新型含非线性生色团的聚炔共聚物的制备和光限幅

制备了一个新型可溶的含非线性生色团的聚炔共聚物,在8ns脉宽532nm下研究了不同浓度溶液的光限幅性能.采用Z-扫描技术测试了聚合物的激发态吸收,基于非线性理论对光限幅机理进行了讨论.结果表明聚合物的激发态吸收截面大于其基态吸收截面,其光限幅性能主要来源于分子的反饱和吸收(RSA).     

对二乙炔基苯与苯乙炔的共聚及共聚物的表征

本文用(Ph_3P)_2PdCl_2为催化剂,合成出对二乙炔基苯(PDEB)与苯乙炔(PhA)共聚物。实验结果表明,当PDEB/PhA(摩尔比)小于1/5时,共聚物可溶可熔,大于1/5时,共聚物不溶不熔,等于1/5时可分为两个组分,前者可熔但不溶,后者可溶可熔。不熔组分的最良溶剂是苯,溶解度参数为9.15cm~(-1.5)·cal~(0.5)。对不溶组分测定了比重、溶胀度,Huggins参数和相邻两交联点间的平均分子量。红外光谱分析表明共聚物具有反式结构,并在共聚物中含有少量未反应炔基。并对反应机理进行了探讨。     

Chiral Nanostructures from Helical Copolymer–Metal Complexes: Tunable Cation–π Interactions and Sergeants and Soldiers Effect

Poly(phenylacetylene) (PPA) copolymers containing (R)‐ or (S)‐MPA as minor chiral pendant can be forced to selectively adopt the right‐ o left‐handed helix, in the presence of small amounts of Na⁺ or Ag⁺ (“Sergeants and Soldiers Effect”) by addition of a donor cosolvent. The helical sense depends exclusively on the chiral monomer/donor cosolvent ratio, and this allows a perfect on/off tuning of the helicity of the copolymer. When the amount of the donor cosolvent is low, the metal ion complex is stabilized by a cation–π interaction, which is selectively cleaved when the amount of cosolvent is higher. Macroscopically chiral nanospheres and nanotubes composed by helical copolymers with P or M helical sense are also described. Our results demonstrate that it is possible to obtain the two enantiomeric helical structures (P and M helicities) and the corresponding nanospheres and nanotubes from a single helical copolymer, by controlled activation/deactivation of the Sergeant and Soldiers Effect with a donor cosolvent.     

Mesoporous silica stabilized MOF nanoreactor for highly selective semi-hydrogenation of phenylacetylene via synergistic effect of Pd and Ru single site

Selective semi-hydrogenation of phenylacetylene to styrene is a crucial step in the polystyrene industry.Although Pd-based catalysts are widely used in this rea...     

Identification of impurities in phenylacetylene by species-selected mass-analyzed threshold ionization spectroscopy

Two-color resonant two-photon mass-analyzed threshold ionization (MATI) spectroscopy was used to identify styrene impurities in a commercial phenylacetylene sample. With the mass-gating setup, the recorded MATI spectra are free of contamination from molecules of different mass. Analysis of these spectra gives information on the precise adiabatic ionization and the active cation vibrations, which can be used as fingerprints for the identification of molecular ions.     

C60和苯乙炔共聚物荧光性能研究

合成表征了Ｃ６０和苯乙炔共聚物。详细地测试了聚合物溶液的荧光性能。研究结果表明溶液浓度为０．５ｇ／Ｌ时,聚合物呈出现了荧光浓度自猝灭效应。对于Ｃ６０含量为５％的聚合物在３５０ｎｍ被激发时,荧光光谱除在４４０ｎｍ有一个聚苯乙炔的荧光发射峰之外,在４０４ｎｍ呈现出了一个新的弱荧光峰,聚合物中Ｃ６０对这个荧光具有猝灭效应,聚合物发光机制被分析。     

多元氨基酸共聚物的合成及性能表征

以本体聚合方法合成了可生物降解的多元氨基酸共聚物,并采用差示扫描量热分析(DSC)、热重(TGA)和X射线衍射(XRD)等手段对所合成的共聚物进行了表征.结果表明,所合成的多元氨基酸共聚物在常温下可微溶于某些非质子有机溶剂及质子强酸,提高温度可明显提高其溶解性;所合成共聚物为一种半结晶性聚合物,其结晶部分主要为6-氨基...     

