最新刊期
卷 ， 期 6 ， 2001
- 摘要：A grouD of polypropylene (PP)／barium sulfate (BaSO4) composites with different polymer-filler interfacial interaction were prepared by treating the fillers with coupling agents or incorporating functionalized PP (PP-g-MAH)．The effect of interfacial modification on the rheological and crystalline behavior of the composites was investigated．It is shown that the interfacial adhesion between the filler and matrix was increased when the fillers were treated with silane or tlle PP-g-MAH was added into the composites．Under such circumstances,the mobility of the PP chains decreased,leading to high shear viscosity,shear stress and melt elasticity．On the other hand,the improved polymer-filler compatibility contributed to the increase of the heterogeneous nucleating activity of the filler on the PP．A model of“effective occupied volume” was employed to illustrate the effect interracial interaction and a parameter was introduced to evaluate the interfacial interaction quantitatively．
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发布时间：2021-03-19 - 摘要：Various poly(vinylidene fluoride) (PVDF)-based gels have been prepared by cooling solutions of PVDF in propylene carbonate (PC) or LiClO4／PC liquid electrolyte．The gelatlon time (tgel) is dependent on the temperature of gelation and polymer concentration,and strongly on salt concentration——salt helps to reduce the tgel LiClO4 in gels increases the gel melting temperature(Tgm)．The higher the LiClO4 concentration in the gels,the higher the Tgm．But there is considerable disparity between the results of Tgm of gels measured by DSA and by balldrop method,which suggests that there could be two parts with different structures：junction loci of polymer chain networks with weak thermal stability and other polymer crystals with rather good stability．The results of FT-IR indicate that there is strong interaction among LiClO4,PC and PVDF in gel electrolytes．The different gelation behavior and Tgm between the gels with and without salt can be attributed to the interactions between salt and polymer／solvent which change the structure and associations among the compositions in gels．
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发布时间：2021-03-19 - 摘要：The photoinduced electron transfer acid generation of four kinds of intra-molecular conjugated charge transfer compounds incorporated with substituted bis(trichloromethlyl)-2,4,6-triazine have been studied in this work．According to the fluorescence quenching and the fluorescence changing of mixed solution with irradiation time it was indicated that the photo-induced electron transfer between triazine as an electron acceptor and intra-molecular charge tranfer compounds as an electron donor have occurred in these systems．From the acidity measurement it can be seen clearly that the systems studied were changed dramatically under irradiation．And the acid-induced cross-linking reaction of phenol-aldehyde resin/hexamethaoxy methyl triazine has also been tested successfully．A probable mechanism was suggested preliminarily．
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发布时间：2021-03-19 - 摘要：Multi-monomer grafted polypropylens (PP-g-(GMA-co-St)) was used as a precursor of／in-situ compatibilizer for incompatible blend of poly(butylene terephthalate) (PBT) and polypropylene(PP). The formation of PBT-g-PP copolymer with addition of PP-g-(GMA-co-St) was confirmed by means of MFR and FT-IR measurements because the epoxy group in glycidyl methacrylate (GMA) of PP-g-(GMA-co-St) reacted with the terminal carboxylic acid group in PBT．Thus the PBT-g-PP copolymer acted as a compatibilizer between PBT and PP during the melt blending．The changes in morphologies of PBT/PP／PP-g-(GMA—co-St) blends with different contents of PP-g-(GMA-co-St) were investigated using scanning electron microscopy (SEM)．The addition of PP-g-(GMA-co-St) markedly improved the morphologies of the blends,and uniform and fine dispersed phase was observed with size being about 0.2 μm for PBT／PP-g-(GMA-co-St) (70／30) blend．Micro-phase separated structure formed in the blend was found by means of transmission electron microscopy (TEM)．The addition of PP-g-(GMA-co-St) also greatly improved the mechanical properties of PBT/PP blends,particularly for PBT／PP／PP-g-(GMA-co-st) (70／20／10)blend．It should be noted that the tensile strength of the blend was kept with the increasing of the lzod impact strength and elongation at break．
