最新刊期
卷 ， 期 4 ， 1998
- 摘要：An experimental method was designed to characterize the thermal stability of nucleating effect of nucleating agents by repeated heating cooling DSC experiments.The DSC results showed that calcium carbonate,sodium benzoate and terephthalic acid were the nucleating agents of polypropylene with high thermal stability of the nucleating effect,while the thermal stability of nucleating effect of pimelic acid,suberic acid,azelaic acid,and the two component nucleating agents suberic acid/calcium carbonate and azelaic acid/calcium carbonate were poor.But the two-component nucleator,pimelic acid/calcium carbonate exhibited good thermal stability,which infer that there are some interactions between pimelic acid and calcium carbonate.
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发布时间：2021-03-19 - 摘要：The mechanical properties and degradable properties of PLA PEG/PU elastomers were determined by DMA,stress strain and degradable experiment.The result shows that the tensile strength and the elongation decreased,as the content and the Mw of PEG increased.The degradable time increased with the Mw of PEG increased,but decreased with the content of PEG increased.The elastomer was degraded mainly from the surface,but sometime faster in the inner in urine.There was an auto- acceleration effect in the degrading process of PLA-PEG/PU elastomer.The animal experimental result shows that the elastomer is fit to Urethra-Supporting.
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发布时间：2021-03-19 - 摘要：The kinetics of non isothermal crystallization of CBP/PEO blends have been investigated by differential scanning calorimetry.Based on the Mandelkern Ziabicki Jeziorny and Ozawa theories,the results show that a blend of non crystallization and rich EO units was obtained.CBP restrains crystallization of PEO.The kinetic crystallizability Gc,Zc have been determined and discussed.Avrami exponent n is between 3.8～5.7 with increasing cooling rate.The values of Zc increase with cooling rate,the values of Gc are constant with cooling rate.In sum,the results show disagreement with the Mandelkern and Ozawa theories.This system accord with Ziabicki theory.
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发布时间：2021-03-19 - 摘要：A kind of intramolecular charge transfer compound——3 methoxy 4' N,N dimethylamino flavone derivateves(DMMF) was used to detect collagen association in aqueous solution.Results showed that,when collagen concentration was increased to 0.5mg/mL or above,the fluorescence intensity of DMMF at 465nm increased dramatically.This indicated that collagen can associate in aqueous solution.A fluorescence polarization study on the same collagen solution also showed that the fluorescence polarization of DMMF rose rapidly when collagen concentration was increased to 0.5mg/mL or above,which proved that the system had high miecro-viscosity.This results also indicated that the aggregation behavior existed in the aqueous solution of collagen.
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发布时间：2021-03-19 - 摘要：A new series of semetic C phase liquid crystal polymers with mesogens laterally fixed onto the main chain was synthesized via low temperature solution polycondensation from 2,5 bis(p alkoxyl benzoloxy) hydroquinone and aliphatdiyl chloride with different structure.The low molecular weight compounds were analyzed by elemental analysis IR 1H-NMR and MS.The polymers were characterized by GPC DSC TG WAXD and polarizing microscope with heating stage.It was found that all the polymers went to liquid crystal phase when heated to their Tm.The Schlieren textyre or focal-conic texture can be observed.Temperature-variable X-ray diffraction realized that they are smectic c phase.Both Tm and Ti of all the polymers decreased with the increase of the end alkoxy group length and the flexible spacer unit in the polymers gets longer,the temperature range of the liquid crystal phase of the polymers becomes narrow.
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发布时间：2021-03-19 - 摘要：During the copolymerization of styrene with divinylbenzene,a series of samples were taken at different gelation time from the beginning to the end of this reaction.For sol samples before and after gelation point time Tg(=18.15h),the weight average molecular weight (Mw), the mean square radius of gyration (Rg) of the polymer chain in solution,the second virial coefficient (A2),hydrodynamic radius (Rh),parameter δ(=Rg/Rh) and the size distribution for these samples were determined by static light scattering and dynamic light scattering.Before Tg,both Mw and Rg increase rapidly,then become divergence near Tg and reach the maximum at Tg.Rh almost follows the same way except not so rapidly.After Tg all go down.A2 decrease gradually following the gelation.δ are 2.78,3.80 and 1.87 at 15h,18.25h and 29h,respectively,which agree with the rules of linear and branching polystyrene.The size distribution of these sol samples always were rather wide and before Tg and after Tg,their diameters tend to increase and decrease,respectively.Based on these data, the evolution rules of these parameters were withdrawn and the quantitative characterization of span process of gelation was carried out successfully.
