最新刊期
卷 ， 期 10 ， 2010
- 摘要：A series of amphiphilic polymer conetworks(APCNs) composed of poly(ethylene oxide)(PEG) and poly(p-dioxanone)(PPDO) segments were synthesized and characterized.Four-arm star-shaped poly(pdioxanone)(4sPPDO) precursor with hydroxyl terminal group was prepared by ringopening polymerization of PDO using stannous 2-ethylhexanoate ［Sn(Oct)2］ as a catalyst and pentaerythritol(PTOL) as initiator.Amphiphilic PPDO-b-PEG conetworks were prepared by directly coupling reaction of the hydroxyl group terminated 4s-PPDO and PEG precursors using toluene 2,4-diisocyanate(TDI) as chain extender.The influences of molecular structure,type of solvents on the swelling ratio of the amphiphilic PPDO-b-PEG conetworks were studied.The co-continuity of the conetworks was characterized via swelling in chloroform,tetrahydrofuran and H2O,respectively,and the results show that amphiphilic PPDO-b-PEG polymer networks had different swelling behaviors in different solvents,which were determined by the dosage of coupling agent and feed ratio of PPDO/PEG.The crystalline behaviors of copolymers were studied by differential scanning calorimetry (DSC).The results indicated that compositions of PPDO and PEG and the degree of crosslinking,which were obtained by using various amount of TDI,had an important influence on the thermal and crystalline behaviors such as melting temperature(Tm),crystallizing temperature(Tc),melting enthalpy(Hm),crystallizing enthalpy(Hc),and degree of crystallinity.The crosslinking structure limited the crystallization of PEG segments,resulting in decreased relative degree of crystallization and crystal size.
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发布时间：2021-03-19 - 摘要：Uniform molecularly imprinted polymer (MIP) microspheres were prepared by precipitation polymerization of methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) using melamine as template in acetonitrileethylene glycol mixed solvent (20∶1,V/V).1HNMR and UV spectrometry were employed to demonstrate the mechanism of the interaction between melamine and MAA,and the structure of the polymer microspheres was characterized by scanning electron microscopic (SEM) photographs and IR spectrometry.The results showed that the melamineMAA complexes of 1∶2 mole ratio were obtained by cooperative hydrogen bonding.The MIP particles with many binding abilities on their surface were microspheres and the diameters ranging from 400 nm to 500 nm were larger than those of the nonimprinted polymer microspheres.The adsorption efficiency was investigated by equilibrium adsorption experiments.The data obtained showed that the imprinted polymer microspheres reached equilibrium after 4 h and had higher adsorption efficiency compared to the nonimprinted polymer microspheres,which had the same chemical composition.Scatchard plots analysis revealed that the apparent maximum binding capacity and the dissociation contents were Qmax1= 22.97 mol/g，Kd1 = 0.1410-3 mol/L for high affinity binding sites and Qmax2 = 157.65 mol/g，Kd2 = 2.5510-3 mol/L for low affinity binding sites,respectively.Thus,the apparent imprinting efficiency and the effective imprinting efficiency were calculated to be 68% and 58%,respectively.The melamine imprinted polymer microspheres synthesised in this method had better performance and could be used for separation,enrichment and analysis of melamine.
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发布时间：2021-03-19 - 摘要：The polylactide (PLA) and polystyrene (PS) films with micro\|patterned surfaces were prepared via solvent-non-solvent (SNS) method and mold method. Based on these prepared micro-patterned PLA films,the effect of surface structure on the wettability was evaluated by water contact angle measurement,and the cell’s behaviors(including adhesion and proliferation) on PLA film were further discussed by scanning elctron microscopy (SEM) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay in this study.The results showed that a dense regular micropits structure with about 20 μm diameter could be got on the surface of PLA and PS films under semiclosed condition,and 1 μm under vacuum condition by SNS method.Using micropits patterned PS films as mold,the PLA films with about 20 μm and 1 μm micro-islands patterned surfaces could be achieved.The surface hydrophobicity of PLA films was enhanced because of the micropatterned surface (water contact angle 90°). Osteoblast showed a better spread on the patterned surface and the amount of cells was higher than that on the smooth surface,but the cell growth curve was gently on the patterned surface,indicating that the micropatterned surface benefited cell’s adhesion,but contributed little for improving cell’s proliferation.
