NETWORK CROWN ETHER POLYMERS WITH CENTRIC FUNCTIONAL GROUPS.Ⅱ.SYNTHESIS OF NETROWK CROWN ETHER POLYMER WITH PENDANT SULFIDE SIDE CHAIN AND ITS PLATINUM COMPLEX

Network crown ether polymer with pendant sulfide side chain in the network structure units has been synthesized via ring-opening copolymerization of β-ethylthioethyl glycidyl ether and diethylene glycol bisglycidyl ether.A kind of active catalyst suitable for this reaction was suggested.The title polymer was found to be a good ligand for platinous chloride,and the platinous complex could catalyze the hydrosilylation of ole fins with triethoxysilane efficiently.     

STRUCTURE AND PROPERTIES OF PHOSPHROUS-CONTAINING POLY（ARYL ETHER KETONE） WITH BISPHENOL-A MOIETY

A phosphrous-containing poly(aryl ether ketone)was synthesized derived from bisphenol-A and bis[4-(4- fluorobenzoyl)phenyl] phenyl phosphine oxide(FPPPO)by nucleophilic substitution reaction.The structure of the polymer was characterized by FT-IR,~1H-NMR and ~(31)p-NMR.The thermal property of the PAEK was measured by DSC and TGA. The glass transition temperature(T_g)of the polymer was 205℃,and the 5% weight loss temperature under nitrogen was 475℃.Good solubility of the polymer in organic solvents,such as N-methylpyrrolidone,dimethylformamide, dimethylacetamide,dimethylsulfoxide and chloroalkanes was observed,flexible film was obtained from the polymer's CH_2Cl_2 solution.The limiting oxygen index(LOI)of the PAEK was 40,which indicated that organic phosphorus moiety can offer good flame retardant property to the polymer.     

SYNTHESIS OF DIAZA CROWN ETHER CHIRAL LIQUID CRYSTAL

A chiral liquid crystal crown ether containing diaza-18-crown-6 was synthesized with the help of CPK atomic model and in the meantime a nonchiral liquid crystal crown ether of alike structure was also synthesized for comparison, indicating that only the former was asymmetric. The present work represents the first attempt of the investigation in chiral liquid crystal crown ether, thus providing basis for further research into problems as such.     

LITHIUM ION CONDUCTING POLYMER ELECTROLYTES BASED ON ALTERNATING MALEIC ANHYDRIDE COPOLYMER WITH OLIGO-OXYETHYLENE SIDE CHAINS

A comb polymer with oligo-oxyethylene side chains of the type -(CH_2CH_2O)_(12)CH_3was prepared from methyl vinyl ether/maleic anhydride copolymer and poly (ethyleneglycol) methyl ether. The polymer can dissolve LiClO_4 salt to form homogeneous amor-phous polymer electrolyte. The ac ion conduction was measured using the complex impedancemethod, and conductivities were investigated as functions of temperatures and salt con-centration. The complexes were first found to have two classes of glass transition whichincrease with increasing salt content. The optimum conductivity attained at 25℃ is inthe order of 5.50×10~(-6)Scm~(-1). IR spectroscopy was used to study the cation-polymerinteraction.     

SYNTHESIS AND CHARACTERIZATION OF POLY(ARYL ETHER KETONE)FROM 4-(3-PHENYL-4-HYDROXYPHENYL)PHTHALAZINONE

A novel soluble poly(aryl ether ketone) was prepared by the reaction of 4-(3-phenyl-4-hydr-oxyphenyl)phthalazinone with 4,4'-difluorobenzophenone. The polymer was characterized by DSC, TGA andX-ray diffraction.     

MELTING AND CRYSTALLIZATION BEHAVIOR OFAN AROMATIC POLY (AZOMETHINE ETHER) WITH NON-LINEARLY SHAPED MOLECULAR CONFORMATIONS

The melting and crystallization behavior have been investigated for an aromatic poly(azomethine ether) with non-linearly shaped molecular conformations. This polymer wasfound to undergo multiple melting processes and its phase transition behavior wasinfluenced sensitively by the thermal history of sample. A significant difference between thepolymer chain aggregation abilities of samples cooled from the different states wasobserved. The possible molecular morphology and aggregation models for describing thestructures of this polymer were proposed and discussed. The crystallization behavior of thesamples cooled from the partially isotropic state and the influence of cooling rate on it havealso been examined with DSC.     