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发布时间：2021-03-19 - 摘要：Syndiotactic polystyrene and atactic polypropene were synthesized with different titanium compounds, in particular of η5 cyclopentadienyltri n propoxy titanium [CpTi(OPrn)3] and modified methylaluminoxane (m-MAO) homogeneous catalytic system.The titanium ligands affect catalytic activity of styrene syndiospecific polymerization and propene polymerization.The effects of the percentage contents of the trimethylaluminum (TMA) coexisted inm-MAO,which can be controlled by changing H2O and TMA molar ratio during the preparation of MAO by partial hydrolysis of TMA with Al2(SO4)3·18H2O, on polymerization of styrene and propene have been studied in detail.The external addition of alkylaluminium(AIR3,trimethylaluminum,triethylaluminum,tri-isobutylalumimum) to CpTi(OPrn)3/m-MAO catalytic systems may also influence both catalytic activity and molecular weights of syndiotactic polystyrene produced.The oxidation states of titanium in different CpTi(OPrn)3/m-MAO catalytic systems were determined by redox titration method.It results that Ti(Ⅲ) is good for styrene syndiospecific polymerization in higher catalytic activity,while Ti(Ⅳ) is good for propene's polymerization.Oxidation state of tinanium in catalyst system does not clearly affect the tacticity of these two kind of polymers obtained.
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发布时间：2021-03-19 - 摘要：The copper (Ⅱ) complex fibers were prepared by heterogeneous coordination replacement reaction of silk fibroin,viscose cellulose and poly(vinyl alcohol)(PVA) fiber in cuprammonium solution.The coordination structures of the fiber were studied by ESR spectra etc.The antibacterial experiment shows that the antibacterial activities of these three copper (Ⅱ) complex fibers are in the following order:Cu2+ PVA fiber >Cu2+ Cellulose fiber >Cu2+ Silk fibroin fiber.It is verified that the antibacterial activity is related with stability of the coordination structure of the copper(Ⅱ) complex fiber.That is the more unstable coordination structure,the better the antibacterial activity.A copper (Ⅱ) complex fiber of citric acid modified cellulose (Cu2+-CA-Cellulose) with moderate stability of the coordination structure which has been designed shows good antibacterial activity and washing fastness,as expectd.
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发布时间：2021-03-19 - 摘要：The water swelling elastomer (WSE) is a new type of sealing materials for water′s stopping,which was developed in the later of seventy′s and used comprehensively in dams,undergrounds of building,tunnels,subways and so on.It was very important how to solve the problem that the hydrophilic component can be solved out from WSE in water.The results obtained in our former experiment showed that the problem could be solved successfully by covulcanizing method.The swelling behavior of three kinds of WSE in still water, toluene,and different salt solutions were studied.The results obtained in water showed that the swelling behavior of PHPAM-WSF,PAANa-WSE and PEU-WSE were all agreed with first order kinetic equation as ln[(Qe-Qo)/(Qe-Qt)]=Kt and the Ea value of PHPAM-WSE was 19.5kJ/mol.The Qe decreased with increasing amount of crosslinking agent S during the swelling in toluene.The results from the effect of different kind of hydrophilic component on swelling behavior showed that the order of swelling specd was PEU>PHPAM>PAANa,while the swelling degree to reach Qe PHPAM>PEU>PAANa.The results gained from the effect of pH of solutions on the swelling behavior showed that the Qe of PEU-WSE was affected lightly by pH,while the Qe of PHPAM-WSE and PAANa-WSE were heavily influenced by pH.The effect of different metal ions on the swelling behavior were also studied and the results were that Qe value was maximum in distilled water and minimum in Portland cement water solution,the PEU-WSE almost wasn't affected by cation's charge number while the Qe of PHPAM-WSE was decreased dramatically with the increasing of cation's charge number.
