最新刊期
卷 ， 期 2 ， 1994
- 摘要：A series of semirigid main Chain thermotropic liquid crystal copolyesters containing two kinds of mesogenic groups were studied by polarizing microscopy,DSC and X-ray diffraction. The results showed that these copolyesters are typical of nematic liquid crystal structure. A possible mode about the packing of two mesogenic moiety in liquid crystal states was proposed, which accounted for the re suits.
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发布时间：2021-03-19 - 摘要：Microphase transition of triblock copolymer styrene - butadiene - styrene (SBS )was studied by rheometrics mechanical spherometer. The transition temperature was certain according to the rheological behavior differences during the transition. For the first time, microphase dissolution was investigated and the phase dissolution was found to proceed through four distinct stages. In the second and forth stage, G' eαt η' eβt, where G' and η' are dynamic modulus and dynamicviscosity reactively, t is the phase dissolution time,a.βare different for different stages and different dissolution temperature. In the framework of Dickie,consider-ing the molecule diffusion and the fluid mechanics reaction under shear condition, the rheological behavior in four stages was analysed and explained,the interiority of rheological properties dependence on time during phase dissolution was mani-fested primitively.
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发布时间：2021-03-19 -
CHARACTERIZATION AND GAS (O2,N2) PERMSELECTIVITIES OF MEMBRANE OF COBALT COMPLEX COORDINATED POLYMER
摘要：hree active mombrane of Cobalt complex Coordinated polymer were fabricated and well characterized by IR, UV - Vis- NIR, EPR and XPS. Permeation properties of O2' N2 were investigated.- 4
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发布时间：2021-03-19 - 摘要：he effeCt of physical aging on the properties of poly(phenylene ether ketone)has been studied. With increasing the aging time at 200 ℃, the stress relaxation rate decreased pronouncedly, while the yield strength, the density, and the excess enthalpy loss increased markedly within the first ten hours. On further aging, only a slow asymptotic approach to equilibrium properties was observed. The time-dependence of the above physical properties was discussed. The occurrence of craze for aged samples during stress relaxation could be attributed to the densification of the glassy matrix in the course of physical aging.
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发布时间：2021-03-19 - 摘要：Oligomer poly (N-isopropylacrylamide) has been made up with azobisisobuty-ronitrile(AIBN) as initiator and methonal as solvent．Graft copolymer PAA-g-PIPA could be prepared by graft polymerization of PIPA onto the chain of polyallylamine-hydrochloride(PAA) with 3-ethyl-3(3-dimethylaminopropyl,)-carbodiimidehy-drochlorid(EDC) as condensation agent．M icrospheres with size range of 10μm or so could be made of graft copolymer PAA-g-PIPA with glutaraldehyde(GA) as cross-link agent in water/oil system．Antitumer drug adriamycin(AD) can be car-ried on the PAA-g-PIPA microspheres by physical adsorption．In vitro drug re-lease behaviour of drug-carrying PAA-g-PIPA microspheres was examinied by dynamic dialysis technique．Data from dialysis experiment were treated with a computer after setting a methematical model which can provide a quantitative as-sessment of drug release．The drug release rate constant Km of drug—carrying PAA-g-PIPA microspheres were achieved．It has been shown that Km of PAA-g-PIPA microspheres representing the specificity of drug release increased with increasing the temperature in the range of 30—45℃．This indicated that drug release of drug-carrying PAA-g-PIPA microspheres was obviously temperature responsive．
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发布时间：2021-03-19 - 摘要：he effects of several polymers upon the development free vapor photolithography (DFVP ) have been studied. Explanations of the difference in etching rates between unirradiated and irradiated areas, high resolution and high aspect ratio in DFVP were suggested.
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发布时间：2021-03-19 - 摘要：On the basis of the preparing method of the general adsorbent and considered the effeCt of the physical and chemical structure, the title adsorbents were prepared by changing the degree of crosslinking, using the different porogenic agent and introducing the proper functional group. The sorption and desolation properties of these adsorbents for the industrial waste water of naphthalene organic compounds were also studied.
