最新刊期
卷 ， 期 1 ， 1994
- 摘要：The formation of ionic complex at the air/water nit6rface could diminish theeleCtrostatic repulsion among the hydrophilic anions of amphiphiles and increasethe stability and transferability of the monolayer. The results of X-- ray distraCtionindicated that Y-type LB films of 2C14SNa were transferred to the polystyrenesubstrates either on pure water or on PEI solution. The difference of the repetitionperiod of these LB films was about 0.30 tim.
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发布时间：2021-03-19 - 摘要：he dynamics of liquid-liquid phase separation of two polymer blends ofpolystyrene/poly (vinyl methe ether) (PS/PVME ) and chlorinatedpolyethylene/ ethylene - vinyl acetate co polymer (CPE / EVA ) was studied bytime-resolved rheometrics meChanical spherometer in spinodal decomposi non (SD) regions. It was found that in the early stage of SD, the dynamicmodulus (G' ) and the dynamic viscosity (n' ) increased with time after the initiation of the isothermal phase mparation; in the intermediate and later stage,G'and η'decreased as the phaseseparation proceeded. This behavior was analyzed and explained in the context of Doi-Edwards model by considering the factors of phase-size increasing,phase bursting and rotating under the shear motion.At the same time,the concept of Dickie's effective volume was introduced to manifest this phenomenon. However, blends of CPE/EVA (25/75, wt/wt) and PS/PVME (90/10,wt/wt),the dynamic viscosity increased slightly in the later stage.it needs further more detailed studies.
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发布时间：2021-03-19 - 摘要：y utiliaing all speCtra data and dividing them into six groups, in the presence of inverted propylene, a ternary copolymerizaholl model was established to calculate the sequence distribuhon of copolymers prepared with different catalyst systems. The results agree with observed values very well. This model is applicableto case both having and not having inverted propylene in chain. This method notonly can be utilind in calculating the area of peaks and kinetic parameters r1, r2 but also can avoid the difficulties of separating peaks and the errors caused by separtaing peaks reluctantly.
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发布时间：2021-03-19 - 摘要：N-Allylcarbazole has not been homopolymerized but copolymerind withmethyl methaCrylate at high temperature. The reactivity ratios of the tWomonomers in copolymerization at temperature range of 200 - 260 t has been es timated, and both r1 and r2 were less than unity at the tffoperature of 250 t.The average molecular weights of the resulting copolymers decreased with theincreasing temperature in copolymerizahon. The results obtained here showed thatboth propagation and degradation existed in the copolymerization system and sug-gested a possible radical proceeding for copolymerization of N-allylcarbazole with methyll methacrylate at high temperature.
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发布时间：2021-03-19 - 摘要：EEK has been synthesize by polycondensation of excess 4, 4'-diflu oro benzo phen o ne (DFBP) with hydroqulnone in diphenyl sulfo ne. B yusing UV, MI, TGA and DSC techniques, the effects of phenoxide groups andits relative concentration on the structure and propenies of PEEK during Synthsisand processing have been studied. The results showed that the phenoxide groupscould lead to branching and cross--linking, and this increased with its relativeconcentration. We can control the molecular weight of product by synthesizing PEEK with excess DFBP, it also helps to preventing side reactions such as branching and crosslinking,and inproving the flow and thermal properties of PEEK. We also discuss in this paper the mechanism of the branching reaction and the mechanism of the thermal degradation of branched PEEK cahin.
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发布时间：2021-03-19 - 摘要：The J-integral method was aPPlied to the amorphous poly (phenylene etherketone ) (PEK-C), which is a high-Performance POlymer with Tg of 220 ℃ made inthis institutinn. The relationships between reta￣g take at temperature of 200 t withthe yield strength fracture toughness JIC critical plastic yielded zone size AL. andresistance to stable crack extension aJ/d(△a) of PEK-C were investigated. Withincreasing the retaining table at 200 t, a pronounced increases of the fold strengthand aJ/d(△a) occur within first a few hours and then only a slow asymptotic approach to equilibrium properties is observed. However the JIC and △LC decrease slowly with increasing the retaining time at 200℃. The time-dependence of yidlding and frac-ture behavior at the elevated temperature was discussed based on molecular motion.
