最新刊期
卷 ， 期 6 ， 2015
- 摘要：Amphiphilic polymers have shown great potential as the promising drug carriers for tumor-targeting drug delivery applications due to their own unique advantage that they can self-assemble into micelles with core-shell structures by the hydrophilic-hydrophobic interaction in aqueous solution.Recently,amphiphilic polymeric micelles based on starch are receiving more and more attention because of their abundant resource and low price of starch,and the good biocompatibility and biodegradability.As drug carriers,polymeric micelles based on starch can improve the solubility of hydrophobic drug,extend drug circulation time in vivo,reduce systemic side effects and increase the preferential acculation at the targeted sites by the enhanced permeability and retention (EPR) effect.In addition,compare with the traditional micellar systems,some groups with stimuli-responsive functions can be easily introduced to starch backbone to prepare smart polymeric micelles realizing rapid and targeted release drug.Therefore,due to these features above,polymeric micelles based on starch as drug carriers have broad development potential.The review highlights the latest progress in polymeric micelles based on starch as novel drug carriers.关键词：Starch;Polymeric micelles;Drug carriers
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发布时间：2021-03-19
Reviews
- 摘要：Polyurethane-poly(butyl methacrylate) copolymer aqueous dispersions (PUBMA) were synthesized via hydroxyl-terminated poly(butyl methacrylate).The hydroxyl-terminated poly(butyl methacrylate) (PBMA-OH) was synthesized via atom transfer radical polymerization with activators regenerated by electron transfer (ARGET ATRP) using hydroxylbutyl -bromoisobutyrate as an initiator,copper(II) bromide(CuBr2)(0.05% molar fraction of monomer) as a catalyst,pentamethyldiethylene triamine (PMDETA) as a ligand,and stannous octoate (Sn(EH)2) as a reducing agent.Polyurethane-poly(butyl methacrylate) copolymer aqueous dispersions (PUBMA) were then synthesized using polyether diols (N220),polyether triols (N330),PBMA-OH,toluene diisocyanate (TDI) and dimethylol propionic acid (DMPA) as the main raw materials.The effects of the amount of PBMA-OH on the properties of PUBMA aqueous dispersions and films were investigated.The results showed that polyurethane-poly(butyl methacrylate) copolymer aqueous dispersions were successfully synthesized.With the increment of the amount of PBMA-OH,the particle sizes of the PUBMA aqueous dispersions increased and the particle size distribution of the PUBMA became broader than that of the pure PU.The results of mechanical properties and water resistance test indicated that the tensile strength of the PUBMA films increased from 6 MPa to 8 MPa,but the elongation at break decreased from 1500% to 800%,and water resistance of the films improved significantly after the PBMA segment was introduced into PU.Atomic force microscope (AFM) and dynamic mechanical analysis (DMA) confirmed that there were obvious two phases in PUBMA,and the PUBMA films had two glass transition temperatures,both the glass transition temperatures increased with the increment of the amount of PBMA.关键词：ARGET ATRP;Hydroxyl terminated poly(butyl methacrylate);Polyurethane aqueous dispersion;Copolymer;Mechanical properties of PUBMA films
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发布时间：2021-03-19 - 摘要：Sulfonated porous zeolite (S-BEA) composite sulfonated polyimide (SPI) proton exchange membranes were prepared by mixing inorganic nanoparticles S-BEA with SPI solution.Scanning electron microscopy showed that inorganic particles S-BEA were fairly uniform dispersed in the SPI PEM,when the S-BEA content was 10% (H1).The agglomerated inorganic particles increased with the content up to 20% (H2),the macro-phase interface separation was clearly observed.The ion exchange capacity (IEC) value of S-BEA composite PEM H1 was decreased by 12% when compared to that of M1 without composite,the water uptake of H1 barely decreased due to the existence of hydrophilic S-BEA.The number of sorbed water molecules per sulfonic acid group increased from 23 for M1 to 26 for H1.No obvious increase of membrane size change in dry/wet environment was observed for SPI/S-BEA composite PEMs due to the hydrogen bonding interaction of the hydroxyl groups on the inorganic