最新刊期
卷 ， 期 4 ， 1997
- 摘要：On the basis of Lederman′s model,the strain rate dependent constitutive relation of open cell foam plastics is derived by supposing the matrix material to be Voigt′s visco elastic body.By means of the constitutive relation,the dependence of some mechanical properties of foam plastics on the strain,strain rate and parameter of cell structure is investigated in this paper.The results have shown that the decrease of Poisson′s ratio of foam plastics is more obvious with the increase of strain rate than the one with the change of other two factors.In addition,the Young's modulus of foam plastics is reduced by introducing viscous effect.
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发布时间：2021-03-19 - 摘要：A new rapid method for the determination of Mark Houwink equation constants from GPC and intrinsic viscocity data on a number of samples ( n >5) with a five point hunting program was described. The Mark Houwink equation constants of poly (Chloromethy thiirane) in THF solution at 30℃, which are 0 771 ( α ) and 0.592×10-4 ( K ), were obtained by this method. The obtained K and α values were reliable and could be used for calculating the molecular weights of poly (chloromethyl thiirane) within the relative error of 6%,which was proved by [η]error checking and VPO analysis.
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发布时间：2021-03-19 - 摘要：When radiation curable coatings exposed to UV in air,the curing rate increases approximately linearly as the concentration of photoinitiator increases at first,but increases sharply at a certain concentration.In this paper,it can be interpreted as being due to the diffusing and exhausting of oxygen in UV coating.The diagrams in line with the deduced equations reflect the characteristics of experimental curves very well.
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发布时间：2021-03-19 - 摘要：Interaction between aqueous dispersion of anionic polyurethane and gelatin was investigated by UV and FTIR spectrometry.A complex formed by Coulomb forces was found in the solution around pH4 6.The influences of weight ratio,pH values,temperature and electrolyte on the mixed system were studied,and parameters(such as temperature,ionic strength)have a considerable impact on the formation of compleies as well.H bond played a part role in the compatibility of the mixed system.The best compatibility was attained in the mixed system at weight ratio 50/50～40/60(gelatinAPU).
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发布时间：2021-03-19 - 摘要：The solution behavior of poly(2,6 dimethyl 1,4 phenylene oxide)(PPO)ionomer(carboxylated PPO or sulfonated PPO)/poly(styrene-co-4 vinylpyridine)(PSVP)blends were investigated.The reduced viscosities of both the two series of blends were higher than those of comparable blends composed of PPO and PSVP.These were attributed to the acid base interactions resulting from proton transfer between the acid groups of the PPO ionomer and the vinylpyridine groups of the PSVP.
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发布时间：2021-03-19 - 摘要：Plasma induced graft copolymerization of styrene(St) to nascent polypropylene(PP) powder was investigated.The samples were characterized by FT IR,SEM,XPS and verified to be grafted copolymer.The dependence of grafting yields on the pressure of the reaction system,plasma treatment power,the diameter and volume of the ampoule,and graft copolymerization time,temperature was studied.The ion exchange membrane was prepared by sulfonation of the grafted copolymer and its electric properties were studied.
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发布时间：2021-03-19 - 摘要：Vinyl chloride/diallyl phthalate(VC/DAP) suspension copolymerizations were carried out in a 5L autoclave and 200ml stainless steel reactors at temperature of 45℃.The apparent reactivity ratios of VC and DAP were calculated as rVC =0.769, rDAP =0.374.The existence of the gel point of the VC/DAP copolymerization system was ascertained and the critical initial concentration of DAP ( fcr ) at which gel began to form was in range of 0 .466～0. 493mmol/mol VC.The degree of polymerization(DP) and indexs of distribution of molecular weight (MWD)of copolymer increased as the initial concentration of DAP (f20) increased when f20 was less than fcr,and DP also increased with increase of conversion.When f20 was larger than fcr,DP and indexs of MWDof sol fraction decreased as f20 increased,but the gel content increased,the gel content also increased as conbersion increased.
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发布时间：2021-03-19 - 摘要：The conformational distributions of a model polymer tail chain was deduced based on the diamond lattice walk confined in the half space by means of the reflection principle.The relationship of the available conformational number C1(N) with the chain length N and the distribution function of end to end distance were obtained for this model tail chain.In the case of 4 choices diamond lattice walk,it was found that C1(N)/4N is proportional directly to N -1/2 .The component of the mean square end-to-end distance normal to the wall for the model tail extends to two times in comparison with the parallel components which is same as the components for the corresponding free chain.These analytical results were confirmed in computer experiments including the exact enumeration and Monte Carlo simulation.