SYNTHESIS OF MAIN CHAIN LIQUID CRYSTALLINE COPOLYESTERS WITH X-SHAPED TWO-DIMENSIONAL MESOGENIC UNIT AND CROWN ETHER CYCLE

A novel series of main chain liquid crystalline copolyesters with X-shaped two-dimensional mesogenic unit and crown ether cycle of cis-4,4′-bis(4-hydroxyphenylazo) dibenzo-18-crown-6 was prepared via solution condensation polymerization from 4,4′-(α,ω-hexanedioyloxy) dibenzoyl dichloride (M1), 2,5-bis(p-octyloxybenzoyloxy) hydro-quinone (M2) and cis-4,4′-bis(4-hydroxyphenylazo) dibenzo-18-crown-6 (M3). Monomer M1 was synthesized by esterification and substitution of adipoyl chloride with p-hydroxybenzoic acid, monomer M2 was synthesized by esterfication and reduction reaction of 2,5-dihydroxybenzoquinone and p-octanoxybenzoyl chloride and monomer M3 was synthesized by diazotization and coupling reaction of cis-diaminodibenzo-18-crown-6 with phenol. The molecular weights of copolyesters are not high,and the intrinsic viscosity [η] of copolyesters ranges from 0.25-0.35. The monomers' structures were identified by using elemental analysis, IR, UV, 1H-NMR, MS, etc. All the copolyesters are yellowish powders and insoluble in THF and CHCl3 at room temperature except CP9. The properties of copolyesters were investigated by using GPC, [η] , DSC, TG,WAXD and POM. It was found that all the copolyesters entered into liquid crystal phase when they were heated to above their melting temperature (Tm). The typical smectic and nematic phase texture can be observed on POM. Their mesophase transition temperature and thermal stability change regularly with varying the content of cis-4,4′-bis(4-hydroxyphenylazo)dibenzo-18-crown-6 unit in the copolyesters.     

聚乙烯吡咯烷酮稳定的钯纳米粒子催化加氢

Nanosized colloidal platinum was prepared by reduction of H2PtCl6 in methanol-water mixture by refluxing. The particle size and morphology were characterized by transmission electron microscopy and electron diffraction. The influence of polyvinylpyrrolidone (PVP) molecular mass (MM),PVP concentration,and reduction time on platinum particle size was investigated. Small (1-2 nm) Pt particles are formed in the case of PVP with MM=1.2×104. With increasing polymer MM and decreasing polymer concentration,large aggregates from small particles appear. High catalytic activity of the obtained colloidal platinum in hydrogenation of acetylene compounds is shown. The effect of Pt particle size on the catalytic activity was studied.     

PHOTOINDUCED HOLOGRAPHIC PHASE GRATINGS BURIED IN AZOBENZENE SIDE-CHAIN POLYMER FILMS WITH A CHIRAL GROUP

An optically active polymer (PM1) containing azobenzene moieties with a chiral group (s-2-methyl-butyl) wassynthesized by homopolymerization of monomer, 4-[2-(methacryloyloxy)ethyloxy-4'-(s-2-methyl-1-butyl oxycarbonyl)azobenzene, using the free radical polymerization method. The polymer dissolved in tetrahydrofuran (THF) could be easilyprocessed into high optical quality films. The optical anisotropy of the polymer films was investigated by polarizing opticalmicroscopy (POM). The experimental results showed that irradiation with a circularly polarized beam could align theorientation of the molecules in the polymer films. Moreover, the holographic phase gratings of photo-induced polymer filmswere detected by atomic force microscopy (AFM) and POM. In comparison with polymer containing no chiral group, it wasfound from the preliminary measurement of the photo-induced holographic phase gratings that PM1 containing a chiralgroup could form holographic phase gratings buried in the films.     

Effect of Rotation Rate on the Formation of Platinum-modified Polyaniline Film and Electrocatalytic Oxidation of Methanol

The oxidation of methanol was investigated on platinum-modified polyaniline electrode.Changes in the electrode rotation rates (Ω) during platinum electrodeposition remarkably affect the formation and distribution of platinum in the polymer matrix and consequently lead to different currents of methanol oxidation. The results show that platinum loading is proportional to rotation rates Ω^1/2.     

STUDIES ON CROWN ETHER CYANINE DYES (X). THE SYNTHESIS OF BENZOXAZOLE CROWN ETHER CYANINE DYES

A simple method for synthesis of benoxazole crown ether cyanine dyes is described.     

