最新刊期
卷 ， 期 1 ， 2003
- 摘要：A new adsorbent for creatinine by starch esterification with 3.5-dinitrobenzoyl chloride DNBZ-ST was prepared．The chemical structures of DNBZ-ST products were characterized by FTIR,elemental analysis and 13C-NMR．The adsorption properties of DNBZ-ST for creatinine were examined．A structure model of complex of 3,5-dinitrobenzoic acid with creatinine was proposed,and the adsorption mechanism was explored fundamentally．Results showed that starch 3,5-dinitrobenzoate has good adsorption properties．The adsorption is complete in 4 h．The adsorption capacity increases with the degree of substitution of adsorbent,as well as with the creatinine concentration．However,the concentration has no apparent effect on adsorption capacity,when the creatinine concentration is higher than 300 mg·L-1．The adsorption capacity decreases with temperature in the range from 19℃ to 37℃．The adsorption capacity first increases and then decreases with the increase of the pH value and has a maximum around pH=8．The adsorption capacity may reach ～25 mg of creatinine per gram of adsorbent at 37℃,pH=7 and a creatinine concentration of 100 mg·L-1．
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发布时间：2021-03-19 - 摘要：The temperature sensitivity of poly(N-isopropyl acrylamide)(PNIPAAm)-grafted films was investigated through water absorbency and water contact angle measurements．Though it contributed little to the water absorbency of grafted films,the introduction of MBAAm retarded water evaporation from the grafted layers and also enhanced their hydrophilicity. It was found that below a certain critical temperature,the surface contact angle of the grafted films decreased during the measurement,which was related with the interaction process between the probing water drops and the film surfaces．A Temperature-dependent Real Time Contact Angle Measurement method (TRTCA),which is especially suitable for the LCST determination of temperature-sensitive grafted films,was developed based on a newly proposed contact angle modification algorithm to eliminate the influence of water evaporation．Finally,a two-stage model was proposed to describe the interaction process between the grafted films and water．Corresponding to this model,the critical grafting yield for grafted films crosslinked with MBAAm showing significant change of surface behavior was found to be around 0.6 mg／cm2．
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发布时间：2021-03-19 -
TERPOLYMERIZATION OF MALEIC ANHYDRIDE/STYRENE/N-PHENYLMALEIMIDE BY RARE EARTH COORDINATION CATALYSTS
摘要：Terpolymerization of maleic anhydride,styrene and N-phenylmaleimide was studied using rare earth coordination catalysts in toluene at 50℃．The dependence of terpolymerization on molar ration of catalyst components,different rare earth element,catalyst concentration,polymerization time and molar ratio of monomers was investigated in detail．Results showed that rare earth coordination catalysts were favorable catalysts for the terpolymerization of maleic anhydride,styrene and N-phenylmaleimide．A suitable condition for terpolymerization was as followed：Ln(naph)3=5.0×10-3 mol／L,[NPMI]=[MAn]=2.25×10-1 mol／L,[St]=4.5×10-1 mol／L,Al／Nd=6,50℃；2 h．The terpolymer was primarily characterized by FT-IR,NMR and thermal analysis．The terpolymer was shown to have high thermal stability.- 23
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发布时间：2021-03-19 - 摘要：Polyelectrolyte ultra-thin multilayers were prepared on single crystal silicon by alternative deposition of acid red 18 as anion and poly(ethylenimine) and poly(allylamine hydrochloride) as polycations．The films were characterized by means of ultra violet-visible light absorption spectrometry and contact angle measurement．The thickness of the ultra-thin self-assembled films was determined with an ellipsometric thickness tester．The friction and wear behavior of the ultra-thin films under one-way dry sliding against AISI-52100 steel was examined on a DF-PM friction coefficient measurement apparatus in a ball-on-block configuration．As the results,the deposition of the ultra-thin films on the single crystal Si leads to alternate variation in the contact angles of distilled water thereon．Both the two kind of ultra-thin films show good friction-reducing and antiwear behavior in sliding against the steel at a relatively low load,while the tribological behavior of the films is dependent on the bilayer numbers of the films．The ultra-thin film of eight bilayers made from poly(ethylenimine) and acid red 18 records a low friction coefficient in sliding against the steel even above a sliding cycle of 2000．Thus it might be a potential candidate as the friction-reducing and wear-resistant ultra-thin film material for some micro devices．