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发布时间：2021-03-19 - 摘要：The mechanism of the gelation reaction of chromium (Ⅲ) oligomers with partially hydrolyzed polyacrylamide was investigated with rheological measurements．The oligomers are prepared in relatively pure form using ion exchange liquid chromatography,characterized by UV-visible spectra,oxidation-reduction and exchange liquid chromatography,allowed to react with polymer．When pH value is in the range of 6～12,polymer concentration in the range of 300～1000 and Cr(Ⅲ) concentrations in the range of 2～25 mg/L,the effects of some components on the gelation are investigated．The results show that the advantages of the dimer are low cost and wide pH ranges,suggesting that the formation of Cr oligomer is the rate-determining step in the gelation reaction and the simple binuclear Croligomer is the most reactive species for crosslinking．Thus the detailed mechanism is understood fully．
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发布时间：2021-03-19 - 摘要：By using in situ UV—Vis spectroscopic technique for ethylene polymerization under atmospheric pressure,three catalvtic systems with different iron or cobalt complexes as catalyst precursor were studied．The corresponding complexes are 2,6-bis[1-(2,6-dimethylphenylimino)ethyl]pyridine iron (Ⅱ) dichloride (a),2,6-bis[1-(2,4,6-trimethylphenylimino)ethyl]pyridine iron (Ⅱ) dichloride (b) and 2,6-bis[1-(2,6-diisopropylphenylimino)ethyl] pyridine cobalt dichloride (c)．The results showed that the activation of MAO to procatalyst is fast；active absorptions at 560 nm,630 nm and 580 nm were observed,respectively．The rule of growth for active absorptions in polymerization and their disappearance when the catalyst was poisoned by anhydrous batches ethanol,were investigated. Catalytic active species and mechanism were discussed．
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发布时间：2021-03-19 - 摘要：Atom transfer radical suspension polymerization (ATRP) of methyl methacrylate (MMA) was conducted at 80℃ using 1-phenylethyl chloride (1-PECl) as initiator,cuprous chloride(CuCl) as catalyst and 1,1-bipyridine (Bpy) as ligand．The polymerization was carried out with a mechanical agitator under the protection of nitrogen atmosphere．In addition of the dispersing agent,NaCl was also used in the water phase to prevent the diffusion of the catalyst complex into water．The results show that the polymerization is a first order Reaction with respect to monomer concentration. From the slop of the plot of ln[M]0／[M] versus time,the concentration of the propagating radical was calculated as 5.74×10-8 mol／L．The polymerization displayed living character as evidenced by a linear increase of molecular weight with conversion and a relatively narrow molecular weight distribution (Mw／Mn ranged from 1.37 to 1.40)．Subsequently the reverse ATRP of MMA at 80℃ was conducted using AIBN as initiator,FeCl3 and triphenylphosphine(PPh3) as catalysts．The results indicate that the bulk polymerization demonstrated good control．The molecular weight increased with conversion and the Mw／Mn ranged from 1.27 to 1.31．The polymerization rate is quite fast．The conversion approached to 75.6％ after 2 h．From the linear plot of ln[M]0／ [M] versus time,the concentration of the growing radical was calculated as 1.64×10-7 mol/L．However the suspension polymerization of MMA using this initiation-catalyst system failed as evidenced by the large molecular weight (ca.100,000) and large value of Mw／Mn (4.8～6.32)．
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发布时间：2021-03-19 - 摘要：Magnetic polymer particles with hydro groups on the surface were synthesized by disperse polymerization in the presence of magnetic fluid,then a novel kind of green magnetic polymer particles (PSFePc(COOH)3) was obtained by bonding the magnetic polymer particles with phthlaocyanine．The structure and properties of PSFePc-(COOH)3 particles were identified by infrared spectroscopy,element analysis and scanning electron microscopy etc．It was found that：(1) the particle size is in the range of l0～100 μm and the grafting ratio of phthlaocyanine is about 4.8％；(2) the particles show a good magnetic response in magnetic field,it takes about 2 h in natural sedimentation to reach a transmittance of 95％,while the same separation results under a magnetic field of 0.42T only need about 10 min；(3) the particles have photoconductivity．It maybe helpful to find a new method for detecting the interaction between bio-active molecules by using photoconduetivity measurements．
