最新刊期
卷 ， 期 1 ， 2016
- 摘要：Owing to the massive use of fossil fuels,environmental pollution,global warming,resource scarcity and energy crisis have become important issues of worldwide concern,both in academia and in industry.The development of eco-green renewable biomass resources is the most important concern in recent years.2,5-Furandicarboxylic acid (FDCA)as one of the most valuable bio-based platform chemicals has attracted more and more attention.This review summarizes recent progress in the preparation of FDCA by chemical and biological methods.The applications of FDCA in the synthesis of polyesters,polyamides,metal organic frameworks,medicines and plasticizers are introduced in detail.Perspectives are also given on the potential applications and future researches of FDCA.关键词：2,5-Furandicarboxylic acid;Bio-based;Polyester;Preparation;Application
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发布时间：2021-03-19 - 摘要：As a sort of smart materials,shape memory polymers (SMPs) have outstanding features and excellent performance with high research and practical values.Especially in recent years,novel methods and new material systems for SMPs spring up at an increasing rate,showing great potential for development.This article summarizes the latest progress in blending methods,including direct blending of polymers,blending with the aid of compatibilizers,blending by microlayer coextrusion,and blending based on the 3D networks from electrospinning.Compared to chemical synthesis methods,these blending methods are efficient,simple to operate,available for wider diversity of raw materials,convenient to manipulate product properties,environment-friendly,and achieve products with equal or better performance,which facilitate blending method to be a major trend of preparing SMPs in the future.In this article,the features and advantages of different blending methods are analyzed from the aspects of preparation processes,microstructures and shape memory properties of the products,with the purpose of spurring future developments.关键词：Hape memory polymers;Blending methods;Phase structure;Shape memory performance
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发布时间：2021-03-19
Reviews
- 摘要：Two Cs- and C1-symmetric doubly hetero-bridged metallocene complexes (Me2C)(Me2Si)-Cp2TiCl2 (1) and [(CH2)5C](Me2Si)Cp2TiCl2 (2) were used in the propylene polymerization under the activation of MAO.The reaction parameters,such as reaction temperature,Al/Ti molar ratio and reaction time were employed in order to study the influences on the polymeration activity and the structures of the resulting polymers.The microstructure,thermodynamic properties,molecular weight and molecular weight distribution of the resulting polymers were characterized by 13C-NMR, DSC and GPC.The catalytic activity of the two complexes was up to 106 gPP/mol h.The high molecular weight and narrow weight distribution polymers (Mw up to 7105,MWD about 2.0) were prepared at 0.1 MPa propylene pressure.The two metallocenes exhibit good catalytic performance at low polymerization temperatures.The polymerization activity and molecular weight decrease with the increase of polymerization temperature.The polymerization activity and molecular weight of polymers showed the trend of increase and then decrease with the Al/Zr molar ratio increase.The results indicated that the resulting polymer was atactic polypropylene with high molecular weight by 13C-NMR and DSC analysis.It was found that the two different shortest bridges,unusually large dihedral angle of two Cp (71.0,70.3),show obvious influence on the catalytic properties and behavior of polymers.关键词：Atactic polypropylene;Ansa-metallocene with doubly hetero-bridges;Molecular weight;Elastomer