SYNTHESIS AND PROPERTIES OF SULFONATED POLY（ARYLENE ETHER） CONTAINING TRIPHENYL METHANE MOIETIES FROM ISOCYNATE MASKED BISPHENOL

A novel sulfonated poly（arylene ether） containing triphenylmethane moieties was synthesized by the sulfonation of a designed parent polymer using chlorosulfonic acid as sulfonation agent. The sulfonation took place at the para position of the pendant phenyl rings because of the specially designed parent polymer. The position and degree of sulfonation were characterized by ^1H-NMR and elemental analysis. The sulfonated polymers are highly soluble in common organic solvents, such as dimethylsulfoxide, N,N＇-dimethylacetamide, dimethylformamide, ethylene glycol monomethyl ether, and can be readily cast into tough and smooth films from solutions. The films showed good thermal and hydrolysis stabilities. Moreover, Fenton＇s reagent test revealed that the films exhibited superior stability to oxidation. The proton conductivities of the films were comparable with Nation 117 under same conditions. The membrane electrode assembly （MEA） prepared with the asmade film （706 EW, 100 μm dry thickness） shows better cell performance than Nation 115-MEA in the whole current density range.     

OPTICAL PHASE CONJUGATION RESPONSE OF PHOTOINDUCED POLYMER FILMS CONTAINING AZOBENZENE MOIETIES WITH CHIRAL GROUP

An optically active monomer containing azobenzene moieties with chiral group (s-2-methyl-butyl), 4-[2-(methacryloyloxy)ethyloxy]-4'-(s-2-methyl-1-butyloxycarbonyl) azobenzene(Ml) was synthesized. Polymer (PMl)possessing optical phase conjugated response was obtained by homopolymerzation of the optically active monomer (Ml)using free radical polymerization. The polymer was very soluble in common solvents and good optical quality films could beeasily fabricated by spin coating. The optical phase conjugated responses of the polymer PM1 were measured by degeneratefour-wave mixing (DFWM). In comparison with polymer containing no chiral group, it was found from the preliminarymeasurement of photoisomeric change that optical phase conjugated response of the PM1 in the long-range order hexagonalsymmetry microstructure could be easily controlled by choosing the appropriate polarization direction of the irradiatingbeams (514.5 nm) and the irradiating number, presumably due to the chiral group in the PM1 molecular structure. For thecase of the polymer investigated here, a chiral group side chain was introduced to increase optical phase conjugated responseintensity with different polarization directions of the irradiating beams, which aims originally at searching for a new photo-ative material.     

STUDIES ON THE EXCIMER FLUORESCENCE OF POLYPHENYL GLYCIDYL ETHER AND POLYNAPHTHYL GLYCIDYL ETHER

Polyphenyl glycidyl ether (PPGE) and polynaphthyl glycidyl ether (PNGE) have beensynthesized by cationic polymerization and their structures characterized by carbon 13 NMRand 1R, etc. The fluorescence spectra of PPGE, PNGE and their corresponding monomersPGE, NGE as model compounds have been studied. In dilute solutions at room temperature,only monomer fluorescence of the chromophore is observed. Comparison between the spectraobtained from dilute solutions, concentrated solutions and solid film shows that there is excimeremission when polymer chains in solution or in film are sufficiently close to each ocher.From the concentration dependence of the excimer emission, further evidence is obtained forthe existence of interchain excimer interaction in these polymers.     

Electrocatalytic Activity of Platinum Particles Electrodeposited onto Poly（vinylpyridine）Films

The electrocatalytic prpertics of platinum microparticles incorporated into poly-(vinylpyridine)(PVP) films ,a conducting polymer with good conductivity and stability,were investigated for hydrogen evolution and formic acid electrooxidation in acidic media,It was found that the catalytic effects depend mainly on the size and amounts of the platinum microparticles dispersed in the polymer layer.     

Synthesis and application of novel degradable crosslinkers

A novel divinyl ether was synthesized by a convenient method with high yield.Then the divinyl ether was combined with 2- hydroxyethyl methacrylate and acrylic acid,respectively,generating difunctional polymeric crosslinkers with(hemi)acetal structure that was labile in acid.The chemical structures of the divinyl ether and crosslinkers were confirmed by ~1H NMR and elemental analysis.The crosslinkers were employed in free-radical polymerization to prepare polymer gel and gel particles. Due to the(hemi)acetal structure in the crosslinking segment,the polymer gel and particles exhibited degradable ability in strong acid.     