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发布时间：2021-03-19 - 摘要：Double network (DN) hydrogels composing of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) as the first network and poly(acrylamide) (PAM) as the second network,which were prepared by ultraviolet irradiation polymerization,were modified by poly(vinyl alcohol) (PVA).By adding the solution of PVA (0;82%) into single network (SN) hydrogels,tiny networks have been made in the PAMPS network structures.DN hydrogels modified by PVA become tougher and harder than those without PVA.The swelling behavior was measured gravimetrically at room temperature (25℃).The structures of SN hydrogels modified by different amounts of PVA were successfully characterized by scanning electron microscopy (SEM).The compressive and tensile properties of hydrogels were examined by using Zwick/Roell tester.The results showed that the DN hydrogels modified by PVA exhibited higher swelling ratio than that of unmodified DN hydrogels.Furthermore,with the increase of PVA solutions’ concentration the swelling ratio was increasing.SN hydrogels modified by PVA （0;82%） showed tiny networks in the SN structures.Tiny networks enhanced the mechanical properties of the DN hydrogels.Photos of SEM demonstrated apparently that tiny networks only were found when the amount of PVA is 082% and 1.64%,however,the tiny network structures of SN hydrogels modified by 0.82% PVA were more regular than those of the SN hydrogels modified by 1.64% PVA.Some aspect of the compressive and tensile properties hand been enhanced,for example when the amount of PVA is 082%,the compressive stress of modified DN hydrogels was 12.8 MPa at 90% compressive strain (still keep integrity),while that of the unmodified ones was 8.7 MPa at 80% compressive strain.Almost 78.6% enhancement of tensile stress compared with unmodified DN hydrogel indicated that the modified DN hydrogels had become tougher and harder.
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发布时间：2021-03-19 - 摘要：Polyaniline/tungsten carbide(PANI/WC) composite was synthesized by chemical oxidative polymerization of aniline in the presence of tungsten carbide(WC) particles,and aniline polymerization mechanism in the surface of WC particles was studied.Then the composites were characterized by means of SEM,TEM,FTIR,Raman and XRD measurements.The results showed that aniline was preferentially polymerized on the surface of WC to form a layer of PANI on the WC surface.Strong interaction existed between PANI and WC particles,and the crystal structure of WC was unchanged in the composites.The FTIR spectra of PANI/WC composites had obvious blueshift phenomenon due to WC existence,and that the 3446 cm-1 absorption peak of the PANI/WC composites became weaker than that of PANI.In the Raman spectra of PANI/WC composites,stretching vibration peak at 1491 cm-1 of quinine ring CN bond had red-shifted 9 cm-1 and the intensity was also largely increased.The results indicated that there was a chemical bond between PANI and WC,and their chemical bond occurred in the N atoms of CN bond.Polymerization took place at the surface of WC particles to form coreshell structure.
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发布时间：2021-03-19 - 摘要：Superhydrophobic surface with lotus leaf effect has many practical and potential applications in different fields.Although attempts to produce artificial superhydrophobic films have always been intensively performed in recent years,however,a simple and economical procedure to massproduce superhydrophobic surfaces is still in nead.In this paper,a novel replicamolding method using CaCO3 particles as template,was developed to fabricate bionic superhydrophobic polymer films.Briefly,CaCO3 particle suspension was first cast onto a glass substrate and then was dried towards forming a thin layer of particles.Then linear lowdensity polyethylene (LLDPE) was thermally pressed onto such a CaCO3 particles template.After being cooled,peeled off from the substrate and rinsed with flowing water,the LLDPE film with superhydrophilic surface was obtained.Then this superhydrophilic LLDPE surface was further etched in 20 wt% HCl solution for 10 min.After washing and drying,the LLDPE film with superhydrophobic surface was obtained,with water contact angle (WCA) up to (152.7±0.8)° and sliding angle less than 3°.Moreover,such superhydrophobicity was confirmed stable under water jet at high pressure and durable in warm water (lower than 50℃).SEM imaging showed that such superhydrophobicity was attributed to the typical micro-and nanometer scale porous surface structure.Other types of polymers such as LDPE,HDPE,polypropylene (PP),polystyrene (PS) and polyurethane (PU) had also been replica molded using the similar process.All formed superhydrophobic and micro-and nano-porous surfaces except for PU,which only formed normal hydrophobic and microporous surface.Because CaCO3 microparticle is low-cost and can be easily covered onto the surface of the rolling mold,which is generally used in flow-casting process in manufacturing plastic films,superhydrophobic plastic films could be thus produced cost-effectively in large scale.