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发布时间：2021-03-19 - 摘要：Stable concentrated emulsions of methyl methacrylate／butyl acrylate(MMA／BA) were prepared by using sodium dodecyl sulfate(SDS) and cetyl alcohol(CA) as the compound surfactant,polyvinyl alcohol(PVA) as the major reinforcer of liquid film．The concentrated emulsions polymerization was carried out with benzoyl peroxide／N,N′-dimethyl phenylamine (BPO／DMA) as redox initiators at low temperature．When the whole reaction time lasts about 300 min,as is expected,the conversion can be as large as over 96％,and which is higher in comparison with that in concentrated emulsion polymerization initiated by heat initiators．The kinetic behaviors of concentrated emulsion polymerization and time-conversion curves in constant rate range (conversions from 20％ to 70％) were investigated．The size and distribution of particle diameter and morphology of latex particles were determined with PCS and TEM．The determination results revealed that concentrations of the compound surfactant and polymerization temperatures etc．affect the shape and size of polymer particles obviously. The experimental results show that with increasing the level of [E],[I] and T,polymerization rate increases．And with increasing the content of [E] and the ratio of [SDS]／[CA],the particle size of polymer latexes and the dispersion index of the particles size decrease： but with increasing the content of [I] and temperature the particle size of the polymer latexes and also the dispersion index of the particles size increase．
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发布时间：2021-03-19 - 摘要：Poly (diallyldimethylammonium chloride) (PolyDADMAC) is one of typical polyelectrolytes having versatile applications in food,medicine,water treatment and other industries．The polyDADMAC hydrogel is transparent and has good water swelling properties,but it’s mechanical properties are quite poor,which limit its use．In order to overcome its poor mechanical properties,the copolymers of poly(DADMAC-AA) were synthesized by radiation copolymerization．The gel strength and solution properties of the hydrogels were studied．It was found that an increase of the total concentration of monomers and the molar ratio of AA would improve the mechanical strength and increase the gel fraction of synthesized hydrogels．The compositions of copolymers were consistant with the molar ratios of DADMAC and AA added in the original feed solutions according to results of infrared spectrum studies and elemental analysis．The swelling ratios of hydrogels decreased with the increase of molar ratio of AA．When DADMAC :AA was 1:2,the swelling measurements showed that the copolymer hydorgels may exhibit the properties of polyampholytes,which were reflected by their absorption of Re(Ⅶ) in aqueous solutions under different pH values．
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发布时间：2021-03-19 - 摘要：The injection molding is by far the most popular process of the production of plastic parts for all kinds of applications. One of the most significant factors that influences the part quality is the polymer flow pattern．By properly guiding the polymer flow at the filling phase．some advantages could be attained,i．e．over-packing,residual stresses,non-uniform shrinkage,and warpage can be eliminated,and the creation of weld-lines and air-traps could be also minimized．A method has been proposed to improve the injection molding filling process by optimizing the injection rate．The numerical simulation for filling processing is combined with the design optimization method to find the optimum injection rate profile and to achieve a constant melt-front speed satisfying the constraint on maximum allowable shear stress．The objective function that can exhibit the flow unevenness is expressed as the sum of the difference between the melt-front speed and a reference value．Since it has great effect on the melt-front speed,the injection rates at some key points are chosen as the design variables．The constraints may limit the wall shear stress below the maximum allowable shear stress and the injection rate in a specified scope,which the injection machine can provide．The design sensitivities are evaluated with the finite difference method,and the optimization problem is solved with the sequential linear programming algorithm．The proposed method,taking under consideration the existence of a finite number of control points of a specific machine,produces a more realistic optimal solution．Finally,the success of the methodology is demonstrated by two examples．
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发布时间：2021-03-19 - 摘要：Some of the natural products are water unsolvable．For such products,it’s better that the sorption should be carried out in nonaqueous system．But common sorption resins are not effective in nonaqueous system,the simple reason for which is that the sorption on common resins is mainly based on the hydrophobic interaction between the resins and the adsorbate．So it is practically important to exploit resins which fit the nonaqueous system and study their sorption behavior．In this paper,a serious of coordination sorption resins have been prepared by loading different transition metal ions on the macroporous sulphonic resin,and the sorption of aniline,N-methyl aniline and N,N-dimethyl aniline on sulphonic resin in Cu2+ form from ethanol,ethyl acetate and bexane has been studied and compared with that from water. The sulphonic resin in Cu2+ form has the highest sorption capacity from hexane,and has lower sorption capacities from ethanol,ethyl acetate and water sequentially．In all the media,the resin shows the highest sorption affinity for aniline,moderate for N-methylaniline and the lowest for N,N-dimethylaniline. The different sorption affinities for the three anilines are attributed to the different steric hindrance of different anilines coordinating to Cu2+ on the resin．The sorptive isotherms of the anilines from different media fit the Freundlich equation,and the sorption enthalpies have been calculated．The sorption enthalpies of aniline from water and ethanol are higher,but nearly zero from ethyl acetate and hexane. The difference of sorption enthalpies from different media is attributed to the coordination of water to Cu2+ on the resin and the different swelling ratio in various media．The sorption rate of the anilines from water is the highest and decreases from ethanol,ethyl acetate and hexane sequentially．The different sorption rates are also attributed to the different swelling ratio in different media．All these conclusions will be useful for applying the coordination resin to the sorptive separation of some water unsolvable natural products．
