最新刊期
卷 ， 期 5 ， 1997
- 摘要：Random copolymerization have been performed for five binary systems using 1 methoxy 2 methyl 1 trimethylsilyloxy propene(initiator) and tetrabutylammonium bibenzoate (catalyst) in tetrahydrofuran solution.The copolymer compositions were determined by elemental analysis for nitrogen and the results calculated by the Kelen Tudos method.The monomer pairs concerned are (1) acrylonitrile (AN) and methyl methacrylate (MMA),(2)AN and ethyl methacrylate (EMA),(3)AN and butyl methacrylate (BMA),(4)AN and butyl acrtlate(BA),(5)AN and dibutyl maleate(DBM).The reactivity ratios determined in this study are:(1)rAN=10.22,rMMA=0.07;(2)rAN=5.68,rEMA=0.16;(3)rAN=8.59,rBMA=0.09;(4)rsub>AN=4.08,rBA=0.06;(5)rAN1.38,rDBM=0.06.The results show that GTP is similar to anionic polymerization with respect to the reactivoty ratios.
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发布时间：2021-03-19 - 摘要：Untreated and 11 amino acid treated montmorillonites were swollen by caprolactam.Then the caprolactam was polymerized in the interlayer of montmorillonites.The silicate layers of montmorillonites were dispersed in nylon6 matrix to form organic inorganic nanocomposites.11 amino acid treated montmorillonite had stronger chemical interaction with nylon6 molecules in comparison with the untreated montmorillonite.The mechanical properties of 11-amino acid treated montmorillonite and nylon6 hybrid was found superior in tensile strength,modulus,elongation at break and impact strength.
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发布时间：2021-03-19 - 摘要：Carboxymethyl cellulose (CMC) was produced in the medium containing benzene and 95% ethanol.Through 1H-NMR method,the distribution of carboxymethyl groups at C2,C3 and C6 positions of anhydroglucose unit (AGU) was measured and the effect of benzene was investigated.It showed that the sequence of distribution was C6>C2>C3 and when DS was lower than 1 0 C2∶C3∶C6 was 1 45∶1∶2 15 approximately;when DS was higher than 1.0 the distribution of substitution tends to be indentical.The distribution of substituent of CMC prepared in medium benzeneethanol-water at substituent had been explained by X-ray diffraction.
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发布时间：2021-03-19 - 摘要：Ten types of polyester fibres in industrial use from various domestic and overseas factories were used in this study.The detail structure of filaments has been analyzed by the data measured from small angle X-ray scattering,wide angle X-ray diffraction,density and birefringence.In addition,hot air shinkage properties of filaments were measured.Then the relations between microstructure and macroscopic shrinkage properies were discussed.The results showed that the A cX Lfvc/fa of generalized structure parameters can summarize the structure factors influencing thermal dimensional stability primarily.The emphasis was on the important role of perfection of crystals and the"degree of continuity" and the perfection of the network of crystalline elements.
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发布时间：2021-03-19 - 摘要：By means of Tyndall effect investigation,electromicroscope observation, electroconductivity measurement,and in combination with the consideration of the polymerization experiment result,it was found that Fe(naph)2 Al(i Bu)3—CH2=CHCH2Cl despersed in hydrogenated gasoline medium was a coalescence unstable colloidal catalyst system.Component ratios and feeding order of catalyst affected the form of the colloidal particles and further affected the catalytic activity and the microstructure of polymer.The optimal component ratio and feeding order were found to be [Fe]:[Cl]:[Al]:=1:2.5:20,and the catalytic were tiny and uniform, so the specifical surface area was large and the catalytic activity was high.But it was not so for other ratios.
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发布时间：2021-03-19 - 摘要：Block copolymer of Poly d,L lactide co polyethylene glycol(PLA PEG) was prepared by ring opening polymerization in vacuum at 180℃ with stannous octoate (SnOc2) as catalyst.By composite emulsion technique the PLA PEG microspheres with micron size encapsulating protein were prepared.An apparent reduction of the crystallinity of the microspheres carrying protein compared with that of non carrying protein determined by DSC indicated that protein can be effectively carried in the PLA-PEG microspheres.The size of the microsphaeres was determined by SEM.The quantification of protoin in the microspheres was carried out with BCA reagent. The results showed that comparing with homopolymer PLA,the ether-ester block copolymer PL-A-PEG is more advantageous to microsphere preparation and protein encapsulation.