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发布时间：2021-03-19 - 摘要：The mechanical properties of polyacrylic acid is investigated on the molecular scale by using of an atomic force microscopy. Polyacrylic acid was adsorbed onto the glass substrate, then picked up at one point of the chain with an AFM tip and stretched. The elongation of individual molecules was recorded as a function of the applied load.In the force curves of PAA,the monotonically rising forces with the elongation of the polymer chain is observed.After normalization according to their contour lengths,all of the force curves can be found,indicating that the mechanical properties of polyacrylic acid scale linearly with their lengths.The force-extension curve can be modeled by a modified Langevin Function.It is found that all of the poly (acrylic acid) chains have the same Kuhn length (0.64±0.05nm) and same segment elasticiy(13000±2000 pN/nm).Both the experimental results and fit results cleaely indicate that single polyacrylic acid chain is stretchen and nanomechanical properties of single poly(acrylic acid)chain is measured.
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发布时间：2021-03-19 - 摘要：The resins of (1,4) 2 amino 2 deoxy β D glucanresins (chitosan) were activated by epichlorohydrin.The effect factors of activation were studied in detail and the reaction conditions were optimized.Then the anti HBsAg monoclonal antibody were coupled to the activated carrier to obtain the immunoadsorbent.The adsorption properties of the immunoadsorbent were studied in serum containing HBsAg and the adsorption efficiency reached 44%.
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发布时间：2021-03-19 - 摘要：The structure and properties of the triblock copolymer HO-PLA-PEG-PLA-OH prepared by lacide (DL-LA) and polyethylene glycol(PEG,M=4000) with various composition ratios, were studied by FTIR spectroscopy, 1H-NMR spectroscopy, dynamic mechanical analysis(DMA). The effect of temperature and pressure in processing on intrinsic viscosity of block copolymer was also studied. The experiment results indicated that the tensile strength and glass transition temperature decreased with the increasing of the content of PEG for block copolymer.The general properties of PLA were improved obviously by PEG.The properties of tri-block copolymer are controlled more easily than PLA polymer, which can be used in the cure urethra-narrowing.
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发布时间：2021-03-19 - 摘要：Dynamic mechanical analysis (DMA) and scanning electron microscopy(SEM) were used to study the compatibility of nylon6/polystyrene(PA6/PS) blends with poly(styrene-b-ethylene oxide) (PSt-b-PEO) diblock copolymers as compatibilizer. It has been found that the compatibility of the blends prepared by pure PA6 and PS is very poor. The boundary between the phase domains of PA6 and PS without PSt-b-PEO is sharp and clear. When 2 parts of PSt-b-PEO copolymer per hundred of resin(phr) were added, the glass transition temperatures of the constituent polymers converge,the size of the disperased phase domain decreases and the thickness of the interfacial layer increases,because PSt-b-PEO is efficient in lowering the interfacial tension and enhancing the interfacial adhesion in PA6/PS blends.And the compatibilization effects PSt-b-PEO diblock copolymers with different molecular weight and composition ratio on PA6/PS(80/20) blends were also discussed.The compatibilizing efficacy of PSt-b-PEO is dependent on the actual amount of the compatibilizers in the boundary region of PA6/PS blends.When the molecular weight is appropriate and ethylene oxide block length in PSt-b-PEO is more than that of styrene,the compatibilization is more efficient for PA6/PS(80/20) blends.
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发布时间：2021-03-19 - 摘要：Surface heparinization of polyethylene was effectively achieved by O.3 induced graft copolymerization of the film with glycidyl methacrylate( GMA), reaction of grafted polyglycidylmethacrylate(PGMA) with Jeffamine, forming polyoxyethylene chain capped with amino group, and then the condensation of the terminal amino group with the carboxy group of heparin in the presence of 1ethyl 3(3 dimethylaminopropyl) carbodiimide(EDC). Three kinds of Jeffamine with molecular weight 600,900,and 2000 were investigated, respectively.It was found that the molecular weight of Jeffamine shows a great influence on the extent of both the reaction with PGMA and the Heparinization.Jeffamine with lower molecular weight shows higher extent of the both.For Jeffamine ED-600 the surface concentration of immobilized heparin amounts to as high as 1.36μg/cm2 and the film shows highest antithrombogenicity.