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发布时间：2021-03-19 - 摘要：Isobutylene(IB) cationic polymerization by DiCumCl／TiCl4 was studied,and the effects of nucleophiles on PIB growing end were analyzed by UV spectroscopy．Using molecular simulation,the activation energy for reaction of nucleophiles with H+ was calculated by Molecular orbital package(MOPAC) method in semi-experiential quantum dynamics,and the change value of carbonic atoms of the growing species of isobutylene reacting with N-containing nucleophile reagent was obtained by QEq method after conformation optimization by using molecular dynamics．It was found that nucleophiles can complex with protons and so prevent chain transfer and chain termination reactions related with protons,and can also stabilize carbocations by reducing their charges．There are different reaction abilities between nucleophiles and protons or carbocations．Piperidine and 2,6-diter-butyl pyridine are strong nucleophiles which may complex with protons. 2,6-Diter-butyl pyridine can only trap protons and cannot complex with carbocations because of its big molecular volume. Piperidine is a good proton trap agent that can complex with carbocations to reduce their charge and increase their stabilization．
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发布时间：2021-03-19 - 摘要：The high oil absorption resin can clean up the oil spill which has been noted as a major cause for environment pollution．But the crosslinking network of the high oil absorption resin by chemical crosslinking agent is so tight that there are two problems for the resin to absorb oil,low oil absorbency and low releasing for oil-absorbed resin．The low oil absorbency will cause more resin to be used．The oil absorbed resin which can not be cyclically used will cause a solid pollution again．In order to solve these two problems,the concept of physical crosslinking is introduced into the research field of oil absorption resin which is traditionally crosslinked chemically only to loose the chemical crosslinking network．Acrylic-based high oil absorption resins with both chemical crosslinking and physical crosslinking were prepared in the suspension polymerization．The oil absorption rate and optimized ratio of two monomers in two kinds of different resins are compared．The oil absorption properties of two kinds of different resins produced from monomer with low affinity to oil and effects of the quantity of chemical crosslinking agent on them are compared too. Results indicate that the introduction of physical crosslinking will improve the oil absorption properties,including raising oil absorption rate and increasing oil absorbency of resins produced from monomer with low affinity to oil. In addition,it increases the quantity of monomer with low affinity to oil in optimized ratio of monomer．Results also indicate that partially physical crosslinking resin have a best amount range of chemical crosslinking agent．
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发布时间：2021-03-19 - 摘要：The heat resistant properties of polyvinyl chloride (PVC) are very poor,so that PVC resin can not be used in many cases．In order to enhance the heat resistant properties of PVC,N-phenyl maleimide (PMI) and／or acrylonitrile (AN) monomer units were introduced into the PVC chain to prepare heat resistant VC-PMI copolymer and VC-PMI-AN terpolymer by suspension polymerization．The Vicat softening point (VSP),glass transition temperature (Tg),dynamical mechanical behavior and morphological structure of heat resistant VC-PMI copolymer and VC-PMI-AN terpolymer were studied in detail．The results showed that the VSP and T of the heat resistant PVC increased with the content of PMI or AN．When the content of the heat resistant monomer units was high than a critical value,the increasing rate of the heat resistant properties was changed,two tanδ peaks appeared,and a dual phase continuity structure,named as “stiff chain frame work”,was formed．On the basis of these experimental phenomena,a new concept that the “stiff chain frame network” can increase the heat resisrant properties of the heat resistant PVC was presented．A heat resistant mechanism was discussed and its physical model was proposed also．The results of dynamic mechanical analysis revealed that the polymers had only one tanδ peak in most cases, however,two tanδ peaks appeared with increasing of the content of AN．The miscibility of the heat resistant agent (VC-PMI copolymer or VC-PMI-AN terpolymer) and PVC will influence the formation of the “stiff chain frame network”.