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发布时间：2021-03-19 - 摘要：The divergent synthesis of a series of polydisperse hyperbranched polyesters based upon pentaerythritol and 1,2,4 benzentricaboxylic anhydride,modified by glycidyl methacrylate and methacrylic anhydride is described,proceeding in a stepwise growth manner starting from an “initiator core”,building hyperbranched arms.These materials have about 8,12 or 16 methacrylate double bonds at the chain extremities on each molecule.Those starburst hyperbranched polyesters have three dimensional and sphere-like molecular architecture without any entanglement between molecular chains.Using a viscometric cup,the flow time of the modified methacrylate hyperbranched oilyesters was compared with epoxyacrylate-modified unsaturated polyester of linear type,and showed that the viscosities of hyperbranched polyesters are rather low.The glass transition temperatures of UV cured films increase with the degree of terminal functionality.Hyperbranched acrylated polyesters are promising for the development of coatings and adhesives in industrial applications.
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发布时间：2021-03-19 - 摘要：Poly(phenylacetylene)(PPA) Langmuir Blodgett(LB) multilayer films were prepared and applied to the field of a separation funtional photoreceptor as a charge generation layer for the first time.From the π A curve,it was found that the PPA monolayer has anisotropies and relaxation of surface pressure.TEM photograph showed the orientation and arrangement of PPA chains in the multilayers.Investigations of transfer ratios and XPS indicated that the deposition of multilayers is uniform.Using PPA LB mutilayer films as a charge generation layer,the photoreceptor exhibited surface potential(V0)=1345V,percentage of potential discharge after one second exposure(△V1s)=65.05% and half decay time(t1/2)=0.58s.its photoconductivities are much better than those of the photoreceptor using PPA coating film.
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发布时间：2021-03-19 - 摘要：Integrally skinned asymmetric cellulose acetate(CA) membranes made by the wet phase inversion for removal of CO2 from natural gas were investigated.The membrane forming system of CA acetone methanol proposed in this paper is quite suitable to prepare integrally skinned asymmetric CA membranes for gas separation with good separation factor α CO2/CH 4 =30 and flux coefficient ( P/L ) CO2 =1.8×10-8cm3(STP)/cm2·s·Pa at the pressure of 0 5MPa.Scanning electron micrographs revealed that optimum membranes consist of an ultrathin,essentially defect-free skin later(～200nm)and an open-cell,sponge-likesubstructure.
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发布时间：2021-03-19 - 摘要：An experimental study of the effect of rubber particle dispersion on the brittle ductile transition of polyvinyl chlorde (PVC)/nitrible rubber (NBR) blends is carried out based on the model of pseudonetwork morphology established in our previous paper.However,two well separated master curves of brittle ductile transition for blends with the morphology of well dispersed rubber particles and with the pseudonetwork morphology were obtained,indicating that the rubber particle dispersion has a great influence on the brittle ductile transition of PVC/NBR blends.The critical matrix ligament thickness for the blends with the morphology of well-dispersed rubber particles is much smaller than that for the blends with the pseudonetwork morphologyy.Therefore,the pseudonetwork morphology is much more efficient in the rubber toughening of PVC than that of well-dispersed rubber particles.The present study strongly supports that the critical matrix ligament thickness is not noly a material property of polymer maxtrix,but it is also a function of interfacial adhesion and rubber particle configuration.
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发布时间：2021-03-19 - 摘要：Six new biodegradable phosphate carbonate copolymers were synthesized by the polycondensation of bisphenol A,phosgene,and ethyl phosphorodichloridate or phenyl phosphorodichloridate.The copolymers obtained were characterized by IR, 1H-NMR,and elemental analysis.The thermal property, n of copolymers were measured.The in vitro degradation of copolymers was studied in pH 7.4 phosphate buffer solution at 37℃ and in the presence of ribonuclease or alkalic phosphatase.The in vitro drug release of the copolymer loading 5-Fu was also investigated.