particles surface with the polymer chain.These composited PEMs also showed excellent mechanical properties.The proton conductivity under low humidity for H1 with lower IEC value was comparable to that of M1.However,when the S-BEA content increased to 20%,the obvious macro-phase separation interface hindered the proton conducting in the PEM matrix,thus the proton conductivity of H2 decreased on the contrary.The proton exchange membrane fuel cell performance test showed H1 did not have clearly higher fuel cell performances than that of M1 at 90 ℃.When the fuel cell temperature increased to 110 ℃,due to the water retention property of inorganic particles S-BEA,H1 showed clearly better fuel cell performances than those of M1.For example,the maximum power output of SPI/S-BEA composite PEM H1 was 0.61 W cm-2,which was 30% higher than that of M1.关键词：Sulfonated polyimide;Sulfonated porous zeolite;Organic/inorganic composite;Proton exchange membrane;Fuel cell
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发布时间：2021-03-19 - 摘要：The density functional theory (DFT) and long range corrections method are applied to simulate the self-assembly system of the molecularly imprinted polymers (MAM-MIPs).Melamine (MAM) was taken as the template molecule and methacrylic acid (MAA) was taken as the monomer,the ethylene glycol dimethacrylate (EGDMA),trimethacrylate (TRIM) and divinylbenzene (DVB) were taken as the cross-linking agents.And the acetonitrile (ACN),methanol (MT),ethanol (EA),toluene (TL),tetrahydrofuran (THF) and dimethylsulfoxide (DMSO) were taken as the solvents.The geometry optimization,the bonding situation of MAM and MAA,the imprinted ratio of the stable complex and the reaction mechanism were discussed.The optimizations of the cross-linking agents and solvents were according to the bond energy (E).The nature of the imprinting effect was also studied by the atoms in molecules (AIM) theory.The results indicate that the N atom on the three triazine rings as well as the H atom on the amine of MAM and MAA monomer have interaction to form imprinted polymers via the hydrogen bonds.The molar ratio of 1:6 had the strongest stability.DVB was the best cross-linking agent of MAM-MIPs in comparison with TRIM and EGDMA.The study can provide a theoretical reference for the optimization of the imprinting ratio and the choice of cross-linking agent and solvent on MAM-MIPs.关键词：Melamine;Methacrylic acid;Molecular imprinting calculation;Imprinted ratio;Cross linking agent;Solvent
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发布时间：2021-03-19 - 摘要：Chitosan oligosaccharide/Pluronic polymer nano-aggregates (COPNs) were designed as building blocks to fabricate (heparin/chitosan)-mimetic multilayered films,and the application of the multilayered films in loading hydrophobic drugs was investigated.Sulfonated Pluronic P123 synthesized from the reaction between Pluronic P123 and 1,3-propane sultone,self-assembled with Pluronic F127 in aqueous solution to form mixed polymeric micelles with negatively charged sulfonic acid groups on the exterior.COPNs were obtained via the electrostatic interaction between chitosan oligosaccharide and the mixed polymeric micelles.The particle size analysis,zeta potential analysis and transmission electron microscopy (TEM) experiments demonstrated the formation of the mixed micelles and COPNs.The mean diameter and the zeta potential of COPNs were about (27.61 2.46) nm and (6.12 1.82) mV.The quartz crystal microbalance (QCM) experiment demonstrated that the layer-by-layer (LBL) films can be fabricated via alternating deposition of heparin and COPNs.The surface morphologies of the LBL films were analyzed using atomic force microscope (AFM),and the AFM images demonstrated the stability of COPNs during the LBL process.The fluorescence emission spectra verified that the hydrophobic pyrene can be incorporated by pre-encapsulation in COPNs,and the amount of pyrene in the LBL films increased with respect to the increase of the number of layers of pyrene-loaded COPNs.The drug loading and release behaviors of the LBL films were investigated using puerarin as a model drug.关键词：Layer-by-layer assembly;Chitosan oligosaccharides;Pluronic;Polymer;Mixed micelles;(Heparin/chitosan) multilayerd films