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发布时间：2021-03-19 - 摘要：A chain-extended urea(TIEU) containing flexible spacer was synthesized from polypropylene glycol PPGl000,toluenediisocyanate (TDl) and imidazole．The reactive activity,dynamic mechanical behavior,impact property and morphology of the curing systems were systematically investigated by DSC,viscoelastic spectroscopy,impact tester and SEM,respectively．Results show that the curing activity of modified E-51／dicy system was so greatly enhanced that the apparent activation energy of curing reaction is reduced from 131 kJ／mol for the unmodified system to 75～80 kJ／mol．The curing reaction mechanism of E～51／dicy system accelerated by TIEU was a little different from that of the system accelerated by imidazole．The impact stength of the curing systems modified with TIEU was 2～3 times higher than that of the unmodified system,while the glass transition temperature and modulus were little changed．and the fracture surfaces of the modified systems displayed tough fracture feature．
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发布时间：2021-03-19 - 摘要：The samarium electropolyurushiol coordination polymer was obtained from samarium chloride and electropolyurushiol in isopropyl alcohol solution．The coordination polymer was characterized by FT-IR,Fluorescence spectrum,XPS,DMTA,DTA-TG and AES,and its composition and structure were determined．Each Sm3+ ion is coordinated by hydroxyls from three units in EPU molecule．It showed that there is a certain coordination between Sm3+ and EPU in the coordination polymer,thus crosslinking was formed．Therefore the polymer with Sm3+ content as high as 13.18％ is insoluble in the organic solvents．Its electric resistance is 9.6×1010 Ω (that of EPU was 7.9×1010 Ω)．Its glass transition temperature and heat resistance are considerably greater than those of EPU．
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发布时间：2021-03-19 - 摘要：The estimation of kinetic parameters is a critical part of developing process model for industrial polymerization processes．For the calculation of a process model,propagation rate constants,which vary from one catalyst system to another,must be known．The propagation rate constants and activation energies of gas-phase ethylene-propylene copolymerization processes catalyzed by the Ziegler-Natta catalyst,combining with the mass transfer research,were estimated．
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发布时间：2021-03-19 - 摘要：Long-branching polyethylene was prepared by using a novel dual-functional catalytic system with (acac)2 ZrCl2／Montmorilonite／AIEt2Cl as the ethylene oligomerization catalyst in which (acac)2ZrCl2 was chemically bonded in between the layers of montmorilonite (MMT) and Et(Ind)2ZrCl2／MAO as the ethylene copolymerization catalyst capable of incorporating ethylene oligomers,of which over 80 percent were hexene and octene,in situ to form long-branching polyethylene．Selectivities for ethylene digomerization with (acac)2ZrCl2 and (acac)2ZrCl2／MMT,relationship between (acac)2ZrCl2 and(acac)2ZrCl2／MMT with reaction time,effects of Al／Zr value on activity of (acac)2ZrCl2／MMT and structure of the resulting polymer were investigated．Experimental results showed that the two catalysts in the dual-functional catalytic system were well matched and exhibited high copolymerization activity and improved properties of the final long-branching polyethylene．
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发布时间：2021-03-19 - 摘要：Block copolymers of β-pinene with styrene (St) and p-methylstyrene (pMeSt) were prepared by sequential living cationic polymerization initiated with HCl-adducts of styrene(a) and 2-chloroethyl vinyl ether(b) respectively,in the presence of TiCl4/Ti(OiPr)4(at 3:1 mole ratio) and nBu4NCl in CH2Cl2 at -40℃．β-pinene macromonomer with methacryloxy group at the α-end was also synthesized by the living cationic polymerization of β-pinene initiated with HCl adducts of vinyl ether (c,CH3CH- (OCH2CH2X)Cl,X=methacrylate)．The macromonomer was copolymerized with methyl methacrylate(MMA) in the presence of AIBN in toluene at 60℃ to give graft eopolymers carrying poly(β-pinene)as graft chain．