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发布时间：2021-03-19
Research Article
- 摘要：A new type of monomer, 2 methylen 1,4 dioxo dispiro[4,2,5,2] pentadecane was prepared through a series of organic reactions from simple commercial materials. This spirocyclic monomer could undergo free radical ring opening polymerization at 120 ℃ with BPO as initiator. The driving force for ring opening was the relief of the strain at the central spiro atom as well as the formation of stable carbonyl group. However, it copolymerized with MMA at the same condition without any ring opening. The structures of the monomer,resulting polymer and copolymer were determined by IR,NMR and MS.Molecular weight and its distribution of the polymers were estimaited by GPC.
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发布时间：2021-03-19 - 摘要：The physical relaxation behaviour of vulcanized rubber is described by the conception of relaxational velocity( V SR ). The results showed that using V SR =5 i =1 A iτ ie (-t/τ i) velocity equation is better to reflect stress relaxation behaviur of vulcanized rubber and have influence on relaxation at different temperatures. The V SR is considered more scientifically to describe vulcanization natural rubber of physical relaxation behaviour.
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发布时间：2021-03-19 - 摘要：Two new binary polysubstiuted acrylamide systems:N, N diethyl acrylamide /N α hydroxyethyl acrylamide and N, N diethyl acrylamide/N hydroxymethyl acrylamide were synthetized, their heat senstive properties were studied. The cloud temperature was changed with the composition of the copolymer. The dependence of cloud temperature on the concentration could be described as lg C=a+b/T .
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发布时间：2021-03-19 - 摘要：Polypropylene (PP) film was surface grafted with glycidyl methacrylate (GMA) by plasma initiation. Heparin was reacted with the GMA grafted PP surface. XPS showed that heparin was fixed on the surface.
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发布时间：2021-03-19 - 摘要：Group transfer block copolymerization of methylmethacrylate (MMA) and C 7～9 methacrylate (C 7～9 MA) was studied by using 1 methoxy 1 (trimethylsiloxly) 2 methyl 1 propene (MTS) and tetrabutylammonium bibenzoate (TBABB) as initiator and catalyst respectively. The influence of temperature、/ and monomer sequence on GTP was discussed. When T =85℃, =0.16 mol/L; /=0.19±0.01, C 7～9 MA as first monomer was favorable to the synthesis of PC 7～9 MA b PMMA block copolymer. According to Arrhenius equation,the activetion energy of PC7～9MA GTP was counted to be (Ea=48.3 KJ/mol).The molecular weight and molecular weight distribution of copolymer were measured by GPC.The structure of block copolymer was characterized by FT-IR and 1H-NMR.
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发布时间：2021-03-19 - 摘要：Many studies have been reported on oxidation of some molecules by potassium diperiodatoargentate(III),in which most experts think that the mechanism of oxidation is a two electron transfer process without radicals, and Ag(III) cannot initiate polymerization of monomers. However, under our experimental conditions the results show that the polymerization of monomers such as acrylamide, acrylonitrile can be initiated by Ag(III) redox system. In this paper, graft copolymerization of methyl acrylate (MA) onto nylon-1010 is carried out by using potassium diperiodatoargentate(Ⅲ) as the initiator.It is found that Ag(Ⅲ)-nylon-1010 system is an efficient redox initiator for the graft copolymerization. The effects of temperature.time and concentrations of initiator and monomer on the reaction are inverstigated.A single electron transfer mechanism is proposed to explain the formation of raducals and the initiation.
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发布时间：2021-03-19 - 摘要：The relation between the quantity of adsorbed partially hydrolyzed polyacrylamide (HPAM) on two porous media and the hydrolysis degree( HD ) of HPAM was studied. The saturation adsorptions ( Ad ) of HPAM on the montmorillonite and the kaolinite decrease with increasing HD up to about 25%, and reach a minimum at about 25～30% HD , but increase with increasing HD if HD %>30%. This result could be explained by the formation of the maximum intramolecular hydrogen bonding of HPAM with the HD in the range of 15～30%.
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发布时间：2021-03-19 - 摘要：Using Sulfonated hydroxyethyl cross linked chitosan beads as adsorbents, adsorption experiments were performed by adding the beads to the plasma. The results showed that this type of adsorbent could cut down the concentration of LDL in plasma by 79.7% at most, while concentration of high density lipoprotein (HDL) and total protein (TP) decreased only by 7.3% and 2.6% at least respectively, so this type of adsorbent can be used to cure hyperlipidaemia in the future.
