最新刊期
卷 ， 期 2 ， 1997
- 摘要：The sulfonated polyether ketone ketones(S-PEKK) with various sulfonation degree were synthesized by reaction of PEKK with sulfuric acid as sulfonating agent and solvent.The effect of concentration of sulfuric acid and PEKK reaction temperature and time on sulfonating degree and ion exchange capacity of products were investigated.S-PEKKs were characterized by IR,DSC and X ray diffraction.The experimental results show that S-PEKKs have the expected structure.Crystallinity and melt temprature of S-PEKKs decrease with the increasing of sulfonating degree of S-PEKK.
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发布时间：2021-03-19 - 摘要：Methyl methacrylate(MMA)was statistically copolymerized with biphenyl methacrylate(BPMA)via group transfer polymerization.The copolymer composition was measured by 1H NMR,the thermal behaviour of these copolymer was determined by DSC.The reactivity ratios were γ 1 =0.56±0.03,0.52±0.03,0.46±0.03 and γ 2 =0.79±0 03,0.81±0.03,0.85±0.03 in benzene,tetrahydrofuran and acetonitrile respectively at 30℃.Copolymers with narrow molecular weight distribution and predetermined molecular weight were obtained.
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发布时间：2021-03-19 - 摘要：AB polybenzoxazole monomer,4 amino 3 hydroxybenzoic acid hydrochloride was synthezised from methyl(or ethyl)4 hydrobnezoate.High molecular weight poly benzoxazole (ABPBO)was synthesized through condensation polymerization of above monomer in poly (phosphoric acid).Apparent stiropalescene,the characteristic of lyotropic liquid crystal polymer,was observed at the later stage of the polymerization.ABPBO film was extruded and ABPBO fiber was spinned by dry jet wet spinning from ABPBO/PPA dope.Specific viscosity of ABPBO was measured in MSA.The structure of ABBBO films and fiber were studied by elemental analysis(EA),X-ray photograph,X-ray diffraction,FTIR,TGA and Rheoribron.The tensile strength of ABPBO fiber is 1.44GPa,tensile modulus is 90GPa,and it begin to decompose at 657.3℃ in nitrogen,at 583.6℃ in air.It suggests that rigid lyotropic crystal ABPBO is a new kind of high performance polymer materials.
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发布时间：2021-03-19 - 摘要：Several aromatic diamines containing carbonyl and ether groups between benzene rings were prepared from the reaction of nitrobenzoyl chlorides with diphenyl ether and isophthelic acid chloride,and reduction of these dinitrocompounds.The polyimides from the reaction of PMDA,BTDA and ODPA with 4,4′ bis(3 aminobenzoyl)diphenyl ether 8 provided transparent orange films with excellent tensile properties,exceptional resistance to solvents and strong base,and high thermoxidetive stability.Glass transition temperature ranged between 205 and 273℃.In addition the polyamic acid from the reaction of 8 with BTDA provided excellent binding strength for aluminium to aluminium and copper to copper.
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发布时间：2021-03-19 - 摘要：Nd-containing monomer,di(isopropyl maleate oyloxyl) isopropoxyl neodymium,is synthesized by the reaction of neodymium isopropoxide with maleic anhydride.Then Nd containing copolymer is prepared by the copolymerization of Nd containing monomer with MMA using AIBN as an initiator.Their structure are characterized by elemental analysis,IR,XPS,and SEM.Studies on the properties of Nd containing copolymer indicate that,in comparison with PMMA, it has excellent heat stability,higher transmittance,larger refractive index,characteristic selective light absorbability,and paramagnetism.
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发布时间：2021-03-19 - 摘要：dispersion polymerization of styrene was carried out in ethanol/water medium in the presense of polyvinylpyrrolidone using azobisisobutyronitrile as initiator. The effects of initial mononer concentration, stabilizer concentration, initiator concentration, medium composition and reaction temperature on the size and size distribution of polymer particles were investigated through condition experiments. An ideal recipe was found out from which monodisperse polymer particles of 4.8 μm in diameter were accessible. Then the seed particles of polystyrene produced by dispersion polymerization were further swollen to about four times in diameter by means of dymanic swelling method.And the effects of water-addingrate and the amount of dispersion agent added in the swollen system on swelling process were studied.Finally,the large-size monodisperse polymer microspheres were obtained by polymerizing the monomen-swollen particles.
