最新刊期
卷 ， 期 4 ， 1994
- 摘要：his paper has investigated the relation between simple shear and pure shear in rubber, from which we conclude that: (1) A simple shear was equivalent to a pure shear plus a rotation. The angle θ of rotation is given by tgθ=1/2(λ1-1/λ1) (2) If φ is the angle from the major axis in simple shear in rubber to the x-axis, β0, is the angle from the major axis in pure shear in rubber to the y-axis, then φ=β0, (3) A general expression of the shear strain γ in two-dimensional extension in rubber is given by In simple shear the resulting expression for is.
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发布时间：2021-03-19 - 摘要：ew rare earth catalyst system suitable for preparing bi-and ter-copolymers of styrene(St) and conjugated dienes has ho report first in our laboratory. In this paper, the copolymerization of St and butadiene (Bd) with the L3Ln' nL'-RX- Rm'AIHM3-m catalyst system was further studied in detail on the effects of ligands, rare earths, alkyl aluminums, the third components etc. on the copolymerzation activihes, molecular weight and stereospeficities of the copolylners. The sequence structures of the copolymer were thoroughly in-vestigated by 13C-NMR spectrum. Some of the experimental results were tentatively explained by the mechanisms of π-allyl and back-biting coordination.
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发布时间：2021-03-19 - 摘要：heological properties at a low shear rate range(10-2-10s-1) and the glass transition temperatures for PEK-C with different moleCular weithts have been studied by using a cone/plate rheometer and DSC' The activation energy for melt flow increases with Mw The dependence of Tg on molecular weight exhibits two linear range and the value of nitersect agrees with the critical molecular weight , Mc' which is first reported for PEK-C' Mc value obtained according to η0 is about 8× 104 g/mol and the relation between Mc and temperature was dis-cussed.
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发布时间：2021-03-19 - 摘要：amples of low molecular weight and thermotropic liquid Crystals of aromatic copolyesters are prepared by a slurry polycondensation of three monomers,i' e. p-hydrobenzoic acid, temphthalic add and bisphenol A. These copolymers obtained from the reaction of ester exchange are called as PHBA/TPA/BPA copolyesters. Many characterizahons for samples with different composihon can be carried out house of their relatiVely good solubilities in proper solvents. The phase diagram expressing the transition temperature-composition for these copolysters is obtained and discussed.
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发布时间：2021-03-19 - 摘要：eries of poly(ethylene terephthalate)(PET) films with different degree of planar orientation [△(xy)z] were prepared by drawing biakially in different stretching ratio. It was found that the depth of discrete trapping levels increased with the rise of △ (xy)z according to the investigations of thermally stimulated current. Due to the changes of conformation and orientation structot of molecular chains, the kinds 'of structural defects increased which caused the number of discrete trapping levels to increase from 2 of amorphous to 6 of specimen T-1 and the distribution width of depth of discrtet trapping levels to broaden from 0.05eV of amorphous to 0.2eV of specimen B-1.
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发布时间：2021-03-19 - 摘要：onjugated poly schiff bases with same back bone but different side groups have ho prepared by polycondensahon of 1, 4-diaminobenzene with glyoxal, 2, 3-butanedione, 3, 4-hexanedione and 4, 5-octanedione respectively. The polymers were characterized by FT-IR, elemental analysis, etc', It' was found that the conjugated poly sehiff bases with alkyl side groups can be dissolved in common organic solvents, and the solubility of the polymers were in the order of propyl>ethyl>methyl. EleCtrical conductivihes of the pristine polymers and their dependence on temperature were measured, showing that the polymers are typical semiconductors. When the polymers were doped with iodine,electrical con-ductivity increased by 7-9 orders of magnitute (up to 10-3-10-4s/cm).The ef-fect of side groups on the conductivity of the I2-doped polymers were discussed.
