最新刊期
卷 ， 期 1 ， 1991
- 摘要：WAXD, PLM, IR and TBA have been used to investigate the morphology, crystallinity, Tg and intermolecular interaction of PEO/PBHE blends as a function of composition and temperature. Up to a content of about 50 wt% of PEO the blend films are completely filled with PEO spherulites, no separated domains of PBHE being observed. Blends with 30?40 wt% of PEO show islands of crystalline PEO within a matrix of PBHE. Blends with lower PEO content (20 wt%) show no evidence of crystallinity. A IR study of PEO PBHE blends reveals that intermolecular interaction occuring between these two polymeric coponents in stronger than that occuring in pur phenoxy.Decrease of crystallinity and increases of Tg in the blend system are accompanied by an increase in the content of PBHE composition,which is in good agreement with FOX equation. These two polymers are compatible in amorphous zone.
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发布时间：2021-03-19 - 摘要：A amorphous ternary polymer, Poly (ethylene oxide-propylene oxide-allyl glycidyl ether) was prepared, and it shows a low glass transition temperature (Tg=-74℃) and a high amorphous ratio (98%). DSC and X-ray diffraction measurements were employed to characterize the P(EO-PO-AGE)-LiClO4 complex morphology, a crystall complex with the composition of Li/O=0.25 was detected. The studies on ionic conductivities of complexes found that the conductivities change with the salt concentration, and reached a maximum of 5×10-5scm-1 at room temperature with Li/O=0.05.
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发布时间：2021-03-19 - 摘要：The present work is to investigate the influences of annealing condition on the micro-structure and superatructure of HEPP by WAXD and SAXS. The crystallinity and orientation of HEPP were studied by FRS-XRSA suggested by author. The results show that the optimum annealing time to obtain the stable structure is tan= 40 min. at Tan= 130℃. Different from previous works, it was found that the lamellae is not extended but twisted or double-oriented. When the annealing time increases, the twisted lamellae extend gradually. From long-spacings obtained from SAXS and crystallinity,crystallite size was obtained from WAXD,it was found that the almellae consists of two-layer crystallites.
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发布时间：2021-03-19 - 摘要：Dimaleimides can improve the thermal stability of silicone rubber in are or oxygen. The results of heat ageing test and kinitic analysis of TG showed that the mechanism may be related to the precedent reaction of dimaleimides with oxygen. So the oxidation of methyl group and the increase of crosslinking density of silicone rubber could be avoided.
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发布时间：2021-03-19 - 摘要：The process of copolymerization of caprolactam (CL) with octamethyl cyclotetrasiloxane (D4) has been investigated. In the course of polymerization of CL and D4, D4 polymerized rapidly at first, then CL continued to polymerize and attained the high conversion of above 85%. The content of siloxane component in the copolymer chain extended with the reaction time and with increase of the monomer ratio of D4. The main reactions in the polymerizing process was proposed and the structure of copolymer was suggested.
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发布时间：2021-03-19 - 摘要：Polypropylaldehyde has been obtained by plasma polymerization in a capacitively coupled rf glow discharge. The influences of various plasma conditions on the polymerization behaviour of propylaldehyde were examined.The structure and properties of the polypropylalde-hyde formed in plasma were studied by means of IR spectra, elementary analysis, GC-MS analysis, X-ray diffraction and surface wettability measurements.
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发布时间：2021-03-19 - 摘要：In the present work, the reactivity ratios of trimethyltin (TMTM), triethyltin (TETM), tributyltin (TBTM) and triphenyltin (TPTM) methacrylates with methyl methacrylate (MMA) have been determined. The experimental determination of the copolymer compositions formed from several different comonomer feed compositions involves the technique of FTIR spectros-copy. The nonlinear least-squares procedure is employed in estimating the r1 and r2 values which are 1.07/0.63 (TMTM/MMA); 0.87/0.62 (TETM/MMA); 0.62/0.58 (TBTM/MMA);0.68/0.60(TPTM/MMA),respectively. The Q and e values of these trialkyltin methacrylate monomers have been calculated. The relative reactivities ofthe organotin monomers have been compared and the effect ofthe differentsubstituenton their copolymerization activity has been discussed.