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发布时间：2021-03-19 - 摘要：The fractionation of a commercial polystyrene by ring thin layer chromatography is described.Twenty one fractions of the sample were separated and collected directly.The average molecular weight ( W) of the polymer is in good agreement with gelpermeation chromatograph.
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发布时间：2021-03-19 - 摘要：A new type of spiro crosslinking agent,3,11 dimethylene 2,10 dione 1,4,9,12 tetraoxodispirobutadecane(2),was synthesized successfully.Its crosslinking polymerization with MMA was carried out at 80℃ in benezne with BPO as initiator.The resulting polymer is of spiro crosslinked structure.Hydrolyses of the crosslinked polymers were undertaken at acidic and basic condition.The results of the hydrolyses have shown that the crosslinked polymer has good resistance to acidic and basic hydrolyses.
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发布时间：2021-03-19 - 摘要：By means of DSC and WAXD methods,Crystallization and crystal structure of poly(aryl ether ketone)s containing meta phenyl links were studied.WAXD results showed that crystallized from both glassy and melting state,only one crystal form of PEKMK was found with unit cell parameters of a=0.767 2nm, b =0.6149nm,and c =1.599nm.DSC results from different crystallization showed that double melting peaks (lower and upper peaks)exits.Lower peak had only 4% to 7% of all heat of fusion which originated from random lamellae produced at low crystallization temperature.At high crystallization temperature,lower peak transformed into upper peak with equillinrium melting point of 295℃.
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发布时间：2021-03-19 - 摘要：The integrated areas of UV visible absorption in 350～700 nm region have been used to characterize the thermal stability of PVC samples.The integrated absorbance of IR bands at 1667 cm -1 and 1650～1560 cm -1 have been used to measure the contents of isolated double bonds and conjugated polyene of PVC samples respectively. The results indicates that the coloration during the initial thermal degradation stage of PVC is dependent on the contents of conjugated polyene and the coloration during long-term thermal degradation is related to the conents of isolated double bonds.
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发布时间：2021-03-19 - 摘要：The crystallization behavior of nylon6/montmorillonite nanocomposites has been studied by means of WADX, DSC, SALS. The results show that the nanoparticles of montmorillonite dispersed in nylon 6 matrix play the role of nucleating agent. The surface modification of montmorillonite particles increase adhesion between nylon6 and montmorillonite which prohibits the crystatllization of nylon thus leading to increase crystallization activition energy.
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发布时间：2021-03-19 - 摘要：Three new amphiphilic polyphosphates containing two long hydrophobic side chains were synthesized by the polycondensation of pentaerythrite di fatty acid esters with β bromoethyl dichorophosphate in benzene,and then by quaterisation with trimethyl amine.The results of IR, 1H-NMR spectra and elemental analyses indicate that all the polymers have the expected chemical structures.Average molecular weight of polymers prior to quaterisation was determined by VPO method.The nitrogen content from elemental anyalyese data showed that the polymers containing 46%～49% of quaternary ammonium side chains.All quaternarized polyphosphates were used to prepare liposome by using reverse phase evaporation method.All of them could form large unilamellar liposome.The diameter of liposome is 2～6 μm.Encapsulation ratio of liposome to 5-fluorouracil was also determined.
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发布时间：2021-03-19 - 摘要：The (PMMA)/SiO2 nano composites was prepered by in situ polymerization,and the properties of this nano composites was studied by the SEM,DMA,TGA and so on. The obtained reveal that the inorganic component SiO2 which has been interfaially modified was dispersed evenly in the composites, while the unmodified ones tend to agglomerated,and the mechanical properties of treated SiO2 filled PMMA is prior to the untreated noes.It was surposed that the SiO 2 particles formed as crosslink point in the matrix because the good interfacial adhesion with PMMA while untreated ones less to do so comparely.Futhermore,the contents of the SiO2 component also have some influnence on the thermal stability,dynamic mechanical behavior,light effect and mechanical properties of the composites.