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发布时间：2021-03-19 - 摘要：Composites of thermotropic polyurethane(TPUR) with rectorite and organic rectorite clays of different composition were prepared by melt processing．The organic rectorite(ORECA) was obtained in an ion-exchange reaction of rectorite with quaternary ammonium salt．The composites were characterized by using FTIR,WAXD,SEM and mechanical measurements．It was found that the door spacing of ORECA crystals increased and even disappeared,when they were mixed with TPUR．These results implied the intercalation phenomenon and the nanoscale disperison of ORECA in the composites．The tensile strength of TPUR composites with 2 parts of ORECA was about 42％ higher than that of the pure TPUR．With increasing the OPECA content the few strength of the composites increased noticeably．An increase 92.8 kN／m to 138.8 kN／m was observed when 8 parts of OBECA was added in the composites．
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发布时间：2021-03-19 - 摘要：Elastomer-modifying is often used to improve the mechanical properties of epoxy resins,and the epoxy resin(EP)／thermoplastic polyurethane(TPU) is a fairly effective system．In this article the phase behavior of EP/TPU blends was investigated by time-resolved small angle light scattering (SALS) analysis．The correlation distance (ac) and mean square dielectric constant fluctuation (η) of EP/TPU blends were calculated．Evolutions of the domain size in EP／TPU blends were discussed under the isothermal curing condition．The results showed that the cured process of EP/TPU was a typical spinodal decomposition and can be well described by Cahn-Hilliard linearized theory at the early stage．With the cure development,the domains grew up and kept constant after 60 min．During the early blend cure process,the correlation distance (ac) and mean square dielectric constant fluctuation (η) of EP／TPU blends increased rapidly．from 0 to 1.00 and 0 to 118,respectively,if the experimental time was from 145 s to 1080 S．After that,the domains of the blends began to coalesce resulting in the decrease of η and increase ofac,which will keep constant after 3210 s when ac and η are 1.30 and 32,respectively．
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发布时间：2021-03-19 - 摘要：Syndiotactic polystyrene (sPS) and polyamide-6 (PA6) are recognized as immiscible and incompatible polymers．In this study,sulfonated syndiotactic polystyrene (SsPS-H) was used as compatibilizer in the blend of sPS/PA6．During melt blending,SsPS-H and PA6 can be well mixed because of the strong interpolymer interactions between the sulfonate groups and the amide groups including the interaction due to the transfer of the sulfonic acid protons to the nitrogens of the amides．In addition,SsPS-H is miscible with sPS when the degree of sulfonation is low. Therefore,the addition of SsPS-H to sPS／PA6 blends reduces the size of the dispersed phase and improves the adhesion between the phases. The glass transition temperatures of the PA6 component in the compatibilized blends shift progressively towards higher temperature with increasing the content of SsPS-H,indicating enhanced compatibility．On the other hand,the progressive lowering of the melting point and crystallization temperatures of PA6 in the blends with increasing SsPS-H contents provides some insight into the level of interaction between PA6 and SsPS-H．The compatibilized blends have significantly higher impact strength than the blends without SsPS-H．The best improvement in the impact strength of the blends was achieved at an SsPS-H (8.65 mol％) content of about 5 wt％.
