最新刊期
卷 ， 期 5 ， 1990
- 摘要：This paper gives the general discussion for chain homopolymers by quasi-harmonic oscillator model and statistical method. It obtain an expression of coefficient of linear expansion. The values of calculation are in good agreement with experiment values. The result is satisfying.
- 38
- |
- 7
- |
- 2
发布时间：2021-03-19 - 摘要：The structural characteristics of poly (p-phenylenebenzobisthiazole) (PBT) film have been studied by X-ray diffraction method. The results of experiments show that PBT film which formed in liquid crystalline phase is high orientated. The molecular chains in the plane which perpendicular to the direction of orientation arrange in two-dimensions order while along the direction of orientation arrange in disorder. By annealing the PBT film, we found the regularity of the two-dimensions arrangement of molecular chains in the plane which perpen-dicular to the direction of orientation increases obviously and the distortion of lattice decreases.Moreover the benzene heterocyclic rings in the molecular chains along the orientation direction exibit cybotactic state and the diffraction pattern of X-ray showing the three-dimensions order appears. The angle between the normal line of the cybotactic plane and theorientation direc-tion is 29°.
- 5
- |
- 8
- |
- 5
发布时间：2021-03-19 - 摘要：Effects of supports and active sepcies, including the degree of croslinking, specific surface area, pore radius of supports and the loading of rhodium etc., on the catalytic properties and stability of polymer-supported rhodium complexes in hydroformylation of 1-hexene were studied under batch reaction conditions. From the experimental results, it was found that these factors show certain influence on rhodium elution.
- 2
- |
- 7
- |
- 0
发布时间：2021-03-19 - 摘要：The theoretical dependency of the glass transition temperature (Tg) on the degree of polymerization DP is deduced from the theory of the glass transition proposed in the previous paper:The theory agrees well with the experimental data taken from the literature for polystyrene, poly (vinyl chloride), poly (a-methyl styrene), poly (dimethyl siloxane) and poly (methyl methacrylate) with various tacticities. The theory leads directly to the relationship between the parameter Kg of the equation (Tg= Tg - Kg/Mn) and the molecular parameters. The agreement between the theoretical predictions and experimental measurments of Kg has been found to be satisfacory for a number of polymers.
- 10
- |
- 10
- |
- 1
发布时间：2021-03-19 - 摘要：The association of living species in the anionic polymerization of e-caprolatone initiated by t-BuOLi in benzene solvent was studied by viscometry. It has been found that after complete conversion of e-caprolatone monomer, association of alkoxyl-lithium is indeed present and the association tendency increases with increasing initiator concentration. However, before monomer was consumed (i.e. during the course of propagation), no intermolecular association between growing species was observed. The result is in good agreement withour kinetic study showing that the monomer lactone itself acts as a strong solvation agent.
- 2
- |
- 7
- |
- 0
发布时间：2021-03-19 - 摘要：The thermally stimulated discharge current of bis(p-toluene sulfonate) of 2,4-hexadiyne-1,6-diol (TS), TS-PTS blend and fully polymerized polymer PTS has been measured in the temperature range of 100 to 300 K. The peaks of current corresponding to their phase transitions at lower temperature in the direction parallel to the stacking were observed. The effect of polymerization on phase transitions was studied. The attribution of another three peaks of current was discussed qualitatively.
- 2
- |
- 7
- |
- 0
发布时间：2021-03-19 - 摘要：The ESR spectrum of the retrofit nickel catalyst system showed that the active center consists of Ni(I) in the system and that the premix of Bd with nickel naphthenate before adding Al(i-Bu)2OC8H17 and BF3OEt2 to the system leads to stabilization of the Ni(I) complexes and the induced period of polymerization of butadiene shorter. The overall energy of polymerization of butadiene do not change.