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发布时间：2021-03-19 - 摘要：Six types of donor-acceptor conjugated polymers were designed by choosing thieno[3,2-b]thiophene (TT) as the electron donor and Benzo[c][1,2,5]thiadiazole (BT),[1,2,5]thiadiazolo[3,4-g]quinoxaline (TdQ) or benzobis[1,2,5]thiadiazole (BBT) as the electron acceptor unit.B3LYP method is employed to investigate the electronic structure and properties of the designed TT-based donor-acceptor alternating copolymers.It is found that the electron-withdrawing ability of the acceptor and the ratio of donor to acceptor units (D/A ratio) play a very important role in the geometries and electronic properties for the donor-acceptor alternating copolymers.The bridge bond length and the average bond length of carbon-carbon single bond (LAS) in the donor unit decreases with an increase in the electron-withdrawing ability of the acceptor moiety.However,the average bond length of carbon-carbon double bond (LAD) in the donor unit shows a same trend as that of the acceptor strength.In addition,the bridge bond length increases with an increase in the D/A ratio for the copolymers.It is of interest to note that the electronic properties of the TT-based copolymers,especially for the copolymers with the D/A ratio of 2:1,also exhibit a systematic trend with the acceptor strength.The band gap (Eg) and effective mass of carriers (both hole and electron,mH and mL) decrease,the bandwidth (both valence and conduction band,WVB and WCB) increases systematically with an increase in the electron-withdrawing ability of the acceptor moiety.The theoretical results also suggest that p-TdQ-TT and p-BBT-DT could have potential applications as an electrically conductive material due to their narrow band gap ( 0.5 eV),large bandwidth and small effective mass of holes and electrons.关键词：Thieno[3,2-b]thiophene;Electron-withdrawing ability;D/A ratio;electronic properties
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发布时间：2021-03-19 - 摘要：A novel poly(phospho-isosorbide) ester (PPI) with series of molecular weight was synthesized from isosorbide and phenyl phosphonic acyl chloride by bulk polymerization and solution polymerization.The structures and molecular weights of PPI were characterized by Flourier transform infrared spectroscopy (FTIR),nuclear magnetic resonance (1H-NMR) and gel permeation chromatography (GPC).The degradation and swelling experiments of the polymer in aqueous solutions and enzyme solutions showed that it had good biodegradation properties and swelling properties when Mw was below 5104.The degradation rate of PPI was 80%,and swelling rate of PPI was 150% after 25 days.However the degradation and swelling rate decreased obviously when Mw was over 5104.The degradation rate and swelling rate of PPI were only 25% and 40%,respectively.It showed that PPI had high glass transition temperature (Tg),which increased significantly with the increasing of its molecular weight.For example,the glass transition temperature (Tg) reached to 176 ℃ when Mw was 6104.The influence of molecular weight on the thermal stability indicated that higher molecular weight was beneficial for improving thermal decomposition temperature of the PPI.The initial decomposition temperature (T5%) of PPI increased from 260 ℃ to 315 ℃,while the Mw was raised from 2104 to 6104.关键词：Isosorbide;Benzyl phosphonic acyl chloride;Polyphosphoester;Biodegradation;Thermal performance
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发布时间：2021-03-19 -
Fabrication and Characterization of Microcapsulated Dementholized Peppermint Oil with Polyurea Shell
摘要：Dementholized peppermint oil (DPO) was successfully encapsulated by polyurea shell which was synthesized through interfacial polymerization of isophorone diisocyanate as monomer with water using N,N,N',N'-tetramethylethylenediamine as catalyst.Morphology,particle size distribution,reaction degree of the monomer and thermal stability of DPO microcapsules were characterized by scanning electron microscope (SEM),laser particle size analyzis,Fourier transform infrared spectroscopy,and thermal gravity analysis.The encapsulation efficiency of DPO microcapsules was determined by ultraviolet (UV) spectrophotometer.In addition,the effect of the homogenization rate on average particle size was analyzed,and the morphologies of DPO microcapsules prepared with different kinds of emulsifiers and with different ratios of core/shell materials were also explored respectively.The results showed that the average particle size decreased with the increase of homogenization rate and tended to be stable as it decreased to 1 m.SEM images showed that the optimal morphology of microcapsules is neat sphere by using polyvinyl alcohol as emulsifier with 4:1 ratio of core/shell materials.The UV measurement results showed that the encapsulation efficiency of the core materials can reach up to 84.09 wt%.And the powder microcapsules prepared by freeze-drying contain 72.64 wt% of dementholized peppermint oil.Encapsulated DPO inside the microcapsules demonstrated much better thermal stability than pure DPO.关键词：Polyurea;Dementholized peppermint oil;Microcapsules;Isophorone diisocyanate;N,N,N',N'-tetramethylethylenediamine- 18