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发布时间：2021-03-19 - 摘要：imethyl - 1, 3 - diethyl - 1, 3 - his(3 - (2, 3 - epoxy propoxy ) propyl )disiloxane (TEDS) was synthesized and used as modifier for epoxy reSin. Basedon the studies on the curing kinetics of TEDS/ DDM system as well as model rcasnon of TEDS/di - n- butylamine, the first order kinetic was proposed for TEDS.Besides, the dynamic mechanical behavior, impact strength and the morphology ofDGEBA/DDM system modified with TEDS were studied. Results showed thatthe impact strength of the modified system was found to be enhanced with the increase of TEDS content, whereas the glass transition temperature (Tg) was de-creased linearly. SEM observation of the fracture surface of the impact specimen al-so showed that as the increase of the modifier content the toughed fracture charac-ters were obviously appeared.
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发布时间：2021-03-19 - 摘要：Due to their stability，polyaniline (PAn) is considered to be one of the most potential applicable conducting polymer．Ion beam effects on polyaniline films un-der the ion implantation with potassium ions (K+) have been investigated by studying P An in pernigraniline form through the FTIR and the temperature depen-dence of the dc conductivity．The pristine pernigraniline forill PAn has conductivi-ty as low as～10-14S／cm2．The energy of K+ ions is 40 keV，while the dose ranged from 1×1015 to 1×1017K+／cm2．Results showed that the conductivity of the PA films enhanced when doses increased．The conductivitv at implanted region of the PAn films approaches 3.3×10-6S／cm when dose is about 1×1017K+/cm2，and is eight magnitudes higher then that of the pristine．FTIR spectra demonstrated that the pernigraniline PAn reveals reduction under the K+ ion implantation, which is proposed to be the reason of conductivity．The mechanism of ion implantation and the relation of temperature dependence of conductivity σ～exp[-(T0／T)1/2] suggested that the conductivity is due to the hopping in granular metals island．
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发布时间：2021-03-19 - 摘要：olyaniline (PANI) with various inherent viscosities have been synthesize under a number of different reaction conditions. Their solubilities in organic solventshave been studied. It was found that the best solvent for PANt isN-methylpyrrolidone (NMP ) and only low molucular weight PANt can be dissolved in organic solvents. Soluble PANt ([η] =0. 49dl/g) in NMP was used tocopolymerize with -COCI terminated low molecular weight poly-(p- phenylene terephathalamide). Through elemental analysis the molecular weight of PANi has been ascertained.
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发布时间：2021-03-19 - 摘要：Nylon- 1010 samples were treated by two methods,method I: annealing after melting；method II：annealing after quenching of melt at room temperature．The diffractional patterns of the isothermal crystallization samples were deter-mined by WAXD．There are three distinct peaks at 20=8.5°，20.05°and 23.92°respectively，the amorphous samples have only a broad peak at about 20=21.50°．Based on the graphic multipeak resolution method，the degree of crystallinity (Wc.x) of the samples after various heat treatments were calculated．In order to confirm the results，the degree of crystallinity( Wc.d) from density measurement and the degree of crystallinity (Wc.h) from DSC measurement were also shown．The Wc,a (a=x，d，h) of every sample has maximum value of the normal distribution with temperature change，indicating that both method I and nethod II have the most suitable annealing temperature (Th) for crystallization of the sam-pies．The Wc,x of the samples from method I were higher than those of the sam-ples from method II when the Th were the same，indicating that method I is bet-ter than method II for the crystallization of Nylon-1010．Based on Variance-Range Function method，the single peak of 002 was sepa-rated into crystalline and amorphous partions by using a computer．After all pro-files were corrected for back：ground，Lorentz factor，polarization factor and absorption factor，the variance W2θ=W0+Kσ can be obtained．The plot of variance (W) vs range (σ) is a straight line．The values of the slope k and intercept Wo were obtained．The crystallite size Lhkl and paracrystallinity parameter g can be calculated．The Lhkl in terms of the Scherrer Equation were also calculated．The result in-dicated that Lhkl calculated from the two methods have maximum values when plotted against the temperature change．The Lhkl of the samples from method I are higher than those of the samples from method II when the Th are the same．The values of g are on the reverse，indicating that the crystal lattices of the samples from method I are more perfect．These showed further method I is advantageous for the formation and stability of the crystals．
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发布时间：2021-03-19 - 摘要：n present paper the aromatic-aliphatic copolyamides with different sequencestructure were synthesize from tefrphthalyl chloride (TPC),p-phenylenediamine (PPD ) and aliphatic diamine (ADA, H2N - (CH2)n -NH2,n=2, 6 ). The relationship between sequence structure of copolyamides, includingrandom degree (B) and number average sequence length (Ln), and the lyotropicliquid crystalline properties, including critical concentration (C*) and the type ofmesogenic phase was studied. The results show that the critical concentration of the liquid crystalline copolyamides increses with the raise of B and decress of Ln and the mesogenic phases of copoly amides transform from nematic to smectic as the LnA/LnP is approximately equal to 0.20.