- 2
- |
- 7
- |
- 3
发布时间：2021-03-19 - 摘要：Sulfonated 3,4-polyisoprene and its ionomers were synthesized. Their structures and cry-stallinity were examined by IR, 1H-NMR, WAXD and SAXS. The results show that the cry-stallinity of the ionomers is reduced with the increasing content of sulfonic acid groups and sodium salts. The peak in various ionomers, which characterizes the structure of clusters of ionic aggregates, was not observed in the pattern of small angle X-ray scattering. It is shown that only multiplets of group of a few tightly bound ion paire exist. IR spectra indicate the presence of the O=S=O symmetrical and asymmetrical stretch peaks at 1040 and 1200cm-1.The 1H-NMR experiments indicated that sulfonic acid groups mainly react with the side chain double bonds of 3,4-polyisoprene.
- 2
- |
- 8
- |
- 0
发布时间：2021-03-19 - 摘要：The photo-oxidation of the photocrosslinked polyethylene was studiedwith surface analyses of ESCA and ATR-IR. It was found that hindered piperidene stabilizer Tinuvin 770 can improve the stability of the material significantly without any interference to the photocrosslink-ing process.
- 6
- |
- 10
- |
- 0
发布时间：2021-03-19 - 摘要：Several new bis (1,2-dicarbonyl) compounds containing benzofuran or benzothiophene ring have been synthesized and identified by elemental analysis and Infra red spectroscopy. A series of new polyphenyl-1,2,4-triazines having either benzofuran or benzothiophene in the main chain were prepared by reacting various bis (1,2-dicarbonyl) compounds with aromatic amida-zones, respectively. The resulting polymers were also characterized by IR spectroscopy and elemental analysis. All of them can form films by casting the polymer solution onglass follow-ed by curing at high temperature. These films not only possessed good mechanical properties but also good thermal stability.
- 38
- |
- 7
- |
- 1
发布时间：2021-03-19 - 摘要：Wettable PTFE was prepared by tretment with allyl alcohol plasma. The water contact angle is 40-60°compared with that of 118?of the untreated PTFE. Analyses by infrared spectroscopy, ESCA, and SEM show that a graft layer which contains-CH3, CH2, C = 0, and C-OH groups was formed on surface of PTFE. With the increase of treating time, the oxygen concentration decreases and contact angle increses.
- 32
- |
- 7
- |
- 2
发布时间：2021-03-19 - 摘要：Eight types of modified PHB/PET terpolyeaters containing eight types of third monomers are synthesized by melted state copolycondensation. The results show that PHB/PET/VA ter-polyester with vanillic acid has faster copolycondensation rate, lower melting temperature, typical thermotropic liquid crystallinity and better spinnability. Vanillic acid is the third monomer suitable for modifying PHB/PET binary copolyester.
- 34
- |
- 7
- |
- 1
发布时间：2021-03-19 - 摘要：The empirical Cole-Cole, Fuoss-KirkwOod distribution models of correlation times, the con-formational jump model proposed by Valeur et al. and the damped orientational diffusion model of polymer local main-chain motion proposed by Skolnick and Yaris were used to fit the experimental 13C-NMR spin-lattice relaxation times (T1) and nuclear Overhauser effect (NOE) data of 1,2-polybutadienes in CDCL3 solution. The dependences of the malecular motion of 1,2-PBD on the chain-structure ad temperature have been discussedin terms of the molel parame-ters obtained.