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发布时间：2021-03-19 - 摘要：Polyvinyl formal (PVF) porous material was fabricated by mechanical stirring after adding surfactant in this research,and the acetalation performance and pore structure of PVF influenced by changing degree of HCHO and SDS (sodium dodecyl sulfate) were studied.Furthermore,the mechanism of mechanical properties and absorbency influenced by acetalation performance and pore structure was discussed.The study shows that,the change of acetalation of PVF influences the absorbency,the crosslinking density,the molecular chain gaps,the proportion of hard segment and the VDW (Van der Waals'force) of PVF.Besides,the sudy shows that the change of pore structure alters the amount of capillaries in the PVF,the specific surface area and the water holding capacity,also the relative density and stress concentration.All of these changes influened by acetaltion and pore structure result in the changing of absorbency and mechanical properties of PVF.High performance PVF porous material with good absorbency and mechanical properties can be prepared through controlling the degree of acetalation and pore structure.As a result,the PVF porous material in the hygrometric state can achieve excellent meananical properties and acetalation performance,with the best water absorption rate of 1627%.Meanwhile,the PVF porous material possesses well rebound resilience.关键词：PVF porous material;Degree of acetalation;Pore structure;Performance
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发布时间：2021-03-19 - 摘要：The polystyrene-polydimethylsiloxane copolymer (PS-b-PDMS) was grafted from the surface of polyethylene terephthalate (PET) film via surface-initiated atom transfer radical polymerization (SI-ATRP).The ATRP was carried out at 90 ℃ in the presence of CuCl as a catalyst,2,2-bpy as a complexing agent,and toluene as a reaction medium.The influences of different reaction times on the surface composition,structures,morphology and properties of polyester films were studied.X-ray photoelectron spectroscopy (XPS),Fourier transform infrared spectroscopy (FTIR/ATR),scanning electron microscopy (SEM) were used to characterize the surface composition,structure and morphology of modified polyester film.And the results could confirm the successfully grafting of initiators and polymers from the surface of PET films.The wettability and effect on bacterial adhesion of modified PET films were measured by contact angle and microbial adhesion tests.The data of contact angle showed that the surface properties of PET films were related to the reaction time.The grafting density and contact angle of PET films increased as the reaction time inereased.It suggests that the SI-ATRP is a living radical polymerization.Further more,the grafting rate was up to 0.72 mg/cm2,and the contact angle increased to 126 when the polymerization time was 12 h,meanwhile,the amount of bacterial adhesion was significantly reduced.关键词：PET film;Surface initiated atom transfer radical polymerization;Hydrophobicity;Bacterial adhesion
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发布时间：2021-03-19 - 摘要：The supramolecular inclusion of -cyclodextrin (-CD) and PEG contained block copolymer Pluronic F127 was used to build a supramolecular hydrogel system.The composition and gelation behavior of the system were evaluated.There were two kinds of crosslinks in the hydrogels.One was the microcrystalline structure of packed PEG/-CD inclusion complexes,and the other was the aggregated hydrophobic blocks of Pluronic F127.An optimized gel system with low solid content (17.7 wt%) and short gelation time (6~8 min) was established for sustained release of insulin.The structure of -CD and PEG inclusion was characterized by wide-angle X-ray diffraction (XRD).The scanning electron microscopy (SEM) images of the freeze-dried powders of the gels showed a porous structure,because of the high water content of the hydrogels. In vitro insulin release was monitored by UV analysis,and the release was sustained in 65 h with a burst release of 30% in the first 5 h.In vitro cytotoxicity studies showed that the hydrogels (without insulin) had no evident growth inhibition to BEL-7402 cells when the concentration was lower than 109 mg/L.Animal experiment showed that the hydrogel was positive to prolong the in vivo insulin release.These results suggested that the supramolecular hydrogels hold great potential as a sustained delivery system of hydrophilic drugs and proteins,such as insulin.关键词：Block copolymer;Cyclodextrin;Insulin;PEG;Supramolecular hydrogels