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发布时间：2021-03-19 - 摘要：A new type of thermally reversible covalent crosslinker was applied to chlorinated polyethylene(CPE) in order to get a thermally reversible covalent crosslinked CPE and a crosslinked product with 81.79％ gel content was obtained by means of solution reaction．The effects of CPE grades,catalysts and their dosage,reaction temperature and time and the dosage of crosslinker on the gel content were studied．It was proved by IR that the gel was generated through esterification between the chlorine on carbon of CPE and the carboxylic salt groups of the crosslinker．The gel content increases with the extension of reaction time and enhancement of temperature and also increases with the increased dosage of crosslinker．It Was found that no gel was generated if the phase transfer catalyst was not applied to the reaction system．The crosslinked CPE exhibited thermally reversible behavior due to the dimer/monomer(cyclopentadiene) conversion of-DCPD-moieties via reversible Diels-Alder cycloaddition．
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发布时间：2021-03-19 - 摘要：A series of vinylidene fluoride (VDF)／tetrafluoroethylene(TFE)／perfluoromethyl vinyl ether (PMVE) ternary copolymer with different composition were synthesized and characterized．The composition,crystallinity and gIass transition temperature of these eopolymers were examined with 19F-NMR,WAXD and DCS respectively．The experimental data showed that the composition of these ternary copolymers measured with 19F-NMR is consistent with those calculated from the apparent monomer reactivity ratios of the monomers．The fluorororubber was made from VDF／TFE/PMVE copolymer and its physical properties were measured．The results showed that the crystallinity of the copolymer decreased with the decrease of concentration of VDF and increase of PMVE in copolymer．The copolymers with low crystallinity have glass transition temperature between 245～251 K．The fluororubber can not be made from copolymers having high VDF composition because of the high crystallinity．The tensile strength of fluororubber decreased and its elongation at break increased with the decreasing of VDF concentration in the copolymer．
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发布时间：2021-03-19 - 摘要：Using the configurational-conformational statistics and the rotational isomeric state theory,the formula of the configurational-conformational parameter(characteristic ratio)＜S2＞／M is derived．The intrinsic viscosity depended on the molecular weight of polystyrene chains is estimated by the formula,and the intrinsic viscosity of isotactic,syndiotactic and atactic polystyrene chains with high molecular weight is compared by the percentages of meso dyads,or the tacticity of chain．The results are in agreement with the experimental data．
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发布时间：2021-03-19 - 摘要：A novel azo monomer 2-[4-(4′-ethoxyphenyl)azophenoxy]ethyl acrylate (EAPEA) was synthesized and characterized by elemental analysis,IR and 1H-NMR spectra．Poly(N-isopropylacrylamide-co-2-[4-(4′-ethoxyphenyl)azophenoxy]ethyl acrylate) (P(NIPA-co-EAPEA)) was prepared through a free radical polymerization of NIPA and EAPEA with different molar concentration of EAPEA．Photo-responsive behavior of the copolymer in aqueous solution was observed．Small amount of EAPEA in P(NIPA-co-EAPEA)had obvious effect on the lower critical solution temperature(LCST) of PNIPA．P(NIPA-co-EAPEA) with 0.98 mol％ EAPEA in the copolymer changed the LCST from 27.2℃ to 29.3℃ after UV irradiation with λ=365 nm for 30 s．The LCST returns to its initial value when cis form recovers to trans form completely．
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发布时间：2021-03-19 - 摘要：The polymerization of ethylene was conducted in the presence of spherical MgCl2 supported MAO-Et·[Ind]2ZrCl2 catalyst with Al(i-Bu)3 as activator．Under the condition of steady state,the parameters of kinetics such as reaction order(n),the concentration of active center([C*]),the chain propagation rate onstant(kp) and the apparent activation energy(Ea) were determined,among then [C*] was obtained by kinetic extrapolation．The result indicated that,the reaction was approximately first order,[C*] was 0.302 mol／mol-Zr,kp was 1.0l×103 L/mol·s and Ea was 66.6 kJ／mol,in which the [C*],Kpand Ea were all determined under high ethylene partial pressure(1.4 MPa)．The morphology of polymer particles in the different polymerization time was observed with SEM．It was found that catalyst particles consisted of many subparticles over which polymerization proceeded,and polymer particles didn’t fragmentize basically,which copied the spherical morphology of catalyst particles．
