最新刊期
卷 ， 期 5 ， 1989
- 摘要：N-H stretching regions of Infrared spectra of polyether urethane polymers prepared by a two-step or one-step polymerization reaction have been compared and their differences indicate the existence of differences in the frequecy and the amount of N-H,,,-O- and N-H.. ..O=C hydrogen bonding formed. Quenching to Lower temperature to retain the degree of phase mixing at the elevated temperature, N-H stretching vibration at 3295 cm-1 which is hydrogen bonded with -O- of soft segments and the vibration hydrogen bonded with -O-of soft segents and the vibration hydrogen bonded with C=O of hard segments at 3330 cm-1 have been directly observed. The frequency at 3295cm-1 of N-H stretching vibration hydrogen bonded with -O- has been confirmed by the spectrum of polyether urethane dissolved in THF solvent.
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发布时间：2021-03-19 - 摘要：High water content poly (vinyl alcohol) elastomers were prepared by repeated freezing-thawing process and the mechanical properties, degree of swelling and solubility of the elastomers have been studied in detail. The results show that the elastomers have both high water content (85-90%) and high tensile strength (105-106Pa) simultaneously and their properties have excellent stability when soaked in water at the temperature of 37℃.
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发布时间：2021-03-19 - 摘要：Monodisperse polyacrolein (PA) microspheres were prepared by means of emulsifier-free emulsion polymerization of acrolein in aqueous medium using sodium hydroxide as catalyst. The diameter of PA microspheres prepared was in the range from 1.45 to 2.21um, the capacity of reactive aldehyde groups was in the range from 2.591 to 5.199 mmol per gram PA microspheres. The optimum polymerization condition was: acrolein, 7-10%(w/v); pH, 8.5-11.2; temp., 16℃; time, 3.5hr. The diameter of PA microspheres changes with concentration of catalyst and acrolien. The capacity of reactive aldehyde groups of PA microspheres chan-ges with the reaction conditions,e.g., the capacity of reactive aldehyde groups of PA micros-pheres increases with the decrease of the catalyst concentration when pH>10. The results of PA microspheres reacting with amino acids and bovine serum albumin at physiological pH ran-ge showed that the PA microspheres have a higher biding capacity.
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发布时间：2021-03-19 - 摘要：The article examines an effct of allylhalide, as chain transfer agent, upon the rate of butadiene polymerization, polymer molecular weight and activity energy in the presence of MoCl3(i-OC5H11)2-(i-Bu)2-AlO and hydrogenated gasoline assolvent. And the chain trasfer constants of allylhalide was induced. The results show that allylbromide has little effect on the rate of butadiene polymerization, however allylchloride and allyliodide result in the drops of the polymerization rate-Molecular weight decreases rapidly as the increase of the amount of allylhalide. In the presence of allybromide,according to Arrhenius'equation,the apparent activity energy is abtained to be 63.6kj/mole,a little more than that there is no allylbro-mide.
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发布时间：2021-03-19 - 摘要：The isothermal crystallization kinetics of polyphenylene sulfide (PPS), and is blends with polyethersulfone (PES) were investigated by DSC. It was found that the crystallization rate constant of the PPS treated with a-chloronaphthalene increased markedly, the Avrami exponent of PPS/PES blends was lower than pure PPS, and the crystallization rate constant had the lowest value following the blend composition change. The secondary crystallization effect appeared in the PPS/PES blends and the linear relationship between tn and tmax has been found.
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发布时间：2021-03-19 - 摘要：The interface structure of poly (ether-ether-ketone) (PEEK)/carbon fiber composite ani the crystal texture of the PEEK matrix have been studied by scanning electron microscopy (SEM) after the samples are properly etched by argon plasma. We find that ail of the PEEK's crystals are induced by nucleating carbon fiber and then they developed the transcry-stalline no matter whatever the samples are crystallized from the melt or from the rubbery state The detail of the oriented crystal growth of PEEK relative to the carbon fiber has been obser-ved by SEM. The results of this work show that the nucheation process of PEEK/carbon fi-ber composite is as follows: the first lamella is formed in carbon fiber surfeace in the way that the a crystallographic direction is parallcl to the radial direction of the carbon fiber, b direction to the tangent line of cross section of the carbon fiber,and c direction to the axis of the carbon fiber.
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发布时间：2021-03-19 - 摘要：In the present paper, a number of mesogenic and nonmesogenic model compounds (Bis azomethines) and Three types of aromatic polyazomethines were prepared. The results showed that the phase transition of model compounds and polymers depend upon molecular structure, conjugated chain and molecular flexibility.
