/chloroform form Py_4Cu~(2 ). A molecular configura-tion is proposed. for Py_4Cu~(2 ) in solution. It is shown that the treatment with D_(2h) symmetryinstead of D_(4h) symmetry leads to a more satisfactory explanation of the ESR spectra.