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发布时间：2021-03-19 - 摘要：The copolymer Rh complexes were used as catalysts to catalyze the reaction of carbonylation of methanol, by going through methyl acetate to produce acetic acid.They were found to have good heat stability and reactivity.On the basis of the research results by authors in the past,we have depicted the cycle scheme of the whole process of the catalytic reaction,and several kinetic parameters have been evaluated.Then the kinetic parameters of copolymer-Rh complexes of four groups of ligands in catalytic reaction were checked.The caculating value is in accord with the wxperimental value.The mechanism of the catalytic reaction has been proved reasonably and the difference of the several ligands have been discussed.
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发布时间：2021-03-19
Research Article
- 摘要：Polystyrene/polyacrylate latex IPN(PS/PACE LIPN) has been synthesized using two stage emulsion polymerization.Effects of various polymerization parameters on the damping performance have been observed systematically.The results show that the multicomponent copolymerization is in favor of broadening the damping temperature range.Changing the sequence of adding raw materials and the crosslink density of every network enables a great improvement of the compatibility of two component with each other.TEM have shown the microscopic morphology of LIPN consistent with the above results.
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发布时间：2021-03-19 - 摘要：Functional PVC with N,N diethyldithiocarbamate groups (PVC SR) prepared by the substitution of paritial chloride of PVC with sodium N,N diethyldithiocarbamate could initiate acrylamide heterogeneous polymerization in THF medium. The results showed that PVc SR had a good initiative aotivity greatly superior to the polymerization system without PVC SR for aorylamide polymerization radiated by UV light. Monomer conversion increased with radiation time and PVC SR amont. was Extracting analysis showed that polymer was mainly homogeneous polyacrylamide and grafting effoiency was not high.This was due to the spliting model of PVC-SR and the properties of heterogeneous polymerization.
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发布时间：2021-03-19 - 摘要：The chitosan and gelatin blends (CGB) were prepared with the gelatin content from 0% to 100%.The compatibility of the blends was discussed by calculating the interaction parameter and by detecting the phase structure with UV VI spectrum and PCM microscopy.As a result the minus interaction parameter and the homogenous structure certified the compatibleness of chitosan and gelatin.The mechanical properties of CGB were also determined.CGB film showed a plastics like stress strain curve in dry state and a rubber like stress strain curve in wet state.The tensile stress of CGB decreased with the increasing of felatin content;the elongation at break decreased with the increasing of gelatin content in dry state but they were higher then that of both chitosan and gelatin except from CGB-90 in wet state.Infrared spectra showed that chitosan and gelatin could form a complex by the reaction of -NH2 in chitosan and-COOH in gelatin.
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发布时间：2021-03-19 - 摘要：Dibutyltin maleate (DBTM) was synthesized by the reaction of maleic anhydride with dibutyltin oxide in THF at 50℃ for 12h.The monomer was characterized to be monomeric which containing only one tin atom by ICP,GPC, 1H NMR,FT IR and elemental analysis.Its copolymerization with VAc using AIBN or under the UV irridation was carried out.The CTC formation of DBTM with VAc was confirmed by absorption spectra.A typical alternative copolymer was obtained either by AIBN or upon UV irridation as maleic anhydride did.
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发布时间：2021-03-19 - 摘要：The carbonyl indexes (CI) of low density polyethylen (LDPE) films containing intergrowth rare earth(La+Ce+Pr) carboxylate (RE(La+Ce+Pr)Car 3) with/without aromatic ketone (AK) mixing photosensitizers during ultraviolet (UV) photooxidation were determined by infrared spectroscopy.The effects of these photosensitizers on UV photooxidative rates and viscosity average molecular weights of LDPE films are studied by using CI as the index,and their action mechanism are discussed.Results show that RE(La+Ce+Pr)Car3 and AK mixing photosensitizers may bring about the accelerated or retarded photooxidative degradation of LDPE films to varing degrees.After both UV irradiation and long stored duration these LDPF films contining above described photosensitizers still continued the stored oxidative degradation to a certain extent.