- 2
- |
- 7
- |
- 0
发布时间：2021-03-19 - 摘要：It is well known that some initiators can be decomposed to two radicals with different reactivities. Based on this fact, an equation of polymerizationis proposed. Semi-log plots of Rp2[I]][M] vs Rp/[M]2 clearly show the effect of un-equally reactive primary radical termination on polymerization in a wide range of concentration of initiator. For example when the concentrations of the initiator like benzoin and O-acyl-a-oximinoketones are greater than 1.0×10-2 (M), polymerization is clearly effected by un-equally reactive primary radicals termination,and this effect will decrease as the temperature of polymerization is increased,which means Eprt-Ei-Ep
- 3
- |
- 7
- |
- 0
发布时间：2021-03-19 - 摘要：The copolymerization of acrylamide (AM) with N.N'-methylenebisacrylamide (Bis) in the aqueous solution has been studied. All the experimental results showed that the reactivity of Bis is obviously greater than that of AM. The monomer reactivity ratios determined by gas-chromatography method are 0.117 and 5.756 for AM and Bis respectively. The effects of the concentration of oxidation-reduction initiator and the reaction temperature on the rate of the copolymerization have been investigated with ultraviolet spectroscopy,the initial rate of the copolymerizationis proportional to the 0.66 power of [(NH4)2S2O8] and 0.55 power of [NaHSO3],and the apparent reactive energy of this copolymerization is 37.1KJ/mol.
- 36
- |
- 10
- |
- 4
发布时间：2021-03-19
Research Article
- 摘要：COPU/PMMA crosslinked copolymer (ABCP) was synthesized from vinyl-terminated castor oil prepolymer and MMA. The Mc densities, dynamic mechanical properties and morphologies of the ABCPs with defferent composition were studied. The results show that COPU/PMMA ABCP is a semicompatible system and has potential application for damping material.
- 4
- |
- 7
- |
- 0
发布时间：2021-03-19 - 摘要：The compatibility in EVA/CPE or PVC was studied by IR spectroscopy. The frequency shifts of the carbonyl stretching vibration near 1739 cm-1 was examined as a function of VA content in EVA, Cl content in CPE(or PVC), blend composition and sample temperature.By comparing with model systems, such as EVA/CCl4, EVA/CHsCCl3 and EVA/CHCl3, the frequency shift observed for the blends was associated mainly with the hydrogen-bonding-like interaction between EVA and CPE (PVC). Based on the temperature dependence of the C=O frequency,the phase separation temperature andits dependence onblend composition were obtained for EVA(VA40%)/CPE9C164%) system.
- 2
- |
- 7
- |
- 2
发布时间：2021-03-19 - 摘要：The effect of high temperature annealing on the higher order structure of a copolymer of vinylidene fluoride and tetrafluoroethylene (TFE 2.8 mol %) has been studied by various method, primarily dynamic mechanical, by also dielectric and microspic. The controversy on the origin of a relaxations is discussed from the point of view of higher order structure studies.
- 36
- |
- 9
- |
- 0
发布时间：2021-03-19 - 摘要：Synthesis of poly (methyl-methacrylate) (PMMA) in tetrahydrofuran at- 78℃ using al-kyllithium as initiator and its characterazation were studied. It was found that PMMA with harrow molecular weight distribution was obtained using 1,1-Kliphenyl-3-methylpentyllithium and 1,1-diphenyl-hexyllithium as initiators respectively. The sample of PMMA in the molecular weight (Mw) range from 1×104 to 2×106 had Mw'/Mn=1.06-1.20, its product possesses narrow molecular weight distribution and good symmetry, it achived level of PMMA standard sample and may be used it as GPC standard samples.