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发布时间：2021-03-19 - 摘要：The chain length distribution of a oligomeric polystyrene sample initiated by n-butyl lithium was determined by high performance size exclusion chromatography on a ultraviolet absorption detector. The effect of the end group on the weight fraction of the individual mono-disperse species both for the experimental UV response data and the theoretical distribution function was discussed. An end group correction factor was introduced for getting the true weight distribution of chain length. The experimental data could be precisely represented by superimposition of two poisson distributions. The deviation from a single poisson distribution is believed as a consequence of the variation of the mode of mixing of the polymerizing reac-tants.
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发布时间：2021-03-19 - 摘要：The copolymerizations of two new perfluoroalkyl vinyl ethers-7,7-dichloro-3-oxa-perfluo-roheptene-1(Mo) and 10,10-dichloro-3,6-dioxa-perfluoro-5-methyl-decene-l(M1)-with tetrafluoro-ethylene and properties of copolymers were studied. The reactivity ratios of TFE-M0 show that the polymerization reactivity of Mo is greater than all known perfluoroalkyl vinyl ethers. The copolymer of TFE-Mo was converted to the corresponding perfluorocarboxylic ester resin by chlorination, hydrolysis and esterification.
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发布时间：2021-03-19 - 摘要：The Poly [4-vinylpyridine] (P4VP) or Poly[2-vinylpyridine] (P2VP)-Poly[styrene-ma-leic acid] (PSM)-Palladium catalysts supported on silica (P4VP-PSM-Pd/SiO2 and P2VP-PSM-Pd/SiO2) were prepared. The catalysts were used to catalyze the hydrogenation of methy-lacrylate under mild conditions. The effects of the compositions of catalysts on the catalytic behaviors were investigated, it was found that the catalyst composed of both P4VP (or P2VP) and PSM exhibits higher activity than that composed of either of them and the catalytic behavior was also influenced by the palladium content (Pb wt%)and polymer content of the catalyst. The calalysts can be reused without lossing activity and selectivity.
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发布时间：2021-03-19 - 摘要：This paper is concerned with synthesis of the title complex and study on its hydrogena-tion activity for olefins and nitrobenzene. Comparison with the activity of the palladium-nitrogen complex, the mixture of the later and the bound molybdenum complex was made.The data indicated that the catalytic activity of the title complex was higher than that of the monometallic analogue, however, the corresponding rates in both cases the bimetallic complex and mixture catalysts are similar to each other. From the result of XPS analysis we can see that complex between some N and PdCl2 or MoClx takes place,however,the bond of Pd-Cl or Mo-Cl remains,the valences of Pd and Mo are 2 and 5 (or 6) in catalysts respectively.
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发布时间：2021-03-19 - 摘要：Thermal analysis of solution cast mixtures of PCL and phenoxy has been carried out with various programmed temperature profiles．Results from experiments conducted in a quasi-equi-librium state show that PCL crystallizes in the mixtures upon cooling．Furthermore，depres-sions were observed in melting and crystallization temperatures．The melting point depres-sion pheonomenon is found tO be explicable in terms of thermodynamic mixing of a crystalli-ne polymer with an amorphous polymer．To this end，an analytical expression appropriate to the crystalline-amorphous polymer pair derived from Scott’s equation for thermodynamic mi-xing of two polymers was used．From this expression the interaction parameter for this poly-met pair is calculated to be—0.155 at 320 K，indicating that the system is well compatible．The crystallization temperature which depends strongly on both the composition and the cooling rate is attributed to the migrate of the PCL segments．Any factor which retards the migration will depress the crystallization temperature,Double crystallization peaks were also observed in the process of cooling．
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发布时间：2021-03-19 - 摘要：Manganese (HI) acetate can be used as an initiator for vinyl radical polymerization. The presence of carboxylic acid will promote the polymerization of acrylamide and enhance the rate of polymerization. The order of promoting reactivity of acid is a-hydroxy polycarboxylic acid (citric acid) >a-hyroxy carboxylic acis (lactic acid) >a-amino acid (glycine) > carboxylic'acid (n-butyric acid). The effect of concentration of sulfuric acid on the rate of acrylamide polymerization in the aqueous solution has been studied. The overall activation energy of polymerization and the kinetics of polymerization of acrylamide initiated with Mn3+,Mn3+-glycolic acid,Mn3+-lactic acid systems were determined respectively.
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发布时间：2021-03-19 - 摘要：A series of poly(tri-n-butyl tin methacrylate) samples have been synthesized in the range of 0° to 130℃ by the radiation initiation and in the higher temperature using initiators. The tacticity of the polymers has been measured by 13C-NMR. The results show that the polymers are all predominantly syndiotactic, as expected, and the tendency to form syndiotactic sequences decreases as the polymerization temperature increases. The tacticity of polymers is mainly influenced by the polarity of substituent group of vinyl monomer. The activation parameters governing the tacticity are similar to those of poly(methyl methacrylate),but smaller than tho-se of poly (trimethyl tin methacrylate).