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发布时间：2021-03-19 - 摘要：PLLA ultrafine fibers with mesopores of 30~150 nm were prepared by electrospinning.Their surface morphology was studied using scanning electron microscopy (SEM).The fiber diameter and morphology could be controlled by adjusting the composition ratio of the dichloromethane (DCM)/N,Ndimethylformamide (DMF) solvent mixture,PLLA concentration and electric filed.Accordingly,fibers with varied surface structure such as smooth surface,shallow pits,or deep pores were obtained.Under optimal electrospinning conditions of DCM/DMF 4∶1,PLLA concentration of 9 wt%,electric field 1 kV/cm and relative humidity of 52%,dense mesoporous PLLA ultrafine fibers with mean pore diameter of 150 nm were fabricated.Moreover,it showed 3-dimensional interconnected porestructure throughout PLLA ultrafine fibers.Most pores were elongated along the fiber axis due to the stretching in the process of electrospinning.The characteristic porous PLLA fiber was formed by a combination of thermal induced phase separation (TIPs) with water assisted breath figure mechanisms,because of the sharp temperature drop caused by the quick solvent evaporation in the electrospinning process.The PLLA fibers with shallow pits or pores of 80 nm in diameter showed water contact angle of 104°，whereas the fibers with deep pores of 150 nm in diameter were highly hydrophobic with water contact angle up to 1466°.The hydrophobic fibrous mats could quickly absorb oil,90 g/g in 90 s and 145 g/g in 25 min.Their maintaining capacity of oil absorption was 90%.
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发布时间：2021-03-19 - 摘要：The OrganoClay was prepared by alkyl phosphonium ions treating of Namontmorillonite. The X-ray diffraction(XRD) patterns of Na-Clay and OrganoClay shows that the position of the (001) plane diffraction peak of the NaClay appears around 5.94°,corresponding to the interlayer distance (d) of 1.48 nm calculated from the Bragg law,and the position of the (001) plane diffraction peak of the Org-Clay appears around 4.99oC,d=1.78 nm. The result proves that the alkyl phosphonium are intercalated into the galleries of the clay layers. The polypropylene (PP)/Org-Clay nanocomposites were prepared by melt intercalation and XRD and transmission electron microscopy (TEM) both indicated that PP chains could be intercalated into the interlayer of the Org-Clay. The nanocomposites possess exfoliation structure and intercalation structure. The process of melting for PP/Org-Clay nanocomposites were studied with differential scanning calorimetry (DSC),and the result indicted that the addition of the Org-Clay had hardly effect on the degree of crystallization for PP. XRD results shows the position of the γ-PP(130) plane diffraction peak of the PP/Org-Clay nanocomposites appears around 19;8°and DSC heating cuvers of PP/Org-Clay nanocomposites at speed of 5 K/min revealed that the γPP melt peak of the PP/OrgClay nanocomposites appearing around 149℃. It can inferred that the Org-Clay may promote the formation of γ-phase PP crystallites in the PP/Org-clay. When adding 5 wt% Org-Clay，the mass fraction of γ-phase PP is about 12%.
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发布时间：2021-03-19 - 摘要：A temperature/pH-sensitive introducing monomer-dimethyl-benzyl-(2-methacryloxyethyl) ammonium bromide (DMBMAAB) was synthesized through the reasonable design of functional groups, combining the hydrophilic cation and hydrophobic benzyl on a same monomer. The structure and purity of DMBMAAB was characterized by 1H-NMR analysis and liquid chromatography analysis respectively.The copolymer P(DMBMAAB-co-AM) of DMBMAAB and acrylamide(AM) was synthesized through the free radical polymerization in aqueous solution.The P(DMBMAAB-co-AM) was characterized by 1H NMR analysis and elemental analysis.The aqueous solution of P(DMBMAAB-co-AM) exhibits a different temperatureresponse property compared to poly(N-isopropylacrylamide) (PNIPAAm), which exhibits a lower critical solution temperature(LCST) at 32℃, however the P(DMBMAAB-co-AM) exhibits a higher critical solution temperature(HCST).The transmittance and apparent viscosity (apparent property) changed evidently when heating the solution of P(DMBMAAB-co-AM) from 50℃ to 70℃.The pH-sensitive property of P(DMBMAAB-co-AM) is another difference compared PNIPAAm, which is sensitive to temperature but not pH-sensitive;the apparent property changed sharply when pH rose from 11 to 12- Moreover, the apparent property of P(DMBMAAB-co-AM) solution can respond to other environmental stimuli, such as surfactant (SDS) and salt (NaCl).The results indicate that P(DMBMAABcoAM) is a kind of novel functional material, which exhibits the properties of multifactor response,and the interaction between hydrophilic and hydrophobic groups in the chains and environmental condition were the main reason for the stimuli-responsive behavior.