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发布时间：2021-03-19 - 摘要：By using of organically modified montmorillionite(MTN),which was prepared by ion exchange between Na+ ion in the clay and palmityltrimethylammonium ion in aqueous medium,MTN-SsPS(sulfonated syndiotactic polystyrene with sulfonation level of 4.13 mol％) and MTN-aPS(atactic polystyrene) intercalation compounds are prepared through solution intercalating and bulk free radical polymerization process,respectively．The intercalation of SsPS or aPS molecular chains with MTN lamellar sheets was demonstrated by the enlargement degree of the interlamellar distance as measured by X-ray diffraction．Then,the novel sPS／PA6／SsPS-H／montmorillonite nanocomposites were prepared through directly melt blending of MTN-SsPS or MTN-aPS with sPS,PA6 and SsPS-H(sulfonation level of 8.65 mol％)．X-ray diffraction and TEM results show that the clay layers are exfoliated into nanoscale layers and randomly dispersed in the polymer matrix．The average nanoscale size ranges from 10 to 60 nm as obtained by statistics computation,which imply that sPS and PA6 molecular chains maybe intercalate between the layers of MTN during melt blending process．The formation of nanocomposites via melt intercalation depends upon the thermodynamic interaction between the polymer chains and the host silicates and the transport of the polymer chains from the bulk melt into the silicates layers．The miscibility of sPS and SsPS-H,together with the specific intermolecular interactions between PA6 and SsPS-H facilitate the sPS and PA6 intercalate between the MTN-SsPS layers,which,in turn,enhance the miscibility between sPS and PA6 in the composites as verified by DMA measurement．In addition,the mechanical testing shows that the properties of the nanocomposites are superior to the pure blend in terms of the strength and modulus without sacrificing their impact strength．
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发布时间：2021-03-19 - 摘要：High molecular weight polyacrylonitrile (PAN) was obtained by the free-radical suspension copolymerization of itaconic acid (IA) and acrylonitrile (AN) which was carried out in DMSO／H2O using azodiisobutyronitrile(AIBN) as initiator．Orthogonal design method was used to study the effect of polymerization parameters,such as the reaction temperature,monomer concentration,DMSO／H2O ratio,initiator content and so on,on the conversion of polymerization．The reaction temperature is the most important factor determining the conversion of copolymerization. The effect of DMSO／H2O ratio on the conversion and viscosity-average molecular weight was specially introduced．The copolymerization reaction rate and the viscosity-average molecular weight of copolymers may decrease as the result of the high chain transfer constant of DMSO．For copolymerization of AN and IA,with the inclusion of good solvent DMSO,the solution degree of AN in DMSO／H2O is higher than in water,as a result,the resulting copolymer pellets becomes porous．The structure and properties of PAN homopolymer and P(AN-co-IA) copolymer were also studied by using DSC,TG and IR measurements．It was shown that the conversion of polymerization could be increased by increasing reaction temperature,decreasing monomer concentration and decreasing the IA content in the feed AN／IA ratio．The results also demonstrated that the conversion of copolymerization of IA and AN decreased with the increase of DMSO content in the feed DMSO／H2 ratio．For the same IA content in the feed AN／IA ratio,the high molecular weight P(AN-co-IA)copolymers have the lower start exothermal reaction temperature and wider DSC exothermal peak as compared to the convertional low molecular weight P(AN-co-IA) copolymers,and these phenomena are consistent with the result of IR studies．
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发布时间：2021-03-19 - 摘要：The crystallization process of uniaxially oriented poly(ethylene terephthalate)(PET)was investigated by using DSC with a constant heating rate．The cold crystallization thermograms of uniaxially oriented PET exhibit multiple-overlapping peaks．This phenomenon was also confirmed by the isothermal DSC studies. A new method was proposed to obtain the crystallization kinetic parameters of polymers from the complicated DSC curves. The result indicated that the theoretical curve calculated from the new method shows a better agreement with the experimental data than that from the other methods．The crystallization process of uniaxially oriented PET was analyzed by using a model that involved three different crystallization mechanisms depending on different temperature ranges. The whole crystallization process of uniaxially oriented PET consists of three sub-processes. Crystallization mechanism was explained based on the change of the Avrami exponent and mass fraction of every sub-process with draw ratio．