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发布时间：2021-03-19 - 摘要：Polycaprolactone (PCL) polyols with different functionalities and molecular weights modified with phosphorylation or epoxidation were designed and synthesised,Based on the effective reaction of hydroxyl group of acidic phosphate ester (P-OH) and alicyclic epoxy (E),adjusting the molar ratios of E/P-OH functional groups,without any additives(such as catalyst,initiator or solvent)that may have some potential risk of biological toxicity when being applied in real clinical situations,two types of cross-linked PCL phosphoester elastic materials were designed and prepared:PCL210P/PCL309E (being called 109 for short),PCL309P/PCL309E (being called 99 for short),The structures of polyhydric alcohol of PCL modified with phosphorylation or epoxidation and cross-linked PCL phosphoester elastomers were characterized by 1H-NMR, 31P-NMR and FTIR.The test and analysis of compressive mechanical properties,water contact angle,the performance of degradation and cells cytotoxicity in vitro,indicated that the cross-linked PCL elastomers had good mechanical properties,biocompatibility and biodegradability.Besides this,the adjustment of mechanical properties and biodegradability of the cross-linked PCL phosphoester elastic materials can be achieved within a certain range by adjusting the E/P-OH molar ratios and functionalities of PCL monomers.关键词：Phosphate bond;PCL;Elastomer;Biodegradability
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发布时间：2021-03-19 - 摘要：The unfolding of bovine serum albumin (BSA) was induced by heating at 80 ℃,and hydrophobic residues were exposed on the BSA surface,which caused the gelation of BSA.Influences of heating temperature and time,pH value and the ratio of BSA to chitosan on the self-assembly behavior between denatured BSA and chitosan (CS) in aqueous solutions were explored by the ultraviolet-visible spectroscopy (UV-Vis) and dynamic light scatter (DLS).The self-assembly behavior of BSA and chitosan occurred at 80 ℃ for 15-20 min.At pH 4.7(the isoelectric point of BSA,pI=4.7),electrostatic interactions between BSA and chitosan enhanced,and as pH is increased,precipitates were formed in the mixture system.At high concentrations of BSA,aggregation of denatured BSA resulted in precipitation of the aggregates.The results indicated that chitosan hindered the gelation process of BSA and self-assembled with denatured BSA by heating at 80 ℃.BSA-CS self-assemblies were fabricated at pH 5.4 in aqueous solutions by heating at 80 ℃.The morphology of nanoparticles was observed by the transmission electron microscopy (TEM) and the size and it distribution were measured by DLS.BSA-CS self-assemblies were constituted by the core consisting of BSA aggregates and the shell consisting of chitosan chains.Self-assemblies were stored without any changes at room temperature for 40 days.关键词：Heat-induced;Protein;Chitosan;Self-assembly;Mechanism
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发布时间：2021-03-19 - 摘要：In order to obtain copolyesters containing sugar-units with high meling point and crystallization ability,poly(butylene succinate-isosorbide succinate) multiblock copolyesters (PBIS) were successfully synthesized by chain-extension of the dihydroxyl terminated prepolymers.GPC results showed that high molecular weight PBS-based copolyesters with high content of isosorbide were easily obtained through chain-extension.Their Mn values were in the range of 35000-70000.TGA and DSC results indicated that the PBISx multiblock copolyesters still maintained the good thermal stability and crystallization ability.When the content of isosorbide was up to 60 mol%,the Tm of copolyesters only declined 2 K compared with that