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发布时间：2021-03-19 - 摘要：Compatibility of very low density polyethylene (VLDPE) with other commercial polyethylenes is studied by DSC, WAXD and SAXS. HDPE/VLDPE blends are compatible through cocrystallization. Copious amorphous part in VLDPE `dissolves' the crystallite defects of HDPE, improving the latter's Tc,Tm and Xc. Half width of HDPE's WAXD crystallite peaks becomes narrower, and unitcell parameters show minimum values with composition. VLDPE and LLDPE are similar in structure, and they are cocrystalline compatible.Mutual interaction between LDPE/VLDPE is evidenced by the increase in unit-cell parameters and crystallite dimension,the appearance of two individual Tm's,and the constantly higher Tc,Tm values of VLDPE and lower Tc,Tm of LDPE than expected of their composition.This is due to the continuous filling of LDPE into VLDPE occupying the space,forming separate incompatible system.
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发布时间：2021-03-19
Research Article
- 摘要：The solution cyclocopolymerization of 1,3divinyl1,1,3,3tetramethyldisiloxane (DVDS) with styrene(St), using dicumy1 peroxide as initiator is reported. The 29Si-NMR spectra indicated that the cyclocopolymers had the fiveand sixmembered ring, saturated acyclic, and unsaturated acyclic structures formed from DVDS. The thermal properties of cyclocopolymer were investigated by DSC and TGA. It showed that the heatresistant properties of St polymer were improved via copolymerizing with DVDS, and the high degradation temperatures existed in the cyclocopolymers having both high molecular weight and DVDS content.
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发布时间：2021-03-19 - 摘要：FT Raman Spectroscopy was used to study the interphasial structure in carbon fiber/polyetheretherketone (CF/PEEK) composites. Spectra of APC 2 laminates with different thermo mechnical histories show a broad band around 1300 cm-1 distinctive either to theA1g scattering of carbon fiber or to PEEK overtones, suggesting different PEEK structure in composites compared to neat resin. To simulate formation of the interphasial structure in the composites, AS4 fiber was coated with PEEK through its chlorophenon solution.The FT-Raman study of the coated fibers reveals that the 1300cm-1 band originates from overlapping of the dispersive branches of graphite A1g and PEEK ring C-O scattering. Comparison of the spectra of coated fibers with those of the melted ones reveals profound effects of melting on interphasial structure.Raman spectra of the unmelted coatings were dominated by E2g and non-dispersive A branches of graphite and localized modes of PEEK.When melted,the spectra became highly dependent on coaling thichness.When thickness of PEEK layer is about a dozen of nanmeter,the broad band around 1600cm-1 can be found stronger compared to that of unmelted coatings.The band center shifted to lower wavenumber when coating thickness decreased.When the PEEK coating approached the order of nanometer,spectra typical to amorphous and mesophase carbon were found.The result suggest that the structure of the polymer near carbon fiber must be different from that in the bulk if PEEK is allowed to melt.The structure different is discernible at least on two scales,one identical to the dimension of chain coil and amother to thickness of the segments.While structure on the latter scale needs further work to be understood more explictily, the limited results hinted matching of graphite crystallites with the polymer segments.Within a dozen of nanometers to the fiber surface orientation of the ether-ether-ketone segments are no doubt stronger than those in neat PEEK. It was thus deducted that interphase forms in composite during processing through interaction of the EEK segments with graphite in short range neighbor to carbon fiber surface and chain orientation within a larger range of tens of nanometers.
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发布时间：2021-03-19 - 摘要：Several new kinds of poly(p phenylene) have been synthesized and their structrue were identified by NMR, IR and element analysis. Side chains with different length have been grafted to the backbone of the poly(p phenylene), which enlarged the configurational entropy of the conjugated polymers. As the result, the solubility of the polymers was greatly increased. All of them were able to be soluble in chloroform. The absorption spectra and fluorescent spectra of polymers were measured.