- 48
- |
- 12
- |
- 2
发布时间：2021-03-19 - 摘要：When divinylbenzene (DVB) is uled as a crosslinking agent, the introduction of DVB units in a copolymer does not always lead to crosslinkages but results in some pendent double bonds depending on preparative conditions，so that there is a difference between the amount of DVB introduced and the true crosslinking degree(CD)．In this paper，the relative content of the pendent vinyl groups，the true CD and compositions of the macroreticular acrylonitrile-styre-ne-DVB copolymers (MR-PSA resins) have been studied by means of the Fourier Transform Infrared Spectrometer (FT-IR)．The MR-PSA resins were prepared by suspension polymeriza-tion，using the linear polystyrene as a pore-creating agent．In the FT-IR study of the MR-PSA resins．selected absorption bands are：2240 cm-1 (nitrile group)，1636 cm-1 (Ar—c=c，vinyl group of aromatic ring，the characteristic of pendent．double bond)，1510 cm-1 and 836 cm-1 (pata-disubstituted phenyl ring)，802 cm-1 (meta-disubgdtuted phenyl ring)，1494 cm-1 and 760 cm-1 (monosubstutited phenyl ring)．These absorption bands were measured by using integral strength method．Through the calculation for integraf strength ratio of the certain absorption peaks，the relationship between the relative content．of pendent vinyl groups and anlount of DVB applied havo been studied. The change of the true CD of the：MR-PSA resins depending on the amount of DVB have be6u studied，too．
- 2
- |
- 7
- |
- 1
发布时间：2021-03-19 - 摘要：The polymerization of acrylamide (AAm) initiated by the combination of N-(N', N'-dimethylaminomethylene)methacrylamide (DMAMMA) or N, N,-dimethylaminoethyl methacry-late with potassium persulfate were studied kinetically. The rate equation for the AAm polymerization initiated by the above initiation systems were given asRp- Kp[AAm][K2S2O8]1/2[DMAMMA]1/2 Rp=Kp[AAm][K2S2O8]1/2[DMAEMA]1/2 respectively. The overall activation energies for the above polymerization were determined to be 8.7 Kcal/mol and 9.2 Kcal/mol respectively. The UV analysis for the PAAm initiated by the above initiation systema showed that the polymerizable amines,DMAMMA and DMAEMA notonly joined the redox initiation but also incorprated into the AAm polymer chains. The super high molecule weight,107of PAAm were obtained by using these initiation systems.
- 40
- |
- 8
- |
- 16
发布时间：2021-03-19 - 摘要：GTP of MMA with zinc bromide catalyst in 1 , 2-dichloroethane solvent with dimethylketene methyl trimethyl silyl acetal (MTS) as initiator at 0℃ were studied. The relationship of MMA concentration with time at 0℃ were shown in Figure. The polymerization rate are zero order with respect to monomer concentration. The relationship of rate constant K between initiator concentrations [I] may be written as:The plots of In K against In [I] present the linear relationship, a is equal to l.
- 2
- |
- 7
- |
- 0
发布时间：2021-03-19 - 摘要：The MA-co-N-p-BrPhMA(Methyl-acrylate-co-N-p-Bromophenylmethacrylamide) and MA-co-N-p-ClPhMA (Methyl-acrylate-co-N-p-Chloro-phenylmethacrylamide) bulk copolymers were prepared and characterized by I. R. and 1H-NMR method.The compositions of the copolymers were determined from the areas of the phenyl group and methoxy group proton peaks in the proton NMR spectra.Reactivity ratios were calculated from the composition data by the Fineman-Ross method; the following values were obtained:r1= 1.33±0.02(MA), r2= 0.42±0.02(N-p-BrPhMA) for MA-co=N-p-BrPhMA copolymer.
- 2
- |
- 7
- |
- 0
发布时间：2021-03-19 - 摘要：A study of ethylene copolymerization with butene-1 using the-MgCl2 supported catalysts of alkoxyl titanium chloride has been- proposed. The main interest of the study was related to the effects of number of butoxyl group on the catalytic behavior and the incorporation of comonomer to the main chain of the polymer. Results show that catalytic activity as well as titanium content in the catalysts decreased when the number of butoxyl group in the catalysts increased. Therefore, it could be considered that butoxyl titanium chloride fixedon the sur-face of MgCl2 mainly through chloride bridge,only in defectof chloride they combined through unstable oxygen bridge. The influence ofbutene-1 concentration on the comonomer incorporation and the various properties ofthe copolymer obtained were also observed. The comonomer sequence distributions were measured by 13C-NMR. It could be couclused that the butene-1 units in copolymer occur principally as isolated branches.
- 2
- |
- 7
- |
- 1
发布时间：2021-03-19
Research Bulletin
- Postal code：100190
- Tel：010-62588927 Email：gfzxb@iccas.ac.cn
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备05002797号-8
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0