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发布时间：2021-03-19 - 摘要：n the microemulsion composed of OP (nonyl phenyl polyoxyethylene,HLB= 13.2). TX- 4 (nonyl phenyl polyoxyethylene, HLB= 8.0), AM, H2O and kerosene, the minimum amount of emulsifier required to produce microemulsion were studied. It was found that there are obvious grafting effect of emulsifier in the process of radiation induce polymerization. The kinetics of radiahon induced microemulsion polymerization were studied with dilatometer and the intrinsic viscosity of the resulted polymer were determined with Ubbelode capillary viscometer. The results were as: In comparison with polyelectrolyte, the latex resulted from microemulsion polymerization is a special thickener with a good electrolyte resistibility and apoor surfactant resistibility.
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发布时间：2021-03-19 - 摘要：he permeability coefficients of six different ODPA-based polyethermide membranes to H2, CO2, O2, N2, and CH4. have ho measured at 0. 7 MPa and at temperatures from ambient up to 150 ℃. Systematic variations in chemical structure were found to lead to sighficant changes in permeability coeffidents and ideal separation factors of polyetherimide membranes. Among the six polyetherimdes, ODPA-IPDA with the largest free-volume and larger intrasegmental mobility has the highest permeability and the lowest permselectivity, ODPA-DABP with the smallest free- volume and the smallest intrasegmental mobility has the lowest permeability and the lowest permselectivity, ODPA-DMMDA with the larger free-volume and smaller intrasegmental mobility has higher permeability and higher permselectivity.
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发布时间：2021-03-19 - 摘要：uthors, directly taking an infinite network as gel model, using Graph Theory and Probability as describing tool, first of all, advanced a new theory about predicting the gel point Pc. The critical state equations of the gelation of three kinds non-linear condensation polymerization are respectively The Pc obtained by above equations lies between Carothers equahons and Statistical theory, are in good agreement with experimental- results.
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发布时间：2021-03-19 - 摘要：Effects of interfacial modifier on rheological behavior of kaolin toughened polyamide 6 (PA6) were studied and compared with those of silane coupling agent KH550. The addition of the interfadal modifier to PA6/Kaolin (80/20) composites improves the melt viscosity and the melt elasticity (first normal stress difference). However, the use of KH550 reduces the melt viscosity and the melt elasticity. This difference is attributed to the stronger interaction betWeen PA6 and kaolin and better elastic resilience of the interfacial modifier than that of KH550. Furthermore, the contents of the interfacial modifier has an influhnence on rheological behavior of the PA6/kaolin composites. The interfacial modifier tends to "saturation" on the kaolin surface when its content is 2% by weight. Further increasing the interfacial modifier affects the rheological behavior of the composites little.
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发布时间：2021-03-19 - 摘要：roplet drformation, Breakup mechanism and formation condition of double sea--island composite struture in immiscible blending polymer system are theoretically analysed. Formation mechanism, structure morphology and forming condition of polystyrene /polypropylene blending double sea-island composite structure are investigeted by mean of electric and optical microscope . A model of double sea-island composite structure in its formation precess is put forward.
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发布时间：2021-03-19 - 摘要：tyrene (S), butyl' methacrylate (Bma), methacrylic acid (SMaa) and maleic anhydrate (SMan) were used to produce copolymers of SMaa, BmaMaa, SMan, and BmaMan with minor components of Maa and Man. The blends of the correspending ionomers of SMaa/BmaMaa and SMan/BmaMan with a series of counter metal ions produced by solvent casting and moulding were examined by DSC and TEM. In the blends both the polymer components possess negative charge. It has ho shown that introducing metal-ions to the blends of SMaa/BmaMaa ap-parently improves the miscibility. This miscibility enhancement dependes on the nature and amount of the counter ions. For the system of SMaa-Na/BmaMaa-Na, even a single phase blend can be produced.