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发布时间：2021-03-19 - 摘要：As a single cationic emulsifier,octadecyl bis-polyoxyethylene benzyl ammonium chloride (OEBA) was applied to prepare the stable octamethylcyclotetrasiloxane (D4) monomer miniemulsion without any co-stabilizers and non-ionic emulsifiers.The monomer droplet size was about 200 nm after being dispersed through a high pressure homogenizer at 30 MPa for 3 times,the size was similar to that of adding extra hexadecanol (HD).The miniemulsion including single emulsifier OEBA (0.0228 mol/L) and the others with extra-adding HD (0.0456 mol/L) were studied as comparative groups.The interfacial shear viscosity () of D4 droplets with different [OEBA] and [HD] was characterized,which was a key parameter of the oil-water interfacial film strength,affecting the stability of monomer miniemulsion.It was discovered that the stability mechanism of monomer miniemulsion with single emulsifier was different from that of conventional miniemulsion.Then D4 miniemulsion was initiated for ring-opening polymerization (ROP) by KOH solution.During the polymerization processes,change of particle size was traced through the dynamic light scattering (DLS).As the polymerization going on,whether using single emulsifier OEBA (0.0228 mol/L) or extra-adding HD (0.0456 mol/L),the droplet size similarly reduced from 200 nm to 100 nm.Furthermore,the abilities of anti-acid,anti-alkali and anti-electrolyte of polydimethylsiloxane (PDMS) miniemulsion were defined by E0/E24.It was discovered that stability properties of the miniemulsion with single emulsifier were more excellent than those of the others.Finally,compared with the comparative group including HD,monomer conversion and corresponding polymerization rate at different polymerization stages were determined by gravimetrical method.As expected,the change of polymerization rate with single OEBA was extremely corresponded to the conventional miniemulsion polymerization mechanism.For example,there was no constant rate period in the whole polymerization process.In conclusion,D4 and PDMS miniemulsions could be successfully prepared with only a single emulsifier OEBA.关键词：Octadecyl bis-polyoxyethylene benzyl ammonium chloride;Octamethylcyclotetrasiloxane;Miniemulsion;Miniemulsion polymerization
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发布时间：2021-03-19 - 摘要：Linear cyclopolymers with 20- and 28- membered rings were synthesized respectively by ATRP.Cyclopolymerization was carried out using CuBr/PMDETA/EBiB as an initiating system with toluene as solvent,which favored intramolecular cyclization over that with DMSO as solvent.The polymerization kinetics showed that the rate of cyclopolymerization reduced with increasing the ring-size of the polymers.Cyclization efficiency of dialkylsilylene-tethered bismethacrylates is highly affected by the monomer concentration,with the increasing of the concentration of monomer,the cyclization efficiency decreases and PDI of polymer obtained becomes broad.The cyclic structures of the polymer were confirmed by the 1H-NMR spectroscopy and the cyclic degree of the polymers was determined by the end-group analysis of the cyclopolymers and GPC.1H-NMR spectroscopy indicated that the polymerizations proceeded with 95% cyclization for monomer A2 and 92% cyclization for monomer B2.The polymers show controlled molecular weights and narrow molecular weight distributions (Mw/Mn 1.3).The thermodynamic properties of the cyclopolymers was investigated by TGA.The results showed that the cyclopolymers have higher thermal stability (372 ℃) than poly(methyl methacrylate).关键词：Linear cyclopolymer;ATRP;Bismethacrylate;Cyclopolymerization