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发布时间：2021-03-19 - 摘要：The intrinsic viscosity([η]) of partially hydrolyzed polyacrylamide(HPAM) was measured in 1 mol／L NaCl aqueous solution．The range of hydrolysis degree(h) of HPAM was 0％～70％ and polymerization degree (DP) of HPAM was 1.48×103～3.79×104．By the theories of polyelectrolyte and the Kowblansky’s studying conclusion,the function of [η] with h,DP was established as：[η]=0.1113 DP0.8329+0.9973 DP0.7531(1-0.81h1/2)h M=71DP(1+23—71h) The M in the equation is molecular weight of HPAM．The results from the equation are in good agreement with the experiments and the reference data．Its average error is±13.74％．Therefore,the molecular weight of HPAM with various degree of hydrolysis was established by these two equation．
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发布时间：2021-03-19 - 摘要：PEO-b-P(lys-z) was synthesized by the ring-opening polymerization of lys(z)-NCA using the primary amine of PEO(PEO-NH2) as an initiator,which was subsequently deprotected to give PEO-b-P(lys)．PEO-b-P(lys-ML) was then obtained by a coupling reacdon of maltonolactone to the ε-amino group of the P(lys) segment of PEO-b-P(lys). The aggregation behavior of the PEO-b-P(lys-ML) was studied in water by fluorescence measurement．The results indicated that above a critical aggregation concentration(cac),the block copolymers tended to selfaggregate into micelle-like molecular assemblies with the glycopolymer segment in the core and the PEO segment in the shell．Concanavalin A(Con A),a protein which shows strong interaction with glucose moiety,was used to induce the aggregation of the polymer at a concentration lower than cac．These results imply the possibility to use this type of block copolymer as a kind of novel drug carrier．
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发布时间：2021-03-19
Research Article
- 摘要：A new effecient catalyst system(FeCl3／2PPh3) for the“living”／controlled radical polymerization of butyl methacrylate by a reverse ATRP process was reported in this paper．With the presence of this catalyst system,the number-average molecular weights of the obtained polymer increased in direct proportion with monom conversion,and the MWDs (molecular weight disctributions) were narrow throughout the reactions(1.17＜Mw／Mn＜1.22). This reaction system did not include the conventional initiators which were used to generate the primary radicals.
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发布时间：2021-03-19 - 摘要：The conformation of polymer chains and the crystal forms of syndiotactic polystyrene (sPS)／isotactic polypropene (iPP) blends,prepared by reactor polymerization were investigated．Results indicated that the crystal forms of sPS and iPP in blends were similar to those in neat polymers．Both sPS and iPP in blends existed in α forms,which were not affected by blending．The results obtained from X-ray and FTIR measurements show that the crystallinity of sPS and iPP was reduced by blending．With increasing the sPS content,especially over 75％,the crystallinity of sPS and dimension of sPS crystals were evidently reduced．
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发布时间：2021-03-19 - 摘要：Spherical MgCl2 supported metallocene catalyst was prepared by supporting MAO on carrier which was prepared from MgCl2·nEtOH．Ethylene polymerization was carried out by addition of MAO／MgCl2,different metallocenes and alkylaluminum,in the absence of soluble MAO．It shows high activity for ethylene polymerization at lower Al／Zr(Al/Zr=45)．The effect of concentration of Al(i-Bu)3 on polymerization activities and activation of Et(Iad)2ZrCl2 were studied．Kinetic behavior of ethylene polymerization on spherical Mgcl2 supported metallocene catalyst was investigated,which indicated the polymers obtained by reaction could affect the diffusion of ethylene in hexane under the experiment condidtion．Different aluminium alkyls have great impact on the whole polymerization behavior,and the relative reactivity decreases in the following order：Al(i-Bu)3＞AlEt3＞AlMe3＞AlEt2Cl,in which Al(i-Bu)3 shows the highest catalytic activity (5.78×107 g PE/mol-Zr·h)．