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发布时间：2021-03-19 - 摘要：he phase behaviour and glass transition temperateal of cellulose diacetate (CDA)/poly (vinyl pyrrolidone)(PVP ) blends were extensively inveshgated by OM,DSC and DMTA. Transparency films were observed in the composition range of CDANVP= 100/0 to 50/50 (by wt.) No any phase separation was found up to the degradation temperature of blending components. A single and composition dependence Tg was obtained in all the range of blending compositions. And a synergism for mechanical properties of CDA/PVP blends was also found. The mixing enthalpy of this blending system was determined and calculated by using the calorimetry and the Hess law. Negative and composition dependent mixing enthalpy was found. All the above experimental results strongly suggest that CDA and PVP are miscible.
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发布时间：2021-03-19
Research Article
- 摘要：series of multiblock copolymers composed of polyetheretherketone (PEEK) and 4, 4'-dihydroxydiphenylsulfone (DHDPS) were synthesized by polycondensation. The property of copolymers were characterics by DSC, IR, WAXD and TGA. The results indicate that the Tg of copolymers increases with increasing DHDPS content' When the DHDPS content of the copolymers is less than 22% (the average degree of polymerization of PEEK oligomers is more than 6), the copolymers are Crystalline polymers. The highest Tg of the Crystalline copolymers is 160℃,the lowest Tm is 304℃.
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发布时间：2021-03-19 - 摘要：Differencial scanning calorimetry (DSC) was uest as a means to visulize the exothermal process in grafting dibutyl maleate moeities onto polyethylene in reactive processing. Residence time of the reactantS in a screw extruder was measured and thus a method of determining reactive extrusion time is proposed.
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发布时间：2021-03-19 - 摘要：heological, micromorphological and DSC studies were carried out for PP/UHMWPE blends. The phase separation, also called co-continuous structure, in the blends was observed by making use of the difference in staining- rates of PP and UHMWPE. Experimental data stronglysuggested that the different components form "linear interpenetrating netWork" in the blends, from which a "network toughening mechanism" was proposed.
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发布时间：2021-03-19 - 摘要：his paper describes a new polyfimctional inihator, 4,4'-azobis[4-cyanopentanoyl (p-dimethylandno)anilide] (ACPDA), for the the radical polymerization. It was obtained by the rcaction of 4,4'-azobis(4-cyanopentanoyl chloride) with p-amino-N, N-dimethylaniline' ACPDA contains two reaction centres with different reactvities that are azo-group and N, N-dimethylaniline-group. By the controlled different conditions this initator can be utilized to make block polymers.
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发布时间：2021-03-19 - 摘要：A series of amorphous copolymers of ethylene and norbornene were prepared by polymerization with Zircorocenes of rac-Et (Ind)2ZrCl2MAO and Cp2ZrCl2/MAO. The Crystallinity decreases with the increase of norbornene contact in the copolymers. Glass transition temperature of the copolymer as high as 88 to 152 ℃ were determined by DSC,Intrinsic vianshes, [η] 0.04 to 2.73dl/g were measured in decalin at 135℃. The copolymer has a narrow molecular weight distribution (Mw/Mn) 2.0 to 25, meased by GPC in orthodichlorobenzene at 140℃.
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发布时间：2021-03-19 - 摘要：By means of measurement of internal friction in amorphous polystyrene, it was demonstrated that the a relaxation Peak had a derivation from the Arrhenius Relationship. It was proved that the varying of activation energy with temperature led to the derivation.
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发布时间：2021-03-19 - 摘要：he chain conformation of polymethylacrylamide (PMAAm) in water solution was studied using fluorescence probe. Results show that the change of PH values has an influence on the conformation of PMAAm. In the presence of strong acid (HCI) the hydrophobic microdimain of PMAAm is damaged due to the extension of molecular chain.
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发布时间：2021-03-19 - 摘要：olyurethane/epoxy resin(PU/EP) IPN was synthesize by the method of microwave radiation and its morphology and properties were studied. In the process of microwave radiation, the molecular motion is accelerated and the reaction rate is increased due to the' influence of eleCtric field, which makes the networks take into shapes before the-thermodynamic phase division takes place' Since the method of microwave radiation has a different reaction process, IPN synthesized by this way has more intensive extent of interpenetration than that by normal heated-polymerization.
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发布时间：2021-03-19
Research Bulletin
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