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发布时间：2021-03-19 - 摘要：Acrylic acid (AA) was grafted onto the powdered isotactic polypropylene (i-PP) by using the electron-beam-induced preirradiation method．Eleven rare earth ions,including La3+,Pr3+,Nd3+,Sm3+,Eu3+,Gd3+,Tb3+,Dy3+,Er3+,Tm3+ and Yb3+,were adsorbed on the graft product PP-g-AA．The properties of RE3+ adsorbed were investigated in detail．These properties include the sorption quantity,the distribution ratio and the sorption rate．We found that “Inclined W Effect” and “Tetrad Effect” exist in the sorption behavior．
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发布时间：2021-03-19 - 摘要：Poria cocos mycelia were cultivated from artificial strain No 5·78 in medium containing bran at 25℃ for eighteen days．Seven polysaccharides coded as ab-PCMl,ab-PCM2-I,ab-PCM2-II,ab—PCM3-I,ab-PCM3-II,ab-PCM4-I and ab-PCM4-II were isolated from the poria cocos mycelia by using 9 g/L NaCI aqueous solution,hot water,0.5 mol／L NaOH aqueous solution and 88％ formic acid,respectively,and an exo-polysaccharide coded as ab-PCMO was isolated from the medium. The components of the polysaccharides were analyzed by using infrared spectroscopy(IR),gas chromatography (GC) and 13C-NMR．The results indicated that the polysaccharides from ab-PCMO to ab-PCM3-I consist ofα-(1→3)-D-glucose,α-D-mannose,β-D-galactose,and N-acetyl glucosamine,and with the isolation progress the glucose content in the polysaccharides increased,namely from heteropolysaccharide toα-glucan．The ab-PCM3-II,ab-PCM4-I and ab-PCM4-II mainly consist of β-(1→3)-D-glucan．Interestingly,α-glucan and β-glucan coexist in the alkali extracted solution of the mycelia．The intrinsic viscosities [η] and weight average molecular weights Mw were determined by viscometry and light scattering．The values of Mw for samples of ab-PCM0,ab-PCM1,ab-PCM2-I,ab-PCM2-II,ab-PCM3-I and ab-PCM4-II are 7.7×104,5.2×104,5.0×104,24.3×lO4,65.2 x 104 and 25.5×lO4,respectively．
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发布时间：2021-03-19 - 摘要：Amphiphilic magnetic polymer microspheres were synthesized by copolymerization of styrene with poly(ethylene oxide) macromonomer(MPEO)in the presence of Fe3O4 magnetic fluid in ethanol／water medium．The effect of MPEO concentration on the average size of magnetic microspheres was investigated．Magnetic microspheres size,morphology and surface roughness were characterized by scanning electron microscopy and atomic force microscopy．The structure of copolymer was determined by infrared spectroscopy．With increasing poly(ethylene oxide) macromonomer used in polymerization,the surface roughness of microspheres increases．Magnetic microspheres containing 0.4～3.5 mg／g hydroxyl groups could be prepared by varying concentration of MPEO．
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发布时间：2021-03-19 - 摘要：The gel effects will bring a violent increase of conversion for methyl methacrylate polymerization．It will be very dangerous for the reactor and causes an increase of molecular weight and broadens the molecular weight distribution. In order to control the kinetics,molecular weight and its distribution of polymerization simultaneously,three characteristic parameters for polymerization of methyl methacrylate；the heat load distribution index,the change of molecular weight and molecular weight distribution index,were suggested for consideration．The effects of the flow rate and feeding mode of the monomer,solvent and chain transfer agent on the three parameters were investigated, respectively. The gel effect can not be eliminated by changing the flow rate of monomer．The change of monomer feed mode will result in a multiple violent increase of conversion,and the molecular weight will increase with the appearance of gel effect．So the method based on varying the flow rate and feed mode of monomer can not meet the demand of properly controlling the kinetics,molecular weight and molecular weight distribution of polymerization and its products The molecular weight of polymers prepared by solution polymerization or by with the participation of chain transfer agent was always lower than that of bulk polymerization．However,by changing the flow rate and feed mode of solvent or chain transfer agent,not only the molecular weight can be equal to that of bulk polymerization,but also the gel effect can be eliminated,and the kinetics,molecular weight and molecular weight distribution of polymerization can be properly controlled simultaneously．The optimum heat load distribution index was even less than 2.0,the change of molecular weight was lower than 10％,and molecular weight distribution index was even in the range of 2.0～2.2,respectively. Two open control methods were selected and satisfied with the experimental data.
