最新刊期
卷 ， 期 6 ， 1996
- 摘要：FRS-XRSA is a new procedure to study crystallinity and orientational distribution of crystallites (ODC) of various preferred orientation polymers. It eliminates the overlapping of multipeaks which occures in the traditional pole figure method (PFM) by CPR,overcomes the difficulty of ghost texture which appears in the orientational distribution function analysis (ODFA) because FRS-XRSA is a direct method,and can obtain ODC of almost all of the important (hkl) plane normals by one measurement sequence. In present paper,the ODC of two kinds of biaxially oriented PET magnetic films were studied.Based on the crystal geometry principle(CGP),the general relationship between crystallite-coordinate and sample-coordinate was set up and the ODC of unmeasured(h′k′l′)plane was dedyced.And up the formula of biaxially orientational function2hkl,i>,i=N,M,T, also was set up. By FRS-XRSA,we obtained biaxial pole figures of ten(hkl)palnes,pole figures of three main planes(100)、(010)、(105)、and their orientation function 2hkl,i>,fchkl,i,etc.The results are very satisfactory.
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发布时间：2021-03-19 - 摘要：By adding different weight of CuBr 2(ratio n=/=24,16,12,8,4)in Polyoxyethylene(molecular weight=5×10 6),We prepared a series of high polymer film of solid electrolyte T(EO) n-CuBr 2 with the method of mixed solution and evaporation in vacuum.Their complex impedance spectra were measured in detail at different hydrostatic pressure in the range from 0.1MPa to 300MPa.Through further spectra decomposition the dependence of ionic conductivity(or dielectric constant)on measuring frequency under different pressure was obtained respenctively.As a result of spectra analysis,the variation of ionic conductivity and dielectric constant with hydrostatic pressure in P(EO)n-CuBr2 film was calculated precisely.On the basis of X-Ray diffraction,above mentioned pressure effects were discussed tentatively according to the physical picture of ionic transport -passage and polarization mechanism of high polymer.Adding the plasticizers,propylene carbonate(CH3-CH-OCH2-OC=O,C4H6O3)with concentration of mol.ratio npc/ntotal=20% can enhance ionic conductivity under 120～300MPa one order of magnitude.
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发布时间：2021-03-19 - 摘要：By use of simplex optimization method and numeritical integration, a mathematic model of the Alfery-Goldfinger differential equation is set up and a general computer stream line program is worked out, which can be used to compute either the reactivity ratios of the monomers in a tercopolymer system according to the initial composition and the composition of the copolymer at any conversion or the composition of a copolymer if the reactivity ratios of monomers are known. The system composed of styrene、 acrylonitrile and β-bromostyrene is used to test the usefullness of the program.
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发布时间：2021-03-19 - 摘要：A novel visible-light sensitive ion-pair photoinitiation system diphenyliodonium salt of ethyl esterified eosine has been synthesized and studied.The results showed that its physicochemical properties and photoinitiation efficiency are influenced by its structure,concentration and the properties of the media in which it is in.When exposed to visible light,the photoinitiated electron transfer from the anion to the cation took place,producing initiating phenyl radical and terminating ethyl esterified eosine radical.The kinetic equation of photopolymerization of vinyl monomers with this photoinitiator,molecular weight and distribution have been measured.Finally comparison of the monoiodonium and bisiodonium salts of eosine have been carried out.
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发布时间：2021-03-19 - 摘要：The hydrolytic degradation in vitro of polydioxanone suture(PDS) was studied by examining the change of tentile strength,weight loss,molecular weight,macromolecular orientation,and the level of crystallinity of the suture samples.It was found that the breaking stress decreased with decrease of molecular weight and degree of macromolecular orientation.The significant decrease of molecular weight while the weight loss changing a little for the PDS suture in the period of four weeks in vitro degradation proved that the reactivity for hydrolysis of ester linkages is the same, whether in the middle of the chain or in the chain end,and only depends upon the accessibility of water molecule.The result of WAXD and DSC showed that the original crystaliline region substantially remained unchanged during the initial four weeks in vitro degradation,and the new ordered regions appeared in the amorphous area.These results could be explained by the change of macromolecular structure of sutures.The whole process of hydrolytic degradation in witro for PDS samples is similiar to that for PGA suture.