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发布时间：2021-03-19 - 摘要：Through the asymmetric reduction of poly(methyl vinyl ketone)and copolymer of mehtyl vinyl ketone and styrene, optical polymers with chiral alcohol groups were synthesized. The effect of measuring solvents on the specific rotatory power of the reduction products was investigated. It was found that the optical rotation was mainly caused by the chiral alcohol groups in the molecules of the synthesized polymeric alcohols.
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发布时间：2021-03-19 - 摘要：The azido copolyethers of 3,3 bis(azidomethyl)oxetane(BAMO) and tetrahydrofuran (THF) were synthesized by cationic ring opening copolymerization and its molecular structure was characterized by IR and 1H-NMR. The chain structure of the polyethers was analyzed with 13C-NMR. It has been found that the feed ratio is good to equalize the chain segmental ratio fairly.
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发布时间：2021-03-19 - 摘要：The introduction of sulfonate groups into polystyrene has made polycarbonate and polystyrene partially miscible. The Tg's shift, revealed by DSC study, showed the partially miscibility between the two polymers. Infrared spectra confirmed that this miscibility was a contribution of the ion dipole interaction between polar groups in polycarbonate and the zinc sulfonate groups in sulfonated polystyrene.
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发布时间：2021-03-19 - 摘要：Intermolecular compositional heterogeneity of ethylene propylene random copolymer produced by homogeneous catalyst was investigated by using fractionation, 13 C NMR and GPC techniques.Combining with degradation,intramolecular compositional heterogeneity was also examined.It was found that in our sample intermolecular compositional heterogeneity existed to some extent,intramolecular compositional heterogeneity was negligible in this copolymer.
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发布时间：2021-03-19 - 摘要：In this paper, main subunits of the silk fibroin were separated by Sephadex G 200 when the silk fibroin was reduced by 2 mercaptoethanol. Then the amino acid compositions of the native silk fibroin and a-、c- subunits were measured and analyzed. The result about silk fibroin subunit composition discussed in the former paper was tested and verified. And some properties of silk was interpreted in view of microcosmic structure of silk fibroin.
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发布时间：2021-03-19 -
SYNTHESES OF N ACRYLOYLPHENOTHIAZINE OXIDES AND THEIR POLYMERS AND THE FLUORESCENCE BEHAVIOR THEREOF
摘要：N Acryloylphenothiazine oxides, namely, N acryloylphenothiazine 5 oxide (APTO) and N acryloylphenothiazine 5,5 dioxide (APTDO) were synthesized by oxidation of N acryloylphenothiazine (APT) using sodium perborate as an oxidant in acidic medium. Their polymers were obtained by radical polymerization using AIBN as an initiator. The fluorescence behavior of these monomers and their polymers has been explored. It has been found that the fluorescenceintensities of APO and APDO are much lower than those of their corresponding polymers at the same chromophore concentration in DMF.A Fluorescence Structural Self-Quenching Effect (SSQE) has also been observed as we have reported previously.Furthermore,the difference of relative fluorescence intensity between P(APT) and APT was larger than that of P(APTO) and APTO.This indicates that the lone pair electrons of the sulfur atom in the phenothiazine moiety play an important role in SSQE.As regards to the fluorescence behavior of APTDO,on account of the absence of two lone pair electrons of sulfur atom in phenothiazine moiety,it does not display obvious SSQE.- 2
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发布时间：2021-03-19 - 摘要：The effects of the emulsifier concentration and emulsifying temperature on the size and morphology of the waterborne particles prepared by phase inversion technique was studied. It is shown that the above mentioned factors will dominate the viscoelasticity ratio after and before phase inversion. The ratio could be correlated with the strength of the interfacial layer in the W/O dispersions before phase inversion point quite well. High and low viscoelasticity ratios will correspond to high and low strength of the interfacial layers respectively.When the strength of the interfacial layer is high,the phase inversion is complete with the small single waterborne particles obtained;on the contrary,when the strength of the interfacial layer is low,the phase inversion is incomplete with the big porous complex spheres obatained.
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发布时间：2021-03-19
Research Bulletin
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