of PBS.The effect of composition on the miscibility of PBS and PIS segments in PBISx multiblock copolyesters was studied by DMA.The results indicated that the miscibility of PBS and PIS segments in PBISx multiblock copolyesters changed from miscible to partially miscible,and finally changed to miscible with increasing isosorbide content.And the Tg values of copolyester increased with the increase of Is content,in which the Tg of PB45I34S60 was as high as 68 ℃.The mechanical properties of PBS were improved and controlled by adjusting the content of isosorbide.The tensile strength of PBISx firstly increased and then decreased,and their elongation at break was double that of pure PBS.When the content of isosorbide was 60 mol% ,its tensile yield increased from 35.0 MPa of PB45S to 43.0 MPa.关键词：Poly(butylene succinate);Isosorbide;Biomass;Multiblock copolyester;Tg;Mechanical properties
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发布时间：2021-03-19 - 摘要：The influence of solvent removal rate on the morphology of DMF annealed cylinder-forming poly-(styrene-block-4-vinylpyridine) (PS-b-P4VP) thin films with different thickness is investigated by atomic force microscopy (AFM) and transmission electron microscopy (TEM).It is found that the final film morphology can be effectively modulated by controlling the solvent removal rate of the swollen film.When the film thickness was 35 nm,under fast solvent removal rate,long range ordered inverted parallel PS cylinders were obtained,as solvent removal rate decreased,the ring-shaped PS nanostructure formed in the whole film,and finally slow solvent removal rate resulted in terrace lamella morphology.Such morphological transformation is mainly due to kinetic effect and preferential affinity of annealing solvent for the minority block,which brings remarkable solvation effect.The unique ring-shaped morphology is caused by the shrinkage of the continuous P4VP phase and bending of the PS cylinders.While when the film thickness was 55 nm,only P4VP cylinder morphology was obtained under the same annealing condition and solvent removal rate.We consider that the low swollen rate will reduce solvation effect when the film is thick,in the mean time the effect of solvent removal rate on the final morphology is weakened.关键词：Block copolymer;Solvent annealing;Solvent removal rate;Phase morphology;Ring morphology
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发布时间：2021-03-19 - 摘要：A polymerizable fluorescent monomer (Eu(AA) (BA)2Phen) was synthesized with Eu3+,acrylic acid (AA),benzoic acid (BA),and 1,10-phenanthroline (Phen),and the chemical structure was characterized by elemental analysis and Fourier-transform infrared spectroscopy (FTIR).The results indicted that the polymerizable fluorescent monomer was successfully prepared.The fluorescent nanoparticles were prepared with styrene (St),sodium p-styrenesulfonate (NaSS),and polymerizable fluorescent monomer using microwave-assisted soap-free emulsion polymerization technique.The chemical structure of poly(St-NaSS-Eu-(AA)(BA)2Phen) was characterized by FTIR.The result revealed that copolymerization occurred among St,NaSS,and Eu(AA) (BA)2Phen,and the poly(St-NaSS-Eu(AA) (BA)2Phen) compolymer was prepared successfully.Moreover,it was found that the poly(St-NaSS-Eu(AA) (BA)2Phen) had good thermal stability shown by thermo-gravimetric analysis (TGA).The morphologies and particle sizes of latexes nanoparticles were observed using transmission electron microscope (TEM) and scanning electron microscope (SEM),and the images showed that the particles had sphere-shapes,whose size was 35 nm.Compared with conventional heating,poly(St-NaSS-Eu(AA) (BA)2Phen) latexes nanoparticles obtained by microwave irradiation were much smaller.The average particle size and its distribution were measured by photon correlation spectroscopy (PCS),and the result showed that the hydrodynamic diameters and distribution of particles both increased gradually with the contents of Eu(AA) (BA)2Phen.In addition,fluorescent spectrum test indicated that the nanoparticles had obvious emission at 595 nm and 619 nm with excitation at 277 nm.关键词：Microwave radiation;Fluorescent;Rare earth;Emulsion nanoparticles