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发布时间：2021-03-19 - 摘要：A novel family of silicone prepolymers, α,ω bis( γ aminopropyl dimethyl ) poly tetramethyl p silphenylene siloxane was synthesized by ring opening copolymerization of octamethylcyclotetrasiloxane (D Me 4),dodecamethyl cyclotri p silphenylenesiloxane (D Phenylene 3),and 1,3 bis( γ aminopropyl) tetramethyldisiloxane (M-NH-22) at temperature 160℃ with 95% yield.The prepolymers were characterized by gel permeation chromatography (GPC),vapor phase osmometer (VPO),infrared spectroscopy (IR),nuclear magnetic resonance (NMR),and thermogravimetric analyses(TGA).The results indicate that the prepolymer has the structure designed.When P-silphenylene siloxane unit contents are over 20%,the temperatures for 20% weight loss in TGA curves are over 540℃,obout 70℃ higher than that of the dimethtl moiety.
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发布时间：2021-03-19 - 摘要：The synthesis of cyclic oligomeric carbonates of 2,2 bis (4 hydroxylphenyl) propane (BPA) were carried out in an interfacial hydrolysis/condensation of BPA bischloroformates.The cyclic oligomeric carbonates are an important intermediate (cyclic monomer) in the preparation of the polycarbonates (BPAPC) vis a ring opening polymerization.The ability of ring opening polymerization of cyclic monomer is influenced by its ring size and ring strain.In this paper,the different ring size of cyclic dimer,trimer and teramer carbonates have been chosen to investigate the effect of the ring strain on their structure and properties.The structure of cyclic dimer,trimer and teramer carbonates were characterized by FTIR,NMR and DSC.The ring strain in the cyclic dimer carbonate is evident from FTIR,1H-NMr and DSC results.The DSC results demonstrate that either cyclic dimer or trimer or tetramer carbonates,the ring opening polymerization take place immediately after melting.Polymerization of the cyclic oligomeric caebonates to polycarbonate with molecular weight 110000 was pbtained by heating at 280℃ for 5min.in the present of catalyst.The polycarbonate has an initial modulus of 0.23GPa,tensile break strrngth 85MPa and an elongation 230%.The DMA measurement showed that the Tg of polycabonate presented at 157℃.
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发布时间：2021-03-19 - 摘要：Novel polymer supported transition metal complexes chloromethyl polystyrene bound ephedrine cobalt(Ⅱ) were synthesized (abbreviated as CPSE Co).The catalytic activity of these complexes was evaluated in terms of their ability to oxidize different olefins in the presence of isobutaldehyde.Reaction temperature and concentration of active center in the catalyst have great influence on the reaction rate.Trans stilbene could be converted quantitatively to epoxy stilbene in 6hrs at 40℃ and the selectivity was over 90%.The catalyst could be recycled at least 5 times without loss of activity.CPSE-Co complexes are highly active,selective and stable catalysts for the epoxidation of olefins.
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发布时间：2021-03-19 - 摘要：The behavior of liquid crystalline polyacrylates with chiral side chain mesogenic units were investigated in magnetic and electric fields by IR dichroism and eletro optical effects.The results indicated that the magnetic induced orientation takes place over the entire temperature range between T m and T i .The orientation level is influenced by temperature and molecular polarity of polymers.In an electrical field,the polymer P-I shows electro optical effects known from low molecular weight liquid crystals.
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发布时间：2021-03-19 -
SYNDIOTATIC POLYMERIZATION OF STYRENE USING TITANIUM DIKETONATE COMPLEXES/ METHYLALUMINOXANE SYSTEMS
摘要：Titanium β diketonate complexes in combination with methylaluminoxane (MAO) as cocatalyst are highly active towards styrene polymerization,giving polymers with high sydiotacticity and high molecular weights.The results of polymerization showed that the catalytic activity of dibenzoylmethane complexes/MAO is higher than that of acetylacetone complexes/MAO,molecular weight and syndiotacticity of polymers from the former is lower than that from the latter.The molecular weight distribution of polymers is broader,indicating the titanium β-diketonate complexes may be a "multi-site"catalyst.- 47
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发布时间：2021-03-19
Research Bulletin
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