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发布时间：2021-03-19 - 摘要：A series of poly(3-hydroxybutyrate) (PHB)／poly (ethylene oxide) (PEO) blends with different compositions were studied by solid-state high-resolution 13C-NMR spectroscopy．The crystallinity,1H spin-spin relaxation time (T2) and 1H spin-lattice relaxation time in the rotating frame (T1ρ) of PHB and PEO in the blends were measured．It was found that the crystallinity of PHB may keep almost constant over the whole composition range,while that of PEO decreased dramatically with decreasing PEO content．1H T2 of the noncrystalline region of PHB increases with the increase of PEO content,indicating that the mobility of the noncrystalline resion of PHB has been enhanced．1H T1ρs of the noncrystalline PHB and PEO become close to each other as composition of the blend changes．PHB and PEO are found to be partially miscible in the noncrystalline region of the blends．The miscibility depends on the composition．The highest miscibility of noncrystalline regions of PHB and PEO is achieved when the weight content of PEO is about 20％．
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发布时间：2021-03-19 - 摘要：The oxidizing process and the oxygen-binding lifetime of 5,10,15,20-tetra (o-pivalamidophenyl)-perphyrinato cobalt(II) (TPPCo) complexed with poly(vinylimidazole-co-fluoropentyl methacrylate) (PFIm) were studied,and the mechanism and dynamics of irreversible oxidation of TPPCo were discussed．The TPPCo displayed a reversible change in the UV-visible absorption spectrum from the deoxy form (λmax=530 nm) to the oxygen-binding one (λmax=548 nm) with an isosbestic point at 538 nm,in response to the partial oxygen pressure of the atmosphere．But the active TPPCo complex in the membrane was slowly changed,via the irreversible oxidation reaction in the open atmosphere,to the TPPCo (Ⅲ) complex without the oxygen-binding ability,which could be monitored by the UV-visible absorption at λmax=548 nm．In the solid membrane state,water molecules in air may attack the TPPCo-bound dioxygen to yield a hydrodioxy radical and TPPCo(Ⅲ),which is the main reason that diminishes the oxygen-binding ability of the TPPCo complex and that of the membrane．The half-lifetime (τ) of the TPPCo complex as an oxygen carrier was measured by allowing the TPPCo-PFIm membrane to stand in dry air (environmental humidity 10％),in laboratory air (humidity ca．50％),and in a water vapor atmosphere (humidity 95％) at room temperature,respectively．The decrease course of the active TPPCo complex approximately follows the first-order kinetics and gives the t values．The τ value of the PFIm-TPPco complexed membrane was as long as ca．250 days even in the water vapor-saturated atmosphere．Under the same laboratory air condition,the lifetime of the PFIm-TPPCo membrane was much longer (ca．13 times) than that of the reference non-fluoro membrane such as the membrane of TPPCo complexed with poly(octyl methacrylate-co-vinylimidazole)．The hydrophobic property of the PFIm polymer is considered to suppress the irreversible oxidation of the active TPPCo carriers caused by water molecules and to significantly prolong the operational lifetime of the TPPCo complex membrane．
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发布时间：2021-03-19 - 摘要：The PS/PMMA blend films were prepared by volatizing the solvent very slowly from the PS/PMMA/THF solution．Various substrates were employed such as glass,PET film,PTFE film and PP film．The SEM pictures showed that the morphologies of both the surface-side (contact with air) and the bottom-side (contact with the substrate) of the film strongly depend on the substrates used．If the substrate was glass or PET films,there were a small amount of PS particles on the bottom-side of the films．On the other hand,a lot of large PS particles could be observed on the bottom-side of the films when PTEF films or PP films were used as substrates．ATR-FTIR analysis was used to detect the composition at the surface side and the bottom side of the blend films．Substrate-segregation was found．It was supposed that this effect might be resulted from the different affinity of PS to the various substrates.
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发布时间：2021-03-19 - 摘要：DMC polyether polyols,prepared by the polymerization of propylene oxid with dimetallic catalyot,have been found to suffer obvious degradation and decrease their viscosity and molecular weight during storage. The degradation was found to be influenced by free-radicals,temperature light,and oxygen．However．the degradation can not be stopped by isolation from air and may be eliminated by addition of anti-oxidants．This implies that the degradation is not an stoichiometric oxidation reaction with oxygen in air,but some kind of free-radical induced chain reaction.