Rapid fabrication of three-dimensional porous films with biomimetic patterns by natural evaporation of amphiphilic polyacetylene solutions under ambient conditions

A simple process for fast fabrication of thin films with biomimetic morphological structures from a group of linear homopolymers is developed. Natural evaporation of tetrahydrofuran, chloroform, and hexane-dichloromethane solutions of poly(phenylacetylene)s that contain amino acid and ethylene glycol moieties under ambient conditions instantly produces three-dimensional porous films with structural patterns reminiscent of honeycombs and radiolarian shells. Morphological analysis by optical and electronic microscopy suggests that vesicles of the amphiphilic polymers serve as building blocks in the self-organization to the biomimetic structures.     

Improvements of Some Physical Properties in Gelatin Layers

The effect of copolymer formation in situ in the photographic layer by the reaction between the gelatin, a cyclodextrin derivative and a diepoxy crosslinking agent was investigated. The melting point increase, the swelling ability and the optical rotatory dispersion were determined. The photographic characteristics were investigated in silver bromide layers containing gelatin-cyclodextrin copolymer.

It has been found that the copolymer makes rapid diffusion of the developing agent possible at a low water absorption and high degree of hardening of the layer. This feature can be explained by the decrease of the hydration of polypeptide chains by copolymer formation and the favourable. spatial structure of the copolymer molecules.     

N-异丙基丙烯酰胺共聚物的温敏性

采用自由基水溶液聚合方法制备出了N-异丙基丙烯酰胺(N IPA)温敏共聚物P(AM-N IPA);首次在P(AM-N IPA)结构中引入丙烯酸钠(N aAA)单体结构单元,合成了离子型共聚物P(AM-N IPA-N aAA);考察了共聚物P(AM-N IPA)和P(AM-N IPA-N aAA)溶液温敏性的影响因素;分别采用荧光光谱分析法以及乌氏黏度计稀释法对共聚物溶液温敏机理进行了研究。结果表明,不同共聚单体的配比以及单体含量对共聚物溶液低临界溶解温度(LCST)均有显著影响;当温度高于共聚物低临界溶解温度时,共聚物分子链上的疏水基团的缔合作用增强,导致疏水聚集结构的形成,聚合物分子链发生去溶剂化作用,在共聚物稀溶液中表现为线团收缩,在共聚物亚浓溶液中表现为共聚物分子间聚集发生相分离。     

Structural effects of a light emitting copolymer having perylene moieties in the side chain on the electroluminescent characteristics

We have synthesized a novel side chain light emitting copolymer. The side chain light emitting copolymer has a perylene moiety as an emitting unit and methylmethacrylate (MMA) as a spacer to decrease the concentration quenching of light emitting site in the polymer intrachain. These polymers are very soluble in most organic solvents such as monochlorobenzene, tetrahydrofuran, chloroform and benzene. The single-layered electroluminescent (EL) device consisting of ITO/carrier transporting copolymer and light emitting copolymer/Al was manufactured. The carrier transporting copolymer has triphenylamine moiety as a hole transporting unit and triazine moiety as an electron transporting unit in the polymer side chain. This device exhibits maximum external quantum efficiency when the MMA contents of light emitting copolymer is 30 wt.%. In particular, the device emits more blue light as MMA contents increase.     