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发布时间：2021-03-19 - 摘要：Based on results of adsorption property of four selected commercial adsorbents,a series of high selectivity polymeric adsorbents were synthesized based on the copolymerization of methyl acrylate (MMA) and divinylbenzene (DVB).The amino functional group was introduced into the adsorbent matrix to produce the hydrogen-bonding interaction with the flavonoides,which has the typical phenolic hydroxyl structure.The influences of the hydrophobic intensity of the adsorbent and the spacer arm length of the functional group on the adsorption property were investigated.When the adsorption was carried out in the aqueous environment reasonable hydrophobic affinity is necessary to assist the hydrogen bonding.In addition,the length of the spacer arm of the functional group affected the adsorption ability owing to the large size of flavonoides molecule.The adsorbent XM20.2 showed the optimal adsorption capacity and selectivity to the flavonoides.Experimental parameters for adsorption and elution were optimized.After purification of the crude extract of sea buckthorn leaves,the content of flavonoides increased from 10.4% to above 50%.The adsorbent showed good reproducibility.
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发布时间：2021-03-19 - 摘要：The CuX/pentamethyldi-ethylenetriamine(PMDETA)catalyzed oxidative copolymerization of 2-(N,N-dimethylamino)ethyl methacrylate (DMAEMA) and methyl methacrylate (MMA) was investigated.The kinetics were compared by varying the monomer ratio,catalyst concentration and the reaction temperature.The results showed that the copolymerization could proceed under the monomer ratio (［DMAEMA］∶［MMA］=10∶0~5∶5),catalyst concentration (［CuCl/PMDETA3］= 3.1×10-5 mol/L ~6×10-3 mol/L) and the reaction temperature (30~80℃) which were investigated in the paper,and the molecular weight increased with the reaction time,while the molecular weight distribution maintained rather broad.It was showed from the 1HNMR that there were DMAEMA units and MMA units in the copolymer,while the DSC indicated that the system of copolymer was partially compatible.The CuCl/PMDETA-catalyzed atom transfer radical polymerization (ATRP) of MMA using the so-obtained PDMAEMA as the macroinitiator was successful,confirming the presence of the C-Cl terminal functionality.Thus, the following mechanism might operate: 1) O2 oxidized CuCl into ［Cu(Ⅱ)Cl］+ species; 2) ［Cu(Ⅱ)Cl］+ oxidized dimethylamino moiety into N—CH2・radicals; 3) N—CH2・radicals and［Cu(Ⅱ)Cl］+ formed the reverse ATRP system.The above processes finally led to polymer with C—Cl end group.
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发布时间：2021-03-19 - 摘要：A poly(N-β-aminoethyl-γ-aminopropylmethylsiloxane-co-dimethylsiloxane) ［ASO,of an amino content of 0.6 mmol/g and the number average molecular weight (Mn)= 14100］ was mixed with poly［γ-(N-β-carboxyacrylamido)propylmethylsiloxane-co-dodecylmethylsiloxane-co-dimethylsiloxane］(RCAS,of a carboxyl content of 0.3 mmol/g and Mn= 4048) in dilute ethyl acetate solution to form a polysiloxane electrostatic complex ASO/RCAS.Film morphology and the performance properties of the polysiloxane complex anchored on an oxidized silicon wafer and cotton fiber substrates were investigated and characterized by atomic force microscope (AFM),X-ray photoelectron microscope (XPS) and other instruments.Like the single polysiloxanes in nature,the polysiloxane,complex ASO/RCAS,exhibited good film-forming ability and formed a macroscopic smooth but actually rugged film on both the wafer and cotton substrates.On the wafer surface,ASO/RCAS showed a morphology very different from ASO and RCAS.There were many small humps on the film surface.The film thickness was 1.501 nm,and the root mean square roughness (Rq) was 0.5 nm in 2 μm ×2 μm scanning field.ASO/RCAS could be used to modify the morphology and performance of the treated fiber/fabric,and provided the treated fabrics with an improved softness,good wettability as well as a pleasant oily tactile in hand evaluation.As ASO/RCAS covered fibers,the stripes or grooves of the treated cotton surface disappeared,and Rq was lowered to 11.7 nm.By contrast,the Rq of the untreated cotton fiber was 246 nm.In addition,the optimum performance was obtained for the cotton fabric treated by ASO/RCAS at mass ratio of ASO to RCAS 1∶1.