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发布时间：2021-03-19 - 摘要：Partial hydrolyzed polyacrylamide (HPAM) is a polyelectrolyte. Due to the electrostatic repulsion of intramolecular -COO- groups, the polyacrylamide molecules in water are extended to form filamentous structure, and its aqueous solution has very high intrinsic viscosity.This paper presents a detailed study on the relationship between structure and viscosity of solution. The influences of hydrolysis degree of PAM molecular weight of HPAM and salt concentration on the morphology have been discussed.
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发布时间：2021-03-19 - 摘要：In this paper syntheses and adsorption properties of some chelating resins which contain S and N, obtained by the reaction of chitonsan with chloromethylthiirane (I) were described. Crosslinking of chitosan by(I) at (I)/NH2 molar ratios of 0.5, 1.0, 2.0, 5.0 and 10.0 gave resins from PCS 1 to PCS 5, the S-content in resins increased with increasing of quanity of (I) used, while the N-content decreased.Within the series of PCS, the more the content of S% in the resins, the higher the adsorption capacities for noble metal ions. The capacities of PCS 5(m mol/g)for Ag(I), Au(III), Pd(II) and Pt(IV) were 4.46,4.86,3.14 and 1.87 respectively. The adsorption percentage andselectivity of PCS 5 for the noble metals were also determined.
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发布时间：2021-03-19 - 摘要：A systematic investigation on thermo-treatment mechanism of PPTA fiber was carried out by X-ray diffraction, TEM, FTIR, PPM, DSC, ect., which resulted in confirmation of secondary crystallization of PPTA fiber in the thermo-treatment process. It is found that elastic modulus of the fiber is mainly affected by the increasment of crystallinity due to the secondry crystallization, and the thermo-treatment temperature has great influences on the secondary crystallization.
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发布时间：2021-03-19 - 摘要：Some Polymeric benzophenones (PVB), having different molecular weight (MW) and various content of benzophenone as pendant group, have been synthesized and determined with absorption and emission spectra. The results obtained indicate that the BP group bound to PVB remains the photochemical properties characteristic of the small molecular BP. Using the Photoinitiation system composed of PVB and tertiary amine to induce photopolymeriza-tion of MMA, the polymerization rate (Rp) is above 2 times higher than that of small mo-lecular BP. Thepolymerization rates increas with increasing content of BP pendant group and the hotoinitiation efficiency increases with increasing molecular weight of PVB. These results can be attributed to the high-efficient energy transfer inpolymer and the high local concentration of reactive chromophore in reaction system.
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发布时间：2021-03-19 - 摘要：Butadiene and isoprene copolymers are prepared with Nd(naph)3-Al(i-Bu)3-Al2Et3Cl3.sub catalytic system in bulk and solution polymerization.The sequence structures of the copolymers are determined by 13C-NMR spectrometry. The dyad distribution, composition and number-average sequence length of these copolymers are calculated on the basis of assignment of 13C-NMR spectra. Meanwhile, the monomer reactivity ratios are obtained by using TUDOS' method which is proper to various copolymerization systems even at high conver-sions. The results of calculations are discussed. It is known that the sequence distribution of monomer units in all copolymers follows first-order Markov statistical model.
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发布时间：2021-03-19 - 摘要：The polymerization of methyl methacrylate (MMA) initiated by organic peroxide, such as benzoyl peroxide (BPO), lauroyl peroxide (LPO), and N-2-hydroxyethyl-N-methyl aniline (HMA) binary systems has been studied. It was found that the presence of HMA can enhance the rate of polymerization and reduce the overall activation energy of polymerization either by using BPO or LPO as an initiator. The order of amine promoting activity is HMA> DMA(N, N-dimethyl aniline). The rate equations of MMA polymerization were found fit-ting well the equation of polymerization with redox initiation system. Based on the ESR studies and the end-group analysis the initiation mechanism of BPO/HMA binary system is then proposed in this papper.