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发布时间：2021-03-19 - 摘要：Ring - opening copolymerization of maleic anhydride alAn ) with propylene oxide (PO) was successfully caacced out by using rare earth complexes (i. e.,Nd (P204)3, Nd (P507)3, Nd (naph)3 and Nd(acac)3 3H2O ) in combinationwith aluminum alkyls as catalysts for the first time. The relative concentration oftriads of the MAn-PO copolylner obtained was investigated on the basis of1H-NMR in devil. The results showed that the rare earth coordination systemswere favourable catalysts for the copolymerizahon of MAn with PO, giving high yield and almost alternating opolymer. The number- average molecular weight and molecular weight distribution were in the range of 2000-3000 and 1.3-1.7 respectively. The composition and the monomer distribution were affect-ed by the monomer charge ratio,the sort of catalyst,and the property of solvent.It was also found that the monmer composition of copolymer predicted from the thire- order Markoffian process fit the observed 1H-NMR data perfectly.
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发布时间：2021-03-19 - 摘要：A poly (β- alanine ) macromer with acrylamido - chain- end was synthesize.Its molecular weight was obtained by end-group titration and IH-NMRmeasurement, and its branching degree was measured by 13C-NMR and NaOHhydrolysis method. Copolymerization of acrylamide and sodium acrylate with thepoly (β- alanine) macromer in aqueous solutions by using a ferrous sulfate/cumenehydroperoxide redox initiation system resulted in formation of poly(acrylamide - co - sodium acrylatc ) - g - poly (β- alanine) graft copolymers,the composition of whichwas determined by 1H-NMR and titration. The solution properties show that the graft copolymers with higher poly (β-alanine) content exhibit better viscosity retentionin brine and high storage stability,compared with partially hydrolyzed polyacrylamide (HPAM).
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发布时间：2021-03-19 - 摘要：he sulfonated polyethylene ion - exchange membrane, which is hydrophilic, resistance to solvents and acid-alkali, was prepared by a heterogeneousphotochemical chlorosulfonation of polyethylene film. Pervaporatioh separation ofdioxane/water mixture through this membrane indicates that both flux and separation factor are vary high when the fed is near azeotropic composition. The effectsof counterions, tffeperature, ion-exchange capacity and fed concentration on themparation properties were discussed. The transport of permeants was supposed to be through a "water channel" formed from the connection of water cluster in the membrane. The "water channel" model was supported by the facts that the dis-tance between two ion-groups is shorter than 10A for the membrane with 1 meq/g,and the apparent permeation activation energy of water in the membrane is near that of in water.