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发布时间：2021-03-19 - 摘要：The composite fibers with electromagnetic function were prepared by using the aqueous mixture of poly(vinyl alcohol)(PVA),poly(3,4-ethylenedioxythiophene)-poly(sodium-p-styrenesulfonate)(PEDOT-PSS) and Co doped Fe3O4 magnetic particles (Co-Fe3O4) as the spinning solution via a conventional wet spinning process.Effects of draw ratios on the structure and properties of PEDOT-PSS/Co-Fe3O4/PVA composite fibers were studied.The morphology,structure,crystallinity,thermal stability,mechanical properties,conductivity and magnetic properties of the composite fibers were studied by scanning electron microscope (SEM),Fourier transform infrared spectrometer (FTIR),powder X-ray diffraction (XRD),thermogravimetric analyzer (TG),electronic single fiber tensile strength tester (ESFTST),four-probe conductivity meter (FPCM) and vibrating sample magnetometer (VSM).The SEM images show that the diameters of the composite fibers are in the range of 20-30 m with a rough surface and reniform cross section.And with the increase of the draw ratio,the fiber diameters decrease.FTIR spectra indicate that with the increase of the draw ratio,most absorption peaks increased indicating the increase of the orientation of polymer molecular chains along with the draw direction.The results of XRD,TG,ESFTST and FPCM present that the composite fiber' s crystal properties,thermal stability and mechanical properties are all improved with the increase of the draw ratio,and the conductivity increased multiply.However,the saturation magnetization of the composite fibers is almost independent of draw ratios,which is about 1.7 A m2/kg.When the draw ratio of the composite fiber is 4,the conductivity can reach to 2.3 S/cm,ten times the conductivity when the draw ratio is 2.关键词：PEDOT-PSS;Co-Fe3O4;Wet spinning;Draw ratio;Electromagnetic function
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发布时间：2021-03-19 - 摘要：Monodispersed polystyrene (PS) microspheres were synthesized by the precipitation polymerization of styrene in low toxic ethanol/water mixed solvent using K2S2O8/NaHSO3 as initiators at 25 ℃.This work aimed at providing a new method of low-temperature preparation of monodispersed PS microspheres without cross-linker.Several reaction conditions,including reaction times,weight contents of initiators,and volume ratios of ethanol and water,were investigated in order to determine the effects of polymerization process on PS microspheres.The monomer conversion,and the size and yield of PS microspheres increased with reaction time and kept constantly after 12 h.With the increase of initiator content,the monomer conversion,and the size and yield of PS microspheres were increased,but the size distribution was nonuniform.When the weight contents of initiators K2S2O8and NaHSO3,relative to that of styrene,were no more than 2.0% and 1.3%,respectively,PS microspheres were monodispersed.When the volume content of water in ethanol/water mixed solvent changed from 10% to 40%,the monomer conversion,and the yield of PS microspheres were increased,and monodispersed PS microspheres can be obtained.However,when the volume content of water was more than 40%,these performances would be decreased with wide microsphere distribution.When the stirring speed was changed from 600 r/min to 1200 r/min,PS microspheres had a little difference in size,yield and monomer conversion.The formation mechanism of PS microspheres was studied.关键词：Polystyrene;Microsphere;Monodispersity;Room temperature;Precipitation polymerization
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发布时间：2021-03-19 - 摘要：Conducting polyaniline was prepared using acidic phosphate (HPAA) as dopant of emeraldine base (EB),which can be nano-dispersed in the polyurethane acrylates,and ultraviolet cured polyaniline anti-corrosion coating without any heavy metals was obtained.The surface drying time of this kind of anti-corrosion painting was only 3-5 s under ultraviolet light.Particle size distribution of conductive polyaniline can be controlled from 60 nm to 765 nm,the particle size increased from 60-100 nm to 190-765 nm when the polyaniline loading in the coating increased from 0.5 wt% to 5.0 wt%,accompanied by the increase