气相色谱法探究聚醚醚酮的热降解及热氧化降解（英文）

Poly(ether ether ketone)(PEEK)was synthesized via polycondensation of hydroquinone with 4,4′-difluorobenzophenone at 320℃for 5 h.Thermal and thermo-oxidative degradation of PEEK was studied over a wide range of temperatures.In an inert medium,decomposition of the polymer occurred in one stage,with the formation of a coke residue accounting for approximately 50%of the original polymer mass.In air,the mass loss curve exhibited two distinct stages.The first stage involved breakdown of the main polymer chain,the speed of which indicated a radical chain failure mechanism.In the second stage,the rate of mass loss clearly decreased,indicating a transition from the radical chain failure mechanism to simple combustion reactions(wherein the polymer combusted completely).To further investigate the nature of the processes occurring during the pyrolysis of PEEK,the investigations were carried out using gas chromatograph under isothermal conditions.It was concluded that during thermal degradation,the decomposition of the polymer starts with the rupture of ketone and ether bonds and proceeds to destruction of the benzene ring at higher temperatures,which is accompanied by the formation of H2O and CH4.Above 500℃,the polymer degradation further involved thermohydrolysis.The thermo-oxidation of PEEK,which was accompanied mainly by the formation ofH2,was noticeable beginning at 325℃.The total yield of the latter indicated oxidation of fragments of the benzene ring.     

SIDE CHAIN LIQUID CRYSTALLINE POLYSILOXANES CONTAINING CROWN ETHER AND BENZYL ETHER MOIETIES

Two kinds of side chain liquid crystalline polysiloxanes containing crownether and benzyl ether were synthesized and characterized by optical polarization mi-croscopy. Both the monomeric liquid crystals and polymeric liquid crystals show smecticphases.     

SYNTHESIS AND NMR CHARACTERIZATION OF PRECURSORS OF EPOXY NETWORK AS POLYMER HOST FOR SOLID ELECTROLYTE

To raise the room temperature ionic conductivity and improve the mechanical strength of a PEO-based polymer electrolyte, a noncrystalline two-component epoxy electrolyte system has been prepared. The diglycidyl ether of polyethylene glycols as precursors of the system were synthesized by a two-step process. The presumed structure of the product was characterized, by ~(13)C, ~1H NMR and IR spectroscopy. It was found that a side-reaction occurred between the secondary hydroxyl group of PEG-chlorohydrin and epichlorohydrin in some degree, resulting in a by- product containing—CH_2Cl side group. By selecting a characteristic signal, which is undistorted by the increase in the length of CH_2 CH_2—O segment, a ~1H NMR approach of determining the equivalent epoxy weight (EEW) was proposed. The method is valid to specimens even though the EEW is as high as 2,000. The examination of the specimens by DSC showed that epoxidation greatly depressed the crystallinity of the PEG's, whereas the T_g was raised.     

PREPARATION OF POLY（ETHYLENEGLYCOL-co-ACRYLIC ACID） MICROSPHERES WITH DIVINYLBENZNE AS CROSSLINKER BY DISTILLATION-PRECIPITATION POLYMERIZATION

Monodisperse poly（poly（ethyleneglycol） methyl ether acrylate-co-acrylic acid） （poly（PEGMA-co-AA）） microspheres were prepared by distillation-precipitation polymerization with divinylbenzene （DVB） as crosslinker with 2,2＇- azobisisobutyronitrile （AIBN） as initiator in neat acetonitrile without stirring. Under various reaction conditions, four distinct morphologies including the sol, microemulsion, microgels and microspheres were formed during the distillation of the solvent from the reaction system. A 2D morphological map was established as a function of crosslinker concentration and the polar monomer AA concentration, in comonomer feed in the transition between the morphology domains. The effect of the covalent crosslinker DVB on the morphology of the polymer network was investigated in detail at AA fraction of 40 vol%. The ratios of acid to ethylene oxide units presenting in the comonomers dramatically affected the polymer-polymer interaction and hence the morphology of the resultant polymer network. The covalent crosslinking by DVB and the hydrogen bonding crosslinking between two acid units as well as between the acid and ethylene oxide unit played key roles in the formation of monodisperse polymer microspheres.