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发布时间：2021-03-19 - 摘要：A series of liquid crystal polymers with mesogens laterally fixed into the main chain was synthesied by solution polycondensations at low temperature using monomers 2,5-dihydroxyl-1,4-phenylene di-p-alkoxybenzoate and 1,12-dodecandioic acid dichloride. It was found that all polymers including the one with methoxy substituents are thermotropic as determined by DSC and polarizing microscopy.
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发布时间：2021-03-19 - 摘要：The effects of the solution pH on the el ectrochemical properties of poly-o-methylani-line are described in this paper. The experimental results show that the cyclic voltammogram, oxidation potential, film colour, charge-discharge capacity, electronic absorption spectrum and electrochemical activity of poly-o-methylaniline depend on the pH value. During the potential sweep, the film colour of poly-o-methylaniline at pH4.13,and the electroche-mical activity is also disappeared.
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发布时间：2021-03-19 - 摘要：A series of segmented copolyether-ester polyimides, based on the polycondensation of poly (tetramethylene oxide) glycol a, w-di-p-amino benzoate (APTMO), 4,4'-oxydianiline (ODA) and 1,2,4,5-benzene tetracaboxylic dianhydride (PMDA) was synthesized. The dynamic mechanical analysis (DMA) and the differential scanning calorimetry (DSC) techniques were used to study the morphology of these polymers. Their thermal stability, mechanical properties, gas permeability and dielectrical constants were also measured. The experiment results indicated that these polymers had multiphase structures and were a new type of thermoplastic elastomer.
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发布时间：2021-03-19 - 摘要：The reaction between the catalyst components in Ni (naph)2-TIBA.DBMP-BF3.OEt2 system which catalyzed the polymerization of butadiene have been studied by IR method. It was found that the main product in the reaction between TIBA and DBMP was iBu2AlOAr which could delay the reduction of Ni(II), so as to stabilize the active center Ni(I). According to the analytical data of the products in the reaction between DBMP and TIBA, Ni (naph)2 and TIBA.DBMP and BF3.OEt2, an octahedra coordinated active center model was proposed.
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发布时间：2021-03-19
Research Article
- 摘要：The dynamic cure kinetics of thermosetting acetylene-terminated sulfone (ATS) and two blends prepared by the ATS and thermoplastic bisphenol A polysulfone (PSF), polyary-lethersulfone with cardo group (PES-C) were determinated by differential scanning calori-metry (DSC). The addition of polysulfone's resin increases the temperature of initial reaction and decreases the activation energy of cure reaction(E), pre-exponnential factor (LnA), and heat of cure reaction (AH). The temperature of reaction peak and final reaction and the reaction order(n) have been no effect.
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发布时间：2021-03-19 - 摘要：Ultra high molecular weight polyacrylonitrile of Mw = 4.0~17.8×105 was obtained by suspension polymerization, using azobisisobutyronitrile as initiator and polyvinyl alcohol as suspension agent. The effects of temperature, time, stirring rate, initiator concentration, and monomer to water ratio on the polymerization and the polymer obtained are investigated. By using this method, ultra high molecular weight copolymers of acrylonitrile with methyl acrylate, a-methyl acrylic acid can be also synthesized.
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发布时间：2021-03-19 - 摘要：The photopolymerization of acrylonitrile sensitized by N-methyl-N-(2-methacryloyloxye-thyl)aniline (MEMA) was studied kinetically. The photopolymerization rate of AN in DMF by using MEMA as sensitizer is proportional to 0.32 th power of MEMA concentration and 1.20 th power of AN concentration. The overall activation energy for the polymerization was found to be 4.82 Kcal/Mol. From the fluorescence analysis of obtained polyacrylonitrile sensitized by MEMA, it was confirmed that MEMA not only joined the inition but also entered into the polyacrylonitrile chains. The initiation mechanism was proposed tentatively.
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发布时间：2021-03-19
Research Bulletin
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