在振动磨中PVC的降解及与MMA共聚反应的研究

考察了温度、振幅、钢球直径等对ＰＶＣ在振动磨中降解的影响，确定ＰＶＣ力化学降解为无规断链过程。用力化学方法在振动磨中合成了ＭＭＡ－ＰＶＣ共聚物，通过ＩＲ和ＮＭＲ对ＭＭＡ－ＰＶＣ共聚物结构进行了鉴定，研究了ＰＶＣ／ＭＭＡ配比和振磨时间对共聚反应产率及共聚物组成的影响。热失重分析、ＳＥＭ观察和冲击强度测定结果表明，ＭＭＡ－ＰＶＣ共聚物比ＰＶＣ具有较高的热稳定性；ＭＭＡ－ＰＶＣ共聚物对ＰＶＣ／ＰＨＭＡ（聚甲基丙烯酸己酯）体系有增容作用     

Studies on novel radiopaque methyl methacrylate: glycidyl methacrylate based polymer for biomedical applications

A new class of radiopaque copolymer using methyl methacrylate (MMA) and glycidyl methacrylate (GMA) monomers was synthesized and characterized. The copolymer was made radiopaque by the epoxide ring opening of GMA using the catalyst o-phenylenediamine and the subsequent covalent attachment of elemental iodine. The copolymer was characterized by Fourier transform infrared (FTIR) spectra, energy dispersive X-ray analysis using environmental scanning electron microscope (EDAX), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). X-ray visibility of the copolymer was checked by X-radiography. Blood compatibility and cytotoxicity of the newly synthesized copolymer were also evaluated. The iodinated copolymer was thermally stable, blood compatible, non-cytotoxic, and highly radiopaque. The presence of bulky iodine group created a new copolymer with modified properties for potential use in biomedical applications.     

Bone substitute biomedical material of multi-(amino acid) copolymer: in vitro degradation and biocompatibility

Degradable polymers with good mechanical strength as bone repair biomaterials have been paid more attention in biomedical application. In this study, a multi-(amino acid) copolymer consisting of 6-aminocaproic acid and five natural amino acids was prepared by a reaction of acid-catalyzed condensation. The results revealed that the copolymer could be slowly degradable in Tris-HCl solution, and lost its initial weight of 31.9 wt% after immersion for 12 weeks, and the changes of pH value of Tris-HCl solution were in range from 6.9 to 7.4 during soaking. The compressive strength of the copolymer decreased from 107 to 68 MPa after immersion for 12 weeks. The proliferation and differentiation of MG-63 cells on the copolymer significantly increased with time, and the cells with normal phenotype extended and spread well on the copolymer surfaces. When the copolymer was implanted in muscle and bone defects of femoral cortex of dogs for 12 weeks, the histological evaluation confirmed that the copolymer exhibited excellent biocompatibility and more effective osteogenesis in vivo. When implanted into cortical bone defects of dogs, the copolymer could be combined directly with the natural bone without fibrous capsule tissue between implants and host bone. The results indicated that the multi-(amino acid) copolymer with sufficient strength, good biocompatibility and osteoconductivity had clinical potential for load-bearing bone repair or substitution.     

Ocular permeability of pirenzepine hydrochloride enhanced by methoxy poly(ethylene glycol)-poly(D, L-lactide) block copolymer

Methoxy poly(ethylene glycol)-poly(D,L-lactide) block copolymer was tested as an ocular permeation enhancer for pirenzepine hydrochloride. The block copolymers with the methoxy poly(ethylene glycol) to poly(D,L-lactide) weight ratio of 80/20, 50/50, 40/60 were synthesized by a ring-opening polymerization procedure. In vitro transcorneal experiments demonstrated that the block copolymer 80/20 significantly enhanced the transcorneal permeation of pirenzepine at the mass ratio of 1/1.4 (pirenzepine hydrochloride/copolymer). Interaction between pirenzepine and copolymer was identified by infrared spectroscopy analysis and dialysis experiments. Ocular pharmacokinetics of pirenzepine/copolymer preparation by in vivo instillation experiments confirmed that block copolymer could enhance the ocular penetration of pirenzepine. Ocular chronic toxicity experiments of block copolymer and pirenzepine/copolymer preparation were studied on rabbits, and no significant toxicity in both groups was observed within 9 months. It could conclude that pirenzepine/copolymer preparation is effective and safe in ocular delivery of pirenzepine.     