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发布时间：2021-03-19 - 摘要：The P(MMA/MSMA)/TiO2 SiO2 hybrid polymer materials with the presence of 3 (trimethoxysilyl)propyl methacrylate(MSMA)were prepared by the sol gel process.The result of solvent extraction shows that the gel content in the hybrids with the presence of chemical bond through the reaction of MSMA with titanium(IV)butoxide and tetraethyl orthosilicate is much higher.The chemical structure of the hybrid was analyzed by the FTIR,and the effects of the whole inorganic content and the content of Ti(OC 4H9)4 on the properties of materials had been inverstigated by TGA and DSC,respectively.
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发布时间：2021-03-19 - 摘要：Stable polyaniline (PAn) aqueous dispersions were obtained using poly(vinyl alcohol)(PVA) as steric stabilizer via dispersion polymerization. The size of PAn was influenced by the steric stabilizer(PVA) concentration,monomer(aniline) concentration,temperature and stirring state. The stable PAn particles with size of 100nm～200nm in diameter were composed of original particles whose size in diameter was about 20nm. The enhanced aggregation of PAn particles was prevented by the presence of PVA which absorbed on the surface of PAn particles via physical interaction,In addition,the interaction between PAn and PVA was moderate.
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发布时间：2021-03-19 - 摘要：Doping and depoping process of PAn in the aqueous dispersions was investigated via the UV vis spectra. The PAn HCl started to dedoped when pH=3.5,the dedoping of PAn HCl was completed when pH=6 0. UV Vis spectra of PAn/PVA blend films was also investigated. It was found that when the size of PAn particles was less than 75～100nm,the absorption bands shifted towards shorter wavelengths compared with that of PAn particles larger than 150～250nm. The conductivity of PAn/PVA blend films depended not only on the PAn content but also the aggregated state of PAn in the blend films.The smaller size of PAn particles led to the lower percolation threshold of PAn/PVA blend films.
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发布时间：2021-03-19 - 摘要：Polymerization of cyclosiloxane initialed by cyclotrisilazane trilithium salt is successfully carried out.The polymer is characterized by NMR,IR,GPC and viscosity measurement.It is confirmed that the polymer is star shaped polymer.The study of kinetics of polymerization shows that reaction order with respect to D 4 is 1.The promoter DMF has a stronger effect on polymerization than diglyme.
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发布时间：2021-03-19 - 摘要：Glass transition of single chain atactic polypropylene,conformational state transition of backbone bond of the polymer were studied by molecular dynamics simulation method through different temperatures,thus validating,developing a new method in characterizing the glass transition of polymers,specially for single chain glassy particles,where the volume of the particle is hard to be determined,without the indicator the glass transition could usually not be obtained.
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发布时间：2021-03-19 - 摘要：A novel syndiotactic polystyrene b polypropene(sPS b PP)copolymer was synthesized in this laboratory with homgenous metallocene catalyst of η 5 cyclopentadienyltripropoxy titanium and MAO. The influence factor of monomers feed ratio,catalyst concentration,Al/Ti molar ratio and polymerization temperature on block copolymerization has been investigated.The copolymerization products were fractionated by succesive solvents extration with boiling butanone,boiling heptane and 40℃ THF. The titled block copolymer with 20～30wt % percent of total product,chiefly existing in butanone soluble fraction,were isolated and characterized by13C-NMR,FTIR,WAXD,DSC methods.
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发布时间：2021-03-19 - 摘要：In this review it is summarized the recent progress in “duckweed” and “reversed duckweed” polymeric ultrathin films in our laboratory. Attention is paid to how to relate molecular architecture with functional assemblies.
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发布时间：2021-03-19 - 摘要：PLM,DSC,IR and WAXD have been used to investigate the morphology,crystallinity, Tg ,intermolecular interaction and compatibility of PEO/PEOx blends as a function of composition. Up to a content of 30wt% of PEO,the blends are completely filled with PEO spherulites,no separated domains of PEOx being observed. The blend with 20wt% PEO shows a twig like morphology and blends with lower than 10wt% show no evidence of crystallinity. Blends with different compositions show a single glass transition temperature ( Tg),which corresponds to the calculated value by the Fox's equation.With increased PEOx content,degree of crystallinity and melting point of the blends decrease.The interaction energy density(B) between PEO and PEOx has been estimated by equation describing the equilibrium melting point.The results show that PEOx is compatible with noncrystalline PEO,as caused by specific intermolecular interaction between PEO and PEOx.
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发布时间：2021-03-19 - 摘要：A novel chemical modification of triblock copolymers of hydrogenated poly(styrene block butadience block styrene)(SEBS) was developed leading to a new kind of carboxylated SEBS ionomer. The behavior of hydrophilic association of sulfonated SEBS ionomers with different counterions in nonpolar solvent was studied by viscometry and dynamic light scattering (DLS) presenting quantitative measurements of the associated aggregates. Meanwhile,the behavior of the complexation between the sulfonated SEBS ionomers and pyriding-containing random coploymers both in dilute solution and in bulk was evidenced by an abnormal increase of the viscosity and Tg.Finally,it was found that slightly carbpxylated SEBS ionomers could form stable colloidal dispersion in water due to stabilization of the ionic groups on the surface of the hydrophobic particles.