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发布时间：2021-03-19 -
THERMO RESPONSIVE BEHAVIORS OF POLYMER AND HYDROGELS BASED ON ITACONATE HAVING PYRROLIDINONYL MOIETY
摘要：4 Methyl-1-(2-N-(2-pyrrolidinonyl) ethyl) itaconate (PyEMI) was synthesized by reaction of 4 methyl itaconate chloride (MIC) with 1 (2 hydroxyethyl) 2 pyrrolidinone (HEPy). It undergoes free radical polymerization easily. The aqueous solution of P(PyEMI) shows a sensitive response against the change of temperature. The solution transmittance was dropped sharply with the increase of temperature at the transition temperature. The transition temperature was increased with the decrease of the solution concentration.The hydrogels of P(PyEMI) were prepared by polymerization of PyEMI in glass mould with ethylene glycol dimethacrylate as a cross-linker.The swelling ratio(SR) of the hydrogels were decreased with the increasing of temperature in water but increased in mixed solvent of DMF/water (4/1).- 2
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发布时间：2021-03-19 - 摘要：The interaction between diazoresin and sodium dodecyl sulfate(SDS) was investigated in aqueous solution. The results show that with addition of SDS into the diazoresin solution, the complex from diazoresin and SDS forms a precipitate in the ratio of SDS-/N+2 (mol/mol)<0.5, then the precipitate become soluble with the further addition of SDS. It was confirmed that the diazoresin SDS complex solution possesses excellent thermostability as well as high photosensitive behavior and exhibits a powerful latent use as a photosensitive agent in the preparation of negative PS plate.
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发布时间：2021-03-19 - 摘要：Poly(3 trimethoxysilylpropyl methacrylate co dibutyltin maleate)/silica (P(MSMA-co-DBTM)/SiO2)hybrid material has been successfully prepared from the free radical polymerization of MSMA and DBTM monomers in the presence of tetraethoxysilane (TEOS) by in situ sol gel process. The results from scanning electron microscopy (SEM) revealed that the phase separation was located in the nanometer scale. The covalent bond between the organic and inorganic phases was introduced by the co condensation of silanol groups of TEOS and MSMA, which was resulted from the hydrolysis of ethoxysilyl groups or methoxysilyl groups.The hybrid material exhibits optical transparency almost as good as silica gel.The thermalgravimetric analysis(TGA) showed that the two weight loss steps existed.The presence of teh first steps was due to the further condensation of residual silanol groups on the inorganic network during the increase of temperature.
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发布时间：2021-03-19 - 摘要：The composition homogeneity of two metallocene based LLDPE samples was evaluated by means of temperature rising elution fractionation technique and DSC. It is found that the W i%/ΔT～T curve is narrow and sharp for one of the sample and one strong peak as well as a very weak melting peak are observed in the DSC curve of isothermally treated this sample, indicating a narrow compositional distribution. In contrast, multiple peaks appear in the Wi%/ΔT～T curve of the other sample, and four melting peaks are detectable after crystallized isothermally at different temperatures stepwise.This shows that this sample has a broad composition distribution.
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发布时间：2021-03-19
Research Bulletin
- 摘要：Mechanism of graft copolymerization of methyl methacrylate onto model compound for chitosan with Ce4+ion was investigated by means of kinetics measurement and oxidation product analysis in addtion to polymer molecule weight analysis. The kinetic feature and product structure analysis of Ce4+ oxidation of model compound for chitosan showed that chelate complex at adjacent hydroxylamine functional group was involved and then disproportionated to radical. The results from GPC suggested that one adjacent hydroxylamine group formed the sole initial radical at 40℃ or two initial radicals at 90℃.
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发布时间：2021-03-19 - 摘要：A series of different molecular weight poly(L Lactide)s containing glucosamine derivative end group were synthesized by bulk ring opening polymerization of LLA with glucosamine derivative and SnOct 2 as initiator system. The chemical structure was confirmed by 1H-NMR and 13C-NMR. The result from GPC showed that there was only one kind of initiation reaction involved the polymerization, which resulted in the formation of PLLA containing glucosamine derivative end group.
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发布时间：2021-03-19
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