Electrospun polymer nanofibers with internal periodic structure obtained by microphase separation of cylindrically confined block copolymers

Continuous fibers are described having concentric layer or aligned sphere microphase-separated, styrene-isoprene block copolymer morphologies. The fibers are obtained by a two-fluid coaxial electrospinning technique in which the desired block copolymer is encapsulated as the core component within a polymer shell having a high glass transition temperature (Tg). The fibers range in diameter from 300 to 800 nm, and the block copolymer core ranges from 50 to 500 nm. Subsequent annealing of the fibers above the upper Tg of the block copolymer but below the Tg of the shell polymer results in microphase separation of the block copolymer under cylindrical confinement. The resulting fibers exhibit improved long-range order. This two-step strategy creates the opportunity to fabricate continuous nanofibers with periodic internal structure.     

Ocular Permeability of Pirenzepine Hydrochloride Enhanced by Methoxy poly(ethylene glycol)–poly(D,L-lactide) Block Copolymer

Methoxy poly(ethylene glycol)–poly(D,L-lactide) block copolymer was tested as an ocular permeation enhancer for pirenzepine hydrochloride. The block copolymers with the methoxy poly(ethylene glycol) to poly(D,L-lactide) weight ratio of 80/20, 50/50, 40/60 were synthesized by a ring-opening polymerization procedure. In vitro transcorneal experiments demonstrated that the block copolymer 80/20 significantly enhanced the transcorneal permeation of pirenzepine at the mass ratio of 1/1.4 (pirenzepine hydrochloride/copolymer). Interaction between pirenzepine and copolymer was identified by infrared spectroscopy analysis and dialysis experiments. Ocular pharmacokinetics of pirenzepine/copolymer preparation by in vivo instillation experiments confirmed that block copolymer could enhance the ocular penetration of pirenzepine. Ocular chronic toxicity experiments of block copolymer and pirenzepine/copolymer preparation were studied on rabbits, and no significant toxicity in both groups was observed within 9 months. It could conclude that pirenzepine/copolymer preparation is effective and safe in ocular delivery of pirenzepine.     

界面法制备三维网状PPy-PEDOT共聚物膜及电容性能

制备具有多电子传输与多孔有序的结构电极是电化学储能技术创新发展的两个重要策略。本工作采用一种界面电化学聚合新法合成聚吡咯-聚3,4-乙撑二氧噻吩(PPy-PEDOT)共聚物薄膜材料。采用FTIR,XPS,EDX,SEM与电化学充放电测试对PPy-PEDOT共聚物膜的化学组成、分布、微观形貌及电容性能进行表征与测试。结果表明:PPy-PEDOT共聚物膜由PPy与PEDOT按一定比例组成,且分布均匀;SEM测试表明共聚物膜具有正反两面各异的特殊形貌,且有机相一侧呈三维网状多孔层状结构。电化学充放电测试表明,PPy-PEDOT共聚物膜表现出优异的超级电容器电极材料的特性,具有较高的比电容,较快的充放电速率与较好的循环稳定性。PPy与PEDOT共聚后实现二者性能互补,提高了共聚物膜的导电性,电荷迁移速率及稳定性,同时三维网状多孔层状结构也有助于充放电过程中电子离子的迁移,使得共聚物膜的储能性能显著提高。     

Graphoepitaxy of cylinder-forming block copolymers for use as templates to pattern magnetic metal dot arrays

We report a method to fabricate high-quality patterned magnetic dot arrays using block copolymer lithography, metal deposition, and a dry lift-off technique. Long-range order of cylindrical domains oriented perpendicular to the substrate and in hexagonal arrays was induced in the block copolymer films by prepatterning the substrate with topographic features and chemically modifying the surface to exhibit neutral wetting behaviour towards the blocks of the copolymer. The uniformity of the domain size and row spacing of block copolymer templates created in this way was improved compared to those reported in previous studies that used graphoepitaxy of sphere-forming block copolymers. The pattern of block copolymer domains was transferred to a pattern of magnetic metal dots, demonstrating the potential of this technology for the fabrication of patterned magnetic recording media.     

共聚物在不相容共混体系中界面行为的MontCarlo模拟

用自由体积扩散算法模拟了不同结构的共聚物在不同相容熔融共混体系中的界面行为,模拟结果表明,加入少量共聚物后,共混体系的相分离程度明显降低,从其形貌来看,分散相区尺寸变得更小。