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发布时间：2021-03-19 - 摘要：13C spin-lattice relaxation times (T 1(C)) of several typical polymers, copolymers, polymer blends and immiscible blends compatibilized by graft copolymer have been measured by 13 C CPMAS NMR technique. The results show that T 1(C) is auseful parameter for characterizing solid polymers, as it can provide information about microscopic morphologic structure and molecular motion of solid polymers. It not only can tell whether or not some intermolecular interactions exist in a blend system,it can also qualitatively show the strength of the intemolecular interaction and accurately indicate the site where the intermolecular initeration occurs.Therefore,it can procide a direct experimental evidence for exploring the miscible mechanism of a polymer blend.Besides,T1(C) value can give a direct experimental evidence,which can not be obtained so far by other techniques,for compatibilizers connecting the two immiscible components.
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发布时间：2021-03-19 - 摘要：The photosensitivity of electrophotographic photoreceptor (P /R) devices incorporating polyphenylacetylene (ct-PPA) sensitized with malachit green (MG) has been investigated by means of potential discharge techniques. It was found that MG is a new and powerful sensitizer for the P /R device of ct-PPA. The P /R device with Al /ct-PPA:MG:PC (100:5:10)(1～1.5 μ m)PVK:TPA:PC(10:10:1)(15～20 μ m)appeared preferable in photosensitivity enhancement and showed good photosensitivity:initial surface potential, VminVt50%(1.0s);half decay time,T1/12=0.87s,and photosensitivity,S=2.3×10-3(1x.s)-1.The possible mechanism of high photosensitivity in MG sensitized ct-PPA may be soectral sensitization only.
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发布时间：2021-03-19 - 摘要：A series of chain-extended ureas containing polyethylene glycol (PEG) spacers with different molecular weight were synthesized and the reactive activity,impact strength,the dynamic mechanical behavior,the morphology and the storage property of the epoxy resin/Ui/dicyandiamide system were studied.Experimental results revealed that the impact strength of the epoxy resin/chain-extended urea containing PEG flexible spacer with molecular weight 400/dicyandiamide system was seven times higher than that of the epoxy resin/dicyandiamide system,and the SEM micrographs of the impact fractured surface showed the tough fracture characters.Re-sults also showed that the molecular weight of PEG flexible spacers in chain-extended ureas basically and no influence on the reactive activity of the ureas.The storage life of epoxy resin/Ui/dicyandiamide systems at 50℃ was one to two days.
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发布时间：2021-03-19 - 摘要：Stable polysiloxane latex were prepared by emulsion copolymerization of ocamethylcyclotetrasiloxane (Me-D4) and tetravinyltetramethylcyclotetrasiloxane (Vi-D4) using H2SO4 as initiator.Crosslinking reaction between vinyl groups on various prepolymers was carried out in the precence of free radical initiator.The distribution of Me-D4 and Vi-D4 residues in the copolymer chain was discussed based on the kinetics data of emulsion ring-opening copolymerization.
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发布时间：2021-03-19 - 摘要：New metalized films were obtained by the reduction of PAN/metal salt chelate films with NaBH4 aqueous solution.The sereductive films exhibited excellent surface conductivity around 10 -1 ～10Ω/□.The structure and existence of the polymer metal chelates were studied and identified by UV,IR spectuocopy.The effests of the surfsce resitance of metallized films were discussed.According to the studies,a mechanism for the polymer surface reduction metallization was proposed.
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发布时间：2021-03-19
Research Article
- 摘要：The effects of molecular weight(M η) on the crystallization and melting of nylon 1010 have been studied by DSC.With the M η increasing,the initial temperatures of crystallization of the samples with different molecular weight are near a constant (178℃);the peak,finish temperatures decreased almost linearly,and the degree of supercooling and the temperature ranges of crystallization increased linearly.The crystallization heat,entropy and crystallinity decreased quickly when M η4,and steady decreased linearly when Mη>104.The relation of melting are higher than that in the crystallization.
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发布时间：2021-03-19 - 摘要：Bioxazoline compounds (BOZ) are effective chain extender for polyesters.The molecular weight (or )of polyester may be quech increased at short time by adding small BOZ,so that,it can be used for “reactive extrusion”.In this paper,we report synthetic method of BOZ and its behaviour of physics and chemistry.