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发布时间：2021-03-19 - 摘要：egenerated cellulose blend membranes were prepared by coagulating a mixed solution of cellulose cuoxam (I) and aqueous polyvinyl alcohol (Ⅱ). SEM results showed that the phase separation on the mixing were seriously formed when the Ⅱ-content was higher than 8% by volume. But, when the Ⅱ-contCnt of blend was smaller than 5%, 1 and Ⅱ are miscible, and the degree of crystallinity, tensile strength, tear strength, breaking elongation and thermostability of the blend membranes were superior to those of membrane from pure cellulose cuoxam. In addi-tion, the mean pore diameter,ethanol permeability and the transmembrane flows of water obtained by using a flow rate and ultrafiltration methods suggeted that the pore properties of the blend membranes were almost not variabe. In conclu-sion, the mechanical properties of blend membranes from regenerated cellu-lose / 5% polyvinyl alcohol were improved, and the blend membranes keep biodegradability yet.
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发布时间：2021-03-19 - 摘要：The rheological properties of poly (ether Sulfone) with different molecular weight have been measured using cone/plate rheometer. All the samples showed shear-thinning behavior and the now aCtivation energy for melts were obtained which were consistent with that reported by ICI. The correlations between zero shear viscosity (η0) and molecular weight at vareus temperatures were established and concluded that the M. of samples were close to Mc The master curve with good superposition was plotted and the two empirical constants of WLF equation were obtained and discussed.
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发布时间：2021-03-19 - 摘要：raft copolymerization of methyl methacrylate (MMA) onto chitosan was carried out by using K2S2O8 as an inititor. By means of different degrees of deacetylatCd chitosan graft copolymerization reaction condition experiments, the effeCts of reaction time, temperature, concentration of initiator and monomer had been investigated. From these experiments, the optinum condition was chosen. The comparison of the reactional results of different degree of deacetylation chitosan with those of N-substitute chitosan under the same reactional condition has demonstrated that the amino groups of chitosan took part in the initiation process.
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发布时间：2021-03-19 - 摘要：A new series of polymethacrylates with a chiral mesogenic pandant group linked to backbone through ethyleneoxide units of different lengths were synthesized. Mesomorphic behaviour of polymers was characterized by polariaing microscopy with hot stage, DSC and X- ray diffraction The results show that phase transition temperature and isotropic temperature depended on the length of ethyleneoxide.
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发布时间：2021-03-19 - 摘要：ainly based on the techniques of transducer and computer' an instrument for automatic determinatoin of swelling of network polymer has been assembled successfully. The instrument with high sensitivity, excellent accuracy and precision can be used for investigation of comprehensive properties of swelling, and possesses the following functions : 1. equilibrium modulus determination, 2. swelling kinetics, 3. stress relaxation kinetics.
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发布时间：2021-03-19 - 摘要：A series of terpolymers of butyl acrylate (BA ), methyl methacrylate (MMA ),and glyddyl methacrylate (GMA) were prepared by sequential emulsion copolymerization. The obtained acrylate elastomers with different structures were used as the modifier for PVC. The results showed that the impact strength of the modified PVC were greatly related with the components and structures of the terpolymers. The utmost impact strength of the modified PVC might reach the level of 20 times over that of the unmodified PVC. Based on the tests of dynamic mechanical analysis and the observation of SEM,it might be proved that the blends of PVC and the studied acrylate modifiers are partially compatible system.The appearance of the fracture surface of the modified PVC behaves typical tough characters. Moreover,the mechanical properties of the modified system were also investigated and discussed.
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发布时间：2021-03-19 - 摘要：The behaviour of N,N'- ditertbutylhydroxylamine (DTBHA ). N,N '- ditertbutyl nitroxyl radical (DTBNO' ), 2, 2,6,6- tetramethyl-4 - hydroxyl piperdinehy droxylamine (TMHPHA) and its nitroxyl radical (TMHPO' ), as inhibitors of the BPO- initiated copolymerization of styrene (M 1 ) with acrylonitrile (M2 ), at 60℃,has been studied. The result showed that the inhibition efficiency of nitroxyl radical is better than that of their hydroxylamines and their relative inhibiting order are TMHPO > DTBNO >TMHPHA>DTBHA. It was also found that the reactivity ratios of St-AN are different in various inhibitors. When the amount of these inhibitors is about 200-500ppn r1 decreases and r2 increases in the hydroxylamine condition but the opposite result is shown in nitroxyl radicals and the azeotropic point of copolymerization of St -AN cahanges from 0.619 to 0.698,0.645,0.589 and 0.533 for TMHPO.DTBNO.TMHPHA and DTBHA respectively.