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发布时间：2021-03-19
Research Article
- 摘要：PP EPR and PP EPR PP copolymers were synthesized by sequential changing olefin monomers in a slurry of δ T iCl3 Et2AlCl hexane. Experiments showed that the polymer chain was living within 100 minutes. By means of measurement of dynamic and internal friction spectra,it was demonstrated that PP EPR and PP EPR PP only have one glass transition temperature ( T g) respectively,and each of them showed good compatibilization for PP/EPT blend. All these indicate that it is possible to prepare di block and tri-block copolymers of ethylene and propylene in sequential polymerization of olefin with Ziegler-Natta catalyst.
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发布时间：2021-03-19 - 摘要：Influence of five kinds of coupling agents on dielectric properties of glass fiber/epoxy matrix composite was studied in this paper. The results show that after glass fiber is treated with coupling agents, surface free energy and wetting activation energy of glass fiber decrease, the reaction activity and wettability between glass fiber and epoxy resin can be improved. thus dielectric properties of glass fibre/epoxy matrix composite are improved, too. Influence of temperature and boiling time on dielectric properties of glass fiber/epoxy matrix composite was especially studied.With increase of temperature and boiling time,dielectric properties of glass fiber/wpoxy matrix composite have obviously changed,which was attributed to the polarity and chemical structure of coupling agents,decrease of voids of composite and change of interface polarization intensity.
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发布时间：2021-03-19 - 摘要：An ionomer,lightly sulfonated polystyrene neutralized with zinc acetate,was partially miscible with PC and LCP respectively through the specific interaction.Its addition into PC/LCP blends was conducted in order to compatibilize the blends.With increasing SPS the Tg′s corresponding to PC decreased,unveiled by DSC and DMA. SEM micrographs showed fine dispersity of the LCP phase in the PC matrix.All the results have shown that the compatibilization achieved by the addition of SPS.
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发布时间：2021-03-19 - 摘要：A lot of polymeric hydrogels undergo volume changes in response to external stimuli such as pH,temperature,electric field and light.These intelligent hydrogels have been used for the preparation of a wide variety of devices,for instance,immobilized enzyme,recyclable absorbents and controlled drug release.However,most of the hydrogels studied previously are responsive to only one kind of stimulus.But for some situations,responsiveness to several stimuli,such as temperature and pH,may be requied.We wish to report here the synthesis of a new intelligent hydrogel which can response to temperature and pH at the same time.Poly (acrylic acid_-co-(acrylonitrile) Hydrogels were synthesized.The Temperatura and pH sensitivities of these hydrogels were studied.The swelling ratio(SR) of hydrogels at various pH values is different.In water medium,SR of hydrogels at elevated temperature(62℃) is increased with the prolongation of time.However,this phenomenon is not so obvious in weak alkaline and acidic solutions.
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发布时间：2021-03-19 - 摘要：The effect of C60 on the polymerization of styrene (St) conducted by using Ziegler Natta catalyst in toluene has been explored.It has been found that the presence of C60 seriously affects the activity of Ziegler Natta catalyst which is represented by polymerization conversion with a concentration maximum of C60 at a certain catalyst concentration and the molar ratio of Al/Ti.Atactic PSt(a-PSt) and isotactic PSt(i-PSt) are separated by extracting with methyl ethyl ketone and are characterized by 1H-NMR and 13C-NMR spectra.It has also found that partial C60 covalently incorporates in the a-PSt fraction evidencing by FT-IR,UV-vis,13C-NMR spectra and the solubility.GPC traces demonstrate that the higher amount of C60 used,the lower molecular weight and the broader molecular weight dispersity has been got.This means that C60 acts as a chain transfer or chain termination agent during the polymerization.
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发布时间：2021-03-19 - 摘要：Copolymer of propylene with a small amount of butene was prepared with supported Ziegler Natta catalyst MgCl2/TiCl4 AlEt3/DPDMS and was fractionated with preparative temperature rising elution fractionation technique.The composition and tacticity distribution of copolymer were studied.It is found that the copolymer has a broad tacticity distribution and fractionation is mainly conducted according to tacticity.Compositional heterogeneity also exists to some extent.Isotacticity of fractions increases with elution temperature,but butene content shows a maximum in the fraction eluted at 70℃.With combination of previous work,this phenomenon is explained to be the result of the presence of electron donor in aspecific active site.
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发布时间：2021-03-19
Research Bulletin
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