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发布时间：2021-03-19 - 摘要：Expanded graphite,prepared from the rapid heating of graphite intercalated compound,was blended with polystyrene via the intercalation and the in situ polymerization of styrene．SEM,STM and etc were used to characterize the nanostructure of the expanded graphite the composite of polymer／expanded graphite,and the changes of the nanostructure during the rolling process．The graphite formed the nanostructure during the expanding process of the GIC．The nanosheets were confirmed to have been dispersed in polystyrene matrix with the thickness of 10～30 nm．The conductivity of PS／expanded graphite composite was sensitive to the rolling process．The intensive rolling caused great decrease in its conductivity,due to the destruction of conducting network．
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发布时间：2021-03-19 - 摘要：Thianaphthene has been electrochemically polymerized in pure boron trifluoride diethyl etherate(BFEE) solution or in a composite electrolyte of BFEE and concentrated sulfuric acid(SA)．The addition of certain amount of sulfuric acid into BFEE accelerated the polymerization and also increased the current efficiency of the electrosynthesis．Polythianaphthene(PTN) in dedoped state is soluble in usual strong polar organic solvents such as dimethyl sulfoxide(DMSO),N,N-dimethylformamide(DMF) and N-methyl pyrrolidinone(NMP)．Its structure has been examined by infrared and UV-spectra．Fluorescent spectral studies indicate the polymer is a strong blue light emitter.
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发布时间：2021-03-19 - 摘要：A new technical approach to the synthesis of novel silicon-containing polyurethane by the noncarbothermal method directly from SiO2 was studied．Firstly a high reactive pentacoordinate organic silicon complex [(KSi(OCH2CH2O)2(OCH2CH2OH)] was prepared,by means of the reaction of a high surface area silica with ethylene glycol and petassium hydroxide．Then a novel tetracoordinate silicon(OCH2)CH2O)Si(OCH2CH2OH)(OCH2CH2OCH2CH2OH) was synthesized by the reaction of lCH2CH2OH with reactive pentacoordinate silicon complex．Lastly a novel silicon-containing polyurethane was synthesized by low-temperature solution condensation between tetracoordinate silicon and 2,4-toluene diisocyanate in dimethyl sulfoxide．The product was characterized and analyzed by FTIR,TG,DSC,GPC etc．The IR spectra exhibited a characteristic strong absorption band for ester carbonyl at 1724.05cm-1. TG analysis showed a better thermal stability．DSC curves declared that its Tg was 115.09℃,GPC analysis showed that the molecular weight of silicon-containing polyurethane is between several ten thousand and a hundred thousand．
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发布时间：2021-03-19 - 摘要：The composite,prepared with polypropylene grafting maleic anhydride and silica crosslinked by 3-aminopropyltriethyoxysilane,was used as the carrier to support titanium chloride．XPS and FTIR measurements were emplyed to investigate the states of several atoms during stepwise supporting catalyst for clarifying the mechanism．The results showed two possible mechanisms of active catalytic sites on the composite carrier：the catalytic sites bridged through MAO on the inorganic silica-gel；on contrary,the catalytic sites bridging with carbonyls of amide formed in the composite．
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发布时间：2021-03-19 - 摘要：The composite,prepared with polypropylene grafting maleic anhydride and silica crosslinked by 3-aminopropytriethyoxysilane,was used as the carrier to support titanium chloride for forming polymerization catalyst．Scanning electron microscope investigated the morphology of support,supported-catalysts and polyethylene particles．The results indicated：silica and polymers have been combined closely,a little silica outside of the polymer net,however；under the proper conditions,the particles of polyethylene had a good replicability for catalysts morphology．
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发布时间：2021-03-19
Research Bulletin
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