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发布时间：2021-03-19 - 摘要：our 13- arm star branched polystyrene samples differing in molecular weighthave been prepared and were determined by GPC combined viscometry. The fadtor in condition is obtained from viscosity data in good solVent by way of linear extrapolation. The difference between the factorpo factor as well as the selechon ofε - value in relationship between andis discused,' and wore compared with results for 4- armand 7 -any star' brarehed polystyrene, obtained in previous paperly,
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发布时间：2021-03-19
Research Article
- 摘要：The kinetic of polymerization of aeqlamide (AM ) inihated by the combination of N - (N,'N L dimethylaminomethyl ) acrylamide (DMAAM ) with potassiumpersulfate was stUdied. The rate equation was given as:Rp= Kp[DMAAM]0.5[K2S2O8]0.5 [AM]The overall aCtivation energy was determined to be 27.86 KJ/mol. DMAAMwas shown not only joined the ndox initiahon but also incorporated intO thepolymer chains, so that the high molecular weight 107 of polyaCrylamide was obtained but the distribution of molecular weight was broad. The effect of additives on molecular weight and its distribution has been studied.
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发布时间：2021-03-19 - 摘要：he copolymerization of vinyl sulphone dyes with acrylonitrile were carried outin HIO media. The effects of the increase in dye concentration on the conversionof copolymerization molecular weight of copolymer, and the content of dyechromophores combined in the copolymer were studied. The eghaneemellt on thetermination of macromolecular radicals by added dyes was discussed.
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发布时间：2021-03-19 - 摘要：n- situ photopolymerizahon of oriented liquid crystals (LC ) is an importantmethod of preparing high quality polymeric LC films for new optical devices. Thisarticle develops a method for characteriaing the kinetics of photopolymerizahon inelectrical fields using poled electrical current and electrical resistance which arise inthe reaction process. It provides with a simple and effective mean.
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发布时间：2021-03-19 - 摘要：ffect of pressure on the swelling of three different tffoperature-sensitivegels was studied. The gels used were polyp - isopropylacrylamide) (I,NIPA), pci Y (N-n - propylacrylamide) (PNNPA) and poly (N, N - dirthylacrylamide)(PNDEA). It was found that both PNNPA gel and PNDEA gel are pressure sensi tive, as PNIPA gel is, in a SPedal ration of tffeperature, and that this phenomenon is caused by the variation of their volume phase transition tffeperatllre withpressure.
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发布时间：2021-03-19 - 摘要：he morphology and properties of highly oriented films of blends ofHDPE/ UHMWPE were investigated by electron microscope, DSC and mechnicalproperty measurements. The as-drawn films of HDPE consist of highly oriented lamellar structure.The lamellar growing direchon is vertical to the drawing direction. AddingUHMWPE into HDPE results in formation of fibrous crystals with their fibrousaxis directions parallel to the drawing direction. The number of the fibers in thefilms of the blends increases with the increase of the content of UHMWPE. The presence of ultra - high molecular weight component in as - drawn blends films results in the increase of tensile modulus considerably.
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发布时间：2021-03-19 - 摘要：N- [( 2-oxo - 1 -pyrrolidinyl) methyl] acrylamide (PyMAM ) andN- [(2 - oxo - 1- pyrrolidinyl ) methyl] methaGrylamide (PyMMAM ) weresynthesized by reaction of N--hydroxymethyl pyrrolidone with correspondingacrylamide. The polymerization of PyMAM was caacced out in aqueous solution,using N, N - dimethylaminoethyl methacrylate (DMAEMA) - potassiumpersulfate (KPS) as initiation system. A superhigh molecular weight of polymewas obtained. A slightly cross- linked hydrogel prepared from these monomers displayed high equilibrium water content (EWC)up to 97.4%.
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发布时间：2021-03-19 - 摘要：The influence of MgCl2 crystal modification (α- MgCl2, β- MgCl2 ) on theproperties of supported catalyst for propylene polymerization has been studied bymeans of XRPD, IR and DTA-TG. The structural difference and similarity between α- MgCl2 and β- MgCl2 was still reclined in its milling produCt withdiisobutyl phthalate and in the catalysts prepared from α- MgCl, and β-MgCl2caaccers respectively. β-MgCl2 supported catslyst gives higher activity and lowerstcreospedficity than α- MgCl2. The catalyst prepared by using Mg(OEt)2 as carrier shows higher activity and stereospecificity than both a-MgCl2 and β-MgCl2 sup-ported catalysts.
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发布时间：2021-03-19
Research Bulletin
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