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发布时间：2021-03-19 - 摘要：The compatibility of the mixed solution of cellulose/paraformaldehyde/dimethyl sulfoxide and polyacrylonitrile/dimethyl sulfoxide was studied by the viscosity and other related methods. And the viscosity of the mixed solution was discribed by the modified Mcallister equation.
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发布时间：2021-03-19 - 摘要：It was found that the conductivity of PA at room temperature for I2-doped PA film wtich was treated by plasma method is the same as non-treatable's, but the stability of conductivity in air and antioxidization of film increase. It was verified by ESCA spectra that the PA film which was treated by air plasma is linked to O and N atoms. It was also investigated that the amount of cis-PA decreases and trans-PA increases with increasing plasma power.
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发布时间：2021-03-19
Research Article
- 摘要：Photopolymerization of N-vinylcarbazole initiated by 4-N,N-diethylaminobenzene diazo-nium fluoroborate has been studied. Based on the solvent and retarder effect as well as spectrum measurement, a cationic initiation mechanism was suggested.
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发布时间：2021-03-19 - 摘要：The morphology structure and glass transition behavior of polybutadiene-based polyuretha-ne/polystyrene (or polymethyl methacrylate) interpenetrating polymer network (PU(HTPB)/ PSt-IPN, PU(HTPB)/PMMA-IPN) were investigated by TEM and DSC. TEM showed that the phase inversion of PU(HTPB)/PSt-IPN occurred in the concentration of 25% PU(HTPB), and the size of dispersed phase domains of the IPN formed was smaller in the concentration about 50% PU(HTPB). Increasing DVB content or proportion of NCO to OH enhanced in-terpenetration of two components. All of IPN samples exhibited special cellular structure. According to the fact that PU(HTPB) was formed first,a formation mechanism of the struc-ture was proposed.
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发布时间：2021-03-19 - 摘要：This paper describes syntheses of five macroreticular poly(styren-divinylbenzene)-supported phase-tranfer catalysts. This kind of catalysts is used in the formation of ether and ester, in halide exchange. The results of the study indicate that the catalytic activities are good, and repetition is good.
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发布时间：2021-03-19 - 摘要：The photopolymerization of AN by using N-acryloyl-N'-phenylpiperazine (APP) and N-methacryloyl-N'-phenylpiperazine (MPP) as sensitizers under UV irradiation has been investigated. The corresponding polymerization kinetic equations are as follows:Rp [APP]0.81[AN]0.61 Rp [MPP]0.48[AN]0.77 Rp [P(APP)]0.53[AN]0.78 From the fluorescent analysis, it was confirmed that APP, MPP and P(APP) not only initiated the polymerization of AN but also entered into the chains of AN polymer. The photopolymerization mechanism for exciplex formation of AN with above sensitizers was proposed.
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发布时间：2021-03-19 - 摘要：The effects of different ligands on the catalytic activity of the propykne polymerization catalyzed by o-XC6H4OTiCl3/MgCl2-EB systems (where X =-CH3, -H,-Cl and -NO2 respectively; EB stands for ethyl benzoate) were studied. It was found that the pKa value of o-XC6H4OH is greafer, the catalytic activity of corresponding catalytic system is higher. The reduction rate of o-CH3C6H5OTiCl3 is faster than that of o-ClC6H5OTiCl3 by AlEt3 Thus, it leads to a higher initial concentration of the active center in O-CH3C6H5OTiCl3/.MgCl2-EB than that in o-ClC6H4OTiCl3/MgCl2-EBsystem. Using tritiated alcohol quench-ing method,the concentrations of active center and the rete constants of propagation in abo-ve systems were also evaluated. The results obtained were consistent with the conclusions be-fore mentioned.
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发布时间：2021-03-19 - 摘要：The molecular weight of polytetramethylene glycol (PTMG) prepared from tetrahydrofu-ran (THF) by using cocatalysts of BF3-etherate and epichlorohydrin (ECH) in the presence of butylene glycol(BG) increased sharply with the polymer conversion, but at yields higher than 80% but could be exactly controlled by the molar ratio of BG to BF3. The polyether obtained possessed around 70 mol% primaly hydrcxyl end-groups and a hydroxyl end-group functionality of two. The content of ECH derived units in each polymer chain containing 18.2 or 33.8THF derived units is around 1.60 or 2.16 respectively.
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发布时间：2021-03-19
Research Bulletin
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