of porosity of anti-corrosion coating,the reason was due to the agglomeration of conducting polyanilines with increasing polyaniline content.The absolute impedance at 0.1 Hz (|Z|0.1 Hz) of the anti-corrosion coating with 1.0 wt% polyaniline content can maintain 1.0108cm2 after 2400 h immersion in 3.5% NaCl solution,where the ES particle size was 110-180 nm.Moreover,for such anti-corrosion coating with 45-50 m thickness,though red rust was found after 300 h due to the red iron oxide from interaction between conductive polyaniline and mild steel,no blister was found in the coating after 500 h cross scratch neutral salt spray test,and the rusted frontier around the scratch was less than 1 mm,indicating its very nice anti-corrosion performance.关键词：Polyaniline;Ultraviolet curing;Anti-corrosion coating
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发布时间：2021-03-19 - 摘要：The reversible complexation mediated polymerization (RCMP) of methyl methacrylate (MMA) was carried out in bulk polymerization utilizing an alkyl iodide in situ formed as initiator and Bu4N+Br-(BNBr)or Bu4N+I-(BNI)as organic salt catalysts.Firstly,the influence of different organic catalysts on RCMP of MMA was examined.The result indicates that BNI has higher catalytic reactivity than BNBr as verified by the reaction mechanics and the resulted polymers under the same experimental conditions ([MMA]:[I2]:[AIBN]=100:0.5:0.75,80 ℃).Secondly,the effect of BNI contents on the controllability of MMA polymerization was investigated in detail.The results showed that good agreement between theoretical and experimental molar masses (characterized by GPC) was observed for the used concentrations ([BNI]=9.43,23.56, 47.20, 117.81 mmol/L).The ratio [MMA]:[I2]:[AIBN]:[BNI]=100:0.5:0.75:0.25 is an optimum formula,affording polymers with predetermined molecular weight and low-polydispersity polymers (Mw/Mn 1.27) at relatively high polymerization rate.Last,the structure and the iodine-end-capped structure of the obtained low-molecular-weight PMMA (Mn,GPC=2400,Mw/Mn=1.11) prepared by RCMP was demonstrated by 1H-NMR spectrum.The calculated Mn,NMR was in good agreement with Mn,th and the fraction of iodine chain end of the PMMA chains was up to 98.8%.关键词：Tetrabutylammonium bromide (BNBr);Tetrabutylammonium iodide (BNI);Methyl methacrylate (MMA);Reversible complexation mediated polymerization (RCMP);in situ;Reversible-deactivation radical polymerization (RDRP)
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发布时间：2021-03-19
Research Article
- 摘要：This paper aimed to describe a bioactive polymer biointerface for specifical of recognition endothelial cells.In particular,a random copolymer,poly(ethylene glycol) methacrylate (PEGMA) and glycidyl methacrylate (GMA) (PEGMA-GMA) was synthesized using AIBN as an initiator and grafted on PET substrate by solvent evaporation method.PEGMA unit could reduce nonspecific adsorption of platelet,protein and cells.GMA unit contains reactive epoxide functional groups on the side chains is beneficial to immobilization of antibody or peptide.The peptide sequence Arg-Gly-Asp (RGD),Arg-Glu-Asp-Val (REDV) and Tyr-Ile-Gly-Ser-Arg (YIGSR) were known to bind preferentially endothelial cells.As a result,endothelial specific peptide (RGD,REDV and YIGSR) was conjugated through the epoxy groups in GMA segments.1H-NMR was used to characterize the composition of the polymer.Surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) to confirm the modification reactions.UV spectrum was used to calculate the content of peptide.Cell adhesion experiments showed that peptide modified surfaces inhibit the adhesion of smooth muscle cells (SMCs) and promote endothelial cells (ECs) growth,exhibiting excellent specific recognition of ECs on biomimetic coatings.Comparing with polymer coating modified by RGD and YIGSR,REDV conjugated surface exhibited the highest selectivity for ECs.The multifunctional polymer coating with anti-fouling and ECs specific adhesion produced an excellent prospect in cardiovascular stent implantation.关键词：PEGMA;SMA;Peptide;Endothelial cells selectivity
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发布时间：2021-03-19
Research Bulletin
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