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发布时间：2021-03-19 - 摘要：Microencapsulated phase change materials (MicroPCMs) were prepared using paraffin as core,methyl methacrylate (MMA) and acrylic acid (AA) copolymer as shell,and nanosilica as modifier via in situ polymerization.The effects of the nanosilica on the properties of the MicroPCMs were investigated.The MicroPCMs were characterized by Fourier transform infrared spectroscopy (FTIR),scanning electron microscopy (SEM),differential scanning calorimetry (DSC) and thermogravimetry (TGA).The results show that the nanosilica effectively improves the thermostability of the MicroPCMs.The MicroPCMs modified by 3 wt% nanosilica present smooth and spherical morphology with the diameter of 250~300 nm.The MicroPCMs have a high latent heat of 134.79 J/g and the degradation temperature is obviously increased by 40 K in comparison with that of the unmodified MicroPCMs,and the paraffin leakage rate of the modified MicroPCMs is only 2.96% after 1000 times thermal cycling test.关键词：Nanosilica;Acrylic ester;Paraffin;Microcapsule phase-change materials;Thermal stability
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发布时间：2021-03-19 - 摘要：Poly(vinyl alcohol)/layered double hydroxide (PVA/LDH) composite films with different LDH contents have been fabricated through casting with an in situ hydrothermal treatment.Wide angle X-ray diffraction (WAXD) results show the characteristic (003) diffraction reflection peak of LDH layers and the corresponding peak becomes stronger with the increase of LDH content,and the size of LDH layers can be tuned by the concentration of reactant.Lower reactant concentration leads to small size of LDH particles while higher concentration gives LDH particles with large size.LDH particles are homogeneously dispersed in PVA matrix as evidenced by SEM observations.The tensile strength and the elastic modulus of PVA films are improved by introducing LDH particles.With the LDH content of 1.0 wt%,the tensile strength and elastic modulus of the corresponding composite films are improved by about 105.4% and 133.2%,respectively,compared with those of a neat PVA film.It is believed that most OH groups of PVA undergo interfacial H-bonding with the LDH layers and other PVA chains,which might be account for the improvement of mechanical properties.Interesting thing is that the in situ PVA/LDH composite aqueous solution shows lower viscosity than that of PVA aqueous solution and the viscosity decreases with LDH content,which is in strong contrast to that by traditional simple mixing.LDH layers are considered to shield the entanglement of PVA chains and thus lead to decreasing solution viscosity.Furthermore,the anti-absorbent of water for the composite films are also improved without losing transparency,while the improvement of gas barrier cannot be observed until the loading of LDH reaches to 3.0 wt%.关键词：In situ;Poly(vinyl alcohol);Layered double hydroxide;Mechanical properties;Optical properties
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发布时间：2021-03-19 - 摘要：The unique amphiphilic structure of graphene oxide (GO) creates the possibility of using it as a new compatibilizer in certain immiscible blends.In the present work,GO was incorporated into immiscible polyamide 6 (PA6) /polystyrene (PS) (80/20 wt%) blends as a special compatibilizer and the mechanisms involved were discussed.Scanning electron microscopy (SEM) images clearly showed that the incorporation of GO in the blends led to a more homogenous morphology.The dimension of PS dispersed particles decreased markedly and became more uniform,indicating a significantly improved compatibility in the GO-filled blends.Dynamic mechanical analysis (DMA) measurements further confirmed the improvement of compatibility.The glass transition temperature of PA6 and PS shifted towards each other.In the view of the amphiphilic chemical structures,the polyaromatic islands in GO could interact with the aromatic structure in PS by - conjugation,while the oxygen-containing groups attached to GO platelets could form hydrogen bond interaction with NH groups in PA6,which made it act as a coupling agent for the PA6/PS blends.The matched surface energy as well as low interfacial energy between PA6 and PS/GO contributed to the improved compatibility as well.The application of GO in PA6/PS blends led to enhanced tensile and impact properties due to both the compatibilizing and reinforcing effect of GO.The elongation at break increased as much as 170% and the rupture energy increased nearly 240% after the addition of 0.1 wt% of GO as compared to the simple PA6/PS blend.This work extends the application of GO in polymer material manufacturing as a new compatibilizer in certain immiscible blends.关键词：Polyamide 6;Polystyrene;Graphene oxide;Compatibilizition