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发布时间：2021-03-19 - 摘要：A diol 1,3-di(2-hydroxyethyl) 5-hydroxyl isophthalate (DHHI) was synthesized through the nucleus substitution reaction of 5-hydroxyl isophthalic acid(HIA)．The monomer was characterized by 1H-NMR,FTIR,elemental analysis and differential scanning calorimetry (DSC)．Then a precursor polymer (PU-OH) containing hydroxyl groups was prepared by step polymerization of DHHI and 4,4′-diphenylmethane-di-isocyanate (MDI).By PU-OH’s functionalization with cinnamoyl chloride,a polyurethane (PU) with cinnamate side-groups (PU-CI) was obtained．The polymers synthesized were characterized with 1H-NMR,DSC,IR spectroscopy and elemental analysis．The photosensitive polymer PU-CI was found to be cross-linked under the irradiation of UV light through a cyclo [2+2] reaction．After processed by Linear Polarized Polymerization (LPP),the spin-coating films of PU-CI were changed into photo alignment layers．Then sandwich-type liquid crystal cells (LC cells) of a 50-μm-thick were assembled via a capillary action using nematic liquid crystal 5CB．The microscopic photographs were obtained which showed the LC-aligning ability of PU-CI photo alignment layers．Therefore,the photosensitive polymer PU-CI synthesized has potential application as photo alignment layer in liquid crystal cells．
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发布时间：2021-03-19
Research Article
- 摘要：Microporous membrane was newly derived from P(VDF-HFP)／acetone／water system by dry-casting in the alr．The structure of microporous P(VDF-HFP) membrane was observed through SEM．It was found that the pores were distributed uniformly in the whole membrane,some pearls were attached onto the skeleton and the diameter of the pores was in the order of a few microns．The porosity of the membrane was measured up to 72％ by weighting the membrane’s mass before and after absorption of n-butanol．The crystallization behavior of the copolymer was studied with DSC before and after the formation of microporous membrane．In order to understand the morphology of the membrane,the process of the formation of micropores was discussed based on both the kinetic and thermodynamic points in the paper．The porous P(VDF-HFP) electrolyte was prepared by impregnating the membrane with PC／EC liquid electrolyte．The resistance of the solid porous electrolyte was measured by the ZL5 intelligent LCR meter,and the conductivity was evaluated from equation,σ=L／(RS)．At ambient temperature the conducting can reach 10-3S／cm. The solution holding of the porous solid electrolyte was tested by isothermal TGA measurements,which illustrate that the mass loss was only 10％ at 60℃ in the open air for 1.5 h．It shows that the porous solid electrolyte prepared by this process has the potential application in the lithium ion battery,and that this method of membrane formation is nonpoisonous to the environment．
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发布时间：2021-03-19 - 摘要：The multifunctional azopolymers (PAZ-R*) containing azobenzene moieties with chiral group were synthesized as a new class of optical polymers．The structure of polymers was characterized by Gpc,elemental analysis and circular dichroism．The optical phase conjugated responses of the polymer films were investigated by the degenerate four-wave mixing (DFWM)．Furthermore,the photo-induced holographic phase gratings of the films were characterized by POM．The experimental results showed that optically active polymers(PAZ-R*) containing chiral groups could form holographic phase gratings buried in the films．From the preliminary measurements of photoalignment,it was found that the chiral group in side-chain azobenzene polymer films could play an important role in responding polarization direction of the irradiating beams and the irradiating number．The chiral group was found to have influence on changing physical properties such as optical phase conjugated characteristics effectively and on the formation of microstructures in the film．Further studies on the photoinduced properties of side-chain azobenzene polymer films with chiral groups are in progress．
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发布时间：2021-03-19 - 摘要：Poly(2-methoxy-5-(2′-ethylhexyloxy)-p-phenylenevinylene) (MEH-PPV) has been prepared by a liquid／solid two-phase reaction．The liquid phase is tetrahydrofuran containing 1,4-bis(chloromethyl)-2-methoxyl-5-(2′-ethylhexyloxy) benzene as the monomer and a certain amount of tetrabutylammonium bromide (TBAB) as phase transfer catalyst (PTC)．The solid phase is potassium hydroxide particles with diameters smaller than 0.5 mm．Gelation was found in the polymerization processes．As a result,MEH-PPV is partly soluble because of its large molar mass．Soluble MEH-PPV was obtained by using bromomethylbenzene as retardant regent．The molar mass of soluble MEH-PPV was measured to be 6.4×lO4 g／mol．The Structure of polymer was identified by IR,Raman,UV／vis and PL spectra．A thin compact film of MEH-PPV can be formed by spin-coating and it emit a yellow light．
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发布时间：2021-03-19 - 摘要：A new copolymer has been synthesized by the copolymerization of acrylic acid with crotonaldehyde in water using K2S2O8 as initiator．The copolymer was characterized by DSC,IR and 13C-NMR．The effects of pH on the rate and conversion of copolymerization and copolymer’s composition have been investigated．The results show that,as pH increases,the rate and conversion decrease,especially at pH 5～7,while the content of crotonaldehyde in copolymer increases．It has been proved by IR that there is hydrogen bond between acrylic acid and crotonaldehyde at low pH．The study indicates that hydrogen bond improves the ability of polymerization．However,at high pH,acrylic acid was found as electron acceptor；crotonaldehyde as electron donor．A model of “charge transfer polymerization” was employed to illustrate the copolymerization at high pH．
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发布时间：2021-03-19
Research Bulletin
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