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发布时间：2021-03-19 - 摘要：A novel acrylic monomer having phenoxazingl moiety,N acrylyl phenoxazine(APO)was synthesized and its polymer P(APO)was obtained by free radical polymerization.The UV Vis spectrum of P(APO) was different from that of APO due to the disappearing of the double bond.It was aslo observed that the fluorescence intensyty of the monomer was much lower than that of its polymer.This was termed as "structral self quenching effect" as we have reported previously.The fluorescence of the polymer could be quenched by electron-deficient quenchers and the Stern-Volmer constants of these quenchers were obtained.Furthermore,the two fluorescence livetimes of P(APO)indicated tha complicated state of the chromophores on the polymer chains.
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发布时间：2021-03-19 - 摘要：There were two obvious transitions on the dynamic mechanical spectrum for the comblike polymer based on methylvinyl ether /maleic anhydride alternating copolymer backbone and on polyethylene oxide side chains(CBP) and its CF3SO3 Li complex.α transition was assigned to main chain glass transition.The initial α glass transition temperatures were dependent upon salt content and all below 25℃,the β transition was assigned to glass transition of polyethylene exide short side chain.And the β glass transition temperature (Tβ)increased with the increasing of salt content.The relation between the conductivity (σ)and salt content (or Li/EO ratio)showed two peaks,which were corresponding to the minimums of Ta. The relation between σand temperature followed the VTF eguetion.Turn of the linear relationship was believed that the α-glass transition was responsible for it.
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发布时间：2021-03-19 - 摘要：α-Chlormethyl α methyl β propiolactone(CMMPL)was synthesized by dehydrochlorination of dichloromethyl propionic acid(DCMPA)in the presence of DOH.The ring opening polymerization of CMMPL was successfully carried out by using Sn(Oct)2,Ti(OBu)4,Al(i OPr)4 and Al(Et)3 as initeators in bulk or solution.Powder X ray diffraction and DSC measurement showed that P(CMMPL) was a kind of high crystalline polymer. Both the polymerization conversion and the properties of the polymer were affected by the monomer concentration and the polymerization time.
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发布时间：2021-03-19 - 摘要：Chromophores (R-HANB) with “push-pull”structures,based on 4-(N,N′-dihydroxyethyl) amino-4-nitroazobenzene (HANB) has been designed and synthesized.Linear polyurethanes with high second-order nonlinear optical activity were obtained through their reaction with toluene diisocyanate (2,4isomer).The second harmonic generation temperal stability of poled polyurethane films was in the following order at the same temperature: o-CH 3-HANB>HANB>o-OCH 3-HANB≈m Cl HANB,which could be explained by the effect of the free volume of the thermal motion for chromophores and the thermotropic initeraction due to polarizability anisotropy of dipoles in films.
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发布时间：2021-03-19 - 摘要：The all para polyether ketone ketone (PEKK) whic possesses good mechanical properties was synthesized by the high temperature condensation reaction between 1,4-bis (4’-hydroxybenzoyl) benzene and 1,4-bis(4’-fluorobenzoyl) benzene,the general properties of PEKK were characterized by DSC,IR,TGA,WAXD and Mechanical Properties Measurement.The results indicate that the melting temperature of PEKK is 50℃ higher than that of PEEK and still keep the high temperature resistant property of PEEK,the crystallization structure of PEKK still assigns to orthorhombic system.When amorphous PEKK was annealed below 230℃,the glass transition temperature increase with the increasing of the heat treatment temperature,while above 230℃,the glass transition temperature keep a constant,the low melting peaks linearly increase when annealing temperature are increased,the high melting peaks keep a constant regardless of the heat treatment temperature.The crystal structure of the slow-cooling crystallization specimens have a distinction with that of heat treatment crystallization samples.
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发布时间：2021-03-19 - 摘要：The comonomer sequence distributions of a series of ethylene -dimethylamino-ethyl methacrylate copolymers(EDAM) were determined by high-resolution 13C-NMR spectroscopy quantitatively. It was found that the crystallinities and the lamellar thickness of EDAM samples reported by Ohmae et al. vary linearly with the numerical average sequence lengths of ethylene sequence. It was demonstrated that only ethylene chains longer than a critical number (25) can enter the crystalline region.This critical number is found to be independent of the molecular weights and the DAM contents of the copolymers under the same crystallization condition.
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发布时间：2021-03-19 - 摘要：The morphology development in blends of polyamide 6/polyethersulfone (PA/PES) has been investigated.These blends were melt blended with different compositions and for different mixing time.Based on macroscopic quantitative characterization and microscopic observation,a procedure for determining the state of co-phase continuity was set up and the relationship among co-phase continuity,composition,and blending time was investigated.
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发布时间：2021-03-19
Research Bulletin
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