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发布时间：2021-03-19
Research Article
- 摘要：Surface graft polymerization of styrene onto poly (tetrafluoroethylene (PTFE )powders by using Co60γ-ray radiation under vacuum was studied by XPS. XPS results showed that the ratios of C1s intensities from polystyrene (PS ) to that from PTFE were related to the grafting degrees determined with gravimetrical method,which is the basis of characterization of grafting with XPS technique. It is shown that the distribution of grafted PS on the powder surface was not uniform. It means that the surfaces of the PTFE powders were not fully covered with PS grafted.
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发布时间：2021-03-19 - 摘要：The melting behaviour of polyphenylene sulfide (PPS ) and its blends with bisphenol A polysulfone (PSF ) and polyetherketone with cardo side groups (PEK-C ) are investigated with DSC technique. It is found that with a rise in melt temperature, Tmelt, and melt time, tmelt, the lower temperature melting peaks increase while the upper ones decrease and disappear in some cases, which can be attributed to the obstructive effect of branching or crosslinking of PPS on the crystallization of PPS at higher temperature. As annealing crystallization tempera-ture increases,not only the peak temperature of the lower melting peaks shifts to higher temperature,but also their intensity increases. PSF and PEK-C have noeffect on the lower melting peaks of PPS but are unfavorable to the crystallization of the higher melting species Tmelt and tmelt exert greater influence on the double melting behaviour of PPS in the blends in comparison with neat PPS.
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发布时间：2021-03-19 - 摘要：PVC/CPE blend modified by rigid particles has good combined properties. In this paper, the effeCts of rigid particles (PMMA. PS. CaCO,) on the rheological behavior of PVC/ CPE systems were studied. The results showed that the apparent viscosity (aha) were decreased, extrusion surface smooth and Newtonian fluidity were slightly improved by filling a little amount of rigid ploymers (PS. PMMA) to PVC/CPE blends. The fluid activition energy (E,). Newtonian fluidity. extrusion surface smooth and ba of PVC/CPE blends were increased by filling CaCO3 and die swelling ratio was decreased.The newtonian fluidity. En and ηa of PVC/CPE/CaCO3 blends can be decreased by filling rigid polymers,and good extrusion surface smooth and low die swelling ratio unchanged.
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发布时间：2021-03-19 - 摘要：The blends of phenolphthalein Polyethersulfone (PES - C ) and a thermotropic liquid crystalline polymer (LCP ) were prepared using melting mixing method.Rheological and mechanical properties of the blends were investigated. It was shown that addition of LCP in PES-C resulted in marked reduction of melt viscosity and improved processibility. The Chadly impact strength of the blend containing 2. 5% LCP increased about 2. 5 times comparing with pure PES-C. The tensile strength, Young's modulus, fie-cural strength and flexural modulus of the PES-C/LCP blends were also improved on some extent. The morphology of these blends were also observed by SEM,and the relationship between the me-chanical properties and the morphology of blends were discussed.
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发布时间：2021-03-19 - 摘要：That work studies the relationship of viscosity and shear rate of polyacrylamide and partial hydrolized polyacrylamide solution by five balls viscometer at low shear rate area. Used solvents were H2O - IN NaCl, H2O - INNaNO3 and H2O - IN NaNO3- ethanolamine systems. The results indicated that 1nηr. [η ] steadily cut down and tend to fixed number along with increase of shear rate.
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发布时间：2021-03-19 - 摘要：An alternative microcrack-shear band chain model for the fracture of polymer materials was proposed. The fractal dimension of the fracture surfaces was derived and correlated with the fracture toughness of the materials. It was demonstrated through this model that the fractal dimension of the fracture surfaces would have an inverse trend with the fracture toughness, which was coincident with the experimental results of some polymer materials.
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发布时间：2021-03-19 - 摘要：The initiation mechanism of photopolymerization has been studied by means of UV spectroscopy, fluorescence spectroscopy and end group analysis methods.UV spectroscopy measurements revealed the formation of charge transfer complexes (CTC ) between N - 4- methylphenyl maleimide (PMPMI ) and N,N - dimethyl - p - toluidine (DMT ). The equilibrium constant of the CTC determined from Benest - Hildebrand equation was 0.056. The fluorescence spedroscopy experimental results identified the formation of exciplex of PMPMI nad DMT. The UV measurements of polymer confirmed the presence of DMT moieties as end groups in resulting polymers. Based on the experimental results,it is proposed that the initiation mechanism of photopolymerization of PMPMI initiated by DMT was via eciplex either by the excitation of CTC formed in the ground state or through the local excitation pathway.
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发布时间：2021-03-19
Research Bulletin
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