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发布时间：2021-03-19 - 摘要：Due to the water-solubility of poly(methacrylic acid) (PMAA),it is hard to synthesize PMAA nanoparticles in water phase.A novel method for the green synthesis of PMAA-based nano-hydrogels in water phase was developed.In the method,small poly(methyl methacrylate) (PMMA) nanolatex particles formed in situ were used as the seeds.Meanwhile,the electrostatic interactions between the surfactants on the surfaces of the seeds and MAA monomers were utilized to realize the selective polymerization of MAA on the surfaces of the PMMA seeds,thus resulting in the formation of PMAA-based nano-hydrogels with PMMA cores and cross-linked PMAA shells.The size and size distribution,surface charges,composition,morphology,structure and pH-response behavior of the resulting nano-hydrogels were characterized by dynamic light scattering,-potential measurement,Fourier transform infrared spectroscopy (FTIR),and transmission electron microscopy (TEM).The core-shell structure of the PMAA-based nano-hydrogels was disclosed by TEM observations.The size of the PMAA-based nano-hydrogels increases as the amount of MAA increases from 2 mL to 3 mL.However,as the amount of MAA increases to 5 mL,besides the PMAA-based nano-hydrogels,small pure PMAA nanoparticles also appear.Finally,the PMAA-based nano-hydrogels display excellent pH-responses:as the pH value increases from 2 to 7,the expansion of their hydrodynamic volumes approaches 80 times.关键词：Poly(methacrylic acid);pH-response;Nano-hydrogels;Eletrostatic interactions;Synthesis
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发布时间：2021-03-19 - 摘要：Thick polypropylene/poly(ethylene-co-octene) (PP/POE) blend samples with three different phase morphologies were prepared by melt blending using an extruder.The blend samples were foamed at a foaming temperature of 110 ℃ in a batch process.The shape,distribution,and size of the cells in the thick foamed samples were effectively tuned by exploiting the differences in the phase morphologies of the blends,and in the viscoelasticities and supercritical carbon dioxide solubilities in the two phases.Three kinds of typical cellular structures were obtained.Ellipsoidal cells appeared in the foamed sample prepared using the 80/20 PP/POE blend sample with ellipsoidal droplets,and both cells and droplets had the same order of magnitudes of average diameter and density.Long hole cells appeared in the foamed sample prepared using the 80/20 blend sample with long fibrils,and both cells and fibrils had a close average diameter.Open-celled structure with higher connectivity was obtained from foaming the 60/40 blend sample with partly continuous phase structure.Further,closely spherical cells with more close to the average diameter and density of the dispersed droplets,and open-celled structure with further higher connectivity were obtained by changing the foaming temperature.关键词：PP/POE blend;Melt blending;Phase morphology;Supercritical carbon dioxide foaming;Cellular structure
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发布时间：2021-03-19
Research Article
- 摘要：Electrospinning technique was utilized to prepare healant-loaded composite fibers,with spinning solutions of polystyrene and healing agent.The morphology and composition of the resultant functional fibers were investigated by SEM,EDX,optical microscopy and FTIR.The influence of the concentration of healing agent in the spinning solution on the fibers morphology and structure was also discussed.The results indicated that the healing agent was loaded in the fibers relatively uniformly,and the amount of healant in the fibers increased gradually with its concentration in the spinning solution,whereas the spinnability declined.Composite of the asformed fibers and resin was prepared and the self-healing of micro-crack on the composite surface was observed by SEM.The healing agent in the fibers could be released under a certain temperature thus healed the micro-crack.The tensile strength of the composite increased 2.81 MPa after the self-healing process and the mechanical properties of the composite were improved obviously.关键词：Electrospinning;Functional fiber;Composites;Self-healing;Mechanical property
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发布时间：2021-03-19
Research Bulletin
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