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发布时间：2021-03-19 - 摘要：In order to study the properties of azobenzene-containing side-chain liquid crystalline polymer for preventing the permeation of small molecule,poly(3［4-(4′-cyanophenylazo)phenoxy］propyl methacrylate) (PM3ABCN) was synthesized in this study.The barrier properties of PM3ABCN was individually determined using in situ glancing incidence X-ray diffraction (GIXRD) scanning technology under the amorphous state and the liquid crystalline (nematic) state.GIXRD was used to collect the metal surface oxidation,which is a quantitative result of oxygen permeated through the polymer films covering the metal surface.The content of oxygen element in oxidized iron matrix samples was analyzed by means of X-ray energy dispersive spectroscopy (EDS),and the amount of oxygen permeated through the synthesized polymer films was calculated based on the results gained from the XRD patterns and EDS analysis.The results indicated that the average permeation rate of oxygen through the PM3ABCN films was 1.92×10-3 cm3 day-1 m-2 and 4.38×10-4 cm3 day-1 m-2 under the isotropic phase and liquid crystalline phase respectively,and the permeation property of liquid crystalline PM3ABCN was 4.4 times slower than that of the amorphous state.In combination with the results of microscopic analysis on the specimen surface,the barrier mechanism of condensed state structure in liquid crystalline PM3ABCN was also investigated.
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发布时间：2021-03-19 - 摘要：A rapid non-chromatographic technique,based on the thiophilic magnetic beads,was exploited to purify antibodies with high purity and bioactivity.After these paramagnetic beads were synthesized with vinyl acetate and divinylbenzene by microsuspension polymerization,an effective surface modification with divinyl sulfone and 2-mercapto-pyrimidine was carried out to endow these beads with the ability to specifically capture immunoglobulin G (IgG) from human serum.The essential mechanism between the thiophilic ligands and IgG was also investigated.It was found that the specific interaction between 2-mercapto-pyrimidine and IgG mainly depended on electron donor acceptor effect,and this responding specific adsorption to IgG could be performed in a salt-independent manner.We also investigated the relevant factors influencing the isolation,such as pH value,temperature,ion kinds and ion strength.The purity of the isolated antibody exceeded 92%,with bioactivity almost fully maintained (99%).Although the maximum yield of the isolation process was only 37.7% at NaCl concentration 0.4 mol/L,the recovery of IgG can reach 86.8% by successive extractions. The easy operation,conventional equipments and rapid process make this technique potential in large-scale purification of antibody.
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发布时间：2021-03-19 - 摘要：By combining the copolymerizing modification with the synthesis of hyperbranched polysiloxane containing terminate amine groups (HBPSi(N)) in one step,a new kind of modified bismaleimide (coded as B/D/H(N)) resins was developed.Comparing to the resin made up of 4,4′-bismaleimidodiphenylmethane (BDM) and o,o′-diallylbisphenol (DBA) (coded as B/D),the effect of HBPSi(N) content on the properties of B/D/H(N) was discussed.Results show that HBPSi(N) content has great influence on the properties of B/D/H(N),the small incorporation of HBPSi(N) into B/D resin not only significantly improves the toughness,but also effectively decreases the gel time,improves the heat resistance and dielectric properties and reduces water absorption.These improvements result from the change in the chemical structure of the network by the incorporation of HBPSi(N).The outstanding integrate properties of B/D/H(N) indicate great potentiality in fabricating advanced polymeric composites and high performance adhesives.
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发布时间：2021-03-19
Research Article
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